/* LLMLab — Shell + hub */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  font-family: var(--font-ui);
  font-size: var(--font-size-md);
  color: var(--fg);
  background: var(--bg);
  overflow: hidden;
}

body {
  display: flex;
  flex-direction: column;
}

/* ── Banner ── */
.edu-banner {
  display: flex;
  align-items: center;
  gap: var(--sp-6);
  padding: var(--sp-3) var(--sp-6);
  background: linear-gradient(90deg, var(--banner-bg) 0%, var(--banner-mid) 100%);
  border-bottom: 1px solid rgba(56, 217, 255, 0.2);
  flex-shrink: 0;
  min-height: 52px;
}

.edu-banner__logo {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  flex-shrink: 0;
}

.edu-banner__logo img {
  height: 32px;
  width: auto;
  border-radius: var(--r-md);
}

.edu-banner__brand {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: #bae6fd;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.edu-banner__by {
  font-weight: 400;
  font-size: var(--font-size-sm);
  color: var(--banner-sub);
  margin-left: var(--sp-1);
}

.edu-banner__info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.edu-banner__label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--banner-text);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.edu-banner__sub {
  font-size: var(--font-size-xs);
  color: var(--banner-sub);
  line-height: 1.4;
}

/* ── App ── */
.app {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ── Hub ── */
.hub {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: var(--sp-8) var(--sp-6);
  background:
    radial-gradient(circle at 18% 8%, rgba(56, 217, 255, 0.14), transparent 32%),
    radial-gradient(circle at 88% 12%, rgba(167, 139, 250, 0.14), transparent 28%),
    radial-gradient(circle at 50% 100%, rgba(100, 244, 172, 0.08), transparent 36%),
    linear-gradient(160deg, #070b16 0%, #0b1020 55%, #0d1325 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--sp-8);
}

.hub__hero {
  text-align: center;
  max-width: 720px;
}

.hub__brand {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--fg-heading);
  line-height: 1.1;
  margin-bottom: var(--sp-3);
}

.hub__brand span {
  background: linear-gradient(90deg, var(--ll-cyan), var(--ll-purple));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hub__lead {
  font-size: var(--font-size-lg);
  color: var(--fg-muted);
  line-height: 1.55;
  max-width: 540px;
  margin: 0 auto;
}

.hub__cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 340px));
  gap: var(--sp-5);
  width: 100%;
  max-width: 720px;
  justify-content: center;
}

@media (max-width: 720px) {
  .hub__cards { grid-template-columns: 1fr; max-width: 400px; }
}

.hub-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--sp-3);
  padding: var(--sp-6);
  background: rgba(16, 24, 45, 0.85);
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  text-align: left;
  color: inherit;
  cursor: pointer;
  transition: border-color var(--trans), transform var(--trans), background var(--trans);
}

.hub-card:hover {
  transform: translateY(-2px);
  background: rgba(21, 31, 58, 0.95);
}

.hub-card--llm:hover { border-color: rgba(56, 217, 255, 0.55); }
.hub-card--rag:hover { border-color: rgba(100, 244, 172, 0.55); }

.hub-card:focus-visible {
  outline: 2px solid var(--ll-cyan);
  outline-offset: 3px;
}

.hub-card__icon {
  width: 48px;
  height: 48px;
  border-radius: var(--r-lg);
  display: grid;
  place-items: center;
  flex-shrink: 0;
}

.hub-card__icon svg { width: 24px; height: 24px; }

.hub-card--llm .hub-card__icon {
  background: var(--ll-cyan-soft);
  color: var(--ll-cyan);
}

.hub-card--rag .hub-card__icon {
  background: var(--ll-green-soft);
  color: var(--ll-green);
}

.hub-card__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--fg-heading);
}

.hub-card__desc {
  font-size: var(--font-size-md);
  color: var(--fg-muted);
  line-height: 1.5;
  flex: 1;
}

.hub-card__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  margin-top: var(--sp-2);
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.hub-card--llm .hub-card__cta { color: var(--ll-cyan); }
.hub-card--rag .hub-card__cta { color: var(--ll-green); }

.hub-card__cta svg { width: 14px; height: 14px; }

.hub__footnote {
  font-size: var(--font-size-xs);
  color: var(--fg-subtle);
  text-align: center;
  max-width: 480px;
  line-height: 1.5;
}

/* ── Sim view (iframe) ── */
.sim-view {
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sim-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-2) var(--sp-4);
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sim-bar__back {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--r-full);
  color: var(--fg-muted);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  transition: background var(--trans), color var(--trans);
}

.sim-bar__back:hover {
  background: var(--bg-hover);
  color: var(--fg);
}

.sim-bar__back svg { width: 14px; height: 14px; }

.sim-bar__title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--fg-muted);
}

.sim-frame {
  flex: 1;
  min-height: 0;
  width: 100%;
  border: 0;
  background: #0b1020;
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }