:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --surface-soft: #ecf2ff;
  --surface-warm: #fff6e7;
  --text: #17304d;
  --muted: #5e748d;
  --line: #d8e2f0;
  --brand: #2f6fed;
  --brand-strong: #184fb7;
  --shadow: 0 20px 50px rgba(28, 61, 114, 0.08);
  --radius-xl: 28px;
  --radius-lg: 20px;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(47, 111, 237, 0.16), transparent 32%),
    radial-gradient(circle at top right, rgba(255, 204, 102, 0.22), transparent 22%),
    var(--bg);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
a { color: inherit; text-decoration: none; }
button, input, textarea { font: inherit; }
.shell { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.page-section {
  position: relative;
}
.page-spark {
  position: absolute;
  z-index: 0;
  border-radius: 999px;
  pointer-events: none;
  filter: blur(2px);
}
.page-spark--left {
  left: -18px;
  top: 18px;
  width: 120px;
  height: 120px;
  background: radial-gradient(circle, rgba(255, 184, 126, .22), rgba(255, 184, 126, 0));
}
.page-spark--right {
  right: 8px;
  top: 96px;
  width: 140px;
  height: 140px;
  background: radial-gradient(circle, rgba(133, 168, 255, .20), rgba(133, 168, 255, 0));
}
.site-header { position: sticky; top: 0; z-index: 20; background: rgba(244,247,251,.86); backdrop-filter: blur(14px); border-bottom: 1px solid rgba(216,226,240,.8); }
.site-header--landing {
  position: relative;
  background: transparent;
  border-bottom: none;
  backdrop-filter: none;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; min-height: 76px; }
.brand { display: inline-flex; align-items: center; gap: 12px; }
.brand strong, .hero-copy h1, .card h3, .section-head h2 { font-family: Georgia, "Times New Roman", serif; }
.brand span { display: block; color: var(--muted); font-size: 13px; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 16px; color: white; background: linear-gradient(135deg, #ff9e4d, #ffc062); box-shadow: 0 12px 28px rgba(255, 166, 89, .26); }
.nav-links { display: flex; align-items: center; gap: 18px; color: var(--muted); }
.nav-links--landing {
  gap: 12px;
}
.nav-user { font-weight: 600; color: var(--text); }
.inline-form { margin: 0; }
.nav-button, .primary-link, .primary-button { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 0 16px; border-radius: 999px; background: var(--brand); color: white; font-weight: 600; border: none; }
.secondary-link { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 0 16px; border-radius: 999px; border: 1px solid var(--line); background: white; color: var(--text); }
.nav-links--landing .nav-button {
  background: linear-gradient(135deg, #4a7df6, #6f9dff);
  box-shadow: 0 12px 24px rgba(74, 125, 246, .20);
}
.nav-links--landing .secondary-link {
  background: rgba(255,255,255,.72);
  border-color: rgba(216,226,240,.95);
}
.notice { padding: 12px 14px; border-radius: 14px; }
.error-notice { background: #fff1f1; border: 1px solid #f1c8c8; color: #9f3030; }
.success-notice { background: #eefaf1; border: 1px solid #bfe3c9; color: #21643a; }
.info-notice { background: #f2f7ff; border: 1px solid #cfe0ff; color: #31548d; }
.page-section { padding: 42px 0; }
.page-mini-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.page-mini-chips span {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  background: rgba(255,255,255,.16);
  border: 1px solid rgba(255,255,255,.22);
  color: white;
  font-size: 13px;
  font-weight: 600;
}
.page-mini-chips--soft span {
  background: rgba(236, 242, 255, .92);
  border-color: rgba(216, 226, 240, .98);
  color: var(--brand-strong);
}
.landing-page {
  min-height: calc(100vh - 108px);
  display: grid;
  place-items: center;
  padding: 28px 0 48px;
}
.landing-page__stage {
  position: relative;
  width: min(100%, 920px);
  min-height: 620px;
  display: grid;
  place-items: center;
}
.landing-panel {
  position: relative;
  z-index: 1;
  width: min(100%, 460px);
  padding: 38px 34px 32px;
  background: linear-gradient(180deg, rgba(255,255,255,.96), rgba(255,248,253,.88));
  border: 1px solid rgba(255,255,255,.84);
  border-radius: 36px;
  box-shadow: 0 34px 96px rgba(93, 110, 157, 0.16);
  backdrop-filter: blur(18px);
}
.landing-panel::before {
  content: "";
  position: absolute;
  inset: 10px;
  border-radius: 26px;
  border: 1px solid rgba(216,226,240,.55);
  pointer-events: none;
}
.landing-panel--welcome {
  width: min(100%, 640px);
  text-align: center;
}
.landing-panel h1 {
  margin: 10px 0 12px;
  font-size: clamp(34px, 4.4vw, 52px);
  line-height: 1.02;
  letter-spacing: -.02em;
}
.landing-mascot {
  position: absolute;
  right: 26px;
  top: -24px;
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  border-radius: 20px;
  background: linear-gradient(135deg, #ff99c8, #ffcc70);
  color: white;
  font-weight: 800;
  box-shadow: 0 16px 28px rgba(255, 160, 170, .24);
}
.landing-sub-badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  margin-left: 8px;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(236, 242, 255, .88);
  color: #6a7ca0;
  font-size: 12px;
  font-weight: 700;
}
.landing-panel p {
  margin: 0;
  color: var(--muted);
  line-height: 1.75;
}
.landing-badge {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 14px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 176, 90, .22), rgba(113, 153, 255, .18));
  color: var(--brand-strong);
  font-weight: 700;
}
.landing-form {
  display: grid;
  gap: 14px;
  margin-top: 24px;
}
.landing-helper-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: #70809a;
  font-size: 13px;
}
.landing-check {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: #556b8c;
  font-weight: 600;
}
.landing-check input {
  width: 16px;
  height: 16px;
  margin: 0;
  accent-color: var(--brand);
}
.landing-helper-text {
  color: #7d8ba4;
}
.landing-mini-pills {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
}
.landing-mini-pills span {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 12px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(238, 243, 255, .96), rgba(255, 240, 247, .96));
  color: #556b8c;
  font-size: 13px;
  font-weight: 600;
}
.landing-form label {
  color: #405374;
  font-weight: 600;
}
.landing-submit {
  width: 100%;
  margin-top: 4px;
  min-height: 48px;
  background: linear-gradient(135deg, #2f6fed, #5f8dff);
  box-shadow: 0 16px 32px rgba(47, 111, 237, .22);
}
.landing-links {
  display: grid;
  gap: 10px;
  justify-items: start;
  margin-top: 18px;
}
.landing-note {
  margin-top: 18px;
  color: #6f7f99;
  font-size: 14px;
}
.landing-sticker {
  position: absolute;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border-radius: 16px;
  font-weight: 700;
  letter-spacing: .02em;
  box-shadow: 0 18px 38px rgba(93, 110, 157, .12);
}
.landing-sticker--left {
  left: 140px;
  top: 210px;
  background: linear-gradient(135deg, #fff0c8, #ffe1a6);
  color: #8f6423;
  transform: rotate(-8deg);
}
.landing-sticker--right {
  right: 134px;
  bottom: 174px;
