/* ==========================================================================
   Demia – design tokens
   ========================================================================== */
:root {
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --primary-soft: #EEF2FF;
  --on-primary: #FFFFFF;
  --success: #16A34A;
  --success-soft: #DCFCE7;
  --warn: #B45309;
  --warn-soft: #FEF3C7;
  --danger: #DC2626;
  --danger-soft: #FEE2E2;
  --bg: #FFFFFF;
  --surface: #F8FAFC;
  --surface-2: #F1F5F9;
  --border: #E5E7EB;
  --border-strong: #CBD5E1;
  --text: #0F172A;
  --text-muted: #475569;
  --text-subtle: #64748B;
  --ring: rgba(79, 70, 229, .3);
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .05);
  --shadow: 0 8px 24px rgba(15, 23, 42, .08);
  --ease: cubic-bezier(.2, .8, .2, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --primary: #818CF8;
    --primary-hover: #A5B4FC;
    --primary-soft: #1E1B4B;
    --on-primary: #0B1120;
    --success: #4ADE80;
    --success-soft: #052E16;
    --warn: #FBBF24;
    --warn-soft: #422006;
    --danger: #F87171;
    --danger-soft: #450A0A;
    --bg: #0B1120;
    --surface: #111827;
    --surface-2: #1F2937;
    --border: #1F2937;
    --border-strong: #374151;
    --text: #F1F5F9;
    --text-muted: #CBD5E1;
    --text-subtle: #94A3B8;
    --ring: rgba(129, 140, 248, .4);
    --shadow-sm: none;
    --shadow: 0 8px 24px rgba(0, 0, 0, .4);
    color-scheme: dark;
  }
}

/* ==========================================================================
   Base
   ========================================================================== */
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; }
body {
  font-family: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 15px;
  line-height: 1.55;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { line-height: 1.3; text-wrap: balance; }
a { color: inherit; text-decoration: none; }
p a, .link, .auth-alt a, .empty a { color: var(--primary); font-weight: 500; }
p a:hover, .link:hover, .auth-alt a:hover, .empty a:hover { text-decoration: underline; }
button { font: inherit; color: inherit; cursor: pointer; background: none; border: 0; padding: 0; }
input, select, textarea { font: inherit; color: inherit; }
code { font-size: .9em; background: var(--surface-2); padding: 1px 6px; border-radius: 4px; }
img { max-width: 100%; }
:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; border-radius: 6px; }
#content:focus { outline: none; }

svg.i { width: 18px; height: 18px; flex: none; stroke: currentColor; fill: none; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; vertical-align: middle; }
svg.i-sm { width: 14px; height: 14px; }
.sr-only { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip-link { position: absolute; left: 12px; top: -48px; z-index: 100; background: var(--primary); color: var(--on-primary); padding: 8px 14px; border-radius: 8px; }
.skip-link:focus { top: 12px; }
.muted { color: var(--text-muted); }
.d-block { display: block; }
.ta-right { text-align: right; }
.chip { display: inline-block; font-size: 12px; line-height: 1.6; padding: 0 7px; border-radius: 6px; background: var(--surface-2); color: var(--text-muted); font-weight: 500; vertical-align: middle; }

/* ==========================================================================
   App shell: rail + panel + main
   ========================================================================== */
.app { display: grid; grid-template-columns: 64px 248px minmax(0, 1fr); min-height: 100vh; }

.rail {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  padding: 16px 0; border-right: 1px solid var(--border); background: var(--bg);
  position: sticky; top: 0; height: 100vh;
}
.rail .logo { display: block; width: 36px; height: 36px; margin-bottom: 14px; }
.rail-btn {
  width: 44px; height: 44px; display: grid; place-items: center;
  border-radius: 10px; color: var(--text-muted);
  transition: background .18s var(--ease), color .18s var(--ease);
}
.rail-btn:hover { background: var(--surface-2); color: var(--text); }
.rail-btn[aria-current="page"] { color: var(--primary); background: var(--primary-soft); }
.rail-btn.new { background: var(--primary); color: var(--on-primary); margin-bottom: 10px; }
.rail-btn.new:hover { background: var(--primary-hover); }
.rail .spacer { flex: 1; }

.panel {
  border-right: 1px solid var(--border); background: var(--surface);
  padding: 16px 12px; display: flex; flex-direction: column; gap: 2px;
  position: sticky; top: 0; height: 100vh; overflow-y: auto;
}
.panel-head { display: flex; align-items: baseline; gap: 8px; padding: 6px 8px 12px; font-weight: 700; font-size: 16px; }
.panel-head .muted { font-weight: 400; font-size: 13px; }
.search {
  display: flex; align-items: center; gap: 8px; padding: 0 12px; height: 42px;
  border: 1px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--text-subtle);
  margin-bottom: 10px; transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.search input { border: 0; outline: 0; background: none; flex: 1; min-width: 0; }
.search:focus-within { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.nav-item {
  display: flex; align-items: center; gap: 10px; min-height: 40px; padding: 8px 10px; border-radius: 8px;
  color: var(--text-muted); font-size: 14px; width: 100%; text-align: left;
  transition: background .15s var(--ease), color .15s var(--ease);
}
.nav-item:hover { background: var(--surface-2); color: var(--text); }
.nav-item[aria-current="true"] { background: var(--surface-2); color: var(--text); font-weight: 600; }
.nav-item .t { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.section-toggle {
  display: flex; align-items: center; gap: 8px; width: 100%; min-height: 44px; padding: 12px 10px 6px;
  font-weight: 600; font-size: 14px; border-top: 1px solid var(--border); margin-top: 8px;
}
.section-toggle .chev { margin-left: auto; transition: transform .2s var(--ease); color: var(--text-subtle); }
.section-toggle[aria-expanded="false"] .chev { transform: rotate(-90deg); }
.section-body[hidden] { display: none; }
.fav-ico { width: 20px; height: 20px; border-radius: 6px; display: inline-grid; place-items: center; color: #fff; font-size: 11px; font-weight: 700; flex: none; }
.fav-lg { width: 36px; height: 36px; border-radius: 10px; font-size: 15px; }
.dot { width: 9px; height: 9px; border-radius: 3px; flex: none; margin: 0 5px; }

