/* ===== Design tokens (palette from the school logo) ===== */
:root {
  --sky: #1aa3dd;
  --primary: #0a6fa8;
  --primary-hover: #085d8d;
  --sky-tint: #e3f4fb;
  --sky-tint-2: #e8f5fc;
  --sky-soft: #f0f9fd;
  --yellow: #ffcf1f;
  --yellow-hover: #ffc400;
  --yellow-tint: #fff6d6;
  --yellow-ink: #8a6200;
  --pink: #e8508f;
  --pink-tint: #fde8f1;
  --pink-ink: #b8336c;
  --orange: #f07a1c;
  --orange-tint: #fff0e3;
  --orange-ink: #b35200;
  --success: #2e9d5b;
  --success-bg: #e6f6ec;
  --success-bg-soft: #f0faf4;
  --success-ink: #1d7a43;
  --danger: #c23a3a;
  --danger-border: #f1c9c9;
  --danger-bg: #fdf0f0;
  --ink: #15212b;
  --muted: #5d6b76;
  --muted-sky: #3d5566;
  --faint: #8b98a2;
  --faint-2: #a9b4bc;
  --bg: #f5f8fa;
  --surface: #ffffff;
  --line: #e3e9ee;
  --input-line: #dfe6eb;
  --divider: #eef2f5;
  --disabled-bg: #f1f4f6;

  --font-ui: "Plus Jakarta Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-zh: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --font-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;

  --shadow-card: 0 30px 60px -24px rgba(10, 80, 120, .35);
  --shadow-hover: 0 6px 18px -8px rgba(10, 111, 168, .25);
  --focus-ring: 0 0 0 4px var(--sky-tint);
  --ease-flip: cubic-bezier(.3, .7, .3, 1);
}

/* ===== Reset ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-ui);
  font-size: 16px;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
}

#app {
  flex: 1;
  display: flex;
  flex-direction: column;
}

a { color: var(--primary); text-decoration: none; }
button { cursor: pointer; font: inherit; }
input, textarea, select { font: inherit; color: inherit; }
img { max-width: 100%; }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ===== Type helpers ===== */
.zh { font-family: var(--font-zh); }
.serif { font-family: var(--font-serif); font-weight: 900; }
.mono { font-family: var(--font-mono); font-weight: 500; letter-spacing: .02em; }
.muted { color: var(--muted); font-size: 14px; font-weight: 400; }
.link { font-size: 14px; font-weight: 600; color: var(--primary); }
.link:hover { color: var(--primary-hover); }
.eyebrow-mono {
  font: 500 11px var(--font-mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}

/* ===== Tints ===== */
.tint-sky { background: var(--sky-tint); color: var(--primary); }
.tint-yellow { background: var(--yellow-tint); color: var(--yellow-ink); }
.tint-pink { background: var(--pink-tint); color: var(--pink-ink); }
.tint-orange { background: var(--orange-tint); color: var(--orange-ink); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: 12px;
  padding: 12px 20px;
  font: 700 15px var(--font-ui);
  line-height: 1.2;
  text-align: center;
  white-space: nowrap;
  transition: background .15s, border-color .15s, box-shadow .15s, transform .1s;
}
.btn:active { transform: scale(.98); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn:focus-visible { outline: none; box-shadow: var(--focus-ring); }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover:not(:disabled) { background: var(--primary-hover); }
.btn-secondary { background: var(--surface); color: var(--ink); border: 1px solid var(--input-line); }
.btn-secondary:hover:not(:disabled) { border-color: var(--sky); }
.btn-danger { background: var(--surface); color: var(--danger); border: 1px solid var(--danger-border); }
.btn-danger:hover:not(:disabled) { background: var(--danger-bg); }
.btn-success { background: var(--success-bg); color: var(--success-ink); border: 1px solid transparent; }
.btn-success:hover:not(:disabled) { border-color: var(--success); }
.btn-yellow { background: var(--yellow); color: var(--ink); font-weight: 800; }
.btn-yellow:hover:not(:disabled) { background: var(--yellow-hover); }
.btn-ink { background: var(--ink); color: #fff; }
.btn-ink:hover:not(:disabled) { background: #26394a; }
.btn-tint { background: var(--sky-tint); color: var(--primary); }
.btn-tint:hover:not(:disabled) { background: #d2ecf8; }
.btn-white { background: #fff; color: var(--primary); }
.btn-white:hover:not(:disabled) { background: var(--sky-soft); }
.btn-outline-light { background: transparent; color: #fff; border: 1.5px solid rgba(255, 255, 255, .7); }
.btn-outline-light:hover:not(:disabled) { background: rgba(255, 255, 255, .12); }

.btn-sm { padding: 9px 14px; font-size: 14px; border-radius: 10px; }
.btn-lg { padding: 15px 26px; font-size: 16px; }
.btn-xl { padding: 18px 40px; font-size: 20px; border-radius: 16px; font-weight: 800; }
.btn-block { width: 100%; }
.btn-pill { border-radius: 99px; }

.btn-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--input-line);
  border-radius: 50%;
  background: var(--surface);
  color: var(--ink);
}

/* ===== Forms ===== */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 18px;
}
.form-group label { font-size: 13px; font-weight: 700; color: var(--ink); }

.form-group input,
.form-group textarea,
.form-group select,
.text-input,
.char-input,
.bulk-textarea {
  width: 100%;
  padding: 13px 16px;
  border: 1.5px solid var(--input-line);
  border-radius: 12px;
  background: var(--surface);
  font-size: 15px;
  color: var(--ink);
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
.form-group input::placeholder,
.text-input::placeholder,
.bulk-textarea::placeholder { color: var(--faint); }
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus,
.text-input:focus,
.char-input:focus,
.bulk-textarea:focus {
  border-color: var(--sky);
  box-shadow: var(--focus-ring);
}
.form-group input:disabled {
  background: var(--disabled-bg);
  border-color: var(--disabled-bg);
  color: var(--muted);
}

.form-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 8px; }

.auth-error {
  padding: 12px 16px;
  margin-bottom: 18px;
  border-radius: 12px;
  background: var(--pink-tint);
  color: var(--pink-ink);
  font-size: 14px;
  font-weight: 600;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  padding: 8px 14px;
  border-radius: 99px;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}
.status-success { background: var(--success-bg); color: var(--success-ink); }

/* ===== Logo, avatars, badges ===== */
.logo {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  padding: 2px;
  border-radius: 50%;
  background: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
/* Show the whole logo so its outer ring stays visible; the white disc keeps
   the light-blue ring distinct on sky backgrounds. */
.logo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
.logo-lg { width: 56px; height: 56px; padding: 4px; }

.avatar {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--sky);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 700 16px var(--font-zh);
}
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.avatar-sm { width: 32px; height: 32px; font-size: 14px; }

.role-badge {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 99px;
  font-size: 11px;
  font-weight: 700;
  background: var(--sky-tint);
  color: var(--primary);
  white-space: nowrap;
}
.role-student { background: var(--yellow-tint); color: var(--yellow-ink); }
.role-teacher { background: var(--sky-tint); color: var(--primary); }
.role-admin { background: var(--pink-tint); color: var(--pink-ink); }

/* ===== Top navigation ===== */
.top-nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px 16px;
  padding: 14px 32px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.brand { display: flex; align-items: center; gap: 12px; color: var(--ink); }
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-zh { font: 700 17px var(--font-zh); color: var(--ink); }
.brand-en { font-size: 11px; color: var(--muted); }

.nav-pills { display: flex; gap: 4px; margin-left: 12px; }
.nav-pill {
  padding: 8px 14px;
  border-radius: 99px;
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
  white-space: nowrap;
}
.nav-pill:hover { color: var(--ink); background: var(--bg); }
.nav-pill.active { background: var(--sky-tint); color: var(--primary); }

.nav-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
}
.nav-link { font-size: 14px; font-weight: 600; color: var(--muted); white-space: nowrap; }
.nav-link:hover, .nav-link.active { color: var(--primary); }

