/* ==========================================================================
   AWS Summit Sydney — Knowledge Base
   Visual System v2 · Refined typography, layered depth, deliberate motion
   ========================================================================== */

/* ---------- Design tokens ---------- */
:root {
  /* Brand */
  --aws-navy-900: #0a1426;
  --aws-navy-800: #0f1b2d;
  --aws-navy-700: #162447;
  --aws-navy-600: #1f2c4f;
  --aws-orange: #FF9900;
  --aws-orange-deep: #ec7211;
  --aws-amber: #ffb84d;
  --aws-cyan: #00a8e8;

  /* Surfaces */
  --surface-bg: #f7f8fb;
  --surface-card: #ffffff;
  --surface-soft: #f1f4f9;
  --surface-tinted: #fffaf0;

  /* Text */
  --text-strong: #0a1426;
  --text-body: #2c3e5a;
  --text-muted: #64748b;
  --text-faint: #94a3b8;

  /* Borders */
  --border: #e4e8ef;
  --border-strong: #d1d8e3;

  /* Shadows — layered for depth */
  --shadow-xs: 0 1px 2px rgba(15, 27, 45, 0.04);
  --shadow-sm: 0 2px 6px -2px rgba(15, 27, 45, 0.08);
  --shadow-md: 0 8px 20px -8px rgba(15, 27, 45, 0.15);
  --shadow-lg: 0 18px 40px -16px rgba(15, 27, 45, 0.22);
  --shadow-orange: 0 12px 28px -12px rgba(255, 153, 0, 0.45);

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --radius-2xl: 28px;

  /* Easings */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

/* ---------- Base typography ---------- */
* {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11', 'ss01';
}
code, pre, .mono, .font-mono { font-family: 'JetBrains Mono', ui-monospace, monospace; font-feature-settings: 'liga' 0; }

html { scroll-behavior: smooth; }
body {
  background: var(--surface-bg);
  color: var(--text-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 { letter-spacing: -0.02em; color: var(--text-strong); }
h1 { letter-spacing: -0.035em; }
.tracking-tight { letter-spacing: -0.025em; }

/* Headings inside dark surfaces (hero, footers, gradient panels) must stay light.
   These selectors win over the global h1..h4 color rule above so utility classes
   like text-white on a parent are respected for all descendant headings. */
.aws-hero h1, .aws-hero h2, .aws-hero h3, .aws-hero h4,
.aws-gradient h1, .aws-gradient h2, .aws-gradient h3, .aws-gradient h4,
[class*="text-white"] h1, [class*="text-white"] h2, [class*="text-white"] h3, [class*="text-white"] h4 {
  color: inherit;
}

/* Selection */
::selection { background: var(--aws-orange); color: var(--aws-navy-900); }

/* ---------- Layered hero ---------- */
.aws-gradient {
  background: linear-gradient(135deg, #232f3e 0%, #131a22 100%);
}
.aws-orange-gradient {
  background: linear-gradient(135deg, var(--aws-orange) 0%, var(--aws-orange-deep) 100%);
}
.aws-hero {
  position: relative;
  background:
    radial-gradient(ellipse 1100px 500px at 85% -10%, rgba(255, 153, 0, 0.22) 0%, transparent 55%),
    radial-gradient(ellipse 900px 500px at 0% 110%, rgba(0, 168, 232, 0.18) 0%, transparent 55%),
    radial-gradient(ellipse 600px 300px at 50% 50%, rgba(255, 184, 77, 0.07) 0%, transparent 70%),
    linear-gradient(135deg, var(--aws-navy-800) 0%, var(--aws-navy-700) 50%, var(--aws-navy-600) 100%);
  overflow: hidden;
}
.aws-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
  pointer-events: none;
}
.aws-hero > * { position: relative; z-index: 1; }

/* Hero text gradient accent */
.text-gradient-orange {
  background: linear-gradient(120deg, var(--aws-orange) 0%, var(--aws-amber) 60%, var(--aws-orange) 100%);
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  background-size: 200% 100%;
  animation: textShimmer 8s ease-in-out infinite;
}
@keyframes textShimmer {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* ---------- Cards ---------- */
.topic-card {
  position: relative;
  transition: transform 0.35s var(--ease-out),
              box-shadow 0.35s var(--ease-out),
              border-color 0.25s ease;
  background: var(--surface-card);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
}
.topic-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--aws-orange), var(--aws-orange-deep));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s var(--ease-out);
}
.topic-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--aws-orange);
}
.topic-card:hover::before { transform: scaleX(1); }

.session-card {
  transition: transform 0.25s var(--ease-out),
              box-shadow 0.25s var(--ease-out),
              border-color 0.2s ease,
              background-color 0.2s ease;
}
.session-card:hover {
  background: var(--surface-card);
  box-shadow: var(--shadow-md);
  border-color: var(--aws-orange);
  transform: translateY(-2px);
}

/* ---------- Badges & chips ---------- */
.badge-foundational { background: #dcfce7; color: #166534; }
.badge-intermediate { background: #dbeafe; color: #1e40af; }
.badge-advanced     { background: #fef3c7; color: #92400e; }
.badge-expert       { background: #fee2e2; color: #991b1b; }
.badge-default      { background: #e2e8f0; color: #334155; }

