/* ============================================================
   crashcourse — Design System
   Linear / Vercel / Raycast aesthetic
   ============================================================ */

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

:root {
  --bg:           #0a0a0f;
  --bg-2:         #0f0f17;
  --surface:      rgba(255,255,255,0.03);
  --surface-2:    rgba(255,255,255,0.06);
  --surface-3:    rgba(255,255,255,0.09);
  --border:       rgba(255,255,255,0.08);
  --border-2:     rgba(255,255,255,0.14);
  --text:         #e4e4e7;
  --text-2:       #a1a1aa;
  --text-muted:   #71717a;
  --code-bg:      #161620;
  --accent-1:     #6366f1;
  --accent-2:     #8b5cf6;
  --accent-3:     #a78bfa;
  --glow:         rgba(99,102,241,0.12);
  --glow-strong:  rgba(99,102,241,0.32);
  --shadow:       0 1px 3px rgba(0,0,0,0.4), 0 4px 16px rgba(0,0,0,0.3);
  --shadow-lg:    0 4px 24px rgba(0,0,0,0.5), 0 16px 64px rgba(0,0,0,0.4);
  --radius:       12px;
  --radius-sm:    8px;
  --radius-pill:  999px;
  --font-mono:    'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --transition:   0.18s cubic-bezier(0.4, 0, 0.2, 1);
  --header-h:     60px;
}

[data-theme="light"] {
  --bg:           #fafafa;
  --bg-2:         #f4f4f5;
  --surface:      rgba(0,0,0,0.02);
  --surface-2:    rgba(0,0,0,0.045);
  --surface-3:    rgba(0,0,0,0.07);
  --border:       rgba(0,0,0,0.06);
  --border-2:     rgba(0,0,0,0.12);
  --text:         #18181b;
  --text-2:       #3f3f46;
  --text-muted:   #71717a;
  --code-bg:      #f4f4f5;
  --glow:         rgba(99,102,241,0.07);
  --glow-strong:  rgba(99,102,241,0.15);
  --shadow:       0 1px 3px rgba(0,0,0,0.08), 0 4px 16px rgba(0,0,0,0.06);
  --shadow-lg:    0 4px 24px rgba(0,0,0,0.1), 0 16px 64px rgba(0,0,0,0.07);
}

/* ----- Base ----- */
html { scroll-behavior: smooth; }

body {
  font-family: system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  transition: background var(--transition), color var(--transition);
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; outline: none; }
input  { font-family: inherit; outline: none; border: none; }
h1,h2,h3,h4 { font-weight: 600; line-height: 1.2; letter-spacing: -0.02em; }
code, pre { font-family: var(--font-mono); }
:focus-visible { outline: 2px solid var(--accent-1); outline-offset: 2px; }

/* ----- View Transitions ----- */
.view { animation: fadeUp 0.22s ease forwards; }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ══════════════════ HEADER ══════════════════ */
#header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 100;
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 12px;
  background: rgba(10,10,15,0.8);
  backdrop-filter: blur(20px) saturate(1.5);
  -webkit-backdrop-filter: blur(20px) saturate(1.5);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}
[data-theme="light"] #header { background: rgba(250,250,250,0.85); }

#logo {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.03em;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text);
  flex-shrink: 0;
  transition: opacity var(--transition);
}
#logo:hover { opacity: 0.75; }
#logo .slash { color: var(--accent-1); font-weight: 400; }

.h-spacer { flex: 1; }

#search-trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-size: 13px;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}
#search-trigger:hover {
  background: var(--surface-2);
  border-color: var(--border-2);
  color: var(--text-2);
}
.search-kbd {
  display: inline-flex;
  align-items: center;
  gap: 1px;
  padding: 1px 5px;
  background: var(--surface-3);
  border: 1px solid var(--border-2);
  border-radius: 4px;
  font-size: 11px;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

#theme-toggle {
  width: 34px; height: 34px;
  display: flex; align-items: center; justify-content: center;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  flex-shrink: 0;
  transition: all var(--transition);
}
#theme-toggle:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-2); }

