:root {
  --bg: #f3efe7;
  --bg-2: #ebe4d6;
  --ink: #161d29;
  --muted: #5c6574;
  --navy: #1c2a44;
  --card: #fffdf8;
  --line: rgba(28, 42, 68, 0.12);
  --teal: #0f7a74;
  --coral: #c43c28;
  --gold: #c49a2a;
  --good: #1f7a45;
  --bad: #b1332c;
  --shadow: 0 16px 36px rgba(22, 29, 41, 0.08);
  --radius: 20px;
}
[data-theme="dark"] {
  --bg: #10151f;
  --bg-2: #0c1018;
  --ink: #eef2f7;
  --muted: #9aa6b8;
  --navy: #d7e0ee;
  --card: #171e2b;
  --line: rgba(238, 242, 247, 0.1);
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.28);
}
* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
html { scroll-behavior: smooth; }
body {
  font-family: "Cairo", "Segoe UI", Tahoma, sans-serif;
  background:
    radial-gradient(900px 420px at 100% -10%, rgba(15, 122, 116, 0.12), transparent 55%),
    radial-gradient(700px 380px at -10% 20%, rgba(196, 60, 40, 0.09), transparent 50%),
    var(--bg);
  color: var(--ink);
  line-height: 1.75;
}
img, svg { max-width: 100%; display: block; }
button { font-family: inherit; }
a { color: inherit; }
.ltr { direction: ltr; unicode-bidi: isolate; }
.skip {
  position: absolute;
  inset-inline-start: -999px;
  background: var(--navy);
  color: #fff;
  padding: 8px 14px;
}
.skip:focus { inset-inline-start: 8px; top: 8px; z-index: 80; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  backdrop-filter: blur(16px);
  background: color-mix(in srgb, var(--bg) 84%, transparent);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  min-width: 190px;
}
.brand-mark {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: var(--teal);
  color: #fff;
  font-weight: 900;
  font-size: 1rem;
}
.brand small { display: block; color: var(--muted); font-size: 0.78rem; }
.nav { display: flex; gap: 6px; flex-wrap: wrap; margin-inline-start: auto; }
.nav a {
  text-decoration: none;
  padding: 7px 12px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.9rem;
}
.nav a.active, .nav a:hover { background: var(--navy); color: var(--bg); }
[data-theme="dark"] .nav a.active,
[data-theme="dark"] .nav a:hover { color: #10151f; }
.icon-btn {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 12px;
  width: 40px;
  height: 40px;
  cursor: pointer;
  color: inherit;
}

.shell { max-width: 1100px; margin: 0 auto; padding: 28px 20px 70px; }
.footer { text-align: center; color: var(--muted); font-size: 0.82rem; padding: 0 16px 28px; }
.kicker { color: var(--coral); font-weight: 800; margin: 0 0 6px; }
h1 { margin: 0 0 10px; font-size: clamp(1.5rem, 4vw, 2.2rem); color: var(--navy); }
h2 { margin: 26px 0 10px; color: var(--navy); font-size: 1.28rem; }
h3 { margin: 0 0 8px; color: var(--navy); }
.lead { font-size: 1.06rem; color: var(--muted); max-width: 48rem; }

.grid { display: grid; gap: 14px; }
.grid-2 { grid-template-columns: 1fr 1fr; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

.card, .panel, .scene, .term, .case, .warn, .discuss, .quiz-card, .abbr, .def {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.card, .panel { padding: 18px 18px 16px; text-decoration: none; display: block; }
a.card { transition: transform 0.15s ease, border-color 0.15s ease; }
a.card:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--teal) 40%, var(--line));
}
.card b { display: block; font-size: 1.4rem; margin-bottom: 6px; }
.card strong { display: block; margin-bottom: 4px; }
.card small { color: var(--muted); }

.ticks { margin: 8px 0 0; padding-inline-start: 1.1rem; }
.ticks li { margin: 6px 0; }

.scene { padding: 18px; border-inline-start: 6px solid var(--gold); }
.scene .punch { margin: 10px 0 0; font-weight: 800; color: var(--navy); }
.term, .def { padding: 16px 18px; background: color-mix(in srgb, var(--teal) 8%, var(--card)); }
.term strong, .def strong { color: var(--teal); }
.case { padding: 18px; border-inline-start: 6px solid var(--coral); }
.warn { padding: 16px 18px; background: color-mix(in srgb, var(--coral) 8%, var(--card)); }
.discuss { padding: 16px 18px; background: color-mix(in srgb, var(--gold) 10%, var(--card)); }

