:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --surface-raised: #ffffff;
  --border: #d9e1ea;
  --border-strong: #c6d1de;
  --text: #152235;
  --muted: #617087;
  --faint: #8b98aa;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --primary-soft: #e8f0ff;
  --success: #12805c;
  --success-soft: #e7f7ef;
  --warning: #b45309;
  --warning-soft: #fff4de;
  --danger: #c2410c;
  --danger-soft: #fff0e8;
  --violet: #7c3aed;
  --violet-soft: #f1eafe;
  --shadow: 0 18px 45px rgba(31, 41, 55, 0.11);
  --shadow-soft: 0 12px 30px rgba(31, 41, 55, 0.08);
  --radius: 8px;
  --radius-lg: 12px;
  --font: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html,
body { min-height: 100%; }

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.5;
  letter-spacing: 0;
}

button,
input,
select,
textarea { font: inherit; }

button { cursor: pointer; }

button:disabled { cursor: not-allowed; opacity: 0.55; }

.icon {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}

.icon-sm { width: 15px; height: 15px; }
.icon-lg { width: 24px; height: 24px; }

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  height: 64px;
  padding: 0 24px;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(14px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  position: sticky;
  top: 0;
  z-index: 20;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: #fff;
  background: linear-gradient(135deg, #2563eb, #0f9f8f);
  box-shadow: 0 8px 18px rgba(37, 99, 235, 0.22);
}

.brand h1,
.brand-title {
  margin: 0;
  font-size: 16px;
  font-weight: 750;
  letter-spacing: 0;
  color: var(--text);
  white-space: nowrap;
}

.brand-subtitle {
  display: block;
  color: var(--muted);
  font-size: 12px;
  margin-top: -2px;
  white-space: nowrap;
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
}

.user-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 34px;
  padding: 0 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  max-width: 220px;
}

.user-chip span:last-child {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.btn,
.icon-btn {
  border: 1px solid transparent;
  border-radius: var(--radius);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 36px;
  color: var(--text);
  background: transparent;
  transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease, transform 0.16s ease, box-shadow 0.16s ease;
}

.btn {
  padding: 8px 14px;
  font-weight: 650;
  white-space: nowrap;
}

.btn *,
.icon-btn *,
.control-tile * { pointer-events: none; }

.btn:hover,
.icon-btn:hover { box-shadow: 0 8px 18px rgba(31, 41, 55, 0.08); }

.btn-primary {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
  box-shadow: 0 9px 18px rgba(37, 99, 235, 0.18);
}

.btn-primary:hover { background: var(--primary-strong); border-color: var(--primary-strong); }

.btn-secondary {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text);
}

.btn-secondary:hover { border-color: var(--border-strong); background: var(--surface-soft); }

.btn-ghost {
  color: var(--muted);
  background: transparent;
  border-color: transparent;
}

.btn-ghost:hover { color: var(--text); background: var(--surface-soft); }

.btn-danger {
  color: var(--danger);
  border-color: #ffd5c5;
  background: var(--danger-soft);
}

.btn-danger:hover { background: #ffe5d9; }

.btn-sm { min-height: 32px; padding: 6px 10px; font-size: 12px; }
.order-pay-btn { margin-top: 8px; }

.icon-btn {
  width: 38px;
  height: 38px;
  padding: 0;
  border-color: var(--border);
  background: var(--surface);
}

.input,
.select,
.textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  color: var(--text);
  outline: none;
  transition: border-color 0.16s ease, box-shadow 0.16s ease, background 0.16s ease;
}

.input,
.select { height: 40px; padding: 0 12px; }

.textarea { min-height: 86px; padding: 10px 12px; resize: vertical; }

.input:focus,
.select:focus,
.textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
}

.field { display: grid; gap: 6px; }

.field label {
  color: var(--muted);
  font-size: 12px;
  font-weight: 650;
}

.range-heading,
.range-hints {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.range-heading strong {
  color: var(--primary);
  font-size: 12px;
  white-space: nowrap;
}

