:root {
  --ink: #17210f;
  --moss: #6a8547;
  --forest: #2f4a24;
  --blue1: #3f6fb0;
  --blue2: #2f5590;
  --cream: #fff;
  --yellow: #ffe787;
  --orange: #F07A1A;
  --font: "Quicksand", system-ui, sans-serif;
}
* { box-sizing: border-box; }
body {
  margin: 0; min-height: 100vh; font-family: var(--font); color: var(--ink);
  background-color: var(--moss);
  background-image: linear-gradient(#7a9557 1.5px, transparent 1.5px), linear-gradient(90deg, #7a9557 1.5px, transparent 1.5px);
  background-size: 34px 34px;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; border: 0; background: none; cursor: pointer; }
img { display: block; max-width: 100%; }

.vid-layout { display: grid; grid-template-columns: 260px 1fr; gap: 26px; align-items: start; padding: 24px; max-width: 1440px; margin: 0 auto; }

/* ---------- sidebar ---------- */
.vid-side {
  position: sticky; top: 24px; background: #fff; border: 2.5px solid var(--ink); border-radius: 22px;
  padding: 22px 16px; box-shadow: 5px 5px 0 var(--ink);
}
.side-head { display: flex; align-items: center; gap: 12px; padding: 0 8px 16px; }
.side-logo { flex: none; width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center; background: var(--forest); color: #fff; }
.side-head h1 { margin: 0; font-size: 18px; font-weight: 700; }
.side-head p { margin: 2px 0 0; font-size: 10px; font-weight: 700; letter-spacing: .06em; color: #6d7a5c; }
.side-link, .side-nav button, .side-topics button {
  display: flex; align-items: center; gap: 12px; width: 100%; text-align: left;
  padding: 11px 12px; border-radius: 12px; font-size: 15px; font-weight: 600; color: #2b3322;
  transition: background .15s;
}
.side-link:hover, .side-nav button:hover, .side-topics button:hover { background: #f1f4ec; }
.side-label { margin: 18px 10px 8px; font-size: 11px; font-weight: 700; letter-spacing: .12em; color: #7d8a6a; }
.side-nav button .name { flex: 1; }
.count {
  flex: none; min-width: 22px; height: 22px; padding: 0 6px; border-radius: 999px; display: grid; place-items: center;
  font-size: 11px; font-weight: 700; background: #eef1e8; color: #3a4430;
}
.side-nav button.active { background: var(--forest); color: #fff; border: 2px solid var(--ink); box-shadow: 2px 2px 0 var(--ink); }
.side-nav button.active .count { background: rgba(255,255,255,.2); color: #fff; }
.side-topics button::before { content: ""; width: 9px; height: 9px; border-radius: 50%; background: #6a8547; flex: none; }
.side-topics button.active { background: #eef1e8; font-weight: 700; }
.vid-side hr { border: 0; border-top: 2px solid #e8ece1; margin: 14px 4px; }
.side-promo {
  display: flex; align-items: center; gap: 12px; padding: 14px; border-radius: 14px;
  background: var(--forest); color: #fff; border: 2px solid var(--ink); box-shadow: 3px 3px 0 var(--ink);
  transition: transform .15s;
}
.side-promo:hover { transform: translate(-2px, -2px); }
.side-promo > span:nth-child(2) { flex: 1; }
.side-promo b { display: block; font-size: 14.5px; line-height: 1.3; }
.side-promo small { display: inline-flex; align-items: center; gap: 4px; margin-top: 6px; background: #ffd23f; color: var(--ink); font-size: 10px; font-weight: 800; padding: 2px 8px; border-radius: 999px; }
.promo-arrow { font-size: 20px; }

/* ---------- teacher card ---------- */
.teacher-card {
  display: flex; gap: 30px; align-items: center; padding: 28px; border-radius: 20px;
  background: linear-gradient(135deg, var(--blue1), var(--blue2)); border: 2.5px solid var(--ink); box-shadow: 5px 5px 0 var(--ink);
  color: #fff; min-height: 330px;
}
.t-photo {
  flex: none; width: 210px; aspect-ratio: 3 / 4; border-radius: 14px; overflow: hidden;
  background: #E08B51; border: 2.5px solid var(--ink);
}
.t-photo img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 20%; }
.t-badge { display: inline-flex; align-items: center; gap: 6px; background: #fff; color: var(--ink); font-size: 12px; font-weight: 700; padding: 5px 14px; border-radius: 999px; border: 2px solid var(--ink); }
.teacher-card h2 { margin: 12px 0 14px; font-size: clamp(22px, 2.4vw, 30px); font-weight: 700; color: #fff4c2; }
.teacher-card ul { margin: 0; padding-left: 20px; display: grid; gap: 8px; font-size: 15px; line-height: 1.5; }

/* ---------- notice ---------- */
.notice {
  display: flex; align-items: center; gap: 20px; margin: 24px 0; padding: 14px 20px;
  background: var(--yellow); border: 2.5px solid var(--ink); border-radius: 14px; box-shadow: 4px 4px 0 var(--ink);
}
.notice p { flex: 1; margin: 0; font-size: 14.5px; font-weight: 600; line-height: 1.5; }
.notice-btns { display: flex; gap: 10px; flex: none; }
.soc-btn { display: inline-flex; align-items: center; gap: 6px; padding: 8px 16px; border-radius: 999px; background: #fff; border: 2px solid var(--ink); font-weight: 700; font-size: 14px; box-shadow: 2px 2px 0 var(--ink); transition: transform .15s; }
.soc-btn:hover { transform: translate(-1px, -1px); }