.promo-card {
  margin-top: auto; padding: 16px; border-radius: var(--radius); background: var(--bg);
  border: 1px solid var(--border); box-shadow: var(--shadow-sm);
}
.panel > .promo-card { margin-top: auto; }
.panel .section-body + .promo-card, .panel .nav-item + .promo-card { margin-top: 24px; }
.promo-card h3 { margin: 0 0 4px; font-size: 14px; }
.promo-card p { margin: 0 0 12px; font-size: 13px; color: var(--text-muted); }
.btn-soft {
  display: inline-flex; align-items: center; gap: 6px; min-height: 36px; padding: 0 14px;
  border-radius: 999px; background: var(--primary-soft); color: var(--primary); font-size: 13px; font-weight: 600;
  transition: filter .15s var(--ease);
}
.btn-soft:hover { filter: brightness(.96); }

main { min-width: 0; display: flex; flex-direction: column; }
.topbar {
  display: flex; align-items: center; gap: 12px; min-height: 64px; padding: 10px 24px;
  border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px);
}
.topbar .menu-btn { display: none; }
.crumbs { min-width: 0; overflow: hidden; font-size: 13px; color: var(--text-muted); }
.crumbs ol { display: flex; align-items: center; gap: 6px; list-style: none; margin: 0; padding: 0; }
.crumbs li { display: flex; align-items: center; gap: 6px; white-space: nowrap; min-width: 0; }
.crumbs a:hover { color: var(--text); }
.crumbs .current {
  padding: 3px 12px; border: 1px solid var(--border); border-radius: 999px; color: var(--text);
  max-width: 320px; overflow: hidden; text-overflow: ellipsis;
}
.crumbs svg.sep { width: 14px; height: 14px; color: var(--text-subtle); }
.topbar .right { margin-left: auto; display: flex; align-items: center; gap: 10px; flex: none; }
.user-chip { display: flex; align-items: center; gap: 8px; padding: 4px 10px 4px 4px; border-radius: 999px; transition: background .15s var(--ease); }
.user-chip:hover { background: var(--surface-2); }
.user-name { font-size: 14px; font-weight: 500; max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.avatar {
  width: 34px; height: 34px; border-radius: 50%; display: inline-grid; place-items: center; flex: none;
  background: linear-gradient(135deg, var(--primary), #A855F7); color: #fff; font-size: 12px; font-weight: 700;
}
.avatar-sm { width: 28px; height: 28px; font-size: 11px; }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 42px; padding: 0 16px;
  border-radius: 10px; font-weight: 500; font-size: 14px; white-space: nowrap; border: 1px solid transparent;
  transition: background .15s var(--ease), border-color .15s var(--ease), color .15s var(--ease), transform .1s var(--ease);
}
.btn:active:not(:disabled) { transform: scale(.98); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: var(--on-primary); }
.btn-primary:hover { background: var(--primary-hover); }
.btn-outline { border-color: var(--border); background: var(--bg); }
.btn-outline:hover:not(:disabled) { background: var(--surface); border-color: var(--border-strong); }
.btn-ghost { color: var(--text-muted); }
.btn-ghost:hover { background: var(--surface-2); color: var(--text); }
.btn-success { background: var(--success-soft); color: var(--success); border-color: transparent; }
.btn-danger:hover:not(:disabled) { color: var(--danger); border-color: var(--danger); background: var(--danger-soft); }
.btn-icon { width: 42px; padding: 0; }
.btn-sm { min-height: 36px; padding: 0 12px; font-size: 13px; border-radius: 8px; }
.btn-sm.btn-icon { width: 36px; padding: 0; }
.btn-lg { min-height: 48px; padding: 0 22px; font-size: 15px; }
.btn-block { width: 100%; }
.btn[aria-pressed="true"][data-bookmark] { color: var(--primary); border-color: var(--primary); background: var(--primary-soft); }
.btn[aria-pressed="true"][data-bookmark] svg { fill: currentColor; }
.btn.is-loading { pointer-events: none; opacity: .75; }

/* ==========================================================================
   Flash, badges, cards
   ========================================================================== */
.flash {
  display: flex; align-items: center; gap: 10px; margin: 16px 24px 0; padding: 12px 14px;
  border-radius: var(--radius); font-size: 14px; animation: drop .3s var(--ease);
  background: var(--primary-soft); color: var(--primary);
}
.flash-success { background: var(--success-soft); color: var(--success); }
.flash-error { background: var(--danger-soft); color: var(--danger); }
.flash span { flex: 1; color: var(--text); }
.flash-close { width: 32px; height: 32px; display: grid; place-items: center; border-radius: 8px; color: var(--text-muted); }
.flash-close:hover { background: rgba(0, 0, 0, .06); }
@keyframes drop { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }

.badge { display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 12px; font-weight: 600; background: var(--surface-2); color: var(--text-muted); }
.badge-primary { background: var(--primary-soft); color: var(--primary); }
.badge-success { background: var(--success-soft); color: var(--success); }
.badge-warn { background: var(--warn-soft); color: var(--warn); }