  background: linear-gradient(135deg, #e8f0ff, #d6e7ff);
  color: #3d66af;
  transform: rotate(7deg);
}
.landing-spark {
  position: absolute;
  z-index: 0;
  border-radius: 999px;
  background: rgba(255,255,255,.72);
  box-shadow: 0 10px 30px rgba(120, 140, 180, .12);
}
.landing-spark--one {
  left: 250px;
  top: 150px;
  width: 14px;
  height: 14px;
}
.landing-spark--two {
  right: 250px;
  top: 260px;
  width: 10px;
  height: 10px;
}
.landing-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 24px;
}
.landing-orb {
  position: absolute;
  border-radius: 999px;
  filter: blur(4px);
  opacity: .88;
}
.landing-orb--left {
  left: 80px;
  top: 80px;
  width: 180px;
  height: 180px;
  background: radial-gradient(circle, rgba(255, 171, 88, .42), rgba(255, 171, 88, 0));
}
.landing-orb--right {
  right: 90px;
  bottom: 90px;
  width: 220px;
  height: 220px;
  background: radial-gradient(circle, rgba(119, 153, 255, .30), rgba(119, 153, 255, 0));
}
.landing-orb--middle {
  left: 50%;
  top: 52%;
  width: 320px;
  height: 320px;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(255,255,255,.72), rgba(255,255,255,0));
}
.landing-grid {
  position: absolute;
  inset: 80px 120px;
  border-radius: 36px;
  background-image:
    linear-gradient(rgba(153, 176, 223, .10) 1px, transparent 1px),
    linear-gradient(90deg, rgba(153, 176, 223, .10) 1px, transparent 1px);
  background-size: 24px 24px;
  mask-image: radial-gradient(circle at center, black 36%, transparent 82%);
  pointer-events: none;
}
.landing-chip {
  position: absolute;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 16px;
  border-radius: 999px;
  background: rgba(255,255,255,.86);
  border: 1px solid rgba(216,226,240,.92);
  box-shadow: 0 16px 40px rgba(69, 95, 146, 0.10);
  color: #5c6786;
  font-weight: 600;
}
.landing-chip--top {
  left: 120px;
  top: 112px;
}
.landing-chip--right {
  right: 112px;
  top: 180px;
}
.landing-chip--left-bottom {
  left: 136px;
  bottom: 120px;
}
.hero { display: grid; grid-template-columns: 1.25fr .95fr; gap: 24px; align-items: stretch; padding: 44px 0 22px; }
.hero-copy, .hero-panel, .card { background: rgba(255,255,255,.92); border: 1px solid rgba(216,226,240,.92); border-radius: var(--radius-xl); box-shadow: var(--shadow); }
.hero-copy { padding: 34px; }
.hero-copy h1 { margin: 10px 0 14px; font-size: clamp(34px, 5vw, 56px); line-height: 1.02; }
.hero-copy p { max-width: 42rem; color: var(--muted); font-size: 17px; line-height: 1.7; }
.hero-panel { padding: 28px; display: grid; gap: 14px; align-content: start; background: linear-gradient(180deg, rgba(255,255,255,.95), rgba(236,242,255,.96)); }
.hero-actions, .inline-actions, .meta-row, .lesson-pills, .option-list, .choice-list { display: flex; flex-wrap: wrap; gap: 10px; }
.eyebrow { font-size: 12px; letter-spacing: .12em; text-transform: uppercase; color: var(--brand-strong); font-weight: 700; }
.hero-metrics, .stats-grid, .grid-2, .stack-grid, .dashboard-grid, .lesson-layout, .auth-grid, .admin-grid { display: grid; gap: 20px; }
.hero-metrics { grid-template-columns: repeat(3, 1fr); }
.hero-metrics div, .stats-grid div { padding: 14px; background: var(--surface-soft); border-radius: 16px; }
.hero-metrics strong, .stats-grid strong { display: block; font-size: 24px; font-weight: 800; }
.hero-metrics span, .stats-grid span, .muted { color: var(--muted); }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 18px; }
.grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.stack-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card { padding: 24px; transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease; }
.card:hover { transform: translateY(-2px); box-shadow: 0 22px 56px rgba(28, 61, 114, 0.12); border-color: rgba(47,111,237,.22); }
.card p, .content-section li { line-height: 1.7; }
.pill { display: inline-flex; align-items: center; min-height: 32px; padding: 0 12px; border-radius: 999px; background: var(--surface-soft); color: var(--brand-strong); }
.progress-bar { width: 100%; height: 10px; background: #e5ecf6; border-radius: 999px; overflow: hidden; margin: 14px 0 18px; }
.progress-bar span { display: block; height: 100%; border-radius: inherit; background: linear-gradient(90deg, var(--brand), #86afff); }
.progress-strip {
  padding: 16px 18px;
  border-radius: 22px;
  background: rgba(255,255,255,.18);
  border: 1px solid rgba(255,255,255,.24);
}
.progress-strip .progress-bar {
  margin: 12px 0 0;
  background: rgba(255,255,255,.18);
}
.progress-strip__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.progress-strip__head strong {
  font-size: 18px;
}
.progress-strip__head span {
  color: rgba(255,255,255,.86);
  font-size: 14px;
}
.progress-pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}
.progress-pill {
  display: grid;
  gap: 2px;
  min-width: 112px;
  padding: 12px 14px;
  border-radius: 18px;
  background: rgba(255,255,255,.16);
  border: 1px solid rgba(255,255,255,.2);
}
.progress-pill strong {
  font-size: 22px;
  line-height: 1;
}
.progress-pill span {
  font-size: 13px;
  opacity: .88;
}
.dashboard-grid, .lesson-layout, .auth-grid, .admin-grid { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.dashboard-main, .admin-main { grid-column: span 8; }
.dashboard-side, .admin-side { grid-column: span 4; display: grid; gap: 20px; }
.lesson-main { grid-column: span 8; }
.lesson-side { grid-column: span 4; display: grid; gap: 20px; }
.auth-grid--welcome .auth-main { grid-column: span 6; }
.auth-grid--welcome .auth-side { grid-column: span 6; }
.auth-side--welcome {
  display: grid;
  gap: 20px;
}
.welcome-card {
  display: grid;
  gap: 12px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(246,249,255,.96));
}
.welcome-card--soft {
  background: linear-gradient(180deg, rgba(255,250,244,.96), rgba(255,255,255,.98));
}
.welcome-card--accent {
  background: linear-gradient(180deg, rgba(245,240,255,.96), rgba(255,255,255,.98));
}
.welcome-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.welcome-modal {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: grid;
  place-items: center;
  padding: 20px;
}
.welcome-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(21, 41, 73, .34);
  backdrop-filter: blur(8px);
}
.welcome-modal__card {
  position: relative;
  z-index: 1;
  width: min(640px, calc(100vw - 28px));
  display: grid;
  gap: 16px;
  padding: 30px 26px 24px;
  border-radius: 34px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(250,245,255,.96));
  border: 1px solid rgba(232, 220, 251, .95);
  box-shadow: 0 28px 70px rgba(54, 78, 128, 0.20);
}
.welcome-modal__close {
  justify-self: end;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid rgba(216,226,240,.92);
  background: white;
  color: var(--muted);
}
.welcome-modal__card h2 {
  margin: 0;
  font-size: clamp(30px, 4.6vw, 42px);
  line-height: 1.06;
}
.welcome-modal__lede {
  margin: 0;
  padding: 16px 18px;
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(244,248,255,.96), rgba(255,250,253,.98));
  border: 1px solid rgba(216,226,240,.92);
  color: var(--muted);
  line-height: 1.8;
  font-size: 16px;
}
.welcome-modal__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.welcome-modal__chips span {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 14px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(238, 243, 255, .98), rgba(255, 240, 247, .98));
  border: 1px solid rgba(220, 229, 245, .96);
  color: #5e6f92;
  font-size: 13px;
  font-weight: 700;
}
.lesson-layout--single .lesson-main,
.lesson-main--wide { grid-column: 1 / -1; }
.lesson-tabs { display: grid; gap: 14px; }
.content-section { padding: 18px; border: 1px solid var(--line); border-radius: 18px; background: white; }
.content-section h3 { margin-top: 0; }
.option-item, .answer-box, .lesson-link, .mini-card { padding: 12px 14px; background: var(--surface-soft); border-radius: 14px; }
.practice-form { display: grid; gap: 14px; }
.preview-grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
.preview-card { height: 100%; }
.preview-bridge { background: linear-gradient(180deg, rgba(250, 251, 255, .98), rgba(240, 246, 255, .98)); }
.preview-checklist { display: grid; gap: 8px; margin: 12px 0 0; padding-left: 20px; }
.lesson-visual-section { background: linear-gradient(180deg, rgba(255,255,255,.99), rgba(250,245,255,.96)); }
.lesson-visual-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  margin-top: 14px;
}
.lesson-visual-card {
  display: grid;
  gap: 14px;
  padding: 16px;
  border: 1px solid rgba(216, 226, 240, .96);
  border-radius: 20px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(245,249,255,.94));
}
.lesson-visual-card__image {
  overflow: hidden;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(247,250,255,.96), rgba(255,255,255,.98));
  border: 1px solid rgba(216, 226, 240, .88);
}
.lesson-visual-card__image img { display: block; width: 100%; height: auto; }
.lesson-visual-card__body h4 { margin: 0 0 8px; font-size: 20px; }
.lesson-visual-points { display: grid; gap: 8px; margin: 12px 0 0; padding-left: 20px; }
.teaching-bridge-grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
.teaching-bridge-card { background: linear-gradient(180deg, rgba(255, 252, 245, .98), rgba(255, 248, 236, .98)); }
.teaching-bridge-card--highlight { background: linear-gradient(180deg, rgba(243, 248, 255, .98), rgba(234, 243, 255, .98)); }
.choice-item { display: inline-flex; align-items: center; gap: 8px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 14px; background: #fbfdff; }
.choice-item input { width: auto; margin: 0; }
.answer-detail summary { cursor: pointer; color: var(--brand-strong); font-weight: 600; }
.answer-detail[open] { display: grid; gap: 10px; }
.practice-feedback-card { display: grid; gap: 10px; padding: 14px; border-radius: 16px; border: 1px solid var(--line); }
.practice-feedback-card--correct { background: #f4fbf6; border-color: #bfe3c9; }
.practice-feedback-card--wrong { background: #fff5f5; border-color: #f1c8c8; }
.practice-summary-panel {
  display: grid;
  gap: 16px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(247,250,255,.98));
}
.practice-summary-panel--success {
  border: 1px solid rgba(190, 227, 201, .95);
  background: linear-gradient(180deg, rgba(244,251,246,.98), rgba(255,255,255,.99));
}
.practice-summary-panel--warm {
  border: 1px solid rgba(241, 220, 184, .95);
  background: linear-gradient(180deg, rgba(255,249,239,.98), rgba(255,255,255,.99));
}
.practice-summary-panel--focus {
  border: 1px solid rgba(237, 200, 200, .95);
  background: linear-gradient(180deg, rgba(255,245,245,.98), rgba(255,255,255,.99));
}
.practice-summary-panel--info {
  border: 1px solid rgba(216,226,240,.92);
}
.practice-summary-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}
.practice-summary-metric {
  display: grid;
  gap: 6px;
  padding: 14px;
  border-radius: 16px;
  border: 1px solid rgba(216,226,240,.92);
  background: rgba(255,255,255,.9);
}
.practice-summary-metric strong {
  font-size: 22px;
  line-height: 1.25;
}
.practice-summary-metric span {
  color: var(--muted);
  font-size: 13px;
}
.practice-summary-next-step {
  background: linear-gradient(180deg, rgba(244,248,255,.96), rgba(255,255,255,.98));
}
.practice-summary-wrongs {
  display: grid;
  gap: 12px;
}
.practice-summary-wrong-card {
  display: grid;
  gap: 10px;
  padding: 16px;
  border-radius: 18px;
  border: 1px solid rgba(216,226,240,.92);
  background: rgba(255,255,255,.96);
}
.practice-question-note { margin-bottom: 0; }
.success-text { color: #21643a; font-weight: 600; }
.error-text { color: #9f3030; font-weight: 600; }
.lesson-outline { display: grid; gap: 10px; }
.wrong-question-toolbar {
  display: grid;
  gap: 14px;
}
.wrong-question-toolbar__group {
  display: grid;
  gap: 10px;
}
.filter-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.filter-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid rgba(216,226,240,.92);
  background: rgba(255,255,255,.92);
  color: var(--text);
  text-decoration: none;
  transition: .2s ease;
}
.filter-chip:hover,
.filter-chip.is-active {
  border-color: rgba(148, 168, 255, .9);
  background: rgba(236, 241, 255, .96);
  color: var(--brand-strong);
}
.wrong-question-grid {
  display: grid;
  gap: 14px;
}
.wrong-question-card {
  display: grid;
  gap: 12px;
  padding: 18px;
  border-radius: 20px;
  border: 1px solid rgba(216,226,240,.92);
  background: linear-gradient(180deg, rgba(255,255,255,.99), rgba(248,251,255,.96));
}
.wrong-question-card__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.admin-overview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.admin-overview-card h3 {
  margin: 6px 0 4px;
  font-size: 30px;
}
.admin-invite-list,
.admin-user-grid {
  display: grid;
  gap: 14px;
}
.admin-invite-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid rgba(216,226,240,.92);
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(248,251,255,.96));
}
.admin-invite-item__meta {
  display: grid;
  justify-items: end;
  gap: 6px;
}
.admin-user-card {
  display: grid;
  gap: 12px;
}
.admin-user-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}
.admin-user-stats div {
  display: grid;
  gap: 4px;
  padding: 12px 14px;
  border-radius: 14px;
  background: var(--surface-soft);
}
.admin-user-stats strong {
  font-size: 20px;
}
.admin-user-stats span,
.admin-user-card__footer {
  color: var(--muted);
}
.admin-user-card__footer {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.pill-success {
  background: rgba(224, 245, 228, .96);
  color: #23633d;
  border-color: rgba(182, 225, 194, .96);
}
.pill-warm {
  background: rgba(255, 243, 226, .96);
  color: #8c4f11;
  border-color: rgba(241, 213, 168, .96);
}
.empty-state {
  display: grid;
  gap: 12px;
  padding: 28px 12px;
  text-align: center;
}
.status-stack { display: grid; gap: 10px; margin: 12px 0; }
.review-box textarea, textarea, input { width: 100%; padding: 12px 14px; border-radius: 14px; border: 1px solid var(--line); background: #fbfdff; }
.landing-form input {
  min-height: 50px;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(251, 253, 255, .98), rgba(245, 248, 255, .96));
  transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease;
}
.landing-form input:focus {
  outline: none;
  border-color: rgba(47,111,237,.45);
  box-shadow: 0 0 0 4px rgba(47,111,237,.10);
  transform: translateY(-1px);
}
.lesson-intro-card {
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(236,242,255,.96));
}
.lesson-topbar {
  display: grid;
  grid-template-columns: 1.35fr .95fr;
  gap: 16px;
  align-items: start;
  background: linear-gradient(180deg, rgba(255,255,255,.99), rgba(243,247,255,.96));
}
.lesson-topbar__main,
.lesson-topbar__status {
  display: grid;
  gap: 12px;
}
.lesson-topbar__main h3 {
  margin: 0;
}
.lesson-topbar__stage {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(255, 241, 219, .95), rgba(240, 246, 255, .95));
  border: 1px solid rgba(228, 214, 190, .9);
}
.lesson-topbar__stage strong {
  font-size: 20px;
}
.lesson-topbar__stage span {
  color: var(--muted);
  line-height: 1.5;
}
.lesson-topbar__metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}
.lesson-topbar__metrics div {
  padding: 12px 14px;
  border-radius: 16px;
  background: var(--surface-soft);
}
.lesson-topbar__metrics strong {
  display: block;
  font-size: 22px;
  font-weight: 800;
}
.lesson-topbar__metrics span {
  color: var(--muted);
  font-size: 13px;
}
.lesson-stepper-card {
  background: linear-gradient(180deg, rgba(251, 252, 255, .98), rgba(243, 247, 255, .96));
}
.lesson-stepper-card--compact {
  padding-top: 14px;
  padding-bottom: 14px;
}
.lesson-stepper {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}
.lesson-stepper--compact {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.lesson-stepper__item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 14px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: white;
}
.lesson-stepper__item.is-current {
  border-color: rgba(47,111,237,.32);
  box-shadow: 0 10px 30px rgba(47,111,237,.10);
}
.lesson-stepper__item.is-done {
  background: #f4fbf6;
  border-color: #cde8d6;
}
.lesson-stepper__index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 999px;
  background: var(--surface-soft);
  color: var(--brand-strong);
  font-weight: 700;
  flex: 0 0 auto;
}
.lesson-stepper__item.is-current .lesson-stepper__index {
  background: var(--brand);
  color: white;
}
.lesson-stepper__item.is-done .lesson-stepper__index {
  background: #2f8f57;
  color: white;
}
.lesson-stats-grid {
  margin: 18px 0;
}
.lesson-stats-grid strong {
  display: block;
  font-size: 22px;
}
.notice {
  padding: 14px 16px;
  border-radius: 16px;
}
.success-notice {
  background: #eaf8ef;
  color: #21643a;
}
.info-notice {
  background: #eef4ff;
  color: var(--brand-strong);
}
.course-banner { padding: 28px; border-radius: var(--radius-xl); background: linear-gradient(135deg, rgba(47,111,237,.98), rgba(111,161,255,.92)); color: white; box-shadow: 0 22px 56px rgba(40, 84, 163, 0.22); }
.course-banner p, .course-banner .eyebrow { color: rgba(255,255,255,.9); }
.course-banner--compact {
  display: grid;
  grid-template-columns: 1.2fr .9fr;
  gap: 20px;
  align-items: stretch;
}
.course-banner__main,
.course-banner__side {
  display: grid;
  gap: 14px;
  align-content: start;
}
.form-card { display: grid; gap: 14px; }
.form-row { display: grid; gap: 8px; }
.auth-main { grid-column: 3 / span 8; }
.auth-main h2 { margin-bottom: 0; }
.assistant-panel-inline textarea { margin-top: 10px; }
.assistant-widget {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 30;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  gap: 12px;
  width: min(420px, calc(100vw - 32px));
  max-height: min(76vh, 760px);
  padding: 16px;
  border: 1px solid rgba(232, 215, 255, .95);
  border-radius: 28px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(255,244,252,.98));
  box-shadow: 0 24px 60px rgba(112, 80, 152, 0.18);
  backdrop-filter: blur(14px);
  transition:
    left .22s ease,
    top .22s ease,
    width .22s ease,
    border-radius .2s ease,
    box-shadow .2s ease,
    padding .2s ease,
    transform .2s ease,
    background .2s ease;
  transform-origin: center bottom;
  overflow: hidden;
}
.assistant-widget::before,
.assistant-widget::after {
  content: "";
  position: absolute;
  border-radius: 999px;
  pointer-events: none;
}
.assistant-widget::before {
  inset: -10px -14px auto auto;
  width: 88px;
  height: 88px;
  background: radial-gradient(circle, rgba(255, 190, 220, .34), rgba(255, 190, 220, 0));
  filter: blur(6px);
}
.assistant-widget::after {
  left: 26px;
  top: -10px;
  width: 14px;
  height: 14px;
  background: radial-gradient(circle, rgba(255,255,255,.92), rgba(255,255,255,0));
  box-shadow:
    22px 18px 0 rgba(255, 220, 247, .52),
    176px 14px 0 rgba(210, 227, 255, .54),
    222px 58px 0 rgba(255, 236, 194, .52);
}
.assistant-collapsed {
  width: 182px;
  max-height: none;
  min-height: 132px;
  padding: 14px 16px;
  border-radius: 32px;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(255, 241, 249, .98));
  box-shadow: 0 22px 40px rgba(112, 80, 152, 0.16);
  animation: assistant-float 4.8s ease-in-out infinite;
}
.assistant-collapsed.assistant-docked-left {
  border-top-left-radius: 20px;
  border-bottom-left-radius: 20px;
}
.assistant-collapsed.assistant-docked-right {
  border-top-right-radius: 20px;
  border-bottom-right-radius: 20px;
}
.assistant-collapsed.assistant-peeking {
  transition: left .22s ease, top .22s ease, width .2s ease, border-radius .2s ease, box-shadow .2s ease, padding .2s ease, transform .2s ease, background .2s ease;
}
.assistant-collapsed .assistant-widget__body,
.assistant-collapsed .assistant-widget__controls {
  display: none;
}
.assistant-collapsed .assistant-widget__header {
  justify-content: center;
  cursor: pointer;
  min-height: 100px;
}
.assistant-collapsed .assistant-widget__title {
  width: 100%;
  display: grid;
  justify-items: center;
  text-align: center;
  gap: 8px;
}
.assistant-collapsed .assistant-widget__title .eyebrow {
  font-size: 11px;
  letter-spacing: .18em;
}
.assistant-collapsed .assistant-widget__title strong {
  font-size: 15px;
  line-height: 1.35;
}
.assistant-collapsed .assistant-widget__hint {
  white-space: normal;
  text-overflow: clip;
  font-size: 12px;
  line-height: 1.45;
}
.assistant-collapsed .assistant-avatar {
  width: 58px;
  height: 58px;
  border-radius: 22px;
  font-size: 21px;
  box-shadow: 0 16px 28px rgba(181, 118, 198, 0.26);
  color: transparent;
  overflow: visible;
}
.assistant-collapsed .assistant-avatar::before {
  inset: -10px;
  border-radius: 26px;
  background:
    radial-gradient(circle at 50% 18%, rgba(255,255,255,.86), rgba(255,255,255,0) 52%),
    radial-gradient(circle, rgba(255, 236, 247, .72), rgba(255, 236, 247, 0));
}
.assistant-collapsed .assistant-avatar::after {
  inset: 0;
  width: 100%;
  height: 100%;
  right: auto;
  top: auto;