.user-chip {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 4px 14px 4px 4px;
  border: 1px solid var(--line);
  border-radius: 99px;
  color: var(--ink);
}
.user-chip:hover { border-color: var(--sky); }
.user-chip-name {
  font-size: 14px;
  font-weight: 700;
  max-width: 160px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.class-switcher {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0 14px;
  border: 1px solid var(--input-line);
  border-radius: 99px;
  background: var(--surface);
}
.class-switcher:hover, .class-switcher:focus-within { border-color: var(--sky); }
.class-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--orange); flex: 0 0 auto; }
.class-switcher select {
  appearance: none;
  -webkit-appearance: none;
  border: 0;
  background: transparent url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%2315212b'/%3E%3C/svg%3E") no-repeat right center;
  padding: 8px 18px 8px 0;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  outline: none;
  max-width: 220px;
}

/* ===== Sub-page header ===== */
.sub-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 40px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}
.back-btn {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--input-line);
  background: var(--surface);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--ink);
}
.back-btn:hover { border-color: var(--sky); color: var(--primary); }
.back-btn-white { border-color: transparent; }
.sub-title { display: flex; flex-direction: column; min-width: 0; flex: 1; }
.sub-crumb { font-size: 12px; color: var(--muted); }
.sub-title h1 {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.sub-title h1 .zh { font-weight: 700; font-size: 24px; }
.sub-title-en { font-size: 18px; font-weight: 700; }
.sub-title h1 .zh + .sub-title-en { color: var(--muted); }
.sub-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }

/* ===== Page layout ===== */
.page {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 36px 48px 48px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.page-narrow { max-width: 900px; padding-left: 40px; padding-right: 40px; }

.page-greeting { display: flex; flex-direction: column; gap: 6px; }
.page-greeting h1 {
  font-size: 34px;
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.15;
  color: var(--ink);
}
.page-greeting-row { flex-direction: row; align-items: flex-end; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.page-eyebrow { font-size: 14px; color: var(--muted); }
.page-intro { margin-top: -8px; }

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 20px;
}
.panel-title { font-size: 17px; font-weight: 800; color: var(--ink); }
.panel-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.panel-head h2 { font: 700 20px var(--font-zh); color: var(--ink); }
.panel-head-en { font: 600 14px var(--font-ui); color: var(--muted); }

.section { display: flex; flex-direction: column; gap: 14px; }
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}
.section-head h2 { font-size: 18px; font-weight: 700; color: var(--ink); }

.empty-msg {
  text-align: center;
  color: var(--muted);
  padding: 40px 16px;
  font-size: 15px;
  background: var(--surface);
  border: 1px dashed var(--input-line);
  border-radius: 16px;
}
.empty-msg-sm { padding: 20px 12px; font-size: 14px; border: 0; }

.icon-tile {
  flex: 0 0 auto;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 700 17px var(--font-zh);
}
.icon-tile-lg { width: 48px; height: 48px; font-size: 24px; }
.icon-tile-lg.serif { font-family: var(--font-serif); font-weight: 900; }
.icon-tile-xl { width: 64px; height: 64px; border-radius: 18px; font-size: 26px; }

.row-score { font-size: 17px; font-weight: 800; color: var(--ink); white-space: nowrap; }
.chevron { font-size: 20px; color: var(--faint-2); padding: 0 4px; }

/* ===== Home ===== */
.hero-panel {
  position: relative;
  overflow: hidden;
  border-radius: 24px;
  padding: 28px;
  background: var(--sky);
  color: #fff;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
}

.teacher-home-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 20px;
}
.resume-panel { min-height: 210px; border-radius: 20px; align-items: flex-start; }
.resume-cards { position: absolute; right: 28px; top: 24px; display: flex; gap: 10px; }
.mini-flashcard {
  width: 64px;
  height: 78px;
  border-radius: 12px;
  background: #fff;
  color: var(--ink);
  display: flex;
  align-items: center;
  justify-content: center;
  font: 900 40px var(--font-serif);
  transform: rotate(-6deg);
}
.mini-flashcard-yellow { background: var(--yellow); transform: rotate(5deg); }
.resume-lesson { display: flex; flex-direction: column; gap: 6px; color: #fff; max-width: calc(100% - 170px); }
.resume-name { font-size: 26px; font-weight: 800; line-height: 1.2; }
.resume-lesson:hover .resume-name { text-decoration: underline; text-underline-offset: 4px; }
.resume-meta { font-size: 14px; font-weight: 500; }

.tile-link {
  border-radius: 20px;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
  color: var(--ink);
  transition: border-color .15s, box-shadow .15s;
}
.tile-link:hover { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.tile-link-feature { border: 1.5px solid var(--sky); }
.tile-link-text { display: flex; flex-direction: column; gap: 4px; }
.tile-link-zh { font-size: 20px; font-weight: 700; }
.tile-link-en { font-size: 14px; color: var(--muted); }

.lesson-card-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}
.lesson-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  color: var(--ink);
  transition: border-color .15s, box-shadow .15s;
}
.lesson-card:hover { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.lesson-card-text { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.lesson-card-name { font-size: 15px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lesson-card-meta { font-size: 13px; color: var(--muted); }

.char-chips { display: flex; gap: 6px; min-height: 44px; }
.char-chip {
  width: 38px;
  height: 44px;
  border-radius: 9px;
  background: var(--bg);
  border: 1px solid var(--line);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 900 20px var(--font-serif);
  color: var(--ink);
}
.char-chips-sm { min-height: 0; gap: 4px; }
.char-chips-sm .char-chip { width: 30px; height: 36px; font-size: 17px; border-radius: 8px; }

/* Student home */
.student-home-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 20px;
  align-items: stretch;
}
.revise-hero { min-height: 260px; padding: 32px; color: #fff; transition: box-shadow .15s; }
.revise-hero:hover { box-shadow: 0 20px 40px -20px rgba(10, 80, 120, .5); }
.revise-hero-chips {
  position: absolute;
  right: 36px;
  top: 36px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
}
.mode-chip {
  padding: 10px 16px;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
}
.mode-chip-white { background: #fff; color: var(--ink); }
.mode-chip-yellow { background: var(--yellow); color: var(--ink); }
.mode-chip-pink { background: var(--pink); color: #fff; }
.revise-hero-zh { font-size: 52px; font-weight: 700; line-height: 1; }
.revise-hero-body { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; }
.revise-hero-title { font-size: 20px; font-weight: 700; }
.revise-hero-text { font-size: 15px; font-weight: 500; line-height: 1.45; max-width: 360px; }

.history-card { border-radius: 24px; padding: 28px; display: flex; flex-direction: column; gap: 4px; }
.history-card .panel-head { margin-bottom: 12px; }
.mini-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  border-top: 1px solid var(--divider);
  color: var(--ink);
}
.mini-row .icon-tile { width: 42px; height: 42px; border-radius: 12px; font-size: 16px; }
.mini-row:hover .mini-row-title { color: var(--primary); }
.mini-row-text { flex: 1; display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.mini-row-title { font-size: 15px; font-weight: 700; }
.mini-row-meta { font-size: 12px; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* Class selection */
.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
}
.nav-grid form { display: contents; }
.nav-card {
  display: flex;
  align-items: center;
  gap: 16px;
  width: 100%;
  padding: 20px;
  border-radius: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--ink);
  text-align: left;
  transition: border-color .15s, box-shadow .15s;
}
.nav-card:hover { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.nav-icon {
  flex: 0 0 auto;
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 700 24px var(--font-zh);
}
.nav-icon-default { background: var(--orange-tint); color: var(--orange-ink); }
.nav-icon-image { object-fit: cover; border-radius: 50%; }
.nav-label { flex: 1; font-size: 18px; font-weight: 800; }

/* ===== Lessons list / search ===== */
.add-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px;
}
.add-row .text-input { flex: 1; min-width: 0; }
.add-row .btn { align-self: stretch; }

.lesson-list { display: flex; flex-direction: column; gap: 10px; }
.lesson-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px 14px 18px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  transition: border-color .15s, box-shadow .15s;
}
.lesson-item:hover { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.lesson-info { flex: 1; display: flex; align-items: center; gap: 16px; min-width: 0; color: var(--ink); }
.lesson-info-text { display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.lesson-name { font-size: 16px; font-weight: 700; color: var(--ink); }
.lesson-meta { font-size: 13px; color: var(--muted); }

.search-bar { margin-bottom: 0; }
.pagination { display: flex; align-items: center; justify-content: center; gap: 12px; }
.page-indicator { font: 500 13px var(--font-mono); color: var(--muted); }