.card { border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--bg); box-shadow: var(--shadow-sm); }

/* Progress ring (server-rendered SVG) */
.ring { --size: 40px; --stroke: 4; position: relative; display: inline-block; width: var(--size); height: var(--size); flex: none; }
.ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring circle { fill: none; stroke-width: var(--stroke); }
.ring .track { stroke: var(--surface-2); }
.ring .bar { stroke: var(--primary); stroke-linecap: round; transition: stroke-dashoffset .6s var(--ease); }
.ring .label { position: absolute; inset: 0; display: grid; place-items: center; font-weight: 600; font-size: 10px; }
.ring[data-value="0"] .bar { stroke: transparent; }
.ring-sm { --size: 38px; --stroke: 4; }
.ring-sm .label { font-size: 9.5px; }
.ring-lg { --size: 68px; --stroke: 4; }
.ring-lg .label { font-size: 15px; }
.ring-success .bar { stroke: var(--success); }

.bar-progress { height: 6px; border-radius: 999px; background: var(--surface-2); overflow: hidden; }
.bar-progress span { display: block; height: 100%; background: var(--primary); border-radius: inherit; transition: width .3s var(--ease); }
.bar-caption { font-size: 12px; color: var(--text-subtle); margin-top: 6px; }

/* ==========================================================================
   Pages
   ========================================================================== */
.page { padding: 24px; max-width: 1240px; width: 100%; }
.page-narrow { max-width: 780px; }
.page-title { font-size: clamp(22px, 2.4vw, 28px); font-weight: 700; margin: 0 0 4px; letter-spacing: -.01em; }
.page-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.page-head p { margin: 4px 0 0; }
.section { margin-top: 32px; }
.section-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.section-title { font-size: 18px; font-weight: 600; margin: 0 0 14px; }
.section-head .section-title { margin: 0; }
.meta { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 13px; color: var(--text-muted); }
.meta span { display: inline-flex; align-items: center; gap: 6px; }
.meta svg.i { width: 15px; height: 15px; }

/* Home */
.hero {
  display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 24px; align-items: center;
  padding: 32px; border-radius: 20px;
  background: radial-gradient(120% 140% at 0% 0%, var(--primary-soft) 0%, transparent 60%), var(--surface);
  border: 1px solid var(--border);
}
.hero h1 { font-size: clamp(24px, 3vw, 34px); margin: 0 0 8px; letter-spacing: -.02em; }
.hero p { margin: 0; color: var(--text-muted); max-width: 52ch; }
.hero-search {
  display: flex; align-items: center; gap: 10px; padding: 6px 6px 6px 16px; border-radius: 14px;
  background: var(--bg); border: 1px solid var(--border); box-shadow: var(--shadow); color: var(--text-subtle);
}
.hero-search input { flex: 1; min-width: 0; border: 0; outline: 0; background: none; height: 44px; font-size: 15px; }
.hero-search:focus-within { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }

.filter-chips { display: flex; gap: 8px; flex-wrap: wrap; }
.filter-chip {
  display: inline-flex; align-items: center; min-height: 36px; padding: 0 14px; border-radius: 999px;
  border: 1px solid var(--border); font-size: 13px; color: var(--text-muted); transition: all .15s var(--ease);
}
.filter-chip:hover { border-color: var(--border-strong); color: var(--text); }
.filter-chip[aria-current="true"] { background: var(--text); border-color: var(--text); color: var(--bg); }

.continue-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; }
.continue-item {
  display: flex; align-items: center; gap: 14px; padding: 14px 16px; border: 1px solid var(--border);
  border-radius: var(--radius); background: var(--bg); transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.continue-item:hover { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.continue-item .body { flex: 1; min-width: 0; }
.continue-item strong { display: block; font-size: 14px; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.continue-item small { color: var(--text-subtle); font-size: 12px; }
.continue-item > svg.i { color: var(--text-subtle); }

.course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }
.course-card {
  display: flex; flex-direction: column; border: 1px solid var(--border); border-radius: var(--radius-lg);
  background: var(--bg); overflow: hidden; transition: box-shadow .2s var(--ease), transform .2s var(--ease), border-color .2s var(--ease);
  position: relative;
}
.course-card:hover { box-shadow: var(--shadow); border-color: var(--border-strong); transform: translateY(-2px); }
.course-card:focus-within { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.cover {
  position: relative; aspect-ratio: 16 / 8; display: grid; place-items: center; overflow: hidden;
  background:
    radial-gradient(80% 120% at 85% 10%, color-mix(in srgb, var(--c) 35%, white) 0%, transparent 60%),
    linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 60%, black));
}
.cover-letter { font-size: 56px; font-weight: 700; color: rgba(255, 255, 255, .9); letter-spacing: -.04em; }
.cover-tag {
  position: absolute; left: 12px; top: 12px; padding: 3px 10px; border-radius: 999px; font-size: 12px; font-weight: 600;
  background: rgba(255, 255, 255, .92); color: #0F172A;
}
.course-body { display: flex; flex-direction: column; gap: 10px; padding: 16px; flex: 1; }
.course-body h3 { margin: 0; font-size: 16px; font-weight: 600; }
.course-body h3 a::after { content: ""; position: absolute; inset: 0; }
.course-body h3 a:focus-visible { outline: none; }
.course-desc { margin: 0; font-size: 13px; color: var(--text-muted); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.course-body .meta { margin-top: auto; }