.range-hints {
  color: var(--faint);
  font-size: 11px;
}

.range-input {
  width: 100%;
  accent-color: var(--primary);
}

.range-input:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.16);
  outline-offset: 3px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: end;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  padding: 4px;
  border-radius: var(--radius);
  background: #eef3f8;
  gap: 4px;
}

.segmented button {
  border: 0;
  border-radius: 6px;
  background: transparent;
  height: 34px;
  color: var(--muted);
  font-weight: 650;
}

.segmented button.active {
  background: #fff;
  color: var(--text);
  box-shadow: 0 5px 12px rgba(31, 41, 55, 0.08);
}

.notice {
  display: none;
  align-items: flex-start;
  gap: 9px;
  padding: 10px 12px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  font-size: 13px;
}

.notice.show { display: flex; }
.notice-error { color: var(--danger); border-color: #ffd5c5; background: var(--danger-soft); }
.notice-success { color: var(--success); border-color: #c7efd9; background: var(--success-soft); }

.status-pill,
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 24px;
  padding: 3px 9px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 650;
  border: 1px solid transparent;
  white-space: nowrap;
}

.badge-blue { color: var(--primary); background: var(--primary-soft); border-color: #cddfff; }
.badge-green { color: var(--success); background: var(--success-soft); border-color: #c7efd9; }
.badge-gray { color: var(--muted); background: #eef3f8; border-color: #dce5ee; }
.badge-red { color: var(--danger); background: var(--danger-soft); border-color: #ffd5c5; }
.badge-violet { color: var(--violet); background: var(--violet-soft); border-color: #ded0ff; }
.badge-warning { color: var(--warning); background: var(--warning-soft); border-color: #ffe1a6; }

.dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--faint);
  box-shadow: 0 0 0 3px rgba(139, 152, 170, 0.14);
}

.dot-online { background: #12b981; box-shadow: 0 0 0 3px rgba(18, 185, 129, 0.16); }
.dot-offline { background: #f97316; box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.16); }

.table-card,
.panel,
.stat-card,
.auth-card,
.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}

.table-card { overflow: hidden; }

.table-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 16px;
  border-bottom: 1px solid var(--border);
}

.toolbar-title h2,
.toolbar-title h3 {
  margin: 0;
  font-size: 16px;
}

.toolbar-title p {
  margin: 2px 0 0;
  color: var(--muted);
  font-size: 12px;
}

.toolbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.search-box {
  position: relative;
  min-width: 240px;
}

.search-box .icon {
  position: absolute;
  left: 11px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--faint);
}

.search-box .input { padding-left: 36px; }

.table-scroll { overflow-x: auto; }

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

.data-table th,
.data-table td {
  padding: 13px 16px;
  text-align: left;
  border-bottom: 1px solid #edf1f6;
  vertical-align: middle;
}

.data-table th {
  color: var(--muted);
  background: var(--surface-soft);
  font-size: 12px;
  font-weight: 750;
}

.data-table tbody tr:hover { background: #fbfdff; }
.data-table tbody tr:last-child td { border-bottom: 0; }

.cell-title { font-weight: 720; color: var(--text); }
.cell-sub { color: var(--muted); font-size: 12px; margin-top: 2px; }
.code-text { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 12px; }

.actions-cell {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.empty-state {
  display: grid;
  place-items: center;
  gap: 8px;
  min-height: 170px;
  color: var(--muted);
  text-align: center;
  padding: 24px;
}

.empty-state .icon { width: 34px; height: 34px; color: var(--faint); }

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.42);
  backdrop-filter: blur(6px);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 60;
}

.modal-backdrop.open { display: flex; }

.modal {
  width: min(460px, 100%);
  padding: 22px;
}

.modal-wide { width: min(760px, 100%); }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
}

.modal-header h2 { margin: 0; font-size: 18px; }
.modal-body { display: grid; gap: 14px; }
.modal-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.modal-grid-full { grid-column: 1 / -1; }
.modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; }

.check-row {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
}

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 220px;
  max-width: min(420px, calc(100vw - 44px));
  padding: 12px 14px;
  border-radius: var(--radius);
  background: #172033;
  color: #fff;
  box-shadow: var(--shadow);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
  z-index: 80;
}