/* ===== Lesson editor ===== */
.lesson-title-input {
  width: 100%;
  border: 1.5px solid transparent;
  border-radius: 8px;
  padding: 0 6px;
  margin-left: -8px;
  background: transparent;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--ink);
  outline: none;
}
.lesson-title-input:not([readonly]):hover { border-color: var(--input-line); }
.lesson-title-input:not([readonly]):focus { border-color: var(--sky); box-shadow: var(--focus-ring); }

.editor-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  align-items: start;
  gap: 24px;
  padding-top: 28px;
  padding-left: 32px;
  padding-right: 32px;
}
.editor-main { display: flex; flex-direction: column; gap: 18px; min-width: 0; }
.editor-main .section-head h2 { font-size: 17px; }

.char-input {
  flex: 0 0 auto;
  width: 72px;
  height: 56px;
  padding: 0;
  border: 1.5px dashed var(--sky);
  text-align: center;
  font: 900 28px var(--font-serif);
}
.char-input::placeholder { color: #9bb4c2; }
#addCardForm .text-input { height: 56px; border-width: 1px; }
#addCardForm .btn { height: 56px; }

.bulk-panel { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.bulk-textarea { min-height: 110px; resize: vertical; }

.card-tile-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.card-tile-grid .empty-msg { grid-column: 1 / -1; }
.card-tile {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 14px 12px 12px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  transition: border-color .15s, box-shadow .15s;
}
.card-tile:hover { border-color: var(--sky); }
.tile-delete {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 26px;
  height: 26px;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--faint-2);
  font-size: 13px;
}
.tile-delete:hover { background: var(--danger-bg); color: var(--danger); }
.tile-char { font: 900 52px/1.15 var(--font-serif); color: var(--ink); }
.tile-pinyin, .tile-meaning {
  width: 100%;
  text-align: center;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  padding: 2px 6px;
  outline: none;
}
.tile-pinyin { font-size: 15px; font-weight: 700; color: var(--primary); }
.tile-meaning { font-size: 13px; color: var(--muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tile-edit { cursor: text; }
.tile-edit::placeholder { color: var(--faint-2); font-weight: 500; }
.tile-edit:hover { border-color: var(--input-line); }
.tile-edit:focus { border-color: var(--sky); background: var(--sky-soft); }
.tile-audio { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px; margin-top: 6px; }
.tile-audio audio { display: none; }
.pill {
  border: 0;
  border-radius: 99px;
  padding: 5px 10px;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}
.pill-play { background: var(--sky-tint); color: var(--primary); }
.pill-play:hover:not(:disabled) { background: #d2ecf8; }
.pill-play:disabled { opacity: .45; cursor: not-allowed; }
.pill-record { background: var(--pink-tint); color: var(--pink-ink); }
.pill-record:hover { background: #fbd6e6; }
.pill-record.is-recording { background: var(--pink); color: #fff; animation: pulse 1.2s ease-in-out infinite; }
@keyframes pulse { 50% { opacity: .7; } }
.audio-status { min-height: 14px; font-size: 11px; color: var(--muted); }

.editor-aside { display: flex; flex-direction: column; gap: 14px; position: sticky; top: 20px; }
.play-panel { display: flex; flex-direction: column; gap: 14px; }
.play-panel .panel-title { font-size: 15px; font-weight: 700; }
.mode-option {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 12px 14px;
  border: 1.5px solid var(--line);
  border-radius: 12px;
}
.mode-option.is-selected { border-color: var(--sky); background: var(--sky-soft); }
.mode-option-title { font-size: 14px; font-weight: 700; }
.mode-option-desc { font-size: 12px; color: var(--muted); }
.action-list { display: flex; flex-direction: column; padding: 8px; }
.action-item {
  border: 0;
  background: transparent;
  padding: 12px;
  border-radius: 10px;
  text-align: left;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
}
.action-item:hover { background: var(--bg); }
.action-success { color: var(--success-ink); background: var(--success-bg); }
.action-success:hover { background: var(--success-bg); box-shadow: inset 0 0 0 1px var(--success); }
.action-danger { color: var(--danger); }
.action-danger:hover { background: var(--danger-bg); }

/* ===== Choose students ===== */
.student-select {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 10px;
}
.student-check {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-radius: 16px;
  background: var(--surface);
  border: 1.5px solid var(--input-line);
  cursor: pointer;
  transition: border-color .15s;
}
.student-check input { position: absolute; opacity: 0; pointer-events: none; }
.student-check:has(input:checked) { border-color: var(--sky); }
.student-check:has(input:focus-visible) { box-shadow: var(--focus-ring); }
.student-check-name { font-size: 15px; font-weight: 700; }

/* Shared custom checkbox */
.check-box {
  flex: 0 0 auto;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  border: 1.5px solid var(--input-line);
  background: var(--surface);
  color: transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 800;
  transition: background .15s, border-color .15s;
}
.student-check input:checked + .check-box,
.revise-lesson input:checked + .check-box {
  background: var(--sky);
  border-color: var(--sky);
  color: #fff;
}

/* ===== Gameplay (teacher) ===== */
body.play-body { background: var(--sky-tint-2); }

.gameplay {
  position: relative;
  flex: 1;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--sky-tint-2);
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

.top-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 32px;
}
.top-info { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.top-title { font-size: 17px; font-weight: 800; color: var(--ink); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.top-progress { font-size: 12px; color: var(--muted-sky); }
.top-actions { display: flex; gap: 8px; margin-left: auto; }
.top-actions .btn-secondary { border-color: #c5dbe7; }

.segment-progress {
  flex: 1;
  max-width: 420px;
  margin: 0 auto;
  display: flex;
  gap: 4px;
}
.segment { flex: 1; height: 6px; border-radius: 3px; background: #cfe3ee; transition: background .2s; }
.segment.is-won, .segment.is-correct { background: var(--sky); }
.segment.is-skip { background: #b9cfdc; }
.segment.is-wrong { background: var(--pink); }
.segment.is-current { background: var(--yellow); }

.card-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding: 12px 24px;
  perspective: 1600px;
}

.flash-card-wrapper {
  width: 340px;
  height: 380px;
  max-width: 100%;
  cursor: grab;
  touch-action: none;
  z-index: 5;
}
.flash-card-wrapper:active { cursor: grabbing; }
.flash-card-wrapper.dragging { z-index: 50; transition: none; }
.flash-card-wrapper.dragging .flash-card { box-shadow: none; }

.flash-card {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform .5s var(--ease-flip);
}
.flash-card-wrapper.flipped .flash-card { transform: rotateY(180deg); }

.flash-card-front, .flash-card-back {
  position: absolute;
  inset: 0;
  border-radius: 28px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-card);
}
.flash-card-front { background: #fff; color: var(--ink); }
.flash-card-back {
  background: var(--sky);
  color: #fff;
  gap: 10px;
  padding: 24px;
  text-align: center;
  transform: rotateY(180deg);
  box-shadow: 0 30px 60px -24px rgba(10, 80, 120, .45);
}
.flash-card .character { font: 900 190px/1 var(--font-serif); }
.flash-card .pinyin-large { font-size: 64px; font-weight: 800; letter-spacing: -.01em; line-height: 1.1; }
.flash-card .meaning { font-size: 24px; font-weight: 600; line-height: 1.3; }
.flash-card .character-small { font: 900 48px var(--font-serif); margin-top: 10px; opacity: .9; }
.audio-play {
  position: absolute;
  top: 18px;
  right: 18px;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 50%;
  background: var(--sky-tint);
  color: var(--primary);
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.audio-play:hover { background: #d2ecf8; }
.card-hint { position: absolute; bottom: 18px; font-size: 13px; color: var(--faint); }

.card-enter { animation: cardSlideIn .3s ease-out; }
@keyframes cardSlideIn {
  from { opacity: 0; transform: translateY(24px) scale(.96); }
  to { opacity: 1; transform: none; }
}

.card-area > .btn-secondary { border-color: #c5dbe7; padding: 10px 22px; font-size: 14px; }

.game-over-msg { display: flex; flex-direction: column; align-items: center; gap: 16px; text-align: center; }
.game-over-zh { font: 700 40px var(--font-zh); color: var(--ink); }
.game-over-en { font-size: 18px; color: var(--muted-sky); }

.gameplay .student-row {
  display: flex;
  justify-content: center;
  gap: 22px;
  padding: 18px 32px 30px;
  background: var(--surface);
  border-top: 1px solid #d6e8f1;
  overflow-x: auto;
}