#gh-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  flex-shrink: 0;
  transition: all var(--transition);
}
#gh-link:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-2); }

/* ══════════════════ APP SHELL ══════════════════ */
#app { padding-top: var(--header-h); min-height: 100vh; }

/* ══════════════════ HERO ══════════════════ */
#hero {
  position: relative;
  overflow: hidden;
  padding: 96px 24px 72px;
  text-align: center;
}

/* Animated blobs */
.hero-blob {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}
.hero-blob-1 {
  width: 700px; height: 700px;
  top: -250px; left: 50%; transform: translateX(-50%);
  background: radial-gradient(circle, rgba(99,102,241,0.20) 0%, transparent 65%);
  animation: blob1 9s ease-in-out infinite;
}
.hero-blob-2 {
  width: 450px; height: 450px;
  bottom: -120px; right: 5%;
  background: radial-gradient(circle, rgba(139,92,246,0.14) 0%, transparent 65%);
  animation: blob2 11s ease-in-out infinite;
}
.hero-blob-3 {
  width: 300px; height: 300px;
  top: 20%; left: 5%;
  background: radial-gradient(circle, rgba(167,139,250,0.10) 0%, transparent 65%);
  animation: blob2 7s ease-in-out infinite reverse;
}
@keyframes blob1 {
  0%,100% { transform: translateX(-50%) scale(1); }
  50%      { transform: translateX(-50%) scale(1.12); }
}
@keyframes blob2 {
  0%,100% { transform: scale(1) rotate(0deg); }
  50%      { transform: scale(1.1) rotate(5deg); }
}

/* Grid overlay */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 90% 90% at 50% 50%, black 20%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 90% 90% at 50% 50%, black 20%, transparent 100%);
  opacity: 0.28;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 780px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 14px;
  background: rgba(99,102,241,0.10);
  border: 1px solid rgba(99,102,241,0.22);
  border-radius: var(--radius-pill);
  font-size: 11.5px;
  font-family: var(--font-mono);
  color: var(--accent-3);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  margin-bottom: 30px;
}
.badge-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-1);
  animation: pulse 2s ease-in-out infinite;
}
@keyframes pulse {
  0%,100% { opacity: 1; box-shadow: 0 0 0 0 rgba(99,102,241,0.5); }
  50%      { opacity: 0.5; box-shadow: 0 0 0 4px rgba(99,102,241,0); }
}

.hero-title {
  font-size: clamp(38px, 6.5vw, 68px);
  font-weight: 700;
  letter-spacing: -0.045em;
  line-height: 1.04;
  margin-bottom: 22px;
}
[data-theme="dark"] .hero-title {
  background: linear-gradient(160deg, #ffffff 30%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
[data-theme="light"] .hero-title {
  background: linear-gradient(160deg, #18181b 30%, #52525b 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: clamp(15px, 2.2vw, 18px);
  color: var(--text-muted);
  max-width: 540px;
  margin: 0 auto 44px;
  line-height: 1.7;
}

.hero-stats {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin-bottom: 44px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.stat-block {
  padding: 16px 32px;
  text-align: center;
}
.stat-block + .stat-block {
  border-left: 1px solid var(--border);
}
.stat-num {
  display: block;
  font-size: 28px;
  font-weight: 700;
  font-family: var(--font-mono);
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.05em;
  line-height: 1;
  margin-bottom: 4px;
}
.stat-label {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.07em;
  text-transform: uppercase;
  font-family: var(--font-mono);
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
  border-radius: var(--radius-sm);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: -0.01em;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
  box-shadow: 0 4px 20px rgba(99,102,241,0.38);
}
.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 36px rgba(99,102,241,0.52);
}
.hero-cta:active { transform: translateY(0); }
.hero-cta svg { transition: transform var(--transition); }
.hero-cta:hover svg { transform: translateX(3px); }

/* ══════════════════ CATEGORIES ══════════════════ */
#categories-section {
  max-width: 1300px;
  margin: 0 auto;
  padding: 48px 24px 80px;
  text-align: center;
}