.empty { text-align: center; padding: 48px 16px; border: 1px dashed var(--border-strong); border-radius: var(--radius-lg); color: var(--text-muted); }
.empty > svg.i { width: 32px; height: 32px; color: var(--text-subtle); }
.empty h3, .empty h1 { color: var(--text); margin: 12px 0 4px; font-size: 17px; }
.empty p { margin: 0 0 4px; }
.empty-lg { border: 0; padding: 80px 16px; }
.empty-lg h1 { font-size: 24px; }
.empty-lg .btn { margin-top: 20px; }
.error-code { font-size: 64px; font-weight: 700; color: var(--primary); line-height: 1; }

/* Course overview */
.course-hero {
  display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 24px; align-items: center;
  padding: 32px; border-radius: 20px; border: 1px solid var(--border);
  background: radial-gradient(100% 140% at 0% 0%, color-mix(in srgb, var(--c) 14%, transparent) 0%, transparent 65%), var(--surface);
}
.course-hero h1 { font-size: clamp(24px, 3vw, 32px); margin: 8px 0; letter-spacing: -.02em; }
.course-hero p { margin: 0 0 12px; color: var(--text-muted); max-width: 64ch; }
.course-hero .actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; align-items: center; }
.lessons-wide { max-width: 820px; }

/* ==========================================================================
   Learn page (course player)
   ========================================================================== */
.content {
  padding: 24px; display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 24px 28px;
  max-width: 1320px; width: 100%; align-items: start;
}
.title-row { grid-column: 1 / -1; display: flex; align-items: flex-start; gap: 16px; }
.title-row h1 { margin: 0 0 8px; font-size: clamp(21px, 2.4vw, 28px); font-weight: 700; letter-spacing: -.015em; }
.title-row .actions { margin-left: auto; display: flex; gap: 10px; flex: none; }

.player { position: relative; aspect-ratio: 16 / 9; border-radius: var(--radius-lg); overflow: hidden; background: #0B1120; }
.player iframe, .player video, .player #ytPlayer { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.player video { object-fit: contain; background: #000; }
.player-empty {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
  padding: 24px; text-align: center; color: #fff;
  background: radial-gradient(100% 120% at 20% 0%, color-mix(in srgb, var(--c) 70%, white) 0%, transparent 60%), linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 50%, black));
}
.player-empty svg.i { width: 40px; height: 40px; }
.player-empty strong { font-size: 18px; }
.player-empty span { max-width: 44ch; opacity: .9; font-size: 14px; }

.lesson-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
.lesson-bar h2 { margin: 2px 0 0; font-size: 18px; font-weight: 600; }
.eyebrow { font-size: 12px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; color: var(--primary); }

.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-top: 16px; overflow-x: auto; scrollbar-width: none; }
.tab {
  display: inline-flex; align-items: center; gap: 6px; min-height: 44px; padding: 10px 12px; font-size: 14px; color: var(--text-muted);
  border-bottom: 2px solid transparent; margin-bottom: -1px; white-space: nowrap; transition: color .15s var(--ease);
}
.tab:hover { color: var(--text); }
.tab[aria-selected="true"] { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }
.tab svg.i { width: 16px; height: 16px; }
.tabpanel { padding-top: 20px; animation: fade .25s var(--ease); }
.tabpanel h3 { font-size: 17px; font-weight: 600; margin: 0 0 8px; }
.tabpanel p { color: var(--text-muted); margin: 0 0 10px; max-width: 70ch; }
.divider { height: 1px; background: var(--border); margin: 24px 0; }
.concepts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 14px; }
.concept {
  display: flex; gap: 14px; align-items: flex-start; padding: 16px; border-radius: var(--radius);
  border: 1px solid var(--border); background: var(--surface); font-size: 14px; color: var(--text-muted);
}
.concept svg.i { color: var(--success); margin-top: 2px; }
.resource-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.resource-list a {
  display: flex; gap: 12px; align-items: center; padding: 12px 14px; border: 1px solid var(--border); border-radius: var(--radius);
  transition: border-color .15s var(--ease);
}
.resource-list a:hover { border-color: var(--primary); }
.resource-list svg.i { color: var(--primary); }
.resource-list span { min-width: 0; }
.resource-list strong { display: block; font-weight: 500; font-size: 14px; }
.resource-list small { display: block; color: var(--text-subtle); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--border); }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

.side { display: flex; flex-direction: column; gap: 14px; min-width: 0; position: sticky; top: 88px; }
.progress-card { display: flex; gap: 16px; align-items: center; padding: 18px; }
.progress-card h2 { margin: 0 0 2px; font-size: 17px; font-weight: 600; }
.progress-card p { margin: 0; color: var(--text-muted); font-size: 13px; }
.list-title { font-size: 17px; font-weight: 600; margin: 8px 0 0; }
.lessons { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 10px; }
.side .lessons { max-height: calc(100vh - 300px); overflow-y: auto; padding: 3px; margin: -3px; }
.lesson {
  width: 100%; display: flex; align-items: center; gap: 14px; padding: 14px 16px; text-align: left;
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg);
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.lesson:hover { border-color: color-mix(in srgb, var(--primary) 45%, var(--border)); }
.lesson[aria-current="true"] { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.lesson .num { font-size: 12px; color: var(--text-subtle); min-width: 16px; text-align: center; font-variant-numeric: tabular-nums; }
.lesson .body { flex: 1; min-width: 0; }
.lesson .name { display: block; font-weight: 500; font-size: 14px; }
.lesson .dur { display: block; font-size: 12px; color: var(--text-subtle); }