  border: none;
  border-radius: inherit;
  background: var(--assistant-face);
  box-shadow:
    inset 0 -8px 16px rgba(255,255,255,.18),
    0 12px 24px rgba(181, 118, 198, 0.24);
  animation: assistant-blink 5.4s ease-in-out infinite;
}
.assistant-collapsed.assistant-docked-left {
  transform-origin: left center;
}
.assistant-collapsed.assistant-docked-right {
  transform-origin: right center;
}
.assistant-collapsed.assistant-docked-left::before {
  inset: auto auto 10px -18px;
}
.assistant-collapsed.assistant-docked-right::before {
  inset: auto -18px 10px auto;
}
.assistant-collapsed.assistant-docked-left .assistant-widget__header,
.assistant-collapsed.assistant-docked-right .assistant-widget__header {
  justify-content: center;
}
.assistant-collapsed.assistant-peeking .assistant-widget__header::before {
  content: "点我展开";
  position: absolute;
  bottom: -12px;
  min-height: 22px;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(255,255,255,.88);
  border: 1px solid rgba(225, 213, 244, .92);
  color: #7b6b96;
  font-size: 11px;
  line-height: 22px;
  letter-spacing: .06em;
  box-shadow: 0 10px 20px rgba(112, 80, 152, 0.10);
}
.assistant-collapsed.assistant-docked-left .assistant-widget__header::before {
  left: 10px;
}
.assistant-collapsed.assistant-docked-right .assistant-widget__header::before {
  right: 10px;
}
.assistant-large {
  width: min(820px, calc(100vw - 40px));
  max-height: 88vh;
  box-shadow: 0 30px 76px rgba(98, 82, 146, 0.22);
}
.assistant-widget__header,
.assistant-widget__controls,
.assistant-widget__actions,
.assistant-submit-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.assistant-widget__header {
  justify-content: space-between;
  position: relative;
  cursor: grab;
  user-select: none;
  touch-action: none;
}
.assistant-widget__header:active {
  cursor: grabbing;
}
.assistant-widget__title { display: flex; align-items: center; gap: 12px; }
.assistant-avatar {
  display: grid;
  place-items: center;
  position: relative;
  width: 44px;
  height: 44px;
  border-radius: 16px;
  background: linear-gradient(135deg, #ff9fd0, #c7a3ff);
  color: transparent;
  font-size: 0;
  overflow: visible;
  font-weight: 700;
  box-shadow: 0 10px 24px rgba(181, 118, 198, 0.28);
  --assistant-face:
    radial-gradient(circle at 35% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 65% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(ellipse at 50% 66%, rgba(255,255,255,.96) 0 5px, transparent 6px),
    linear-gradient(135deg, #ff9fd0, #c7a3ff);
  --assistant-shell-motion: assistant-avatar-breathe 4.8s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 5.4s ease-in-out infinite;
  transform-origin: center 72%;
  animation: var(--assistant-shell-motion);
}
.assistant-avatar::after {
  content: "";
  position: absolute;
  right: -2px;
  top: -2px;
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #8ef0b0;
  border: 2px solid white;
}
.assistant-avatar::before {
  content: "";
  position: absolute;
  inset: -8px;
  border-radius: 20px;
  background:
    radial-gradient(circle at 50% 12%, rgba(255,255,255,.9), rgba(255,255,255,0) 42%),
    radial-gradient(circle, rgba(255, 236, 247, .62), rgba(255, 236, 247, 0));
  z-index: -1;
}
.assistant-avatar::after {
  inset: 0;
  width: 100%;
  height: 100%;
  right: auto;
  top: auto;
  border: none;
  border-radius: inherit;
  background: var(--assistant-face);
  box-shadow:
    inset 0 -8px 16px rgba(255,255,255,.18),
    0 12px 24px rgba(181, 118, 198, 0.24);
  animation: var(--assistant-face-motion);
}
.assistant-avatar[data-expression="curious"] {
  --assistant-face:
    radial-gradient(circle at 35% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 65% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 50% 62%, rgba(255,255,255,.96) 0 4px, transparent 5px),
    linear-gradient(135deg, #ff9fd0, #c7a3ff);
  --assistant-shell-motion: assistant-avatar-breathe 4.8s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 5.6s ease-in-out infinite;
}
.assistant-avatar[data-expression="focus"] {
  --assistant-face:
    linear-gradient(160deg, transparent 0 33%, #2f3552 34% 42%, transparent 43%) 27% 36%/12px 8px no-repeat,
    linear-gradient(20deg, transparent 0 33%, #2f3552 34% 42%, transparent 43%) 73% 36%/12px 8px no-repeat,
    linear-gradient(#ffffff, #ffffff) center 67% / 10px 2px no-repeat,
    linear-gradient(135deg, #ff9fd0, #c7a3ff);
  --assistant-shell-motion: assistant-avatar-focus-nod 2.8s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 4.4s ease-in-out infinite;
}
.assistant-avatar[data-expression="cheer"] {
  --assistant-face:
    radial-gradient(ellipse at 33% 42%, transparent 0 5px, #2f3552 5px 6px, transparent 7px),
    radial-gradient(ellipse at 67% 42%, transparent 0 5px, #2f3552 5px 6px, transparent 7px),
    radial-gradient(circle at 30% 62%, rgba(255, 201, 226, .9) 0 4px, transparent 5px),
    radial-gradient(circle at 70% 62%, rgba(255, 201, 226, .9) 0 4px, transparent 5px),
    radial-gradient(ellipse at 50% 66%, rgba(255,255,255,.96) 0 6px, transparent 7px),
    linear-gradient(135deg, #ffa7c9, #a88dff);
  --assistant-shell-motion: assistant-avatar-cheer-bob 2.6s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 5.2s ease-in-out infinite;
}
.assistant-avatar[data-expression="peek"] {
  --assistant-face:
    radial-gradient(circle at 35% 42%, #2f3552 0 1.8px, transparent 2.8px),
    radial-gradient(circle at 65% 42%, #2f3552 0 1.8px, transparent 2.8px),
    linear-gradient(#ffffff, #ffffff) center 67% / 11px 3px no-repeat,
    linear-gradient(135deg, #ff9fd0, #c7a3ff);
  --assistant-shell-motion: assistant-avatar-peek-sway 3.2s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 6.2s ease-in-out infinite;
}
.assistant-avatar[data-expression="sparkle"] {
  --assistant-face:
    radial-gradient(circle at 22% 18%, rgba(255,255,255,.95) 0 2px, transparent 3px),
    radial-gradient(circle at 78% 22%, rgba(255,245,179,.95) 0 2px, transparent 3px),
    radial-gradient(circle at 35% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 65% 40%, #2f3552 0 2px, transparent 3px),
    radial-gradient(ellipse at 50% 66%, rgba(255,255,255,.96) 0 6px, transparent 7px),
    linear-gradient(135deg, #ffb0db, #98b5ff);
  --assistant-shell-motion: assistant-avatar-sparkle-pop 1.8s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 4.8s ease-in-out infinite;
}
.assistant-avatar[data-expression="thinking"] {
  --assistant-face:
    radial-gradient(circle at 22% 20%, rgba(255,255,255,.92) 0 2px, transparent 3px),
    radial-gradient(circle at 36% 42%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 66% 44%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 58% 66%, rgba(255,255,255,.96) 0 4px, transparent 5px),
    linear-gradient(135deg, #ffacd8, #b7a0ff);
  --assistant-shell-motion: assistant-avatar-thinking-tilt 3s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 5.8s ease-in-out infinite;
}
.assistant-avatar[data-expression="confused"] {
  --assistant-face:
