/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:        #0d1117;
  --bg-card:   #161b22;
  --bg-hover:  #1c2128;
  --border:    #30363d;
  --border-sub:#21262d;
  --text:      #e6edf3;
  --text-sub:  #8b949e;
  --text-muted:#656d76;
  --accent:    #58a6ff;
  --accent-bg: #1f3a5f;
  --green:     #3fb950;
  --orange:    #d29922;
  --red:       #f85149;
  --purple:    #bc8cff;
  --radius:    6px;
  --radius-lg: 10px;
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Header ───────────────────────────────────────────────── */
.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(13, 17, 23, 0.95);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
}
.logo svg { color: var(--accent); }
.logo:hover { text-decoration: none; color: var(--accent); }

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav a {
  padding: 6px 12px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  color: var(--text-sub);
  font-weight: 500;
  transition: color 0.15s, background 0.15s;
  text-decoration: none;
}
.nav a:hover { color: var(--text); background: var(--bg-hover); }
.nav a.active { color: var(--text); background: var(--bg-card); border: 1px solid var(--border); }

.nav-gh {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 8px;
  border: 1px solid var(--border) !important;
}

/* ── Hero (homepage) ──────────────────────────────────────── */
.hero {
  padding: 80px 0 64px;
  text-align: center;
  border-bottom: 1px solid var(--border-sub);
}

.hero-eyebrow {
  display: inline-block;
  background: var(--accent-bg);
  color: var(--accent);
  border: 1px solid rgba(88,166,255,0.2);
  padding: 3px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 20px;
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 14px;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-sub);
  max-width: 480px;
  margin: 0 auto;
}

/* ── Lab Grid (homepage cards) ───────────────────────────── */
.lab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  padding: 48px 0 64px;
}

.lab-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-decoration: none;
  transition: border-color 0.15s, transform 0.1s, box-shadow 0.15s;
}
.lab-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  text-decoration: none;
}

.lab-card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.pdf-icon   { background: rgba(248,81,73,0.12);  color: #f85149; }
.data-icon  { background: rgba(63,185,80,0.12);  color: #3fb950; }
.code-icon  { background: rgba(88,166,255,0.12); color: #58a6ff; }

.lab-card-body { flex: 1; }
.lab-card-body h2 { font-size: 1rem; font-weight: 600; color: var(--text); margin-bottom: 4px; }
.lab-card-body p  { font-size: 0.85rem; color: var(--text-sub); }
.lab-card-arrow { color: var(--text-muted); font-size: 1.2rem; transition: transform 0.15s; }
.lab-card:hover .lab-card-arrow { transform: translateX(4px); color: var(--accent); }

/* ── Page Header (sub-pages) ──────────────────────────────── */
.page-header {
  padding: 40px 0 32px;
  border-bottom: 1px solid var(--border-sub);
}

.breadcrumb {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--accent); }

.page-header h1 { font-size: 1.75rem; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.page-header p  { font-size: 0.9rem; color: var(--text-sub); }

/* ── Toolbar ──────────────────────────────────────────────── */
.toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  padding: 24px 0 20px;
}

.search-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 14px;
  flex: 1;
  min-width: 200px;
  max-width: 360px;
}
.search-wrap svg { color: var(--text-muted); flex-shrink: 0; }
.search-wrap input {
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 0.875rem;
  width: 100%;
}
.search-wrap input::placeholder { color: var(--text-muted); }

.tag-filters { display: flex; flex-wrap: wrap; gap: 6px; }

.tag-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-sub);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
}
.tag-btn:hover  { border-color: var(--accent); color: var(--accent); }
.tag-btn.active { background: var(--accent-bg); border-color: var(--accent); color: var(--accent); }

/* ── Resource List ────────────────────────────────────────── */
.resource-list { display: flex; flex-direction: column; gap: 1px; }

.resource-item {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  transition: border-color 0.15s, background 0.15s;
  margin-bottom: 8px;
}
.resource-item:hover { border-color: var(--accent); background: var(--bg-hover); }

.resource-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.pdf-icon-sm   { background: rgba(248,81,73,0.12);  color: #f85149; }
.data-icon-sm  { background: rgba(63,185,80,0.12);  color: #3fb950; }
.code-icon-sm  { background: rgba(88,166,255,0.12); color: #58a6ff; }

.resource-body { flex: 1; min-width: 0; }
.resource-title { font-weight: 600; font-size: 0.95rem; color: var(--text); margin-bottom: 3px; }
.resource-desc  { font-size: 0.82rem; color: var(--text-sub); margin-bottom: 8px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.resource-meta  { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }

.tag {
  background: var(--bg-hover);
  border: 1px solid var(--border);
  color: var(--text-sub);
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 0.72rem;
  font-weight: 500;
}

.meta-chip {
  background: transparent;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-family: 'JetBrains Mono', monospace;
}

.lang-dot {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  color: var(--text-muted);
}
.lang-dot-circle {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--lc, #8b949e);
  display: inline-block;
}

/* ── Resource Actions ─────────────────────────────────────── */
.resource-actions { display: flex; gap: 8px; flex-shrink: 0; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius);
  font-size: 0.82rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  border: 1px solid transparent;
  text-decoration: none;
  transition: all 0.15s;
  white-space: nowrap;
}

.btn-download {
  background: var(--green);
  color: #000;
  border-color: var(--green);
}
.btn-download:hover {
  background: #46c65a;
  border-color: #46c65a;
  text-decoration: none;
  color: #000;
}