.avatar-wrapper {
  position: relative;
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 8px;
  border-radius: 18px;
  transition: transform .15s, background .15s;
}
.avatar-wrapper.is-over { background: var(--sky-tint); transform: scale(1.05); }
.avatar-circle {
  width: 76px;
  height: 76px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--sky);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font: 700 22px var(--font-zh);
  box-shadow: 0 0 0 4px #fff, 0 0 0 6px var(--ring, var(--sky));
}
.avatar-circle img { width: 100%; height: 100%; object-fit: cover; pointer-events: none; }
.avatar-name {
  max-width: 96px;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.score-badge {
  position: absolute;
  top: 2px;
  right: 0;
  min-width: 28px;
  height: 28px;
  padding: 0 6px;
  border-radius: 14px;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: badgeBounce .35s ease-out;
}
@keyframes badgeBounce {
  0% { transform: scale(.4); }
  70% { transform: scale(1.2); }
  100% { transform: scale(1); }
}

.paused-overlay {
  position: absolute;
  inset: 0;
  z-index: 100;
  background: rgba(21, 33, 43, .55);
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Legacy swipe mode (no longer served, kept for game.js) */
.swipe-indicators { display: flex; justify-content: space-between; padding: 0 32px 12px; font-weight: 700; }
.swipe-hint-wrong { color: var(--pink-ink); }
.swipe-hint-correct { color: var(--success-ink); }
.swipe-score { display: flex; justify-content: center; gap: 16px; padding: 0 0 24px; font-weight: 800; }
.swipe-correct { color: var(--success-ink); }
.swipe-wrong { color: var(--pink-ink); }
.flash-card-wrapper.swipe-right-hint .flash-card-front { box-shadow: 0 0 0 4px var(--success); }
.flash-card-wrapper.swipe-left-hint .flash-card-front { box-shadow: 0 0 0 4px var(--pink); }

/* ===== Confetti ===== */
.confetti-container { position: fixed; inset: 0; pointer-events: none; z-index: 200; }
.confetti-piece {
  position: absolute;
  width: 10px;
  height: 14px;
  border-radius: 2px;
  animation: confettiFall 1s ease-out forwards;
}
@keyframes confettiFall {
  0% { transform: translate(0, 0) rotate(0); opacity: 1; }
  100% { transform: translate(calc((var(--dx, 0) * 1px)), 180px) rotate(540deg); opacity: 0; }
}

/* ===== Summary (teacher game) ===== */
.summary {
  flex: 1;
  width: 100%;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 44px 48px 36px;
  background: var(--surface);
  text-align: center;
}
.summary-title { font-size: 40px; font-weight: 700; color: var(--ink); }
.summary-sub { font-size: 16px; color: var(--muted); }

.summary-stage {
  flex: 1;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 20px;
}
.podium { display: flex; align-items: flex-end; gap: 18px; }
.podium-slot {
  width: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  --place: var(--sky);
}
.podium-avatar {
  width: var(--size, 84px);
  height: var(--size, 84px);
  border-radius: 50%;
  background: var(--place);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font: 700 24px var(--font-zh);
  box-shadow: 0 0 0 5px #fff, 0 0 0 8px var(--place);
}
.podium-name { font-size: 17px; font-weight: 700; color: var(--ink); max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.podium-bar {
  width: 100%;
  height: var(--bar-h, 150px);
  border-radius: 18px 18px 0 0;
  background: var(--bar-bg);
  color: var(--bar-ink);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding-top: 18px;
  animation: podiumRise .6s var(--ease-flip) both;
  transform-origin: bottom;
}
@keyframes podiumRise { from { transform: scaleY(0); } to { transform: scaleY(1); } }
.podium-score { font-size: 44px; font-weight: 800; letter-spacing: -.02em; line-height: 1.1; }
.podium-label { font-size: 12px; letter-spacing: .08em; }
.podium-1 { --place: var(--sky); --size: 104px; --bar-h: 220px; --bar-bg: var(--yellow); --bar-ink: var(--ink); }
.podium-2 { --place: var(--pink); --size: 84px; --bar-h: 150px; --bar-bg: var(--pink-tint); --bar-ink: var(--pink-ink); }
.podium-3 { --place: var(--orange); --size: 76px; --bar-h: 110px; --bar-bg: var(--orange-tint); --bar-ink: var(--orange-ink); }

.scoreboard { width: 260px; display: flex; flex-direction: column; gap: 8px; padding-bottom: 4px; }
.score-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  text-align: left;
}
.rank { font-size: 13px; color: var(--faint); }
.score-name { flex: 1; font-size: 15px; font-weight: 600; color: var(--ink); }
.score-value { font-size: 16px; font-weight: 800; color: var(--ink); }

.summary-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin-top: 28px; }

/* Score ring (revise + legacy swipe summaries) */
.score-ring {
  width: 240px;
  height: 240px;
  border-radius: 50%;
  background: conic-gradient(var(--yellow) 0 var(--pct), rgba(255, 255, 255, .25) var(--pct) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
}
.score-ring-inner {
  width: 196px;
  height: 196px;
  border-radius: 50%;
  background: var(--sky);
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.score-ring-value { font-size: 56px; font-weight: 800; letter-spacing: -.03em; line-height: 1.1; white-space: nowrap; }
.score-ring-label { font-size: 14px; font-weight: 600; }
.score-ring-light { margin: 32px 0 8px; background: conic-gradient(var(--yellow) 0 var(--pct), var(--sky-tint) var(--pct) 100%); }

/* ===== Revise summary ===== */
.revise-summary {
  flex: 1;
  min-height: 100dvh;
  display: grid;
  grid-template-columns: 420px minmax(0, 1fr);
  background: var(--surface);
}
.revise-summary-hero {
  background: var(--sky);
  color: #fff;
  padding: 48px 40px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.revise-summary-title { font-size: 34px; font-weight: 700; }
.revise-summary-sub { font-size: 15px; font-weight: 500; line-height: 1.45; }
.revise-summary-hero .score-ring { margin-top: 36px; }
.revise-summary-mode { margin-top: 12px; font-size: 16px; font-weight: 700; }
.revise-summary-actions { margin-top: auto; padding-top: 24px; display: flex; flex-wrap: wrap; gap: 10px; }

.revise-summary-answers { padding: 40px 44px; display: flex; flex-direction: column; gap: 16px; }
.revise-review {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}
.revise-review-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  border-radius: 14px;
  background: #f3faf6;
}
.revise-review-row.is-wrong { background: #fef3f8; }
.revise-review-mark {
  flex: 0 0 auto;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--success);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 800;
}
.revise-review-row.is-wrong .revise-review-mark { background: var(--pink); }
.revise-review-character { font: 900 34px/1 var(--font-serif); color: var(--ink); }
.revise-review-detail { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.revise-review-pinyin { font-size: 14px; font-weight: 700; color: var(--primary); }
.revise-review-meaning { color: var(--ink); font-weight: 600; }
.revise-review-picked { font-size: 12px; font-weight: 600; color: var(--pink-ink); }

/* ===== History ===== */
.history-list { display: flex; flex-direction: column; gap: 10px; }
.history-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--ink);
  transition: border-color .15s, box-shadow .15s;
}
.history-item:hover { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.history-text { flex: 1; display: flex; flex-direction: column; gap: 3px; min-width: 0; }
.history-name { font-size: 16px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.history-meta { font-size: 13px; color: var(--muted); }