.abbr {
  padding: 14px 16px;
  display: grid;
  gap: 4px;
}
.abbr .en {
  font-weight: 900;
  color: var(--navy);
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.abbr .ar { color: var(--muted); font-size: 0.95rem; }

.speak-btn {
  flex-shrink: 0;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--teal) 14%, var(--card));
  cursor: pointer;
  font-size: 0.95rem;
  line-height: 1;
  display: inline-grid;
  place-items: center;
  padding: 0;
  transition: transform 0.15s ease, background 0.15s ease;
}
.speak-btn:hover {
  background: var(--teal);
  transform: scale(1.06);
}
.speak-btn.playing {
  background: var(--coral);
  animation: pulse-speak 0.9s ease;
}
@keyframes pulse-speak {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.12); }
}

.tw-en {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-inline: 4px;
  vertical-align: middle;
  flex-wrap: wrap;
  white-space: normal;
}
.tw-en b {
  font-weight: 800;
  color: var(--teal);
  font-size: 0.92em;
}
.tw-full {
  font-weight: 700;
  color: var(--muted);
  font-size: 0.84em;
}
.tw-full::before {
  content: "·";
  margin: 0 5px;
}
.tw-en .speak-btn {
  width: 28px;
  height: 28px;
  font-size: 0.8rem;
}
.measure .tw-en, .panel .tw-en, h1 .tw-en, h2 .tw-en, h3 .tw-en {
  white-space: normal;
}

.vocab-strip {
  margin: 22px 0 8px;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.vocab-strip h3 {
  margin: 0 0 12px;
  font-size: 1rem;
  color: var(--navy);
}
.vocab-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.vocab-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px 8px 8px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--teal) 8%, var(--bg-2));
  border: 1px solid var(--line);
  max-width: 100%;
}
.vocab-en {
  font-weight: 900;
  color: var(--navy);
  font-size: 0.92rem;
}
.vocab-ar {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.path {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 18px 0 22px;
}
.path a {
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
}
.path a:hover { border-color: var(--teal); }
.path .num {
  display: inline-block;
  background: var(--navy);
  color: #fff;
  font-weight: 900;
  font-size: 0.8rem;
  padding: 3px 9px;
  border-radius: 999px;
  margin-bottom: 8px;
}
[data-theme="dark"] .path .num { color: #10151f; }
.path strong { display: block; color: var(--navy); margin-bottom: 6px; font-size: 1.05rem; }
.path small { display: block; color: var(--muted); line-height: 1.55; }
.path .path-mean {
  display: block;
  color: var(--ink);
  font-weight: 700;
  margin: 0 0 8px;
  padding: 8px 10px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--teal) 10%, var(--card));
  border: 1px solid var(--line);
}

.lesson-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin: 0 0 18px;
  padding: 10px 12px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
}
.lesson-bar .meta { color: var(--muted); font-size: 0.88rem; font-weight: 700; margin-inline-end: auto; }
.lesson-bar a, .pager a {
  text-decoration: none;
  background: var(--navy);
  color: var(--bg);
  padding: 7px 13px;
  border-radius: 12px;
  font-weight: 800;
  font-size: 0.88rem;
}
[data-theme="dark"] .lesson-bar a,
[data-theme="dark"] .pager a { color: #10151f; }
.lesson-bar a.ghost, .pager a.ghost {
  background: transparent;
  color: var(--navy);
  border: 1px solid var(--line);
}
[data-theme="dark"] .lesson-bar a.ghost,
[data-theme="dark"] .pager a.ghost { color: var(--ink); }

.pager {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.subnav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 8px 0 18px;
}
.subnav a {
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 0.86rem;
  font-weight: 700;
}
.subnav a.active {
  background: var(--navy);
  color: var(--bg);
  border-color: transparent;
}
[data-theme="dark"] .subnav a.active { color: #10151f; }

.graphic {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  margin: 14px 0 18px;
  box-shadow: var(--shadow);
}
.graphic figcaption { color: var(--muted); font-size: 0.88rem; padding: 8px 6px 2px; }