/* ==========================================================================
   Forms
   ========================================================================== */
.form { display: flex; flex-direction: column; gap: 18px; }
.form-card { padding: 24px; margin-top: 20px; }
.field { display: flex; flex-direction: column; gap: 6px; border: 0; padding: 0; margin: 0; min-width: 0; }
.field label, .field legend { font-size: 14px; font-weight: 500; }
.field legend { margin-bottom: 6px; padding: 0; }
.req { color: var(--danger); }
.field input:not([type=checkbox]):not([type=radio]):not([type=color]), .field select, .field textarea, .input-prefix {
  width: 100%; min-height: 44px; padding: 10px 12px; border: 1px solid var(--border-strong); border-radius: 10px;
  background: var(--bg); transition: border-color .15s var(--ease), box-shadow .15s var(--ease); font-size: 15px;
}
.field textarea { resize: vertical; line-height: 1.5; }
.field input:focus, .field select:focus, .field textarea:focus, .input-prefix:focus-within {
  outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring);
}
.input-prefix { display: flex; align-items: center; gap: 2px; padding: 0 0 0 12px; }
.input-prefix span { color: var(--text-subtle); font-size: 14px; }
.field .input-prefix input { border: 0 !important; box-shadow: none !important; padding-left: 0; min-height: 42px; }
.field input[type=color] { width: 64px; height: 44px; padding: 4px; border: 1px solid var(--border-strong); border-radius: 10px; background: var(--bg); cursor: pointer; }
.field-hint { margin: 0; font-size: 13px; color: var(--text-subtle); }
.field-error { margin: 0; font-size: 13px; color: var(--danger); font-weight: 500; }
.has-error input, .has-error textarea, .has-error .dropzone { border-color: var(--danger) !important; }
.field-row { display: flex; gap: 16px; flex-wrap: wrap; }
.field-row > .field { flex: 1 1 180px; }
.field-row > .field.grow { flex: 3 1 260px; }
.field-row > .field.field-sm { flex: 0 1 140px; }
.field-row > .field.field-color { flex: 0 0 auto; }
.form-actions { display: flex; justify-content: flex-end; gap: 10px; padding-top: 8px; border-top: 1px solid var(--border); margin-top: 4px; padding-top: 18px; }
.form-error {
  display: flex; gap: 8px; align-items: center; padding: 12px 14px; border-radius: 10px;
  background: var(--danger-soft); color: var(--danger); font-size: 14px; font-weight: 500; margin: 12px 0;
}
.password-wrap { position: relative; }
.password-wrap input { padding-right: 48px !important; }
.pw-toggle { position: absolute; right: 4px; top: 50%; transform: translateY(-50%); width: 40px; height: 40px; display: grid; place-items: center; border-radius: 8px; color: var(--text-subtle); }
.pw-toggle:hover { color: var(--text); background: var(--surface-2); }

.segmented { display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 4px; background: var(--surface-2); border-radius: 12px; }
.segmented label { position: relative; cursor: pointer; }
.segmented input { position: absolute; opacity: 0; inset: 0; cursor: pointer; }
.segmented span { display: inline-flex; align-items: center; min-height: 38px; padding: 0 14px; border-radius: 9px; font-size: 14px; color: var(--text-muted); transition: all .15s var(--ease); }
.segmented input:checked + span { background: var(--bg); color: var(--text); font-weight: 600; box-shadow: var(--shadow-sm); }
.segmented input:focus-visible + span { outline: 2px solid var(--primary); outline-offset: 1px; }
.dropzone {
  display: flex; align-items: center; justify-content: center; gap: 10px; min-height: 88px; padding: 16px;
  border: 1.5px dashed var(--border-strong); border-radius: 12px; color: var(--text-muted); cursor: pointer; text-align: center;
  transition: border-color .15s var(--ease), background .15s var(--ease);
}
.dropzone:hover, .dropzone.is-over { border-color: var(--primary); background: var(--primary-soft); color: var(--primary); }
input[type=file]:focus-visible + .field-error, input[type=file]:focus-visible ~ .dropzone { outline: 2px solid var(--primary); }
.field:has(input[type=file]:focus-visible) .dropzone { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.upload-progress small { display: block; margin-top: 6px; color: var(--text-muted); }

.switch { display: flex; align-items: center; gap: 12px; cursor: pointer; }
.switch input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.switch-ui { width: 44px; height: 26px; border-radius: 999px; background: var(--border-strong); position: relative; flex: none; transition: background .2s var(--ease); }
.switch-ui::after { content: ""; position: absolute; top: 3px; left: 3px; width: 20px; height: 20px; border-radius: 50%; background: #fff; box-shadow: var(--shadow-sm); transition: transform .2s var(--ease); }
.switch input:checked + .switch-ui { background: var(--primary); }
.switch input:checked + .switch-ui::after { transform: translateX(18px); }
.switch input:focus-visible + .switch-ui { outline: 2px solid var(--primary); outline-offset: 2px; }

/* Auth */
.auth-wrap { display: grid; place-items: center; padding: 48px 16px; flex: 1; }
.auth-card { width: 100%; max-width: 420px; padding: 32px; }
.auth-card h1 { margin: 16px 0 4px; font-size: 24px; }
.auth-card > p.muted { margin: 0 0 20px; }
.auth-alt { text-align: center; margin: 20px 0 0; font-size: 14px; color: var(--text-muted); }

/* ==========================================================================
   Admin
   ========================================================================== */
.stats { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 16px; }
.stat { display: flex; flex-direction: column; gap: 2px; padding: 20px; transition: border-color .15s var(--ease); }
a.stat:hover { border-color: var(--primary); }
.stat-ico { width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; background: var(--primary-soft); color: var(--primary); margin-bottom: 10px; }
.stat-value { font-size: 28px; font-weight: 700; font-variant-numeric: tabular-nums; }
.stat-label { font-size: 13px; color: var(--text-muted); }