/* ===== Leaderboard ===== */
.leaderboard-tabs { display: flex; flex-wrap: wrap; gap: 8px; }
.leaderboard-tab {
  padding: 8px 14px;
  border-radius: 99px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}
.leaderboard-tab.active { background: var(--sky-tint); border-color: var(--sky); color: var(--primary); }
.leaderboard-how { font-size: 14px; color: var(--muted); margin-top: -8px; }
.leaderboard-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.leaderboard-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 20px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
}
.leaderboard-row.is-top { background: var(--yellow-tint); border-color: #ffe68a; }
.leaderboard-row.is-me { border: 2px solid var(--sky); box-shadow: var(--shadow-hover); }
.leaderboard-rank { width: 32px; text-align: center; font-size: 18px; font-weight: 700; color: var(--muted); }
.leaderboard-row.is-top .leaderboard-rank { font-size: 24px; }
.leaderboard-text { flex: 1; display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.leaderboard-name { font-size: 16px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.leaderboard-you {
  margin-left: 4px;
  padding: 2px 8px;
  border-radius: 99px;
  background: var(--sky);
  color: #fff;
  font-size: 11px;
  font-weight: 800;
  vertical-align: middle;
}
.leaderboard-week { font-size: 12px; font-weight: 700; color: var(--success-ink); }
.leaderboard-stars { font-size: 18px; font-weight: 800; color: var(--ink); white-space: nowrap; }
.leaderboard-reset { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.leaderboard-reset-text { font-size: 14px; color: var(--muted); margin-top: 4px; max-width: 520px; }
.leaderboard-term summary {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  cursor: pointer;
  font-size: 14px;
}
.leaderboard-term-dates { font-weight: 700; color: var(--ink); }
.leaderboard-term-top { color: var(--muted); }
.leaderboard-term-list { margin: 12px 0 0 20px; display: flex; flex-direction: column; gap: 6px; font-size: 14px; list-style: none; }
.leaderboard-term-list .mono { display: inline-block; width: 24px; color: var(--muted); }
.leaderboard-term-stars { color: var(--muted); font-weight: 700; margin-left: 6px; }
.stars-pill {
  align-self: flex-start;
  padding: 8px 14px;
  border-radius: 99px;
  background: var(--yellow-tint);
  color: var(--yellow-ink);
  font-size: 14px;
  font-weight: 800;
}
.stars-pill:hover { background: #ffedb0; }
.revise-summary-stars { font-size: 18px; font-weight: 800; }
.summary-stars-note { font-size: 14px; color: var(--muted); }

/* ===== Profile ===== */
.profile-layout {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}
.profile-card {
  border-radius: 24px;
  padding: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}
.profile-avatar {
  width: 148px;
  height: 148px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--sky);
  color: #fff;
  box-shadow: 0 0 0 6px #fff, 0 0 0 9px var(--sky);
  margin: 9px 0 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font: 700 56px var(--font-zh);
}
.profile-avatar img { width: 100%; height: 100%; object-fit: cover; }
.profile-name { font-size: 22px; font-weight: 700; color: var(--ink); }
.profile-card .role-badge { padding: 3px 10px; }
.profile-photo-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 6px; }
.profile-photo-actions label { cursor: pointer; }

.profile-form {
  border-radius: 24px;
  padding: 32px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px 24px;
}
.profile-form .form-group { margin-bottom: 0; }
.profile-form .form-actions { grid-column: 1 / -1; margin-top: 6px; }
.form-divider {
  grid-column: 1 / -1;
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding-top: 18px;
  border-top: 1px solid var(--divider);
  font-size: 17px;
  font-weight: 800;
  color: var(--ink);
}
.form-divider .muted { font-size: 13px; }
.form-half { grid-column: 1 / -1; max-width: calc(50% - 12px); }

/* ===== Auth (login / set password) ===== */
.auth-page {
  flex: 1;
  min-height: 100dvh;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  background: var(--surface);
}
.auth-hero {
  position: relative;
  overflow: hidden;
  background: var(--sky);
  color: #fff;
  padding: 48px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 32px;
}
.auth-hero-brand { display: flex; align-items: center; gap: 12px; font-size: 15px; font-weight: 700; position: relative; z-index: 1; }
.auth-hero-cards { position: relative; flex: 1; min-height: 320px; }
.hero-card {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-weight: 900;
  box-shadow: 0 24px 50px -16px rgba(0, 40, 80, .4);
}
.hero-card-white { left: 38%; top: 0; width: 170px; height: 210px; border-radius: 22px; background: #fff; color: var(--ink); font-size: 110px; transform: rotate(-9deg); }
.hero-card-yellow { left: calc(38% + 150px); top: -30px; width: 150px; height: 185px; border-radius: 20px; background: var(--yellow); color: var(--ink); font-size: 96px; transform: rotate(7deg); }
.hero-card-pink { left: calc(38% + 90px); top: 180px; width: 130px; height: 160px; border-radius: 18px; background: var(--pink); color: #fff; font-size: 80px; transform: rotate(-3deg); }
.auth-hero-title { display: flex; flex-direction: column; gap: 10px; position: relative; z-index: 1; }
.auth-hero-title .zh { font-size: 64px; font-weight: 700; line-height: 1; letter-spacing: .02em; }
.auth-hero-title span:last-child { font-size: 20px; font-weight: 600; opacity: .95; }

.auth-panel { display: flex; align-items: center; justify-content: center; padding: 48px; }
.auth-form { width: 100%; max-width: 380px; display: flex; flex-direction: column; gap: 22px; }
.auth-form form { display: flex; flex-direction: column; }
.auth-form .btn-block { margin-top: 4px; }
.auth-heading { display: flex; flex-direction: column; gap: 6px; }
.auth-heading h1 { font-size: 30px; font-weight: 800; letter-spacing: -.02em; color: var(--ink); }
.auth-heading p { font-size: 15px; color: var(--muted); line-height: 1.45; }
.auth-form .auth-error { margin-bottom: 0; }
.auth-note, .auth-link { font-size: 13px; color: var(--muted); line-height: 1.5; }

/* ===== Revise setup ===== */
.revise-setup {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}
.revise-column { display: flex; flex-direction: column; gap: 14px; }
.step-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; min-height: 36px; }
.step-head h2 { font-size: 17px; font-weight: 800; color: var(--ink); }
.step-num { color: var(--sky); margin-right: 6px; }

.revise-lessons { display: flex; flex-direction: column; gap: 10px; }
.revise-lesson {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  border-radius: 16px;
  background: var(--surface);
  border: 1.5px solid var(--input-line);
  cursor: pointer;
  transition: border-color .15s;
}
.revise-lesson:hover { border-color: #a9d8ee; }
.revise-lesson.is-selected { border-color: var(--sky); }
.revise-lesson:focus-within { box-shadow: var(--focus-ring); }
.revise-lesson .lesson-name { flex: 1; }

.revise-hint { font-size: 13px; font-weight: 600; color: var(--orange-ink); transition: opacity .15s; }
.revise-hint.is-hidden { opacity: 0; }

.revise-modes { display: flex; flex-direction: column; gap: 14px; }
.mode-card {
  display: flex;
  align-items: center;
  gap: 18px;
  width: 100%;
  padding: 22px;
  border-radius: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  text-align: left;
  color: var(--ink);
  transition: border-color .15s, box-shadow .15s, opacity .15s;
}
.mode-card:hover:not(:disabled) { border-color: var(--sky); box-shadow: 0 8px 20px -10px rgba(10, 111, 168, .3); }
.mode-card:disabled { opacity: .45; cursor: not-allowed; }
.mode-card-text { flex: 1; display: flex; flex-direction: column; gap: 4px; }
.mode-card-title { font-size: 19px; font-weight: 800; }
.mode-card-desc { font-size: 14px; color: var(--muted); }
.mode-card-arrow { font-size: 22px; color: var(--primary); }

/* ===== Revise quiz ===== */
.revise-play {
  flex: 1;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  background: var(--sky-tint-2);
  padding-bottom: 118px;
}
.revise-play .top-bar { padding: 20px 40px; }
.revise-play .top-title { font-size: 18px; }
.progress-pill {
  padding: 8px 14px;
  border-radius: 99px;
  background: #fff;
  font-size: 14px;
  color: var(--ink);
  white-space: nowrap;
}

.revise-stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 28px;
  padding: 16px 40px 32px;
}
.revise-stage .empty-msg { max-width: 560px; }
.revise-prompt { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.revise-audio-btn {
  width: 150px;
  height: 150px;
  border: 0;
  border-radius: 50%;
  background: var(--sky);
  color: #fff;
  font-size: 48px;
  margin: 28px;
  box-shadow: 0 0 0 14px rgba(26, 163, 221, .18), 0 0 0 28px rgba(26, 163, 221, .08);
  transition: transform .1s, background .15s;
}
.revise-audio-btn:hover { background: #1496cc; }
.revise-audio-btn:active { transform: scale(.96); }
.revise-character {
  width: 210px;
  height: 220px;
  border-radius: 26px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font: 900 140px/1 var(--font-serif);
  color: var(--ink);
  box-shadow: 0 24px 50px -24px rgba(10, 80, 120, .35);
}
.revise-instruction { font-size: 16px; font-weight: 600; color: var(--muted-sky); margin-top: 10px; text-align: center; }