.vid {
  margin: 14px 0 20px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.vid iframe { width: 100%; aspect-ratio: 16/9; border: 0; background: #000; }
.vid figcaption { padding: 10px 14px 12px; color: var(--muted); font-size: 0.88rem; }

.watch {
  margin: 16px 0 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.watch-body { padding: 16px 18px 4px; }
.watch-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}
.watch-badge {
  display: inline-block;
  background: var(--teal);
  color: #fff;
  border-radius: 999px;
  padding: 2px 12px;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0;
}
.watch-meta { color: var(--muted); font-size: 0.86rem; font-weight: 700; }
.watch-title {
  margin: 8px 0 4px;
  font-size: 1.12rem;
  text-align: left;
}
.watch-why { margin: 0 0 12px; color: var(--muted); }
.watch .vid {
  margin: 0;
  border: 0;
  border-radius: 0;
  box-shadow: none;
  background: #000;
}
.watch-focus {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 12px 16px 16px;
}
.watch-focus li {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 0.86rem;
  font-weight: 800;
}

.video-lib {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 8px;
}
.video-card {
  display: grid;
  grid-template-columns: 168px 1fr;
  min-height: 132px;
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.video-card:hover { border-color: var(--teal); }
.video-thumb { position: relative; background: #111; min-height: 132px; }
.video-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.video-thumb .play {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(12, 16, 24, 0.28);
}
.video-thumb .play::before {
  content: "";
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.28);
}
.video-thumb .play::after {
  content: "";
  position: absolute;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 8px 0 8px 13px;
  border-color: transparent transparent transparent #fff;
  margin-inline-start: 3px;
}
.video-copy {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 14px;
  min-width: 0;
}
.video-copy strong { color: var(--navy); line-height: 1.35; }
.video-copy small { color: var(--muted); line-height: 1.45; }

.hero-art {
  position: relative;
  margin: 18px 0 22px;
  border-radius: calc(var(--radius) + 4px);
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: #1a1520;
}
.hero-art img { width: 100%; height: auto; display: block; }
.hero-art-overlay {
  position: absolute;
  inset: auto 0 0 0;
  padding: 28px 20px 18px;
  background: linear-gradient(180deg, transparent 0%, rgba(12, 10, 18, 0.55) 35%, rgba(12, 10, 18, 0.92) 100%);
  color: #f4efe6;
}
.hero-art-overlay .tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 800;
  background: rgba(196, 60, 40, 0.92);
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.hero-art-overlay h2 {
  margin: 0 0 6px;
  color: #fff;
  font-size: clamp(1.05rem, 2.6vw, 1.35rem);
}
.hero-art-overlay p {
  margin: 0;
  color: #d7cfc4;
  font-size: 0.92rem;
  max-width: 42rem;
}

.chain {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 8px;
  align-items: stretch;
  margin: 18px 0 22px;
}
.chain .box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px;
  text-align: center;
}
.chain .box strong { display: block; color: var(--navy); }
.chain .arr { align-self: center; color: var(--coral); font-size: 1.4rem; font-weight: 900; }

.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.compare .yes, .compare .no {
  border-radius: var(--radius);
  padding: 16px;
  border: 1px solid var(--line);
}
.compare .yes {
  background: color-mix(in srgb, var(--good) 10%, var(--card));
  border-inline-start: 5px solid var(--good);
}
.compare .no {
  background: color-mix(in srgb, var(--bad) 10%, var(--card));
  border-inline-start: 5px solid var(--bad);
}

.cmp-wrap {
  overflow-x: auto;
  margin: 12px 0 20px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--card);
  box-shadow: var(--shadow);
}
.cmp {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
}
.cmp th, .cmp td {
  padding: 12px 14px;
  text-align: right;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
  font-size: 0.92rem;
  line-height: 1.55;
}
.cmp th {
  background: #1c2a44;
  color: #fff;
  font-weight: 800;
}
[data-theme="dark"] .cmp th { background: #243044; }
.cmp tr:last-child td { border-bottom: 0; }
.cmp td:first-child { font-weight: 800; color: var(--navy); }
.cmp .tag-ok { color: var(--good); font-weight: 800; }
.cmp .tag-bad { color: var(--bad); font-weight: 800; }

