/* Campus Lab Hub — recorded lab demonstrations.
   Light, functional, teal accent. Sidebar + list, not a card grid. */

:root {
  --bg: #fbfbfc;
  --surface: #ffffff;
  --panel: #f1f4f5;
  --ink: #12343b;
  --ink-2: #5b6b70;
  --edge: #dde3e6;
  --teal: #0f766e;
  --teal-soft: #e3f0ee;
  --warm: #c2763a;

  --ui: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "DejaVu Sans Mono", Menlo, Consolas, monospace;

  --shell: 1200px;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--ui);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

.shell { width: 100%; max-width: var(--shell); margin: 0 auto; padding: 0 24px; }
.sr { position: absolute; left: -9999px; }
.sr:focus { left: 12px; top: 12px; z-index: 30; background: var(--teal); color: #fff; padding: 8px 14px; border-radius: 4px; }

/* masthead */

.mast { background: var(--surface); border-bottom: 1px solid var(--edge); }
.mast-in { display: flex; align-items: center; justify-content: space-between; gap: 16px 28px; flex-wrap: wrap; min-height: 62px; padding: 10px 0; }

.brand { display: flex; align-items: center; gap: 11px; }
.brand-mark { width: 30px; height: 30px; border-radius: 7px; background: var(--teal); flex: none; position: relative; }
.brand-mark::after {
  content: ""; position: absolute; left: 9px; right: 9px; top: 7px; bottom: 7px;
  border: 2px solid #fff; border-radius: 2px; border-top-width: 6px;
}
.brand b { font-size: 1.125rem; font-weight: 650; letter-spacing: -0.01em; }
.brand i { font-style: normal; display: block; font-size: 0.6875rem; color: var(--ink-2); letter-spacing: .03em; }

.nav { display: flex; gap: 20px; font-size: 0.9375rem; }
.nav a { color: var(--ink-2); padding: 4px 0; border-bottom: 2px solid transparent; }
.nav a:hover { color: var(--ink); }
.nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--teal); }

/* intro */

.intro { padding: 36px 0 26px; }
.intro h1 { font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 650; letter-spacing: -0.025em; line-height: 1.1; margin: 0 0 10px; max-width: 24ch; }
.intro p { margin: 0; color: var(--ink-2); max-width: 62ch; font-size: 1rem; }

/* two-column layout */

.cols { display: grid; grid-template-columns: 212px minmax(0, 1fr); gap: 42px; align-items: start; padding-bottom: 56px; }

.side h2 { font-size: 0.6875rem; font-weight: 650; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 9px; }
.side ul { list-style: none; margin: 0 0 26px; padding: 0; }
.side li { margin-bottom: 1px; }

.opt {
  display: flex; justify-content: space-between; align-items: center; gap: 8px;
  width: 100%; text-align: left; background: none; border: none; font: inherit;
  font-size: 0.9375rem; color: var(--ink-2); padding: 6px 10px; border-radius: 6px; cursor: pointer;
}
.opt:hover { background: var(--panel); color: var(--ink); }
.opt[aria-pressed="true"] { background: var(--teal-soft); color: var(--teal); font-weight: 600; }
.opt span { font-family: var(--mono); font-size: 0.75rem; opacity: .7; }

.count { font-family: var(--mono); font-size: 0.75rem; color: var(--ink-2); margin: 0 0 16px; }

/* list of recordings */

.items { list-style: none; margin: 0; padding: 0; display: grid; gap: 16px; }

.item {
  display: grid; grid-template-columns: 196px minmax(0, 1fr);
  gap: 20px; background: var(--surface); border: 1px solid var(--edge);
  border-radius: 10px; padding: 14px; align-items: start;
}
.item:hover { border-color: var(--teal); }

.item-fig { border-radius: 6px; overflow: hidden; background: var(--panel); }
.item-fig img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; }

.item-top { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: 7px; }
.badge { font-family: var(--mono); font-size: 0.6875rem; background: var(--teal); color: #fff; padding: 2px 7px; border-radius: 4px; letter-spacing: .02em; }
.item-lab { font-size: 0.75rem; color: var(--ink-2); }