.revise-options {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  width: 100%;
  max-width: 980px;
}
.revise-option {
  min-height: 120px;
  border-radius: 20px;
  background: #fff;
  border: 2px solid #fff;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px;
  text-align: center;
  transition: border-color .2s, background .2s, opacity .2s, box-shadow .2s;
}
.revise-text-option:hover:not(:disabled) { border-color: var(--sky); box-shadow: var(--shadow-hover); }
.revise-text-option:disabled { cursor: default; color: var(--ink); }
.revise-option-label { font-size: 20px; font-weight: 800; line-height: 1.15; }
.revise-option-character { font: 900 54px/1.1 var(--font-serif); }
.revise-play-btn {
  border: 0;
  background: transparent;
  font-size: 20px;
  font-weight: 800;
  color: var(--ink);
  padding: 6px 10px;
  border-radius: 10px;
}
.revise-play-btn:hover { color: var(--primary); background: var(--sky-soft); }
.revise-option-reveal { font: 900 20px var(--font-serif); min-height: 0; }
.revise-option-reveal:empty { display: none; }
.revise-pick-btn {
  border: 0;
  border-radius: 99px;
  padding: 6px 18px;
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
}
.revise-pick-btn:hover { background: var(--primary-hover); }
.revise-options.is-answered .revise-pick-btn { display: none; }

.revise-option.is-correct { background: var(--success-bg); border-color: var(--success); color: #1d6b3d; }
.revise-option.is-wrong { background: var(--pink-tint); border-color: var(--pink); color: #9c2658; }
.revise-option.is-dimmed { opacity: .45; }
.revise-option.is-correct .revise-play-btn,
.revise-option.is-wrong .revise-play-btn { color: inherit; }

.revise-feedback {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 20;
  min-height: 118px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 40px;
  background: #fff;
  border-top: 1px solid #d6e8f1;
}
.revise-feedback.is-correct { background: var(--success-bg-soft); }
.revise-feedback.is-wrong { background: #fef3f8; }
.revise-waiting { font-size: 14px; color: var(--muted); }
.revise-feedback-inner {
  width: 100%;
  max-width: 980px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px 24px;
}
.revise-verdict { font-size: 22px; font-weight: 800; }
.revise-feedback.is-correct .revise-verdict { color: var(--success-ink); }
.revise-feedback.is-wrong .revise-verdict { color: var(--pink-ink); }
.revise-answer {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 18px;
  border-radius: 14px;
  background: #fff;
  min-width: 0;
}
.revise-answer-character { font: 900 36px var(--font-serif); color: var(--ink); }
.revise-answer-pinyin { font-size: 18px; font-weight: 700; color: var(--primary); }
.revise-answer-meaning { font-size: 16px; color: var(--muted); }
.revise-answer-audio {
  width: 34px;
  height: 34px;
  border: 0;
  border-radius: 50%;
  background: var(--sky-tint);
  color: var(--primary);
  font-size: 12px;
  flex: 0 0 auto;
}
.revise-feedback-inner #nextBtn { margin-left: auto; border-radius: 14px; padding: 16px 30px; }

/* ===== Admin ===== */
.page-header { display: flex; align-items: center; gap: 12px; }
.page-header h1 { font-size: 30px; font-weight: 800; letter-spacing: -.02em; }
.page h2 { font-size: 18px; font-weight: 700; }
.admin-panel { background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 20px; }
.card-surface { background: var(--surface); border: 1px solid var(--line); border-radius: 18px; padding: 20px; }

.tab-bar { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; padding-bottom: 14px; border-bottom: 1px solid var(--divider); }
.tab-btn {
  border: 0;
  border-radius: 99px;
  padding: 8px 14px;
  background: transparent;
  font-size: 14px;
  font-weight: 600;
  color: var(--muted);
}
.tab-btn:hover { background: var(--bg); color: var(--ink); }
.tab-btn.active { background: var(--sky-tint); color: var(--primary); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

.student-list { display: flex; flex-direction: column; gap: 8px; }
.student-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
}
.student-item:hover { border-color: #a9d8ee; }
.student-avatar-sm {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--sky);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font: 700 14px var(--font-zh);
  flex: 0 0 auto;
}
.student-avatar-sm img { width: 100%; height: 100%; object-fit: cover; }
.student-details { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.student-details .student-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.student-name { flex: 1; min-width: 0; display: flex; align-items: center; flex-wrap: wrap; gap: 6px; font-size: 15px; font-weight: 700; }
.student-username { font-size: 13px; font-weight: 400; color: var(--muted); }
.student-actions { display: flex; flex-wrap: wrap; gap: 6px; margin-left: auto; }
.student-actions form { display: inline; }
.student-actions .btn { white-space: nowrap; }

.role-select { display: flex; gap: 8px; }
.role-option {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: 1.5px solid var(--input-line);
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600 !important;
  cursor: pointer;
}
.role-option:has(input:checked) { border-color: var(--sky); background: var(--sky-soft); }
.role-option input { width: auto !important; accent-color: var(--primary); }
.photo-preview { width: 96px; height: 96px; border-radius: 50%; object-fit: cover; margin-bottom: 10px; }

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 300;
  background: rgba(21, 33, 43, .55);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  animation: fadeIn .15s ease-out;
}
.modal-content {
  width: 100%;
  max-width: 480px;
  max-height: calc(100dvh - 32px);
  overflow-y: auto;
  background: var(--surface);
  border-radius: 24px;
  padding: 28px;
  animation: slideUp .2s ease-out;
}
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.modal-header h2 { font-size: 20px; font-weight: 800; }
.modal-close {
  width: 36px;
  height: 36px;
  border: 1px solid var(--input-line);
  border-radius: 50%;
  background: var(--surface);
  color: var(--muted);
}
.modal-close:hover { color: var(--ink); border-color: var(--sky); }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes slideUp { from { transform: translateY(16px); opacity: 0; } to { transform: none; opacity: 1; } }

/* ===== Phone-only chrome (hidden above 640px) ===== */
.phone-only, .mobile-avatar, .tabbar, .me-panel, .more-menu { display: none; }
.link-btn { border: 0; background: none; padding: 0; font-size: 13px; font-weight: 600; color: var(--primary); }

.lesson-meta, .history-meta { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ===== Tablet: 641–1024px ===== */
@media (max-width: 1024px) {
  .page, .page-narrow { padding: 28px 24px 40px; }
  .top-nav, .sub-header { padding-left: 24px; padding-right: 24px; }
  .editor-layout { grid-template-columns: minmax(0, 1fr) 260px; padding: 24px; }
  .lesson-card-grid, .card-tile-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .teacher-home-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .resume-panel { grid-column: 1 / -1; }
  .revise-setup { gap: 24px; }
  .profile-layout { grid-template-columns: 280px minmax(0, 1fr); }
  .revise-summary { grid-template-columns: 340px minmax(0, 1fr); }
  .revise-summary-hero { padding: 40px 28px; }
  .revise-summary-answers { padding: 32px 24px; }
  .revise-review { grid-template-columns: 1fr; }
  .auth-hero { padding: 36px; }
  .hero-card-white { left: 12%; }
  .hero-card-yellow { left: calc(12% + 150px); }
  .hero-card-pink { left: calc(12% + 90px); }
  .summary { padding: 36px 24px; }
  .revise-options { max-width: 720px; }
}

@media (max-width: 900px) {
  .nav-pills { order: 3; width: 100%; margin-left: 0; overflow-x: auto; }
  .card-tile-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .editor-layout { grid-template-columns: minmax(0, 1fr) 240px; }
  #addCardForm { flex-wrap: wrap; }
  #addCardForm .text-input { flex: 1 1 calc(100% - 82px); }
  #addCardForm .btn { flex: 1; }
  .lesson-card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .profile-form { grid-template-columns: 1fr; }
  .form-half { max-width: none; }
  .revise-options { grid-template-columns: repeat(2, minmax(0, 1fr)); max-width: 560px; }
  .top-bar { flex-wrap: wrap; }
  .segment-progress { order: 3; flex-basis: 100%; max-width: none; }
}

/* ===== Phone: ≤ 640px ===== */
@media (max-width: 640px) {
  .hide-phone { display: none !important; }
  .phone-only { display: inline; }

  /* Inputs at 16px so iOS does not zoom on focus */
  .form-group input, .form-group textarea, .form-group select,
  .text-input, .bulk-textarea, .tile-edit, .lesson-title-input { font-size: 16px; }