.section-eyebrow {
  font-size: 10.5px;
  font-family: var(--font-mono);
  color: var(--accent-1);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 8px;
}
.section-heading {
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.025em;
  margin-bottom: 24px;
}
.cat-grid {
  text-align: left;
}

.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 12px;
}
@media (min-width: 640px)  { .cat-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px)  { .cat-grid { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 1200px) { .cat-grid { grid-template-columns: repeat(4, 1fr); } }

.cat-card {
  position: relative;
  padding: 18px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.cat-card::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  opacity: 0;
  transition: opacity var(--transition);
  background: linear-gradient(135deg, var(--c-alpha) 0%, transparent 55%);
}
.cat-card:hover {
  background: var(--surface-2);
  border-color: var(--border-2);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.cat-card:hover::after { opacity: 1; }

.cat-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  position: relative;
  z-index: 1;
}
.cat-icon-wrap {
  width: 38px; height: 38px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 10px;
}
.cat-arrow {
  color: var(--text-muted);
  transition: transform var(--transition), color var(--transition);
  flex-shrink: 0;
}
.cat-card:hover .cat-arrow { transform: translate(2px, -2px); color: var(--text-2); }

.cat-body { position: relative; z-index: 1; }
.cat-name {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: 3px;
}
.cat-count {
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.cat-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  position: relative;
  z-index: 1;
}
.cat-pill-tag {
  padding: 2px 7px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

/* ══════════════════ COURSE LIST ══════════════════ */
#list-view {
  max-width: 880px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 13px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text-muted);
  cursor: pointer;
  margin-bottom: 32px;
  transition: all var(--transition);
}
.back-btn:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-2); }

.list-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 32px;
}
.list-icon {
  width: 46px; height: 46px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 12px;
  flex-shrink: 0;
}
.list-name { font-size: 22px; font-weight: 600; letter-spacing: -0.025em; }
.list-meta { font-size: 12.5px; color: var(--text-muted); font-family: var(--font-mono); margin-top: 4px; }

.course-pills-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}
.c-pill {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 10px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-2);
  cursor: pointer;
  transition: all var(--transition);
}
.c-pill:hover {
  background: var(--surface-2);
  border-color: var(--border-2);
  color: var(--text);
  transform: translateY(-1px);
}
.c-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  opacity: 0.55;
  flex-shrink: 0;
}
.c-chevron {
  color: var(--text-muted);
  opacity: 0;
  margin-left: auto;
  transition: opacity var(--transition), transform var(--transition);
}
.c-pill:hover .c-chevron { opacity: 1; transform: translateX(2px); }

/* ══════════════════ READER ══════════════════ */
#reader-view {
  max-width: 840px;
  margin: 0 auto;
  padding: 32px 24px 100px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 32px;
  flex-wrap: wrap;
}
.bc-btn {
  background: none;
  color: var(--text-muted);
  font-size: 13px;
  cursor: pointer;
  transition: color var(--transition);
}
.bc-btn:hover { color: var(--accent-1); }
.bc-sep { color: var(--border-2); }
.bc-current { color: var(--text-2); font-weight: 500; }