.toast.show { opacity: 1; transform: translateY(0); }
.toast.success .icon { color: #6ee7b7; }
.toast.error .icon { color: #fdba74; }

.auth-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, 0.12), transparent 36%),
    radial-gradient(circle at bottom right, rgba(15, 159, 143, 0.10), transparent 32%),
    var(--bg);
}

.auth-layout {
  width: min(980px, 100%);
  display: grid;
  grid-template-columns: minmax(0, 1fr) 400px;
  gap: 28px;
  align-items: center;
}

.auth-copy { padding: 28px; }
.auth-copy h1 { margin: 18px 0 10px; font-size: clamp(28px, 5vw, 48px); line-height: 1.05; letter-spacing: 0; }
.auth-copy p { margin: 0; max-width: 520px; color: var(--muted); font-size: 16px; }

.auth-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 28px;
}

.auth-metric {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: rgba(255,255,255,0.72);
  padding: 14px;
}

.auth-metric strong { display: block; font-size: 18px; }
.auth-metric span { color: var(--muted); font-size: 12px; }

.auth-card { padding: 26px; }
.auth-card-header { display: flex; align-items: center; gap: 12px; margin-bottom: 22px; }
.auth-card-header h2 { margin: 0; font-size: 20px; }
.auth-card-header p { margin: 2px 0 0; color: var(--muted); font-size: 12px; }
.auth-form { display: grid; gap: 15px; margin-top: 16px; }

.admin-page {
  background: linear-gradient(135deg, #eef4f8 0%, #f8fafc 44%, #edf7f2 100%);
}

.admin-page .topbar {
  background: rgba(255,255,255,0.78);
  border-bottom-color: rgba(198, 209, 222, 0.72);
}

.admin-main { width: min(1760px, calc(100% - 24px)); margin: 0 auto; padding: 16px 0 32px; }

.learn-page { background: #f3f6fa; }

.learn-main,
.billing-main {
  width: min(1400px, calc(100% - 40px));
  margin: 0 auto;
  padding: 22px 0 42px;
}

.learn-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 18px;
  align-items: stretch;
  margin-bottom: 18px;
}

.learn-hero > div:first-child,
.learn-metrics {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}

.learn-hero > div:first-child { padding: 24px; }
.learn-hero h1 { margin: 12px 0 8px; max-width: 760px; font-size: 30px; line-height: 1.16; letter-spacing: 0; }
.learn-hero p { margin: 0; max-width: 820px; color: var(--muted); }

.learn-metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  padding: 16px;
  gap: 10px;
}

.learn-metrics div {
  display: grid;
  align-content: center;
  gap: 6px;
  min-height: 92px;
  padding: 12px;
  border-radius: var(--radius);
  background: var(--surface-soft);
}

.learn-metrics span { color: var(--muted); font-size: 12px; }
.learn-metrics strong { font-size: 26px; line-height: 1; }

.learn-layout {
  display: grid;
  grid-template-columns: 390px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}

.course-catalog,
.course-detail-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}

.course-catalog { padding: 16px; }
.course-detail-panel { min-height: 520px; padding: 16px; }

.section-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 14px;
}

.section-heading h2 { margin: 0; font-size: 18px; }
.section-heading p { margin: 2px 0 0; color: var(--muted); font-size: 12px; }

.course-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.course-card {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 12px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-soft);
  transition: border-color 0.16s ease, background 0.16s ease, transform 0.16s ease;
}

.course-card.active,
.course-card:hover { border-color: var(--border-strong); background: #fff; }

.course-cover {
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  color: var(--primary);
  background: var(--primary-soft);
}

.course-body { min-width: 0; }
.course-meta { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 12px; }
.course-card h3 { margin: 6px 0 4px; font-size: 16px; line-height: 1.3; }
.course-card p { margin: 0; min-height: 40px; color: var(--muted); font-size: 13px; }