  /* Touch targets */
  .btn { min-height: 44px; }
  .back-btn, .revise-answer-audio, .pill { position: relative; }
  .back-btn::after, .audio-play::after, .revise-answer-audio::after, .tile-delete::after, .pill::after {
    content: "";
    position: absolute;
    inset: -6px;
  }

  /* Header + bottom tab bar */
  .top-nav { padding: 12px 20px; flex-wrap: nowrap; gap: 10px; }
  .brand { gap: 10px; }
  .brand .logo { width: 34px; height: 34px; }
  .brand-en, .nav-pills, .nav-right { display: none; }
  .mobile-avatar { display: inline-flex; margin-left: auto; }
  .mobile-avatar .avatar { width: 34px; height: 34px; font-size: 14px; }

  body:has(.tabbar) { padding-bottom: calc(76px + env(safe-area-inset-bottom)); }
  .tabbar {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 150;
    padding: 8px 12px calc(8px + env(safe-area-inset-bottom));
    background: var(--surface);
    border-top: 1px solid var(--line);
  }
  .tab {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    min-height: 52px;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
    color: var(--muted);
  }
  .tab-glyph {
    width: 44px;
    height: 28px;
    border-radius: 99px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
  }
  .tab.active { color: var(--primary); }
  .tab.active .tab-glyph { background: var(--sky-tint); }

  .sub-header { padding: 12px 20px; gap: 12px; flex-wrap: nowrap; }
  .sub-title h1 { font-size: 18px; }
  .sub-title h1 .zh { font-size: 20px; }
  .sub-title-en { font-size: 16px; }
  .sub-crumb { font-size: 11px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .sub-actions .class-switcher { display: none; }
  .sub-actions:not(:has(> :not(.class-switcher))) { display: none; }

  /* Page rhythm */
  .page, .page-narrow { padding: 20px 20px 32px; gap: 18px; }
  .page-greeting h1 { font-size: 28px; }
  .page-eyebrow { font-size: 13px; }
  .section-head h2 { font-size: 15px; }
  .panel { padding: 16px; border-radius: 16px; }

  /* Stack two-column layouts */
  .student-home-grid, .revise-setup, .profile-layout, .editor-layout,
  .teacher-home-grid { grid-template-columns: minmax(0, 1fr); }
  .lesson-card-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .lesson-card { padding: 14px; }
  .char-chip { width: 32px; height: 38px; font-size: 17px; }
  .char-chips { min-height: 38px; gap: 4px; }
  .resume-cards { display: none; }
  .resume-lesson { max-width: none; }
  .tile-link { flex-direction: row; align-items: center; justify-content: flex-start; padding: 16px; gap: 14px; }
  .add-row { flex-wrap: wrap; }
  .lesson-item { padding: 12px 14px; min-height: 48px; }
  .lesson-info { gap: 12px; }
  .lesson-item .char-chips { display: none; }
  .history-item { padding: 12px 14px; gap: 12px; min-height: 48px; }
  .history-item .icon-tile { width: 40px; height: 40px; border-radius: 12px; font-size: 15px; }
  .history-name { font-size: 15px; }
  .history-meta { font-size: 12px; }
  .row-score { font-size: 15px; }
  .leaderboard-row { padding: 12px 14px; gap: 10px; }
  .leaderboard-name { font-size: 15px; }
  .leaderboard-stars { font-size: 16px; }

  /* Login (4a) */
  .auth-page { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  .auth-hero { height: 330px; padding: 48px 24px 24px; justify-content: flex-end; gap: 6px; }
  .auth-hero-brand { position: absolute; top: 48px; left: 24px; }
  .auth-hero-brand > span:last-child { display: none; }
  .auth-hero-brand .logo { width: 44px; height: 44px; }
  .auth-hero-cards { position: absolute; inset: 0; min-height: 0; }
  .hero-card-white { left: auto; right: 70px; top: 60px; width: 96px; height: 118px; border-radius: 16px; font-size: 60px; }
  .hero-card-yellow { left: auto; right: 14px; top: 92px; width: 84px; height: 104px; border-radius: 14px; font-size: 52px; transform: rotate(8deg); }
  .hero-card-pink { display: none; }
  .auth-hero-title { gap: 6px; }
  .auth-hero-title .zh { font-size: 40px; }
  .auth-hero-title span:last-child { font-size: 15px; }
  .auth-panel { align-items: stretch; padding: 28px 24px; }
  .auth-form { max-width: none; gap: 16px; }
  .auth-heading h1 { font-size: 26px; }
  .auth-form .form-group { margin-bottom: 16px; }
  .auth-form .form-group input { padding: 15px 16px; }
  .auth-note { text-align: center; }

  /* Student home (4b) */
  .revise-hero { min-height: 0; padding: 22px; border-radius: 22px; gap: 14px; justify-content: flex-start; }
  .revise-hero-body { display: contents; }
  .revise-hero-zh { order: 1; font-size: 38px; }
  .revise-hero-title { order: 2; font-size: 16px; margin-top: -10px; }
  .revise-hero-text { display: none; }
  .revise-hero-chips { order: 3; position: static; flex-direction: row; flex-wrap: wrap; align-items: flex-start; gap: 6px; }
  .mode-chip { padding: 7px 11px; border-radius: 10px; font-size: 13px; }
  .revise-hero .btn { order: 4; width: 100%; }
  .revise-hero-badge {
    display: inline-block;
    position: absolute;
    top: 22px;
    right: 22px;
    padding: 6px 10px;
    border-radius: 99px;
    background: rgba(255, 255, 255, .2);
  }
  .history-card { padding: 16px; border-radius: 18px; }
  .history-card .panel-head { margin-bottom: 4px; }
  .panel-head h2 { font-size: 17px; }
  .mini-row { min-height: 48px; }
  .mini-row .icon-tile { width: 40px; height: 40px; font-size: 15px; }
  .mini-row-title { font-size: 14px; }

  /* Revise setup (4c) */
  .revise-column { gap: 10px; }
  .step-head h2 { font-size: 15px; white-space: nowrap; }
  .step-head { min-width: 0; }
  .revise-lesson { padding: 12px 14px; min-height: 48px; gap: 12px; border-radius: 14px; }
  .revise-lesson .lesson-name { font-size: 15px; }
  .revise-lesson .check-box { width: 24px; height: 24px; border-radius: 7px; font-size: 14px; }
  .revise-hint { font-size: 12px; }
  .mode-card { padding: 12px 14px; gap: 14px; border-radius: 16px; }
  .mode-card .icon-tile-xl { width: 44px; height: 44px; border-radius: 13px; font-size: 19px; }
  .mode-card-title { font-size: 15px; }
  .mode-card-desc { font-size: 12px; }
  .mode-card-arrow { font-size: 18px; }

  /* Revise quiz (4d) */
  .revise-play { padding-bottom: 150px; }
  .revise-play .top-bar { padding: 16px 20px 10px; gap: 10px 10px; }
  .revise-play .top-title { font-size: 15px; }
  .progress-pill { margin-left: auto; font-size: 12px; padding: 7px 11px; }
  .segment-progress { gap: 3px; }
  .segment { height: 5px; }
  .revise-stage { padding: 8px 20px 16px; gap: 16px; }
  .revise-prompt { gap: 10px; }
  .revise-character { width: 170px; height: 176px; border-radius: 24px; font-size: 112px; }
  .revise-audio-btn { width: 120px; height: 120px; font-size: 38px; margin: 24px 0 14px; box-shadow: 0 0 0 12px rgba(26, 163, 221, .18), 0 0 0 24px rgba(26, 163, 221, .08); }
  .revise-instruction { font-size: 14px; margin-top: 0; }
  .revise-options { grid-template-columns: 1fr 1fr; gap: 10px; }
  .revise-option { min-height: 92px; border-radius: 18px; gap: 4px; padding: 6px; }
  .revise-option-label { font-size: 16px; }
  .revise-option-character { font-size: 44px; }
  .revise-play-btn { font-size: 16px; min-height: 44px; }
  .revise-pick-btn { min-height: 32px; }
  .revise-feedback { min-height: 132px; padding: 16px 20px calc(20px + env(safe-area-inset-bottom)); }
  .revise-feedback-inner { flex-wrap: wrap; gap: 12px 10px; }
  .revise-verdict { font-size: 17px; }
  .revise-answer { margin-left: auto; padding: 0; gap: 8px; background: transparent; min-width: 0; }
  .revise-answer-character { font-size: 26px; }
  .revise-answer-pinyin { font-size: 15px; }
  .revise-answer-meaning { font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .revise-feedback-inner #nextBtn { flex-basis: 100%; margin-left: 0; padding: 15px; }