.loader {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 64px 24px;
  color: var(--text-muted);
  font-size: 13.5px;
  font-family: var(--font-mono);
}
.spin {
  width: 18px; height: 18px;
  border: 2px solid var(--border-2);
  border-top-color: var(--accent-1);
  border-radius: 50%;
  animation: spin 0.65s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ----- Markdown Content ----- */
#md-out {
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--text);
}
#md-out h1 {
  font-size: clamp(22px, 4vw, 32px);
  font-weight: 700;
  letter-spacing: -0.04em;
  margin: 0 0 28px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
[data-theme="dark"] #md-out h1 {
  background: linear-gradient(135deg, #fff 0%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
#md-out h2 {
  font-size: 1.3rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 44px 0 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}
#md-out h2::before {
  content: '';
  display: inline-block;
  width: 3px; height: 1em;
  background: linear-gradient(180deg, var(--accent-1), var(--accent-2));
  border-radius: 2px;
  flex-shrink: 0;
}
#md-out h3 {
  font-size: 1.08rem;
  font-weight: 600;
  margin: 30px 0 10px;
  color: var(--text-2);
}
#md-out h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin: 22px 0 8px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
  font-family: var(--font-mono);
}
#md-out p { margin: 0 0 16px; }
#md-out a {
  color: var(--accent-3);
  text-decoration: underline;
  text-decoration-color: rgba(167,139,250,0.3);
  text-underline-offset: 3px;
}
#md-out a:hover { text-decoration-color: var(--accent-3); }
#md-out ul, #md-out ol { padding-left: 1.5em; margin: 0 0 16px; }
#md-out li { margin-bottom: 6px; }
#md-out li::marker { color: var(--accent-1); }
#md-out blockquote {
  margin: 22px 0;
  padding: 13px 18px;
  border-left: 3px solid var(--accent-1);
  background: var(--glow);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-2);
}
#md-out blockquote p { margin: 0; }
#md-out code {
  font-family: var(--font-mono);
  font-size: 0.83em;
  padding: 2px 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--accent-3);
}
#md-out pre {
  margin: 20px 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
#md-out pre::before {
  content: attr(data-lang);
  display: block;
  padding: 7px 16px;
  background: rgba(255,255,255,0.025);
  border-bottom: 1px solid var(--border);
  font-size: 10.5px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  letter-spacing: 0.07em;
  text-transform: uppercase;
}
[data-theme="light"] #md-out pre::before { background: rgba(0,0,0,0.025); }
#md-out pre code {
  display: block;
  padding: 16px 20px;
  font-size: 13.5px;
  line-height: 1.65;
  background: var(--code-bg) !important;
  border: none;
  border-radius: 0;
  color: inherit;
  overflow-x: auto;
}
#md-out table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
#md-out th {
  padding: 9px 14px;
  background: var(--surface-2);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-weight: 600;
}
#md-out td { padding: 9px 14px; border-bottom: 1px solid var(--border); vertical-align: top; }
#md-out tr:last-child td { border-bottom: none; }
#md-out tr:hover td { background: var(--surface); }
#md-out hr { border: none; border-top: 1px solid var(--border); margin: 36px 0; }
#md-out strong { color: var(--text); font-weight: 600; }

/* ══════════════════ COMMAND PALETTE ══════════════════ */
#pal-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0,0,0,0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 80px 16px 16px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.14s ease;
}
#pal-overlay.open { opacity: 1; pointer-events: all; }

#pal-box {
  width: 100%;
  max-width: 600px;
  background: var(--bg-2);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: scale(0.96) translateY(-10px);
  transition: transform 0.15s ease;
}
#pal-overlay.open #pal-box { transform: scale(1) translateY(0); }

#pal-input-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 13px 16px;
  border-bottom: 1px solid var(--border);
}
#pal-input-row svg { color: var(--text-muted); flex-shrink: 0; }
#pal-input {
  flex: 1;
  background: transparent;
  font-size: 15px;
  color: var(--text);
  caret-color: var(--accent-1);
}
#pal-input::placeholder { color: var(--text-muted); }
#pal-esc {
  padding: 2px 6px;
  background: var(--surface-2);
  border: 1px solid var(--border-2);
  border-radius: 4px;
  font-size: 10.5px;
  font-family: var(--font-mono);
  color: var(--text-muted);
}

#pal-list { max-height: 400px; overflow-y: auto; }

.pal-section {
  padding: 10px 16px 4px;
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.pal-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 16px;
  cursor: pointer;
  transition: background var(--transition);
}
.pal-item:hover, .pal-item.hi { background: var(--surface-2); }
.pal-item-ic {
  width: 28px; height: 28px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 6px;
  background: var(--surface-2);
  flex-shrink: 0;
}
.pal-item-text { flex: 1; min-width: 0; }
.pal-item-name {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.pal-item-sub {
  font-size: 11.5px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 1px;
}
.pal-badge {
  padding: 2px 7px;
  border-radius: var(--radius-pill);
  font-size: 10px;
  font-family: var(--font-mono);
  flex-shrink: 0;
}
.pal-empty {
  padding: 40px 16px;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
}