.course-card .btn {
  grid-column: 1 / -1;
  justify-self: start;
}

.course-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
}

.course-card-footer strong { color: var(--text); }

.progress-line {
  height: 7px;
  border-radius: 999px;
  background: #e8eef6;
  overflow: hidden;
  margin-top: 10px;
}

.progress-line span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), #0f9f8f);
}

.progress-line.small { height: 5px; }

.detail-content.hidden,
.hidden { display: none !important; }

.detail-header {
  display: grid;
  gap: 12px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.detail-header h2 { margin: 10px 0 6px; font-size: 20px; }
.detail-header p { margin: 0; color: var(--muted); }
.detail-actions { display: flex; gap: 10px; flex-wrap: wrap; }

.learning-workspace {
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(0, 1.28fr);
  gap: 14px;
  margin-top: 14px;
}

.chapter-list { display: grid; gap: 10px; align-content: start; }

.chapter-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  cursor: pointer;
}

.chapter-item.locked { background: var(--surface-soft); }
.chapter-item.active { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1); }
.chapter-icon { width: 42px; height: 42px; border-radius: var(--radius); display: grid; place-items: center; color: var(--primary); background: var(--primary-soft); }
.chapter-item.locked .chapter-icon { color: var(--faint); background: #eef3f8; }
.chapter-main { min-width: 0; }
.chapter-top { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: 12px; }
.chapter-top strong { margin-left: auto; font-weight: 650; }
.chapter-item h3 { margin: 4px 0; font-size: 14px; }
.chapter-item p { margin: 0; color: var(--muted); font-size: 12px; }
.chapter-actions { display: flex; align-items: center; justify-content: flex-end; min-width: 88px; }

.learning-pane { min-width: 0; }

.lesson-panel {
  min-height: 360px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: #fff;
  display: grid;
  align-content: start;
  gap: 14px;
}

.lesson-title { display: grid; gap: 8px; }
.lesson-title h3 { margin: 0; font-size: 20px; line-height: 1.25; }
.lesson-copy { margin: 0; color: var(--muted); }

.course-video,
.video-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-lg);
  background: #0f172a;
}

.course-video { display: block; }

.video-placeholder {
  display: grid;
  place-items: center;
  align-content: center;
  gap: 8px;
  color: #dbeafe;
  text-align: center;
  padding: 22px;
}

.video-placeholder span { color: #b7c7e6; font-size: 12px; }

.quiz-list { display: grid; gap: 12px; }

.quiz-item {
  margin: 0;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-soft);
}

.quiz-item legend { padding: 0 4px; font-weight: 720; }

.quiz-option {
  display: flex;
  align-items: center;
  gap: 9px;
  min-height: 34px;
  margin-top: 8px;
  padding: 7px 9px;
  border-radius: var(--radius);
  background: #fff;
  cursor: pointer;
}

.practice-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.practice-steps div {
  display: grid;
  gap: 6px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-soft);
}

.practice-steps .icon { color: var(--primary); }
.practice-steps strong { font-size: 13px; }
.practice-steps small { color: var(--muted); }

.locked-panel { place-items: center; text-align: center; color: var(--muted); }

.billing-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 18px;
  margin-bottom: 18px;
}

.billing-hero > div,
.membership-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: rgba(255,255,255,0.88);
  box-shadow: var(--shadow-soft);
  padding: 22px;
}

.billing-hero h1 { margin: 12px 0 8px; font-size: 30px; line-height: 1.16; }
.billing-hero p { margin: 0; color: var(--muted); }
.membership-card h2 { margin: 10px 0 6px; }
.membership-card p { margin: 0; color: var(--muted); }
.membership-usage { display: flex; justify-content: space-between; gap: 12px; margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--border); }

.billing-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 18px;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding: 16px;
}

.plan-card {
  display: grid;
  gap: 12px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-soft);
}

.plan-top { display: flex; align-items: center; justify-content: space-between; color: var(--primary); }
.plan-top strong { font-size: 28px; color: var(--text); }
.plan-card h3 { margin: 0; font-size: 18px; }
.plan-card p { margin: 0; color: var(--muted); }
.plan-features { display: flex; gap: 8px; flex-wrap: wrap; color: var(--muted); font-size: 12px; }