  /* Revise summary (4e) */
  .revise-summary { grid-template-columns: 1fr; min-height: 0; padding-bottom: calc(80px + env(safe-area-inset-bottom)); }
  .revise-summary-hero {
    display: grid;
    grid-template-columns: 120px 1fr;
    grid-template-areas: "ring title" "ring mode" "ring sub";
    align-content: center;
    column-gap: 18px;
    row-gap: 6px;
    padding: 24px 20px 22px;
  }
  .revise-summary-title { grid-area: title; align-self: end; font-size: 26px; }
  .revise-summary-mode { grid-area: mode; margin: 0; font-size: 14px; }
  .revise-summary-sub { grid-area: sub; align-self: start; font-size: 12px; }
  .revise-summary-hero .score-ring { grid-area: ring; margin: 0; width: 120px; height: 120px; }
  .revise-summary-hero .score-ring-inner { width: 96px; height: 96px; }
  .revise-summary-hero .score-ring-value { font-size: 26px; }
  .revise-summary-hero .score-ring-label { font-size: 10px; }
  .revise-summary-actions {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 20;
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 8px;
    margin: 0;
    padding: 12px 20px calc(12px + env(safe-area-inset-bottom));
    background: var(--surface);
    border-top: 1px solid var(--line);
  }
  .revise-summary-actions .btn { padding: 12px 0; font-size: 14px; }
  .revise-summary-actions .btn-white { background: var(--primary); color: #fff; }
  .revise-summary-actions .btn-outline-light { background: var(--surface); color: var(--ink); border: 1px solid var(--input-line); }
  .revise-summary-answers { padding: 16px 20px; gap: 8px; }
  .revise-summary-answers .panel-title { font-size: 15px; }
  .revise-review { gap: 8px; }
  .revise-review-row { padding: 8px 12px; gap: 12px; border-radius: 12px; }
  .revise-review-mark { width: 24px; height: 24px; font-size: 12px; }
  .revise-review-character { font-size: 26px; }
  .revise-review-pinyin { font-size: 13px; }
  .revise-review-picked { font-size: 11px; }

  /* Teacher game (4f) */
  .gameplay .top-bar { padding: 16px 20px 8px; gap: 12px 8px; }
  .gameplay .top-title { font-size: 15px; }
  .top-progress { font-size: 11px; }
  .top-actions .btn { padding: 9px 12px; font-size: 13px; }
  .card-area { gap: 16px; padding: 8px 20px; perspective: 1400px; }
  .flash-card-wrapper { width: 260px; height: 300px; }
  .flash-card-front, .flash-card-back { border-radius: 26px; }
  .flash-card .character { font-size: 150px; }
  .flash-card .pinyin-large { font-size: 50px; }
  .flash-card .meaning { font-size: 20px; }
  .flash-card .character-small { font-size: 38px; margin-top: 6px; }
  .audio-play { top: 14px; right: 14px; width: 40px; height: 40px; font-size: 14px; }
  .card-hint { bottom: 14px; font-size: 12px; }
  .card-area > .btn-secondary { padding: 11px 24px; }
  .gameplay .student-row {
    justify-content: flex-start;
    gap: 6px;
    padding: 14px 14px calc(20px + env(safe-area-inset-bottom));
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  .avatar-wrapper { width: 68px; padding: 6px 0; gap: 6px; border-radius: 14px; }
  .avatar-circle { width: 54px; height: 54px; font-size: 17px; box-shadow: 0 0 0 3px #fff, 0 0 0 5px var(--ring, var(--sky)); }
  .avatar-name { max-width: 64px; font-size: 12px; }
  .score-badge { top: 0; right: 2px; min-width: 22px; height: 22px; padding: 0 5px; border-radius: 11px; font-size: 12px; }
  .game-over-zh { font-size: 32px; }

  /* Game summary */
  .summary { padding: 28px 16px; min-height: 0; }
  .summary-title { font-size: 32px; }
  .summary-stage { flex-direction: column; align-items: center; margin-top: 12px; }
  .podium { gap: 8px; }
  .podium-slot { width: 30vw; max-width: 120px; }
  .podium-name { font-size: 14px; }
  .podium-score { font-size: 32px; }
  .podium-1 { --size: 72px; --bar-h: 160px; }
  .podium-2 { --size: 60px; --bar-h: 112px; }
  .podium-3 { --size: 54px; --bar-h: 84px; }
  .scoreboard { width: 100%; }
  .summary-actions { width: 100%; margin-top: 20px; }
  .summary-actions .btn { flex: 1; }

  /* Lesson editor (4g) */
  .editor-layout { padding-bottom: calc(96px + env(safe-area-inset-bottom)); }
  .editor-main { gap: 12px; }
  #addCardForm {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: 8px;
    padding: 12px;
  }
  #addCardForm .char-input { width: 60px; height: 52px; font-size: 24px; }
  #addCardForm .text-input { height: 52px; padding: 0 12px; }
  #addCardForm .add-card-btn { grid-column: 1 / -1; height: 46px; }
  .card-tile-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .card-tile {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    grid-template-areas: "char pinyin" "char meaning" "audio audio" "status status";
    align-items: center;
    column-gap: 10px;
    row-gap: 1px;
    padding: 10px 12px;
    border-radius: 14px;
  }
  .tile-char { grid-area: char; font-size: 36px; line-height: 1; }
  .tile-pinyin { grid-area: pinyin; text-align: left; font-size: 14px; padding: 2px 4px; margin-right: 22px; }
  .tile-meaning { grid-area: meaning; text-align: left; font-size: 12px; padding: 2px 4px; }
  .tile-audio { grid-area: audio; justify-content: flex-start; margin-top: 6px; gap: 4px; }
  .audio-status { grid-area: status; min-height: 0; }
  .tile-delete { top: 4px; right: 4px; }
  .pill { padding: 6px 9px; font-size: 11px; }
  .editor-aside { position: static; }
  .editor-aside .action-list, .play-panel .panel-title, .play-panel .mode-option { display: none; }
  .play-panel {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 20;
    padding: 12px 20px calc(12px + env(safe-area-inset-bottom));
    border: 0;
    border-top: 1px solid var(--line);
    border-radius: 0;
  }
  .play-panel .btn { border-radius: 14px; padding: 16px; }
  .lesson-title-input { font-size: 17px; }

  .more-menu { display: block; position: relative; margin-left: auto; }
  .more-menu summary {
    list-style: none;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-size: 20px;
    color: var(--muted);
    cursor: pointer;
  }
  .more-menu summary::-webkit-details-marker { display: none; }
  .more-menu[open] summary { background: var(--bg); color: var(--ink); }
  .more-menu-list {
    position: absolute;
    right: 0;
    top: calc(100% + 6px);
    z-index: 160;
    min-width: 220px;
    display: flex;
    flex-direction: column;
    padding: 8px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 16px;
    box-shadow: 0 16px 40px -16px rgba(10, 80, 120, .35);
  }
  .more-menu-list .action-item { min-height: 44px; }

  /* Profile / Me (3e) */
  .profile-card { padding: 24px; gap: 12px; border-radius: 20px; }
  .profile-avatar { width: 112px; height: 112px; font-size: 44px; }
  .profile-form { padding: 20px; border-radius: 20px; gap: 16px; }
  .me-panel { display: flex; flex-direction: column; padding: 4px 16px; border-radius: 20px; }
  .me-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    min-height: 52px;
    border-bottom: 1px solid var(--divider);
    font-size: 15px;
    font-weight: 700;
    color: var(--ink);
  }
  .me-row:last-child { border-bottom: 0; }
  .me-label { color: var(--muted); font-weight: 600; font-size: 14px; }
  .me-row .class-switcher { min-height: 40px; }
  .me-logout { color: var(--danger); }

  /* Select students, admin */
  .student-select { grid-template-columns: 1fr 1fr; gap: 8px; }
  .student-check { padding: 10px 12px; gap: 8px; min-height: 52px; }
  .student-check .avatar { display: none; }
  .student-check-name { font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .page-header h1 { font-size: 24px; }
  .student-actions { margin-left: 0; }
  .modal-content { padding: 20px; border-radius: 20px; }
}