.table-wrap { overflow-x: auto; }
.table { width: 100%; border-collapse: collapse; font-size: 14px; }
.table th { text-align: left; font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .04em; color: var(--text-subtle); padding: 12px 16px; border-bottom: 1px solid var(--border); white-space: nowrap; }
.table td { padding: 12px 16px; border-bottom: 1px solid var(--border); vertical-align: middle; }
.table tr:last-child td { border-bottom: 0; }
.table tbody tr:hover { background: var(--surface); }
.cell-user { display: flex; align-items: center; gap: 10px; }
.row-actions { display: flex; gap: 6px; justify-content: flex-end; align-items: center; flex-wrap: wrap; }
.row-actions form { display: contents; }
.inline-form { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }

.admin-lessons { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.admin-lesson { display: flex; align-items: center; gap: 14px; padding: 12px 16px; scroll-margin-top: 90px; }
.admin-lesson .num { width: 28px; height: 28px; border-radius: 8px; background: var(--surface-2); display: grid; place-items: center; font-size: 13px; font-weight: 600; flex: none; }
.admin-lesson .body { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.admin-lesson:target { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }

.scrim { display: none; }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1200px) {
  .content { grid-template-columns: minmax(0, 1fr) 300px; }
}
@media (max-width: 1024px) {
  .app { grid-template-columns: 64px minmax(0, 1fr); }
  .panel {
    position: fixed; left: 64px; top: 0; z-index: 40; width: 272px;
    transform: translateX(calc(-100% - 64px)); visibility: hidden;
    transition: transform .25s var(--ease), visibility 0s linear .25s; box-shadow: var(--shadow);
  }
  .app.panel-open .panel { transform: none; visibility: visible; transition: transform .25s var(--ease); }
  .app.panel-open .scrim { display: block; position: fixed; inset: 0; z-index: 30; background: rgba(15, 23, 42, .4); }
  .topbar .menu-btn { display: inline-flex; }
  .hero { grid-template-columns: 1fr; }
}
@media (max-width: 880px) {
  .content { grid-template-columns: minmax(0, 1fr); }
  .side { position: static; }
  .side .lessons { max-height: none; }
  .course-hero { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .app { grid-template-columns: minmax(0, 1fr); }
  .rail { display: none; }
  .panel { left: 0; transform: translateX(-100%); }
  .topbar { padding: 10px 16px; gap: 8px; }
  .crumbs li:not(:last-child) { display: none; }
  .crumbs .current { max-width: 46vw; }
  .user-name, .hide-sm { display: none; }
  .user-chip { padding: 0; }
  .page, .content { padding: 16px; }
  .flash { margin: 12px 16px 0; }
  .hero, .course-hero { padding: 20px; }
  .hero-search { flex-wrap: wrap; padding: 8px; }
  .hero-search > svg.i { display: none; }
  .hero-search input { flex-basis: 100%; padding: 0 8px; }
  .hero-search .btn { width: 100%; }
  .title-row { flex-wrap: wrap; }
  .title-row .actions { margin-left: 0; }
  .concepts { grid-template-columns: 1fr; }
  .form-card, .auth-card { padding: 20px; }
  .form-actions .btn { flex: 1; }
  .admin-lesson { flex-wrap: wrap; }
  .admin-lesson .row-actions { width: 100%; justify-content: flex-start; }
  .table th:nth-child(4), .table td:nth-child(4) { display: none; }
}
/* ==========================================================================
   Ảnh bìa, thumbnail video
   ========================================================================== */
.cover img, .course-hero-cover img, .video-thumb img, .admin-thumb img {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover;
}
.course-hero-cover {
  position: relative; width: min(380px, 38vw); aspect-ratio: 16 / 9; border-radius: var(--radius-lg); overflow: hidden;
  display: grid; place-items: center; box-shadow: var(--shadow);
  background: radial-gradient(80% 120% at 85% 10%, color-mix(in srgb, var(--c) 35%, white) 0%, transparent 60%), linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 60%, black));
}
.course-hero-cover .cover-letter { font-size: 72px; }
.progress-inline { margin-top: 20px; max-width: 420px; }
.player-empty.has-cover { background: #0B1120; }
.player-cover { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: .35; }
.player-empty > :not(.player-cover) { position: relative; }

.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 18px; }
.video-card { position: relative; display: flex; flex-direction: column; gap: 10px; }
.video-thumb {
  position: relative; display: grid; place-items: center; aspect-ratio: 16 / 9; border-radius: var(--radius); overflow: hidden; color: #fff;
  background: linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 55%, black));
}
.video-thumb > svg.i { width: 36px; height: 36px; opacity: .8; }
.video-play {
  position: absolute; width: 46px; height: 46px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(15, 23, 42, .55); backdrop-filter: blur(4px); opacity: 0; transform: scale(.9);
  transition: opacity .2s var(--ease), transform .2s var(--ease);
}
.video-play svg.i { margin-left: 3px; }
.video-card:hover .video-play, .video-card:focus-within .video-play { opacity: 1; transform: none; }
.video-dur { position: absolute; right: 8px; bottom: 8px; padding: 1px 7px; border-radius: 6px; background: rgba(0, 0, 0, .72); font-size: 12px; font-weight: 600; font-variant-numeric: tabular-nums; }
.video-tag { position: absolute; left: 8px; top: 8px; padding: 2px 9px; border-radius: 999px; font-size: 11px; font-weight: 700; background: #FBBF24; color: #422006; }
.video-tag.is-new { background: #16A34A; color: #fff; }
.video-body h3 { margin: 0; font-size: 14px; font-weight: 600; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.video-body h3 a::after { content: ""; position: absolute; inset: 0; }
.video-body h3 a:focus-visible { outline: none; }
.video-card:focus-within .video-thumb { outline: 2px solid var(--primary); outline-offset: 2px; }
.video-body p { margin: 2px 0 0; font-size: 12px; color: var(--text-subtle); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.promo-strip {
  display: flex; align-items: center; gap: 16px; margin-top: 32px; padding: 16px 20px; border-radius: var(--radius-lg);
  border: 1px solid color-mix(in srgb, var(--primary) 25%, var(--border));
  background: linear-gradient(90deg, var(--primary-soft), transparent 80%), var(--bg);
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.promo-strip:hover { border-color: var(--primary); box-shadow: 0 0 0 3px var(--ring); }
.promo-strip .body { flex: 1; min-width: 0; }
.promo-strip strong { display: block; font-size: 15px; }
.promo-strip small { color: var(--text-muted); font-size: 13px; }
.promo-ico { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: var(--primary); color: var(--on-primary); flex: none; }
.promo-warn { margin: 0 0 20px; border-color: color-mix(in srgb, var(--warn) 35%, var(--border)); background: linear-gradient(90deg, var(--warn-soft), transparent 80%), var(--bg); }
.promo-warn .promo-ico { background: var(--warn); color: #fff; }