    linear-gradient(160deg, transparent 0 34%, #2f3552 35% 43%, transparent 44%) 27% 34%/12px 8px no-repeat,
    linear-gradient(20deg, transparent 0 34%, #2f3552 35% 43%, transparent 44%) 73% 34%/12px 8px no-repeat,
    radial-gradient(circle at 35% 48%, #2f3552 0 1.8px, transparent 2.8px),
    radial-gradient(circle at 65% 48%, #2f3552 0 1.8px, transparent 2.8px),
    linear-gradient(180deg, transparent 0 45%, #ffffff 46% 48%, transparent 49%) center 70%/12px 8px no-repeat,
    linear-gradient(135deg, #ffb3cf, #9db8ff);
  --assistant-shell-motion: assistant-avatar-confused-wobble 2.4s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 4.8s ease-in-out infinite;
}
.assistant-avatar[data-expression="proud"] {
  --assistant-face:
    radial-gradient(circle at 24% 20%, rgba(255,245,179,.95) 0 2px, transparent 3px),
    radial-gradient(circle at 76% 20%, rgba(255,255,255,.92) 0 2px, transparent 3px),
    radial-gradient(ellipse at 33% 42%, transparent 0 5px, #2f3552 5px 6px, transparent 7px),
    radial-gradient(ellipse at 67% 42%, transparent 0 5px, #2f3552 5px 6px, transparent 7px),
    radial-gradient(ellipse at 50% 68%, rgba(255,255,255,.96) 0 7px, transparent 8px),
    linear-gradient(135deg, #ff9fd0, #90b6ff);
  --assistant-shell-motion: assistant-avatar-proud-bounce 2.2s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 5s ease-in-out infinite;
}
.assistant-avatar[data-expression="celebrate"] {
  --assistant-face:
    radial-gradient(circle at 14% 18%, rgba(255,255,255,.96) 0 2px, transparent 3px),
    radial-gradient(circle at 82% 18%, rgba(255,243,166,.98) 0 2.2px, transparent 3.2px),
    radial-gradient(circle at 28% 44%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 72% 44%, #2f3552 0 2px, transparent 3px),
    radial-gradient(circle at 24% 66%, rgba(255, 214, 232, .92) 0 4px, transparent 5px),
    radial-gradient(circle at 76% 66%, rgba(255, 214, 232, .92) 0 4px, transparent 5px),
    radial-gradient(ellipse at 50% 68%, rgba(255,255,255,.97) 0 8px, transparent 9px),
    linear-gradient(135deg, #ff9ece, #8cbaff);
  --assistant-shell-motion: assistant-avatar-celebrate 1.25s ease-in-out infinite;
  --assistant-face-motion: assistant-blink 3.8s ease-in-out infinite;
}
.assistant-widget__hint {
  margin-top: 2px;
  color: #7a6a95;
  font-size: 13px;
}
.assistant-widget__body {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto auto auto;
  gap: 12px;
  min-height: 0;
  overflow: hidden;
}
.assistant-dragging {
  transition: none;
  animation: none;
  box-shadow: 0 26px 52px rgba(112, 80, 152, 0.22);
}
.assistant-widget__meta {
  padding: 10px 12px;
  border-radius: 16px;
  background: linear-gradient(135deg, #f3eaff, #eef5ff);
  color: #5a5f88;
  font-size: 14px;
}
.assistant-conversation-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(255,255,255,.92), rgba(243, 239, 255, .92));
  border: 1px solid rgba(230, 219, 250, .92);
}
.assistant-conversation-bar__text {
  display: grid;
  gap: 2px;
}
.assistant-conversation-bar__text strong {
  font-size: 14px;
  color: #4f4167;
}
.assistant-conversation-bar__text span {
  color: #8a7ba5;
  font-size: 12px;
}
.assistant-clear-button {
  min-height: 32px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid rgba(226, 214, 247, .96);
  background: rgba(255,255,255,.9);
  color: #75678f;
  font-size: 13px;
  font-weight: 700;
}
.assistant-quick-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.assistant-quick-chip {
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid rgba(228, 213, 255, .96);
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 245, 251, .98), rgba(239, 245, 255, .98));
  color: #66557f;
  font-weight: 600;
  box-shadow: 0 10px 24px rgba(124, 108, 170, 0.08);
}
.assistant-quick-chip:hover {
  transform: translateY(-1px);
}
.assistant-size-button {
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid #e6d7fb;
  background: rgba(255,255,255,.9);
  color: #5b4c7d;
}
.assistant-messages {
  display: grid;
  gap: 10px;
  min-height: 160px;
  max-height: min(44vh, 420px);
  overflow: auto;
  padding-right: 4px;
  padding-bottom: 4px;
  overscroll-behavior: contain;
  scrollbar-width: thin;
  scrollbar-color: rgba(157, 138, 208, .62) rgba(239, 234, 248, .72);
}
.assistant-messages::-webkit-scrollbar {
  width: 10px;
}
.assistant-messages::-webkit-scrollbar-track {
  background: rgba(239, 234, 248, .72);
  border-radius: 999px;
}
.assistant-messages::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, rgba(162, 142, 214, .82), rgba(125, 157, 244, .72));
  border-radius: 999px;
  border: 2px solid rgba(239, 234, 248, .72);
}
.assistant-message {
  padding: 12px 14px;
  border-radius: 18px;
  line-height: 1.6;
}
.assistant-message p {
  margin: 0;
}
.assistant-message p + p {
  margin-top: 10px;
}
.assistant-message br {
  line-height: 1.9;
}
.assistant-message ul {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 8px;
}
.assistant-message li {
  line-height: 1.7;
}
.assistant-message--reply {
  background: linear-gradient(135deg, #f7eeff, #edf5ff);
  color: #33415f;
}
.assistant-message--user {
  background: linear-gradient(135deg, #ffe8f3, #f1ebff);
  color: #4d3f6b;
  justify-self: end;
}
.assistant-form {
  display: grid;
  gap: 10px;
}
.assistant-composer {
  position: relative;
  display: grid;
  gap: 12px;
  padding: 14px 14px 12px;
  border-radius: 24px 24px 20px 20px;
  background:
    radial-gradient(circle at 12% 12%, rgba(255,255,255,.74), rgba(255,255,255,0) 18%),
    linear-gradient(180deg, rgba(255,255,255,.74), rgba(247, 242, 255, .78));
  border: 1px solid rgba(232, 220, 251, .72);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,.88),
    0 10px 22px rgba(131, 114, 175, 0.08);
  backdrop-filter: blur(10px);
}
.assistant-composer::before {
  content: "";
  position: absolute;
  left: 18px;
  top: -8px;
  width: 52px;
  height: 16px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 180, 211, .72), rgba(202, 173, 255, .68));
  filter: blur(.2px);
  opacity: .9;
}
.assistant-composer::after {
  content: "";
  position: absolute;
  right: 18px;
  top: 12px;
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: rgba(255,255,255,.86);
  box-shadow:
    -22px 4px 0 rgba(255, 231, 247, .68),
    -38px 18px 0 rgba(222, 234, 255, .52);
}
.assistant-composer__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  color: #7d6e98;
  font-size: 13px;
  font-weight: 700;
}
.assistant-composer__head span:first-child {
  color: #57486f;
}
.assistant-widget textarea {
  border: 1px solid #eadcf9;
  background: rgba(255,255,255,.92);
  width: 100%;
  min-height: 108px;
  resize: vertical;
  padding: 14px 16px;
  border-radius: 18px;
  line-height: 1.65;
  box-shadow: inset 0 1px 2px rgba(120, 112, 170, 0.06);
}
.assistant-large .assistant-widget__body {
  gap: 14px;
}
.assistant-large .assistant-messages {
  min-height: 0;
  max-height: none;
}
.assistant-large .assistant-message {
  padding: 14px 16px;
  font-size: 15px;
}