#pal-foot {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 8px 16px;
  border-top: 1px solid var(--border);
  font-size: 11px;
  color: var(--text-muted);
}
#pal-foot span { display: flex; align-items: center; gap: 4px; }
#pal-foot kbd {
  padding: 1px 4px;
  background: var(--surface-2);
  border: 1px solid var(--border-2);
  border-radius: 3px;
  font-size: 10px;
}
#pal-indexing { margin-left: auto; font-size: 11px; color: var(--accent-1); font-family: var(--font-mono); }

/* ══════════════════ FOOTER ══════════════════ */
#site-footer {
  border-top: 1px solid var(--border);
  padding: 44px 24px;
  text-align: center;
}
.footer-inner { max-width: 540px; margin: 0 auto; }
.footer-author {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.footer-author a {
  color: var(--accent-1);
  font-weight: 600;
  text-decoration: none;
}
.footer-author a:hover { text-decoration: underline; }
.footer-quote {
  font-size: 14px;
  color: var(--text-muted);
  font-style: italic;
  line-height: 1.65;
  margin-bottom: 22px;
}
.footer-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}
.f-link {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12.5px;
  color: var(--text-muted);
  transition: color var(--transition);
}
.f-link:hover { color: var(--text); }
.f-star {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 10px;
  background: rgba(245,158,11,0.09);
  border: 1px solid rgba(245,158,11,0.2);
  border-radius: var(--radius-pill);
  font-size: 11.5px;
  color: #f59e0b;
  font-family: var(--font-mono);
}
.f-dot { width: 3px; height: 3px; border-radius: 50%; background: var(--border-2); }

/* ══════════════════ PROGRESS & BOOKMARKS ══════════════════ */

/* Category progress bar */
.cat-progress {
  position: relative;
  z-index: 1;
  margin-top: 2px;
}
.cat-progress-bar {
  width: 100%;
  height: 3px;
  background: var(--surface-3);
  border-radius: 2px;
  overflow: hidden;
}
.cat-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-1), var(--accent-2));
  border-radius: 2px;
  transition: width 0.4s ease;
}
.cat-progress-text {
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  margin-top: 4px;
}

/* Course pill read state */
.c-pill.is-read {
  border-color: rgba(99,102,241,0.25);
}
.c-pill .c-read-check {
  display: none;
  color: var(--accent-1);
  flex-shrink: 0;
}
.c-pill.is-read .c-read-check { display: flex; }
.c-pill.is-read .c-dot { opacity: 0.2; }

/* Course pill bookmark star */
.c-pill .c-star {
  display: none;
  color: #f59e0b;
  flex-shrink: 0;
  margin-left: -4px;
}
.c-pill.is-bookmarked .c-star { display: flex; }

/* Reader action buttons */
.reader-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}
.reader-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}
.reader-action-btn:hover {
  background: var(--surface-2);
  border-color: var(--border-2);
  color: var(--text-2);
}
.reader-action-btn.active {
  color: var(--accent-1);
  border-color: rgba(99,102,241,0.3);
  background: rgba(99,102,241,0.08);
}
#btn-bookmark.active {
  color: #f59e0b;
  border-color: rgba(245,158,11,0.3);
  background: rgba(245,158,11,0.08);
}
#btn-bookmark.active svg { fill: #f59e0b; }

/* Continue reading section */
#continue-section, #bookmarks-section {
  max-width: 1300px;
  margin: 0 auto;
  padding: 32px 24px 0;
}
.continue-grid, .bookmarks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 10px;
  margin-top: 12px;
}
.continue-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
}
.continue-card:hover {
  background: var(--surface-2);
  border-color: var(--border-2);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}
.continue-card-icon {
  width: 34px; height: 34px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 8px;
  flex-shrink: 0;
}
.continue-card-text {
  flex: 1;
  min-width: 0;
}
.continue-card-title {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.continue-card-cat {
  font-size: 11px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-top: 2px;
}