/* Admin: image upload field */
.image-field .label { font-size: 14px; font-weight: 500; }
.image-field-row { display: flex; gap: 16px; align-items: flex-start; flex-wrap: wrap; }
.image-preview {
  position: relative; width: 220px; max-width: 100%; border-radius: 12px; overflow: hidden; flex: none;
  border: 1.5px dashed var(--border-strong); background: var(--surface); display: grid; place-items: center;
}
.image-field .image-preview[style*="1/1"] { width: 160px; }
.image-preview img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.image-preview span { display: flex; flex-direction: column; align-items: center; gap: 6px; font-size: 12px; color: var(--text-subtle); }
.image-preview.is-removed img { opacity: .25; }
.image-actions { display: flex; flex-direction: column; gap: 8px; align-items: flex-start; flex: 1; min-width: 200px; }
.image-actions .btn { cursor: pointer; }
.field:has(input[type=file]:focus-visible) .image-actions .btn { outline: 2px solid var(--primary); outline-offset: 2px; }
.check { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; cursor: pointer; min-height: 32px; }
.check input { width: 18px; height: 18px; accent-color: var(--danger); }
.cover-thumb { width: 64px; height: 36px; border-radius: 8px; object-fit: cover; flex: none; font-size: 15px; }
.admin-thumb { position: relative; width: 72px; aspect-ratio: 16 / 9; border-radius: 8px; overflow: hidden; flex: none; display: grid; place-items: center; color: #fff; background: linear-gradient(135deg, var(--c), color-mix(in srgb, var(--c) 55%, black)); }
.mono { font-family: ui-monospace, "Cascadia Code", Consolas, monospace; font-size: 14px !important; }

/* ==========================================================================
   Thư viện prompt
   ========================================================================== */
.hero-prompts { background: radial-gradient(120% 140% at 0% 0%, color-mix(in srgb, #E11D48 12%, transparent) 0%, transparent 55%), radial-gradient(100% 120% at 100% 100%, var(--primary-soft) 0%, transparent 60%), var(--surface); }
.hero-prompts .eyebrow { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 8px; }
mark { background: color-mix(in srgb, #FBBF24 35%, transparent); color: inherit; border-radius: 4px; padding: 0 2px; }
.industry-chips { display: flex; gap: 8px; overflow-x: auto; padding: 4px 2px 8px; margin: 24px 0 8px; scrollbar-width: thin; }
.industry-chip {
  display: inline-flex; align-items: center; gap: 8px; min-height: 40px; padding: 0 14px; border-radius: 999px; white-space: nowrap;
  border: 1px solid var(--border); background: var(--bg); font-size: 14px; color: var(--text-muted); transition: all .15s var(--ease);
}
.industry-chip:hover { border-color: var(--border-strong); color: var(--text); }
.industry-chip[aria-current="true"] { border-color: var(--text); background: var(--text); color: var(--bg); }
.industry-chip[aria-current="true"] .chip { background: color-mix(in srgb, var(--bg) 20%, transparent); color: var(--bg); }
.industry-chip .dot { margin: 0; }
.prompt-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 18px; margin-top: 12px; }
.prompt-card { display: flex; flex-direction: column; gap: 10px; padding: 18px; border-top: 3px solid var(--c); }
.prompt-card header { display: flex; align-items: center; justify-content: space-between; gap: 8px; flex-wrap: wrap; }
.prompt-industry { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 600; color: var(--text-muted); }
.prompt-industry:hover { color: var(--text); }
.prompt-industry .dot { margin: 0; }
.prompt-tool { font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 999px; background: var(--surface-2); color: var(--text-muted); }
.prompt-card h2 { margin: 0; font-size: 16px; font-weight: 600; }
.prompt-desc { margin: 0; font-size: 13px; color: var(--text-muted); }
.prompt-content { position: relative; max-height: 168px; overflow: hidden; border-radius: 10px; background: var(--surface); border: 1px solid var(--border); }
.prompt-content::after { content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 56px; background: linear-gradient(transparent, var(--surface)); pointer-events: none; }
.prompt-content.is-open { max-height: none; }
.prompt-content.is-open::after, .prompt-content.no-overflow::after { display: none; }
.prompt-content pre { margin: 0; padding: 12px 14px; white-space: pre-wrap; word-break: break-word; font-family: inherit; font-size: 13px; line-height: 1.6; color: var(--text); }
.prompt-card footer { display: flex; justify-content: flex-end; align-items: center; gap: 8px; margin-top: auto; }
.prompt-card footer [data-expand] { margin-right: auto; }
.btn.is-copied { background: var(--success); color: #fff; }