.assistant-large .assistant-message p + p {
  margin-top: 12px;
}
.assistant-large .assistant-message ul {
  gap: 10px;
}
.assistant-large .assistant-form {
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}
.assistant-large .assistant-composer {
  padding: 16px 18px 14px;
  border-radius: 28px 28px 22px 22px;
}
.assistant-large .assistant-widget textarea {
  min-height: 148px;
  font-size: 15px;
}
.assistant-large .assistant-submit-row {
  align-items: end;
}
.assistant-large .assistant-submit-row .primary-button {
  min-height: 46px;
  padding: 0 20px;
}
.assistant-widget .secondary-link {
  border-color: #eadcf9;
  color: #5b4c7d;
  background: rgba(255,255,255,.92);
}
.assistant-widget .primary-button {
  background: linear-gradient(135deg, #6f8fff, #9f7bff);
}
.assistant-submit-row {
  justify-content: space-between;
}
.assistant-submit-tip {
  color: #8b7ba8;
  font-size: 13px;
  line-height: 1.55;
  max-width: 34ch;
}
.assistant-submit-row .primary-button {
  box-shadow: 0 14px 28px rgba(111, 143, 255, .20);
}
.assistant-open-button { width: 100%; }
@keyframes assistant-float {
  0% { transform: translateY(0) rotate(-1deg); }
  25% { transform: translateY(-6px) rotate(.5deg); }
  50% { transform: translateY(-2px) rotate(1deg); }
  75% { transform: translateY(-8px) rotate(-.5deg); }
  100% { transform: translateY(0) rotate(-1deg); }
}
@keyframes assistant-avatar-breathe {
  0%, 100% { transform: translateY(0) scale(1) rotate(-1.6deg); }
  50% { transform: translateY(-1px) scale(1.03) rotate(1.2deg); }
}
@keyframes assistant-avatar-focus-nod {
  0%, 100% { transform: translateY(0) rotate(-1.4deg) scale(1); }
  28% { transform: translateY(-1px) rotate(.8deg) scale(1.02); }
  44% { transform: translateY(1px) rotate(3deg) scale(.99); }
  62% { transform: translateY(-1px) rotate(-.8deg) scale(1.01); }
}
@keyframes assistant-avatar-cheer-bob {
  0%, 100% { transform: translateY(0) rotate(-1deg) scale(1); }
  30% { transform: translateY(-4px) rotate(2.4deg) scale(1.04); }
  60% { transform: translateY(-1px) rotate(-1.8deg) scale(1.02); }
}
@keyframes assistant-avatar-peek-sway {
  0%, 100% { transform: translateY(0) rotate(-2deg) scale(1); }
  50% { transform: translateY(-2px) rotate(2deg) scale(1.02); }
}
@keyframes assistant-avatar-sparkle-pop {
  0%, 100% { transform: translateY(0) scale(1) rotate(-1deg); }
  40% { transform: translateY(-3px) scale(1.08) rotate(2.5deg); }
  72% { transform: translateY(-1px) scale(1.03) rotate(-1.5deg); }
}
@keyframes assistant-avatar-thinking-tilt {
  0%, 100% { transform: translateY(0) rotate(-1.2deg) scale(1); }
  24% { transform: translateY(-1px) rotate(-4deg) scale(1.01); }
  52% { transform: translateY(-2px) rotate(3.2deg) scale(1.03); }
  76% { transform: translateY(0) rotate(.4deg) scale(1); }
}
@keyframes assistant-avatar-confused-wobble {
  0%, 100% { transform: translateY(0) rotate(0deg) scale(1); }
  20% { transform: translateY(-1px) rotate(-4deg) scale(1.01); }
  40% { transform: translateY(0) rotate(3deg) scale(1); }
  60% { transform: translateY(-1px) rotate(-2deg) scale(1.02); }
  80% { transform: translateY(1px) rotate(2deg) scale(.99); }
}
@keyframes assistant-avatar-proud-bounce {
  0%, 100% { transform: translateY(0) scale(1) rotate(-.8deg); }
  22% { transform: translateY(-3px) scale(1.05) rotate(2deg); }
  48% { transform: translateY(0) scale(1.02) rotate(-1deg); }
  70% { transform: translateY(-1px) scale(1.03) rotate(1.2deg); }
}
@keyframes assistant-avatar-celebrate {
  0%, 100% { transform: translateY(0) scale(1) rotate(0deg); }
  22% { transform: translateY(-4px) scale(1.08) rotate(-5deg); }
  46% { transform: translateY(1px) scale(1.02) rotate(4deg); }
  72% { transform: translateY(-2px) scale(1.06) rotate(-2deg); }
}
@keyframes assistant-blink {
  0%, 44%, 48%, 100% {
    clip-path: inset(0 0 0 0 round 22px);
  }
  46% {
    clip-path: inset(20px 0 20px 0 round 22px);
  }
}
@media (prefers-reduced-motion: reduce) {
  .assistant-avatar,
  .assistant-avatar::after,
  .assistant-widget {
    animation: none !important;
    transition-duration: .01ms !important;
  }
}
.chapter-card {
  display: grid;
  gap: 14px;
}
.chapter-card--rail {
  min-width: 248px;
  width: min(276px, 68vw);
  scroll-snap-align: start;
  padding: 18px;
  gap: 12px;
}
.chapter-card__visual,
.chapter-lesson-card__visual {
  overflow: hidden;
  border-radius: 18px;
  border: 1px solid rgba(216,226,240,.92);
  background: linear-gradient(180deg, rgba(247,250,255,.98), rgba(255,255,255,.98));
}
.chapter-card__visual img,
.chapter-lesson-card__visual img {
  display: block;
  width: 100%;
  height: auto;
}
.chapter-card--rail .chapter-card__visual {
  border-radius: 16px;
}
.chapter-card--rail h3 {
  margin: 0;
  font-size: 18px;
}
.chapter-card__summary {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.chapter-card__lesson-pills {
  margin-top: -2px;
}
.chapter-card__highlights {
  display: grid;
  gap: 10px;
}
.chapter-card__highlight {
  display: grid;
  gap: 4px;
  padding: 12px 14px;
  border-radius: 16px;
  background: linear-gradient(180deg, rgba(244,248,255,.96), rgba(255,255,255,.98));
  border: 1px solid rgba(216,226,240,.92);
}
.chapter-card__highlight strong {
  font-size: 15px;
}
.chapter-card__highlight span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}
.chapter-card__quick-list {
  display: grid;
  gap: 8px;
}
.chapter-card__quick-item {
  display: grid;
  gap: 4px;
  padding: 10px 12px;
  border-radius: 14px;
  background: linear-gradient(180deg, rgba(244,248,255,.96), rgba(255,255,255,.98));
  border: 1px solid rgba(216,226,240,.92);
}
.chapter-card__quick-item strong {
  font-size: 14px;
}
.chapter-card__quick-item span {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}
.course-directory-section {
  display: grid;
  gap: 18px;
}
.section-head--tight {
  margin-bottom: 0;
}
.chapter-rail {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  padding: 4px 2px 8px;
  scroll-snap-type: x proximity;
}
.chapter-rail::-webkit-scrollbar {
  height: 10px;
}
.chapter-rail::-webkit-scrollbar-thumb {
  background: rgba(159, 179, 214, .55);
  border-radius: 999px;
}
.progress-panel--compact {
  margin-top: 18px;
  background: linear-gradient(180deg, rgba(255,255,255,.98), rgba(244,248,255,.96));
}
.progress-summary-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(120px, 1fr));
  gap: 12px;
  margin-top: 16px;
}
.progress-summary-grid div {
  padding: 14px;
  border-radius: 16px;
  background: var(--surface-soft);
}
.progress-summary-grid strong {
  display: block;
  font-size: 24px;
  font-weight: 800;
}
.progress-summary-grid span {
  color: var(--muted);
}
.home-continue-hero {
  width: min(1120px, 100%);
}
.home-preview-panel__visual {
  overflow: hidden;
  border-radius: 20px;
  border: 1px solid rgba(216,226,240,.92);
  background: rgba(255,255,255,.92);
}
.home-preview-panel__visual img {
  display: block;
  width: 100%;
  height: auto;
}
.chapter-lesson-grid {
  display: grid;