/* Completion stat */
#completion-num {
  background: linear-gradient(135deg, #22c55e, #16a34a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Mermaid diagram containers */
.mermaid-wrap {
  margin: 20px 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow-x: auto;
  display: flex;
  justify-content: center;
  align-items: center;
}
.mermaid-wrap svg {
  width: 100%;
  min-width: 300px;
  max-width: 100%;
  height: auto;
}

/* ══════════════════ TERMINAL DEMO ══════════════════ */
.terminal-demo {
  margin: 24px 0;
  border-radius: 12px;
  overflow: hidden;
  background: #1a1b2e;
  box-shadow: 0 8px 32px rgba(0,0,0,0.35), inset 0 1px 0 rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.06);
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'JetBrains Mono', monospace;
}
.terminal-demo .terminal-titlebar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(255,255,255,0.04);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.terminal-demo .terminal-dot {
  width: 12px; height: 12px; border-radius: 50%;
}
.terminal-demo .terminal-dot.red    { background: #ff5f57; }
.terminal-demo .terminal-dot.yellow { background: #febc2e; }
.terminal-demo .terminal-dot.green  { background: #28c840; }
.terminal-demo .terminal-title {
  flex: 1;
  text-align: center;
  color: rgba(255,255,255,0.4);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}
.terminal-demo .terminal-body {
  padding: 20px 24px;
  line-height: 1.7;
  font-size: 0.9rem;
  overflow-x: auto;
  max-height: 500px;
  overflow-y: auto;
  scroll-behavior: smooth;
}
.terminal-demo .term-line {
  white-space: pre;
  opacity: 0;
}
.terminal-demo.term-animate .term-line {
  animation: termFadeIn 0.3s ease forwards;
}
.terminal-demo .term-prompt {
  color: #28c840;
  font-weight: 600;
}
.terminal-demo .term-cmd {
  color: #e2e4f0;
  font-weight: 500;
}
.terminal-demo .term-output {
  color: rgba(255,255,255,0.55);
}
.terminal-demo .term-highlight {
  color: #7c6ff7;
  font-weight: 600;
}
.terminal-demo .term-success {
  color: #28c840;
}
.terminal-demo .term-warn {
  color: #febc2e;
}
.terminal-demo .term-info {
  color: #64d2ff;
}
.terminal-demo .term-cursor {
  display: inline-block;
  width: 8px; height: 8px;
  background: #28c840;
  border-radius: 50%;
  margin-left: 6px;
  opacity: 0;
}
.terminal-demo.term-animate .term-cursor {
  animation: termBlink 1.2s ease-in-out infinite;
}
@keyframes termFadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes termBlink {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.2; }
}



/* ══════════════════ CLI PLAYGROUND ══════════════════ */
#cli-playground-section {
  margin-top: 40px;
}
#cli-playground-section h2 {
  font-size: 1.3rem;
  color: var(--text-1);
}
.cli-split {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 16px;
  align-items: start;
}
@media (max-width: 900px) {
  .cli-split {
    grid-template-columns: 1fr;
  }
}
.cli-split-terminal {
  min-width: 0;
}
#cli-terminal {
  height: 480px;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.06);
  background: #1a1b2e;
  box-shadow: 0 8px 32px rgba(0,0,0,0.35), inset 0 1px 0 rgba(255,255,255,0.05);
}
#cli-terminal .xterm {
  padding: 12px;
}
/* Reference panel */
.cli-split-reference {
  border-radius: 12px;
  background: var(--surface-1);
  border: 1px solid var(--border);
  overflow: hidden;
  max-height: 480px;
  display: flex;
  flex-direction: column;
}
.cli-ref-header {
  padding: 12px 16px;
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-1);
  border-bottom: 1px solid var(--border);
  background: var(--surface-2, rgba(255,255,255,0.02));
  letter-spacing: 0.02em;
}
.cli-ref-body {
  overflow-y: auto;
  padding: 8px 0;
  flex: 1;
}
.cli-ref-group {
  padding: 0 12px;
  margin-bottom: 8px;
}
.cli-ref-group-title {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-3, #888);
  padding: 8px 4px 4px;
}
.cli-ref-cmd {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.78rem;
  color: var(--text-2);
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.cli-ref-cmd:hover {
  background: var(--accent-1);
  color: #fff;
}
.cli-ref-cmd .cli-ref-desc {
  font-family: var(--font-sans, sans-serif);
  font-size: 0.7rem;
  color: var(--text-3, #888);
  margin-left: 6px;
}
.cli-ref-cmd:hover .cli-ref-desc {
  color: rgba(255,255,255,0.7);
}