.admin-split { display: grid; grid-template-columns: 260px minmax(0, 1fr); gap: 20px; align-items: start; }
.industry-admin { padding: 16px; position: sticky; top: 88px; }
.industry-admin h2 { margin: 0 0 8px; font-size: 15px; }
.industry-list { display: flex; flex-direction: column; gap: 2px; max-height: 50vh; overflow-y: auto; }
.industry-list a { display: flex; align-items: center; gap: 8px; min-height: 38px; padding: 6px 8px; border-radius: 8px; font-size: 14px; color: var(--text-muted); }
.industry-list a span:nth-child(2) { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.industry-list a:hover { background: var(--surface-2); color: var(--text); }
.industry-list a[aria-current="true"] { background: var(--primary-soft); color: var(--primary); font-weight: 600; }
.industry-list .dot { margin: 0 4px; }
.industry-new { gap: 10px; margin-top: 14px; padding-top: 14px; border-top: 1px solid var(--border); }
.input-with-color { display: flex; gap: 8px; }
.input-with-color input[type=color], .industry-edit input[type=color] { width: 44px !important; height: 44px; padding: 3px; border: 1px solid var(--border-strong); border-radius: 10px; background: var(--bg); flex: none; cursor: pointer; }
.industry-edit { display: flex; gap: 8px; align-items: center; padding: 12px; margin-bottom: 14px; }
.industry-edit input:not([type=color]) { flex: 1; min-width: 0; min-height: 40px; padding: 8px 12px; border: 1px solid var(--border-strong); border-radius: 10px; background: var(--bg); }

/* ==========================================================================
   Nút Zalo nổi
   ========================================================================== */
.zalo { position: fixed; right: 20px; bottom: 20px; z-index: 50; display: flex; flex-direction: column; align-items: flex-end; gap: 12px; }
.zalo-fab {
  position: relative; width: 60px; height: 60px; border-radius: 50%; background: #0068FF; color: #fff;
  font-weight: 700; font-size: 14px; letter-spacing: -.01em; box-shadow: 0 8px 24px rgba(0, 104, 255, .4);
  transition: transform .2s var(--ease);
}
.zalo-fab:hover { transform: scale(1.06); }
.zalo-fab::before {
  content: ""; position: absolute; inset: -6px; border-radius: 50%; border: 2px solid #0068FF; opacity: 0;
  animation: zalo-pulse 2.4s var(--ease) infinite;
}
.zalo-fab[aria-expanded="true"]::before { animation: none; }
@keyframes zalo-pulse { 0% { transform: scale(.85); opacity: .6; } 80%, 100% { transform: scale(1.25); opacity: 0; } }
.zalo-card {
  position: relative; width: min(320px, calc(100vw - 40px)); padding: 18px; border-radius: var(--radius-lg);
  background: var(--bg); border: 1px solid var(--border); box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 12px; animation: drop .2s var(--ease);
}
.zalo-close { position: absolute; right: 8px; top: 8px; width: 36px; height: 36px; display: grid; place-items: center; border-radius: 8px; color: var(--text-subtle); }
.zalo-close:hover { background: var(--surface-2); color: var(--text); }
.zalo-head { display: flex; align-items: center; gap: 12px; padding-right: 32px; }
.zalo-badge { width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: #0068FF; color: #fff; font-weight: 700; font-size: 12px; flex: none; }
.zalo-head h2 { margin: 0; font-size: 16px; }
.zalo-hours { margin: 2px 0 0; font-size: 12px; color: var(--text-muted); display: flex; align-items: center; gap: 6px; }
.dot-online { width: 8px; height: 8px; border-radius: 50%; background: #16A34A; box-shadow: 0 0 0 3px color-mix(in srgb, #16A34A 25%, transparent); }
.zalo-text { margin: 0; font-size: 14px; color: var(--text-muted); }
.zalo-qr { margin: 0; text-align: center; }
.zalo-qr img { width: 160px; height: 160px; object-fit: contain; border-radius: 12px; border: 1px solid var(--border); background: #fff; padding: 6px; }
.zalo-qr figcaption { font-size: 12px; color: var(--text-subtle); margin-top: 4px; }
.btn-zalo { background: #0068FF; color: #fff; }
.btn-zalo:hover { background: #0054CC; }

@media (max-width: 1024px) {
  .admin-split { grid-template-columns: 1fr; }
  .industry-admin { position: static; }
  .course-hero-cover { width: 100%; }
}
@media (max-width: 880px) {
  .course-hero-cover { order: -1; }
}
@media (max-width: 640px) {
  .prompt-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
  .promo-strip { flex-wrap: wrap; }
  .promo-strip .btn { width: 100%; }
  .zalo { right: 14px; bottom: 14px; }
  .zalo-fab { width: 54px; height: 54px; font-size: 13px; }
  .image-preview { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

/* Cài đặt website */
.brand-logo { object-fit: contain; border-radius: 8px; }
.panel .panel-head { flex-direction: column; align-items: flex-start; gap: 0; line-height: 1.3; }
.panel-name { overflow-wrap: anywhere; }
.panel .panel-head .muted { font-size: 12px; }
.form-section { margin: 8px 0 0; font-size: 17px; font-weight: 600; padding-top: 4px; }
.form-section + .field-row, .form-section-note { margin-top: -6px; }
.form-section:not(:first-of-type) { border-top: 1px solid var(--border); padding-top: 20px; }