/* ---------- video grid ---------- */
.vid-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 22px; }
.v-card {
  display: flex; flex-direction: column; overflow: hidden; text-align: left; background: #fff;
  border: 2.5px solid var(--ink); border-radius: 16px; box-shadow: 4px 4px 0 var(--ink);
  transition: transform .2s, box-shadow .2s;
}
.v-card:hover { transform: translate(-3px, -3px); box-shadow: 7px 7px 0 var(--ink); }
.v-thumb { position: relative; aspect-ratio: 16 / 8.8; background: #222; border-bottom: 2.5px solid var(--ink); overflow: hidden; }
.v-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
.v-card:hover .v-thumb img { transform: scale(1.05); }
.v-cat { position: absolute; top: 8px; left: 8px; background: #fff; color: var(--ink); font-size: 10.5px; font-weight: 700; letter-spacing: .04em; padding: 3px 10px; border-radius: 999px; border: 1.5px solid var(--ink); }
.v-level { position: absolute; top: 8px; right: 8px; background: var(--ink); color: #fff; font-size: 11px; font-weight: 700; padding: 3px 9px; border-radius: 999px; }
.v-dur { position: absolute; right: 8px; bottom: 8px; background: rgba(23,33,15,.85); color: #fff; font-size: 12px; font-weight: 700; padding: 3px 8px; border-radius: 8px; }
.v-play {
  position: absolute; left: 50%; top: 50%; width: 54px; height: 54px; transform: translate(-50%, -50%) scale(.85);
  display: grid; place-items: center; border-radius: 50%; background: rgba(255,255,255,.92); color: var(--ink);
  opacity: 0; transition: opacity .2s, transform .2s;
}
.v-card:hover .v-play { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.v-body { padding: 14px 16px 16px; }
.v-body h3 { margin: 0; font-size: 15px; font-weight: 700; line-height: 1.35; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.v-date { margin: 10px 0 4px; font-size: 13px; color: #6d7a5c; font-weight: 600; }
.v-desc { margin: 0; font-size: 12.5px; color: #7d8a6a; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.vid-empty {
  grid-column: 1 / -1; padding: 40px 24px; text-align: center; background: #fff; border: 2.5px dashed var(--ink);
  border-radius: 16px; font-weight: 600; color: #4b5540;
}
.vid-empty b { display: block; font-size: 18px; margin-bottom: 6px; color: var(--ink); }

/* ---------- player ---------- */
.player { position: fixed; inset: 0; z-index: 100; display: grid; place-items: center; padding: 20px; }
.player[hidden] { display: none; }
.player-backdrop { position: absolute; inset: 0; background: rgba(15, 22, 10, .7); backdrop-filter: blur(3px); }
.player-box {
  position: relative; width: min(920px, 100%); max-height: calc(100vh - 40px); overflow: auto; background: #fff;
  border: 2.5px solid var(--ink); border-radius: 20px; box-shadow: 6px 6px 0 var(--ink); animation: pop .25s ease;
}
@keyframes pop { from { transform: scale(.94); opacity: 0; } }
.player-close { position: absolute; top: 10px; right: 10px; z-index: 2; width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center; background: #fff; border: 2px solid var(--ink); }
.player-media { aspect-ratio: 16 / 9; background: #111; border-bottom: 2.5px solid var(--ink); position: relative; }
.player-media iframe { width: 100%; height: 100%; border: 0; display: block; }
.player-media img { width: 100%; height: 100%; object-fit: cover; opacity: .35; }
.player-soon { position: absolute; inset: 0; display: grid; place-content: center; justify-items: center; gap: 14px; padding: 20px; text-align: center; color: #fff; }
.player-soon b { font-size: clamp(18px, 2.4vw, 24px); }
.player-soon p { margin: 0; max-width: 520px; line-height: 1.6; opacity: .9; }
.player-soon .soon-btns { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.player-soon a { padding: 10px 20px; border-radius: 999px; font-weight: 700; background: var(--orange); color: #fff; border: 2px solid #fff; }
.player-soon a.ghost { background: transparent; }
.player-info { padding: 18px 24px 24px; }
.player-meta { margin: 0; font-size: 12px; font-weight: 700; letter-spacing: .08em; color: #6d7a5c; text-transform: uppercase; }
.player-info h2 { margin: 6px 0 8px; font-size: 22px; }
.player-info p:last-child { margin: 0; color: #4b5540; line-height: 1.6; }

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .vid-layout { grid-template-columns: 1fr; padding: 16px; }
  .vid-side { position: static; }
  .side-nav { display: flex; flex-wrap: wrap; gap: 6px; }
  .side-nav button { width: auto; }
  .side-topics { display: flex; flex-wrap: wrap; gap: 4px; }
  .side-topics button { width: auto; }
  .teacher-card { flex-direction: column; align-items: flex-start; min-height: 0; }
  .t-photo { width: 160px; }
  .notice { flex-direction: column; align-items: flex-start; }
}