  gap: 16px;
}
.chapter-lesson-card {
  display: grid;
  gap: 12px;
  padding: 12px;
  border-radius: 20px;
  border: 1px solid rgba(216,226,240,.92);
  background: linear-gradient(180deg, rgba(255,255,255,.99), rgba(248,251,255,.96));
  box-shadow: 0 14px 28px rgba(28, 61, 114, 0.05);
}
.chapter-lesson-card__body {
  display: grid;
  gap: 6px;
}
.chapter-lesson-card__index {
  color: var(--brand-strong);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.chapter-lesson-card__body strong {
  font-size: 20px;
  font-family: Georgia, "Times New Roman", serif;
}
.chapter-lesson-card__body p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}
.chapter-tip-list {
  display: grid;
  gap: 12px;
  margin: 18px 0;
}
.chapter-tip-item {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(255,248,236,.94), rgba(255,255,255,.98));
  border: 1px solid rgba(241, 220, 184, .95);
}
.chapter-tip-item strong {
  font-size: 15px;
}
.chapter-tip-item span {
  color: var(--muted);
  line-height: 1.6;
}
@media (max-width: 920px) {
  .hero, .grid-2 { grid-template-columns: 1fr; }
  .dashboard-main, .dashboard-side, .lesson-main, .lesson-side, .auth-main, .admin-main, .admin-side { grid-column: 1 / -1; }
  .auth-grid--welcome .auth-main, .auth-grid--welcome .auth-side { grid-column: 1 / -1; }
  .hero-metrics, .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .course-banner--compact { grid-template-columns: 1fr; }
  .progress-summary-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .lesson-topbar { grid-template-columns: 1fr; }
  .lesson-stepper--compact { grid-template-columns: 1fr; }
  .page-spark { display: none; }
  .landing-page__stage { min-height: auto; }
  .landing-orb--left { left: 10px; top: 20px; width: 140px; height: 140px; }
  .landing-orb--right { right: 0; bottom: 20px; width: 160px; height: 160px; }
  .landing-orb--middle { width: 220px; height: 220px; }
  .landing-grid { inset: 40px 40px 70px; }
  .landing-chip--top { left: 20px; top: 40px; }
  .landing-chip--right { right: 18px; top: 110px; }
  .landing-chip--left-bottom { left: 30px; bottom: 50px; }
  .landing-sticker--left { left: 24px; top: 180px; }
  .landing-sticker--right { right: 24px; bottom: 130px; }
  .landing-spark--one { left: 190px; top: 120px; }
  .landing-spark--two { right: 190px; top: 220px; }
  .assistant-widget {
    right: 16px;
    left: 16px;
    bottom: 16px;
    width: auto;
  }
  .assistant-large { width: auto; max-height: 78vh; }
  .assistant-collapsed { width: 168px; }
}
@media (max-width: 640px) {
  .shell { width: min(100% - 20px, 1120px); }
  .header-inner { flex-direction: column; justify-content: center; padding: 10px 0; }
  .nav-links { width: 100%; justify-content: space-between; flex-wrap: wrap; }
  .hero-metrics, .stats-grid { grid-template-columns: 1fr; }
  .progress-summary-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .chapter-card--rail { width: min(248px, 80vw); min-width: 232px; }
  .lesson-topbar__metrics { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .landing-page { min-height: auto; padding-top: 20px; }
  .landing-panel { padding: 26px 20px; border-radius: 26px; }
  .landing-panel h1 { font-size: 32px; }
  .landing-panel::before,
  .landing-grid { display: none; }
  .landing-mascot {
    right: 18px;
    top: -18px;
    width: 48px;
    height: 48px;
    border-radius: 18px;
  }
  .landing-sub-badge { margin-left: 0; margin-top: 10px; }
  .landing-helper-row {
    align-items: start;
    flex-direction: column;
  }
  .landing-chip { display: none; }
  .landing-sticker { display: none; }
  .landing-spark { display: none; }
  .landing-orb--left { width: 120px; height: 120px; }
  .landing-orb--right { width: 140px; height: 140px; }
  .nav-links--landing { justify-content: flex-end; }
  .assistant-widget {
    right: 10px;
    left: 10px;
    bottom: 10px;
    padding: 14px;
    border-radius: 20px;
  }
  .assistant-collapsed {
    width: 156px;
    min-height: 120px;
    padding: 12px 14px;
    border-radius: 26px;
  }
  .welcome-modal__card {
    width: min(100vw - 20px, 640px);
    padding: 24px 18px 20px;
    border-radius: 26px;
  }
  .welcome-modal__card h2 {
    font-size: 28px;
  }
  .welcome-modal__lede {
    padding: 14px 14px;
    font-size: 15px;
    line-height: 1.72;
  }
  .assistant-collapsed.assistant-peeking .assistant-widget__header::before {
    content: none;
  }
  .assistant-widget__header { align-items: start; }
  .assistant-messages { max-height: none; }
  .assistant-widget textarea {
    min-height: 96px;
    padding: 12px 14px;
  }
  .assistant-composer {
    padding: 12px;
    border-radius: 20px;
  }
  .assistant-composer::before {
    left: 16px;
    top: -6px;
    width: 42px;
  }
  .assistant-composer__head {
    font-size: 12px;
  }
  .assistant-conversation-bar {
    padding: 9px 10px;
    border-radius: 16px;
  }
  .assistant-conversation-bar__text strong {
    font-size: 13px;
  }
  .assistant-conversation-bar__text span {
    font-size: 11px;
  }
  .assistant-clear-button {
    min-height: 30px;
    padding: 0 10px;
    font-size: 12px;
  }
  .assistant-submit-tip {
    max-width: none;
  }
}
@media (min-width: 768px) {
  .assistant-large {
    width: min(900px, calc(100vw - 56px));
  }
  .assistant-large .assistant-widget__body {
    gap: 16px;
  }
  .assistant-large .assistant-widget textarea {
    min-height: 168px;
    font-size: 16px;
  }
  .assistant-large .assistant-composer__head {
    font-size: 14px;
  }
  .assistant-large .assistant-submit-tip {
    font-size: 14px;
  }
  .assistant-large .assistant-conversation-bar {
    padding: 12px 14px;
  }
  .assistant-large .assistant-conversation-bar__text strong {
    font-size: 15px;
  }
  .assistant-large .assistant-conversation-bar__text span {
    font-size: 13px;
  }
  .assistant-large .assistant-widget textarea {
    border-radius: 20px;
  }
  .assistant-collapsed.assistant-docked-left {
    box-shadow: 18px 20px 38px rgba(112, 80, 152, 0.14);
  }
  .assistant-collapsed.assistant-docked-right {
    box-shadow: -18px 20px 38px rgba(112, 80, 152, 0.14);
  }
}
@media (max-width: 900px) {
  .practice-summary-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
@media (max-width: 640px) {
  .practice-summary-grid {
    grid-template-columns: 1fr;
  }
  .admin-overview-grid,
  .admin-user-stats {
    grid-template-columns: 1fr;
  }
  .wrong-question-card {
    padding: 16px;
  }
}
@media (max-width: 900px) {
  .admin-overview-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .admin-user-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}
@media (min-width: 1024px) {
  .assistant-large {
    width: min(980px, calc(100vw - 72px));
  }
  .assistant-large .assistant-messages {
    max-height: none;
  }
  .assistant-large .assistant-widget textarea {
    min-height: 186px;
  }
  .assistant-large .assistant-submit-row {
    justify-content: space-between;
  }
  .assistant-large .assistant-submit-tip {
    max-width: 40ch;
  }
}