.item-title { font-size: 1.0625rem; font-weight: 650; line-height: 1.26; margin: 0 0 6px; letter-spacing: -0.01em; }
.item:hover .item-title { color: var(--teal); }
.item-sum { margin: 0 0 8px; font-size: 0.875rem; color: var(--ink-2); max-width: 66ch; }
.item-foot { font-family: var(--mono); font-size: 0.6875rem; color: var(--ink-2); }

.blank { padding: 30px 0 46px; color: var(--ink-2); }
.blank button { background: none; border: none; font: inherit; color: var(--teal); text-decoration: underline; cursor: pointer; padding: 0; }

/* single recording */

.single { max-width: 880px; margin: 26px auto 60px; }

.crumb { font-family: var(--mono); font-size: 0.75rem; color: var(--ink-2); margin-bottom: 13px; }
.crumb a { color: var(--teal); }

.stage { position: relative; background: #0b1416; aspect-ratio: 16 / 10; border-radius: 10px; overflow: hidden; border: 1px solid var(--edge); }
.stage video { width: 100%; height: 100%; display: block; }

.stage-msg { position: absolute; inset: 0; display: none; flex-direction: column; justify-content: center; gap: 10px; padding: 30px; background: var(--panel); }
.stage-msg.visible { display: flex; }
.stage-msg h2 { margin: 0; font-size: 1.125rem; font-weight: 650; }
.stage-msg p { margin: 0; color: var(--ink-2); font-size: 0.9375rem; max-width: 52ch; }

.stage-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 18px; padding: 10px 0 0; font-family: var(--mono); font-size: 0.75rem; color: var(--ink-2); }
.stage-bar select { background: var(--surface); border: 1px solid var(--edge); color: var(--ink); font: inherit; font-size: 0.75rem; padding: 3px 7px; border-radius: 5px; }

.single h1 { font-size: clamp(1.5rem, 3.6vw, 2.05rem); font-weight: 650; letter-spacing: -0.025em; line-height: 1.14; margin: 22px 0 12px; }

.meta { margin: 0 0 24px; padding: 0; border-top: 1px solid var(--edge); font-size: 0.9375rem; }
.meta > div { display: grid; grid-template-columns: 170px minmax(0, 1fr); gap: 16px; padding: 9px 0; border-bottom: 1px solid var(--edge); }
.meta dt { color: var(--ink-2); margin: 0; font-size: 0.8125rem; }
.meta dd { margin: 0; }

.summary { font-size: 1rem; line-height: 1.62; max-width: 66ch; margin: 0 0 38px; }

.related h2 { font-size: 0.6875rem; font-weight: 650; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 13px; padding-bottom: 9px; border-bottom: 1px solid var(--edge); }
.related ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.related .item { grid-template-columns: 120px minmax(0, 1fr); gap: 14px; padding: 11px; }
.related .item-title { font-size: 0.9688rem; }

/* text pages */

.page { max-width: 68ch; margin: 32px 0 64px; }
.page h1 { font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 650; letter-spacing: -0.025em; margin: 0 0 10px; }
.page .lede { font-size: 1.0625rem; color: var(--ink-2); margin: 0 0 26px; }
.page h2 { font-size: 1.125rem; font-weight: 650; margin: 30px 0 9px; }
.page p { margin: 0 0 14px; line-height: 1.62; }
.page a { color: var(--teal); text-decoration: underline; }

.facts { list-style: none; margin: 24px 0 0; padding: 0; border-top: 1px solid var(--edge); }
.facts > li { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 16px; padding: 11px 0; border-bottom: 1px solid var(--edge); font-size: 0.9375rem; }
.facts .k { color: var(--ink-2); }

/* footer */

.foot { border-top: 1px solid var(--edge); background: var(--surface); padding: 22px 0 40px; font-size: 0.8125rem; color: var(--ink-2); }
.foot-in { display: flex; flex-wrap: wrap; gap: 8px 26px; justify-content: space-between; }

/* responsive */

@media (max-width: 900px) {
  .cols { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .side ul { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 18px; }
  .opt { width: auto; border: 1px solid var(--edge); }
  .opt span { display: none; }
}

@media (max-width: 620px) {
  .shell { padding: 0 16px; }
  .item { grid-template-columns: minmax(0, 1fr); gap: 12px; }
  .related .item { grid-template-columns: 90px minmax(0, 1fr); }
  .meta > div, .facts > li { grid-template-columns: minmax(0, 1fr); gap: 2px; }
}