/* ══════════════════ GISCUS COMMENTS ══════════════════ */
#giscus-container {
  margin-top: 40px;
  padding: 0 4px;
}
#giscus-container h2 {
  font-size: 1.3rem;
  color: var(--text-1);
}
.giscus-frame {
  width: 100% !important;
  border: none;
}

/* ══════════════════ UTILITIES ══════════════════ */
.hidden { display: none !important; }
mark {
  background: rgba(99,102,241,0.22);
  color: var(--accent-3);
  border-radius: 2px;
  padding: 0 2px;
}

/* ══════════════════ RESPONSIVE ══════════════════ */
@media (max-width: 600px) {
  #header { padding: 0 14px; gap: 8px; }
  #gh-link .gh-label { display: none; }
  .search-text { display: none; }
  .search-kbd { display: none; }
  .hero-stats { flex-direction: column; gap: 0; border: none; background: none; }
  .stat-block { border: 1px solid var(--border); border-radius: var(--radius-sm); width: 100%; }
  .stat-block + .stat-block { border-left: 1px solid var(--border); margin-top: 8px; }
}

/* ══════════════════ NAV TABS ══════════════════ */
.nav-tab {
  background: var(--surface-2);
  border: 1.5px solid var(--border);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.15s;
}
.nav-tab:hover { border-color: var(--accent-1); color: var(--accent-1); }
.nav-tab.active { background: var(--accent-1); color: #fff; border-color: var(--accent-1); }

/* ══════════════════ LABS LISTING ══════════════════ */
#labs-view {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}
#lab-detail-view {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 24px 80px;
}

.labs-filter {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.lab-filter-btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 5px 14px;
  border-radius: 20px;
  cursor: pointer;
  transition: all 0.15s;
}
.lab-filter-btn:hover { border-color: var(--accent-1); color: var(--text); }
.lab-filter-btn.active { background: var(--accent-1); color: #fff; border-color: var(--accent-1); }

.labs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 20px;
  padding-bottom: 40px;
}

.lab-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
}
.lab-card:hover {
  border-color: var(--accent-1);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.12);
}

.lab-card-tier {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 3px 10px;
  border-radius: 12px;
  margin-bottom: 12px;
}
.lab-card-tier[data-tier="Foundation"] { background: rgba(34,197,94,0.12); color: #22c55e; }
.lab-card-tier[data-tier="Intermediate"] { background: rgba(59,130,246,0.12); color: #3b82f6; }
.lab-card-tier[data-tier="Senior"] { background: rgba(168,85,247,0.12); color: #a855f7; }

.lab-card-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}
.lab-card-app {
  font-size: 0.82rem;
  color: var(--text-2);
  margin-bottom: 10px;
}
.lab-card-desc {
  font-size: 0.84rem;
  color: var(--text-2);
  line-height: 1.5;
  margin-bottom: 16px;
}
.lab-card-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}
.lab-tool-pill {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 10px;
  color: var(--text-2);
}
.lab-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.lab-card-duration {
  font-size: 0.78rem;
  color: var(--text-2);
  font-family: var(--font-mono);
}
.lab-card-progress {
  flex: 1;
  max-width: 180px;
}
.lab-card-progress-bar {
  height: 4px;
  background: var(--surface-2);
  border-radius: 2px;
  overflow: hidden;
}
.lab-card-progress-fill {
  height: 100%;
  background: var(--accent-1);
  border-radius: 2px;
  transition: width 0.3s;
}
.lab-card-progress-text {
  font-size: 0.72rem;
  color: var(--text-2);
  margin-top: 4px;
  text-align: right;
  font-family: var(--font-mono);
}