.btn-ghost {
  background: transparent;
  color: var(--text-sub);
  border-color: var(--border);
}
.btn-ghost:hover { background: var(--bg-hover); color: var(--text); border-color: var(--accent); text-decoration: none; }

.btn-outline {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* ── Empty State ──────────────────────────────────────────── */
.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 48px 0;
  font-size: 0.9rem;
}

/* ── About Section ────────────────────────────────────────── */
.about-section {
  margin-top: auto;
  border-top: 1px solid var(--border-sub);
  padding: 64px 0;
}
.about-inner { max-width: 520px; margin: 0 auto; text-align: center; }
.about-inner h2 { font-size: 1.4rem; font-weight: 700; margin-bottom: 12px; }
.about-inner p  { color: var(--text-sub); margin-bottom: 24px; }

/* ── Footer ───────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border-sub);
  padding: 20px 0;
  margin-top: auto;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.footer-inner a { color: var(--text-muted); }
.footer-inner a:hover { color: var(--accent); }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 640px) {
  .resource-item { flex-wrap: wrap; }
  .resource-actions { width: 100%; justify-content: flex-start; }
  .resource-icon { display: none; }
  .footer-inner { flex-direction: column; gap: 8px; text-align: center; }
  .hero { padding: 48px 0 40px; }
  .lab-grid { grid-template-columns: 1fr; }
  .toolbar { flex-direction: column; align-items: stretch; }
  .search-wrap { max-width: 100%; }
}

/* ── Unified Archive Layout ──────────────────────────────── */
.hero-labs {
  padding: 72px 0 48px;
  text-align: left;
  border-bottom: 1px solid var(--border-sub);
}

.hero-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.9fr);
  gap: 24px;
  align-items: stretch;
}

.hero-panel {
  background: linear-gradient(180deg, rgba(88,166,255,0.08), rgba(22,27,34,0.95));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
}

.hero-panel-label {
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.72rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.hero-panel-path {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--text);
  padding: 12px 14px;
  border-radius: 12px;
  background: rgba(0,0,0,0.24);
  border: 1px solid var(--border-sub);
  margin-bottom: 12px;
  overflow-x: auto;
}

.hero-panel p {
  color: var(--text-sub);
  font-size: 0.92rem;
}

.archive { padding-bottom: 64px; }

.year-section {
  padding-top: 28px;
  margin-top: 28px;
  border-top: 1px solid var(--border-sub);
}

.year-section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}

.year-section-header h2 {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.year-section-header span {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.course-group {
  margin-bottom: 32px;
}

.course-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
  padding-left: 8px;
  border-left: 3px solid var(--accent);
  cursor: pointer;
  user-select: none;
  transition: opacity 0.15s;
}

.course-header:hover {
  opacity: 0.8;
}

.toggle-icon {
  flex-shrink: 0;
  transition: transform 0.2s ease;
  color: var(--text-sub);
}

.course-group.open .toggle-icon {
  transform: rotate(0deg);
}

.course-group:not(.open) .toggle-icon {
  transform: rotate(-90deg);
}

.course-header h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.course-header span {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.course-group:not(.open) .lab-list {
  display: none;
}

.lab-list {
  display: grid;
  gap: 14px;
}

.lab-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 20px;
}

.lab-card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.lab-card-head h3 {
  font-size: 1.05rem;
  line-height: 1.35;
}

.lab-path {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.lab-date {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.76rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.lab-description {
  color: var(--text-sub);
  font-size: 0.92rem;
  margin-bottom: 14px;
}

.lab-tags { margin-bottom: 14px; }

.lab-assets {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.asset-chip {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.16);
  color: var(--text);
  min-width: 170px;
  text-decoration: none;
}

.asset-chip:hover { text-decoration: none; border-color: var(--accent); }

.asset-chip span {
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.asset-chip strong {
  font-size: 0.88rem;
  font-weight: 600;
}

.asset-pdf { box-shadow: inset 0 0 0 1px rgba(248,81,73,0.12); }
.asset-code { box-shadow: inset 0 0 0 1px rgba(88,166,255,0.12); }
.asset-data { box-shadow: inset 0 0 0 1px rgba(63,185,80,0.12); }

.asset-chip small {
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.4;
  word-break: break-word;
}

.lab-card-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 14px;
}

.lab-open-btn {
  min-width: 120px;
}

.archive .lab-card {
  display: block;
  align-items: initial;
  gap: 0;
}

.lab-detail {
  padding: 28px 0 64px;
}

.detail-shell {
  display: grid;
  gap: 18px;
}

.detail-head,
.detail-assets {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 22px;
}

.detail-kicker {
  color: var(--accent);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.detail-head h2 {
  font-size: clamp(1.4rem, 3vw, 2.1rem);
  line-height: 1.2;
  margin-bottom: 10px;
}

.detail-meta {
  color: var(--text-sub);
  margin-bottom: 14px;
}

.detail-tags { display: flex; flex-wrap: wrap; gap: 6px; }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.back-link:hover { color: var(--accent); text-decoration: none; }

.detail-assets-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 16px;
}

.detail-assets-header h3 { font-size: 1.05rem; }
.detail-assets-header span { color: var(--text-muted); font-size: 0.82rem; }

.detail-asset-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

@media (max-width: 860px) {
  .hero-shell { grid-template-columns: 1fr; }
  .lab-card-head { flex-direction: column; }
  .lab-date { white-space: normal; }
  .detail-assets-header { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 640px) {
  .hero-labs { padding-top: 56px; }
  .asset-chip { width: 100%; min-width: 0; }
  .lab-card-actions { justify-content: stretch; }
  .lab-open-btn { width: 100%; }
}