.admin-hero {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 12px;
  padding: 18px;
  border: 1px solid rgba(198, 209, 222, 0.72);
  border-radius: 16px;
  background: rgba(255,255,255,0.66);
  backdrop-filter: blur(18px);
  box-shadow: var(--shadow-soft);
}

.admin-hero h2 { margin: 0; font-size: 26px; letter-spacing: 0; }
.admin-hero p { margin: 4px 0 0; color: var(--muted); }

.admin-tabs {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  align-items: center;
  gap: 6px;
  width: 100%;
  padding: 6px;
  border: 1px solid rgba(198, 209, 222, 0.72);
  border-radius: 16px;
  background: rgba(255,255,255,0.62);
  backdrop-filter: blur(18px);
  box-shadow: var(--shadow-soft);
  margin-bottom: 14px;
  position: sticky;
  top: 76px;
  z-index: 12;
}

.admin-tab {
  border: 0;
  background: transparent;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 0 14px;
  border-radius: 10px;
  font-weight: 700;
  justify-content: center;
  min-width: 0;
}

.admin-tab.active {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.18);
}

.admin-page-section { display: none; }
.admin-page-section.active { display: block; }

.admin-page .table-card,
.admin-page .stat-card {
  background: rgba(255,255,255,0.82);
  backdrop-filter: blur(16px);
}

.admin-page .table-toolbar { padding: 14px 16px; }
.admin-page .toolbar-actions,
.admin-page .actions-cell { flex-wrap: nowrap; }
.admin-page .data-table th,
.admin-page .data-table td { white-space: nowrap; }
.admin-page .cell-sub { max-width: 360px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.admin-page .btn span { white-space: nowrap; }
.row-selected { background: #f3f7ff; }

.payment-config-card { margin-bottom: 18px; }

.payment-config-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding: 16px;
}

.payment-config-full { grid-column: 1 / -1; }

.payment-methods {
  min-height: 40px;
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.payment-methods label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
}

.payment-config-actions {
  display: flex;
  justify-content: flex-end;
  padding: 0 16px 16px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-bottom: 18px;
}

.stat-card { padding: 18px; }
.stat-top { display: flex; align-items: center; justify-content: space-between; color: var(--muted); }
.stat-card strong { display: block; margin-top: 12px; font-size: 32px; line-height: 1; }
.stat-card small { display: block; margin-top: 8px; color: var(--muted); }
.stat-card .icon { color: var(--primary); }

.overview-grid {
  display: grid;
  grid-template-columns: 1.35fr 0.65fr;
  gap: 18px;
}

.admin-course-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(360px, 0.85fr);
  gap: 18px;
}

.admin-activity-card { margin-top: 18px; }

.admin-chapter-list {
  display: grid;
  gap: 10px;
  padding: 16px;
}

.admin-chapter-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-soft);
}

.admin-chapter-item h4 { margin: 0; font-size: 14px; }
.admin-chapter-item p { margin: 4px 0 0; color: var(--muted); font-size: 12px; }
.admin-chapter-meta { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }

.health-list { display: grid; gap: 10px; padding: 16px; }
.health-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 0; border-bottom: 1px solid #edf1f6; }
.health-row:last-child { border-bottom: 0; }
.health-row span { color: var(--muted); }

.dashboard-page {
  min-height: 100vh;
  background: #eef3f8;
}

.phone-layout {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 18px;
  width: min(1440px, calc(100% - 36px));
  margin: 0 auto;
  padding: 18px 0;
  min-height: calc(100vh - 64px);
}

.device-stage,
.control-panel {
  min-width: 0;
}

/* 醒目的专注学习按钮 */
.btn-focus {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: #fff;
  border: none;
  box-shadow: 0 6px 16px rgba(99, 102, 241, 0.32);
  font-weight: 600;
}
.btn-focus:hover {
  filter: brightness(1.05);
  box-shadow: 0 8px 20px rgba(99, 102, 241, 0.42);
}
.btn-focus.active {
  background: linear-gradient(135deg, #ef4444, #f97316);
  box-shadow: 0 6px 16px rgba(239, 68, 68, 0.32);
}

/* 专注学习模式：隐藏右侧控制面板，画面占满 */
body.focus-mode .control-panel {
  display: none;
}
body.focus-mode .phone-layout {
  grid-template-columns: 1fr;
  width: min(1600px, calc(100% - 36px));
}
body.focus-mode .device-stage {
  min-height: calc(100vh - 96px);
}

.device-stage {
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 16px;
  background:
    linear-gradient(180deg, rgba(255,255,255,0.88), rgba(255,255,255,0.70)),
    repeating-linear-gradient(45deg, #edf2f7 0 1px, transparent 1px 14px);
  overflow: hidden;
  min-height: 520px;
  padding: 22px;
}

.device-shell {
  position: relative;
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: #111827;
  border: 1px solid rgba(15, 23, 42, 0.18);
  box-shadow: 0 28px 60px rgba(15, 23, 42, 0.22), inset 0 0 0 8px #172033;
  padding: 10px;
  max-width: 100%;
  max-height: 100%;
  overflow: hidden;
}

.device-shell.fullscreen {
  width: 100vw;
  height: 100vh;
  border-radius: 0;
  padding: 0;
}

#screen {
  display: block;
  width: 320px;
  height: 568px;
  max-width: 100%;
  max-height: 100%;
  border-radius: 10px;
  background: #0b1220;
  cursor: default;
  touch-action: none;
}

.pointer-layer {
  position: absolute;
  left: 10px;
  top: 10px;
  width: 320px;
  height: 568px;
  border-radius: 10px;
  overflow: hidden;
  pointer-events: none;
  opacity: 0;
  z-index: 4;
  transition: opacity 0.12s ease;
}

.pointer-layer.active { opacity: 1; }

.remote-cursor {
  position: absolute;
  left: 0;
  top: 0;
  width: 18px;
  height: 18px;
  border: 2px solid #ffffff;
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.12);
  box-shadow: 0 0 0 1px rgba(37, 99, 235, 0.58), 0 8px 18px rgba(15, 23, 42, 0.24);
  transform: translate(-50%, -50%);
  transition: width 0.12s ease, height 0.12s ease, background 0.12s ease, border-color 0.12s ease;
}

.remote-cursor::before,
.remote-cursor::after {
  content: "";
  position: absolute;
  background: #ffffff;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  border-radius: 999px;
}

.remote-cursor::before {
  width: 5px;
  height: 5px;
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.18);
}

.remote-cursor::after { display: none; }

.remote-cursor.pressed {
  width: 28px;
  height: 28px;
  background: rgba(18, 185, 129, 0.24);
  border-color: #b7f7dc;
}

.touch-ring {
  position: absolute;
  left: 0;
  top: 0;
  width: 46px;
  height: 46px;
  border: 2px solid rgba(255, 255, 255, 0.92);
  border-radius: 999px;
  background: rgba(37, 99, 235, 0.22);
  transform: translate(-50%, -50%) scale(0.5);
  opacity: 0;
}

.touch-ring.pulse { animation: touchPulse 0.42s ease-out; }

@keyframes touchPulse {
  0% { opacity: 0.95; transform: translate(-50%, -50%) scale(0.35); }
  100% { opacity: 0; transform: translate(-50%, -50%) scale(1.45); }
}

.drag-line {
  position: absolute;
  left: 0;
  top: 0;
  height: 3px;
  width: 0;
  transform-origin: 0 50%;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.95), rgba(37, 99, 235, 0.2));
  box-shadow: 0 0 0 1px rgba(37, 99, 235, 0.28);
  opacity: 0;
}

.drag-dot {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.35);
  transform: translate(-50%, -50%);
  opacity: 0;
}

.pointer-layer.dragging .drag-line,
.pointer-layer.dragging .drag-dot { opacity: 1; }