.measure {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 12px;
  align-items: start;
  padding: 16px 18px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.measure .ico {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: color-mix(in srgb, var(--navy) 10%, var(--card));
  font-size: 1.35rem;
}
.measure small { color: var(--muted); display: block; margin-top: 4px; }

.pill-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.pill {
  background: color-mix(in srgb, var(--teal) 12%, var(--card));
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 12px;
  font-weight: 700;
  font-size: 0.9rem;
}
.panel .ex, .measure .ex {
  margin: 10px 0 0;
  padding: 10px 12px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--gold) 12%, var(--card));
  border: 1px solid var(--line);
  font-size: 0.95rem;
}

.backup-flow {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 14px 0;
}
.backup-flow .step {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
  text-align: center;
  box-shadow: var(--shadow);
}
.backup-flow .step .n {
  width: 36px;
  height: 36px;
  margin: 0 auto 10px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--teal);
  color: #fff;
  font-weight: 900;
}

.quiz-card { padding: 18px; margin: 14px 0; }
.quiz-opts { display: grid; gap: 8px; margin-top: 12px; }
.quiz-opts button {
  text-align: right;
  border: 1px solid var(--line);
  background: var(--bg-2);
  color: inherit;
  border-radius: 12px;
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
}
.quiz-opts button:hover { border-color: var(--teal); }
.quiz-opts button.correct {
  background: color-mix(in srgb, var(--good) 18%, var(--card));
  border-color: var(--good);
}
.quiz-opts button.wrong {
  background: color-mix(in srgb, var(--bad) 16%, var(--card));
  border-color: var(--bad);
}
.feedback {
  display: none;
  margin-top: 12px;
  padding: 12px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--teal) 10%, var(--card));
  font-weight: 700;
}
.feedback.on { display: block; }

.reveal { margin-top: 10px; }
.reveal button {
  background: var(--navy);
  color: #fff;
  border: 0;
  border-radius: 12px;
  padding: 8px 14px;
  cursor: pointer;
  font-weight: 800;
}
[data-theme="dark"] .reveal button { color: #10151f; }
.answer {
  display: none;
  margin-top: 10px;
  padding: 12px;
  border-radius: 12px;
  background: color-mix(in srgb, var(--teal) 10%, var(--card));
}
.answer.on { display: block; }

.path-en {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
  font-weight: 800;
  color: var(--teal);
  font-size: 0.92rem;
}

.scheme {
  display: grid;
  gap: 16px;
  margin: 16px 0 22px;
}
.scheme-block {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.scheme-block header {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 14px;
  align-items: start;
  padding: 16px 18px;
  background: color-mix(in srgb, var(--navy) 6%, var(--card));
  border-bottom: 1px solid var(--line);
}
.scheme-block header .num {
  background: var(--navy);
  color: #fff;
  font-weight: 900;
  font-size: 0.85rem;
  padding: 6px 11px;
  border-radius: 999px;
}
[data-theme="dark"] .scheme-block header .num { color: #10151f; }
.scheme-block header strong {
  display: block;
  color: var(--navy);
  font-size: 1.1rem;
  margin-bottom: 4px;
}
.scheme-block header p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.55;
}
.scheme-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 14px 16px 16px;
}
.scheme-topics a {
  text-decoration: none;
  background: color-mix(in srgb, var(--teal) 10%, var(--card));
  border: 1px solid var(--line);
  color: var(--ink);
  padding: 8px 13px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.9rem;
}
.scheme-topics a:hover {
  background: var(--navy);
  color: var(--bg);
  border-color: transparent;
}
[data-theme="dark"] .scheme-topics a:hover { color: #10151f; }

.flow-list {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 12px 0;
  display: grid;
  gap: 10px;
}
.flow-list li {
  counter-increment: step;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px 16px 14px 16px;
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 12px;
  align-items: start;
  box-shadow: var(--shadow);
}
.flow-list li::before {
  content: counter(step);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--teal);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 900;
}

@media (max-width: 900px) {
  .grid-3, .grid-2, .path, .chain, .compare, .backup-flow, .video-lib { grid-template-columns: 1fr; }
  .video-card { grid-template-columns: 1fr; }
  .video-thumb { min-height: 180px; }
  .video-thumb img { height: 180px; }
  .chain .arr { transform: rotate(90deg); justify-self: center; }
  .topbar-inner { flex-wrap: wrap; }
  .nav { margin-inline-start: 0; }
}