.labs-continue-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 12px;
  margin-bottom: 28px;
}

/* ══════════════════ LAB DETAIL ══════════════════ */
.lab-header {
  margin-bottom: 24px;
}
.lab-header-top {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}
.lab-header-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
}
.lab-header-app {
  font-size: 0.85rem;
  color: var(--text-2);
  font-family: var(--font-mono);
}
.lab-header-desc {
  font-size: 0.9rem;
  color: var(--text-2);
  line-height: 1.6;
  margin-top: 8px;
  max-width: 700px;
}

.lab-stages-bar {
  display: flex;
  align-items: center;
  gap: 0;
  margin-bottom: 28px;
  overflow-x: auto;
  padding-bottom: 4px;
}
.lab-stage-dot {
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  min-width: 80px;
  position: relative;
}
.lab-stage-circle {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 2px solid var(--border);
  background: var(--surface);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-mono);
  color: var(--text-2);
  transition: all 0.2s;
  position: relative;
  z-index: 1;
}
.lab-stage-dot.done .lab-stage-circle {
  background: var(--accent-1);
  border-color: var(--accent-1);
  color: #fff;
}
.lab-stage-dot.current .lab-stage-circle {
  border-color: var(--accent-1);
  color: var(--accent-1);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.2);
}
.lab-stage-dot.pending .lab-stage-circle {
  opacity: 0.5;
}
.lab-stage-label {
  font-size: 0.68rem;
  color: var(--text-2);
  margin-top: 6px;
  text-align: center;
  max-width: 90px;
  line-height: 1.3;
}
.lab-stage-connector {
  flex: 1;
  height: 2px;
  background: var(--border);
  min-width: 20px;
  margin-top: -14px;
}
.lab-stage-connector.done {
  background: var(--accent-1);
}

.lab-content-area {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 24px;
  margin-bottom: 24px;
}
.lab-main {
  min-width: 0;
}
#lab-md-out {
  font-size: 0.92rem;
  line-height: 1.7;
}
#lab-md-out h1 { font-size: 1.4rem; }
#lab-md-out h2 { font-size: 1.15rem; margin-top: 28px; }
#lab-md-out h3 { font-size: 1rem; margin-top: 20px; }
#lab-md-out pre { font-size: 0.82rem; }

.lab-sidebar {
  position: sticky;
  top: 80px;
  align-self: start;
}
.lab-sidebar-section {
  margin-bottom: 20px;
}
.lab-sidebar-title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-2);
  margin-bottom: 10px;
}
.lab-sidebar-link {
  display: block;
  font-size: 0.82rem;
  color: var(--accent-1);
  text-decoration: none;
  padding: 4px 0;
  cursor: pointer;
  transition: opacity 0.15s;
}
.lab-sidebar-link:hover { opacity: 0.8; }
.lab-file-link { display: flex; align-items: center; gap: 6px; }
.lab-file-link svg { flex-shrink: 0; opacity: 0.6; }

.lab-exercise-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 0;
  font-size: 0.82rem;
  color: var(--text-2);
}
.lab-exercise-item input[type="checkbox"] {
  accent-color: var(--accent-1);
  width: 15px;
  height: 15px;
  cursor: pointer;
}

.lab-nav-btns {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 20px 0 40px;
  border-top: 1px solid var(--border);
}
.lab-nav-btn {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  display: flex;
  align-items: center;
  gap: 8px;
}
.lab-nav-btn:hover { border-color: var(--accent-1); }
.lab-nav-btn:disabled { opacity: 0.3; cursor: default; }

@media (max-width: 768px) {
  .labs-grid { grid-template-columns: 1fr; }
  .lab-content-area { grid-template-columns: 1fr; }
  .lab-sidebar { position: static; }
  .lab-stages-bar { gap: 0; }
  .lab-stage-dot { min-width: 60px; }
  .lab-stage-label { font-size: 0.6rem; max-width: 60px; }
}

/* ══════════════════ REDUCED MOTION ══════════════════ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}