.pointer-action {
  position: absolute;
  left: 10px;
  top: 10px;
  min-height: 26px;
  padding: 4px 9px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.72);
  color: #ffffff;
  font-size: 12px;
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.24);
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity 0.14s ease, transform 0.14s ease;
}

.pointer-action.show {
  opacity: 1;
  transform: translateY(0);
}

.screen-overlay {
  position: absolute;
  inset: 10px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 12px;
  padding: 24px;
  color: #dbeafe;
  background: rgba(15, 23, 42, 0.82);
  text-align: center;
  z-index: 6;
}

.screen-overlay.hidden { display: none; }

.loader {
  width: 34px;
  height: 34px;
  border: 3px solid rgba(255,255,255,0.22);
  border-top-color: #fff;
  border-radius: 999px;
  animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.control-panel {
  display: grid;
  gap: 14px;
  align-content: start;
}

.panel { padding: 16px; }
.panel h2,
.panel h3 { margin: 0; font-size: 15px; }
.panel p { margin: 4px 0 0; color: var(--muted); font-size: 12px; }
.panel-header { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }

.control-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.control-tile {
  min-height: 72px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-soft);
  color: var(--text);
  display: grid;
  justify-items: center;
  align-content: center;
  gap: 6px;
  font-weight: 650;
  transition: transform 0.16s ease, border-color 0.16s ease, background 0.16s ease;
}

.control-tile:hover { border-color: var(--border-strong); background: #fff; }
.control-tile .icon { color: var(--primary); }

.meta-list { display: grid; gap: 10px; }
.meta-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; color: var(--muted); }
.meta-row strong { color: var(--text); font-weight: 720; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.canvas-actions,
.form-actions { display: flex; gap: 10px; flex-wrap: wrap; }

@media (max-width: 1080px) {
  .learn-hero,
  .learn-layout,
  .learning-workspace,
  .billing-hero,
  .billing-layout,
  .admin-course-grid { grid-template-columns: 1fr; }
  .course-detail-panel { position: static; }
  .phone-layout { grid-template-columns: 1fr; }
  .control-panel { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .control-panel .panel:first-child { grid-column: 1 / -1; }
  .device-stage { min-height: 460px; }
  .overview-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  .topbar { height: auto; min-height: 60px; padding: 12px 14px; align-items: flex-start; }
  .topbar-actions { flex-wrap: wrap; justify-content: flex-end; }
  .brand-subtitle { display: none; }
  .auth-layout { grid-template-columns: 1fr; }
  .auth-copy { display: none; }
  .admin-main,
  .learn-main,
  .billing-main,
  .phone-layout { width: min(100% - 24px, 100%); }
  .learn-hero h1 { font-size: 24px; }
  .learn-metrics,
  .course-grid,
  .plan-grid,
  .payment-config-grid,
  .practice-steps { grid-template-columns: 1fr; }
  .payment-config-full { grid-column: auto; }
  .chapter-item { grid-template-columns: 38px minmax(0, 1fr); }
  .chapter-actions { grid-column: 1 / -1; justify-content: flex-start; }
  .modal-grid { grid-template-columns: 1fr; }
  .modal-grid-full { grid-column: auto; }
  .admin-chapter-item { grid-template-columns: 1fr; }
  .admin-hero { align-items: flex-start; flex-direction: column; }
  .admin-tabs { overflow-x: auto; grid-template-columns: repeat(5, minmax(132px, 1fr)); top: 68px; }
  .admin-tab { flex: 1 0 auto; justify-content: center; }
  .admin-page .toolbar-actions,
  .admin-page .actions-cell { flex-wrap: wrap; }
  .stats-grid { grid-template-columns: 1fr; }
  .table-toolbar { align-items: stretch; flex-direction: column; }
  .toolbar-actions { align-items: stretch; }
  .search-box { min-width: 0; width: 100%; }
  .phone-layout { padding: 12px 0; }
  .device-stage { min-height: 360px; padding: 12px; }
  .control-panel { grid-template-columns: 1fr; }
  .control-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .field-row { grid-template-columns: 1fr; }
  .auth-metrics { grid-template-columns: 1fr; }
}