.type-keynote   { background: linear-gradient(135deg, var(--aws-orange), var(--aws-orange-deep)); color: #fff; box-shadow: 0 2px 6px -2px rgba(255,153,0,0.4); }
.type-breakout  { background: #eef2ff; color: #4338ca; }
.type-lightning { background: #fef3c7; color: #92400e; }
.type-workshop  { background: #f3e8ff; color: #6b21a8; }
.type-chalktalk { background: #fce7f3; color: #9f1239; }
.type-default   { background: #e2e8f0; color: #334155; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.22rem 0.65rem;
  border-radius: 9999px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  line-height: 1.4;
}

/* ---------- Prose body ---------- */
.prose-body p {
  margin-bottom: 1.1rem;
  line-height: 1.78;
  color: var(--text-body);
  font-size: 1.0625rem;
}
.prose-body strong { color: var(--text-strong); font-weight: 600; }
.prose-body em { color: var(--aws-orange-deep); font-style: italic; }

/* ---------- Playbook panels ---------- */
.playbook-section {
  background: linear-gradient(180deg, #fffaf0 0%, #ffffff 100%);
  border: 1px solid #fde7c7;
  border-radius: var(--radius-xl);
  position: relative;
  overflow: hidden;
}
.playbook-section::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--aws-orange) 0%, var(--aws-amber) 50%, var(--aws-orange) 100%);
}

.playbook-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding-bottom: 1rem;
  border-bottom: 1px dashed #fde7c7;
}
.playbook-header-icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--aws-orange), var(--aws-orange-deep));
  color: white;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  box-shadow: var(--shadow-orange);
}

.playbook-block {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.35rem 1.4rem;
  position: relative;
  transition: transform 0.25s var(--ease-out), box-shadow 0.25s var(--ease-out), border-color 0.2s;
}
.playbook-block:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--aws-orange);
}

.playbook-block-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.6rem;
  color: var(--text-strong);
}
.playbook-block-label .pb-icon {
  width: 26px; height: 26px;
  border-radius: 8px;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 0.75rem;
}

.playbook-block-body {
  color: var(--text-body);
  line-height: 1.7;
  font-size: 0.95rem;
}

.pb-concept     { background: #e0f2fe; color: #075985; }
.pb-why         { background: #fef3c7; color: #92400e; }
.pb-hard        { background: #fee2e2; color: #991b1b; }
.pb-moves       { background: #dcfce7; color: #166534; }
.pb-surprise    { background: #f3e8ff; color: #6b21a8; }

/* Surprise insight callouts on topic page */
.surprise-card {
  background: linear-gradient(135deg, #faf5ff 0%, #f3e8ff 100%);
  border: 1px solid #e9d5ff;
  border-left: 3px solid #a855f7;
  border-radius: var(--radius-md);
  padding: 1rem 1.15rem;
  font-size: 0.9rem;
  line-height: 1.65;
  color: #4a044e;
  position: relative;
  transition: transform 0.2s var(--ease-out), box-shadow 0.2s;
}
.surprise-card:hover {
  transform: translateX(2px);
  box-shadow: var(--shadow-sm);
}
.surprise-card .surprise-source {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #a855f7;
  text-transform: uppercase;
}
.surprise-card .surprise-source a { color: inherit; }
.surprise-card .surprise-source a:hover { text-decoration: underline; }

/* ---------- Theme cards (cross-cutting themes) ---------- */
.theme-card {
  position: relative;
  background: var(--surface-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 1.75rem;
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
  overflow: hidden;
}
.theme-card::before {
  content: attr(data-num);
  position: absolute;
  top: -10px; right: 14px;
  font-size: 6rem;
  font-weight: 800;
  color: rgba(255, 153, 0, 0.07);
  line-height: 1;
  letter-spacing: -0.05em;
  pointer-events: none;
}
.theme-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.theme-card .theme-num {
  display: inline-flex;
  align-items: center; justify-content: center;
  width: 36px; height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--aws-orange), var(--aws-orange-deep));
  color: white;
  font-weight: 700;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-orange);
}

/* ---------- External link cards ---------- */
.ext-link {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.9rem 1.05rem;
  background: var(--surface-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-strong);
  text-decoration: none;
  transition: all 0.22s var(--ease-out);
  position: relative;
}
.ext-link::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(120deg, transparent, rgba(255,153,0,0.05), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}
.ext-link:hover {
  background: var(--surface-tinted);
  border-color: var(--aws-orange);
  transform: translateX(3px);
  box-shadow: var(--shadow-sm);
}
.ext-link:hover::after { opacity: 1; }
.ext-link i.fa-external-link-alt { color: var(--text-faint); }
.ext-link:hover i.fa-external-link-alt { color: var(--aws-orange); }

/* ---------- Topic icon ---------- */
.topic-icon {
  background: linear-gradient(135deg, var(--aws-orange) 0%, var(--aws-orange-deep) 100%);
  color: white;
  width: 48px; height: 48px;
  border-radius: 14px;
  display: inline-flex;
  align-items: center; justify-content: center;
  font-size: 20px;
  box-shadow: var(--shadow-orange);
  transition: transform 0.3s var(--ease-out);
}
.topic-card:hover .topic-icon { transform: rotate(-6deg) scale(1.05); }
.topic-icon-lg {
  width: 76px; height: 76px;
  font-size: 32px;
  border-radius: 20px;
}

/* ---------- TOC ---------- */
.toc-link {
  display: block;
  padding: 0.5rem 0.85rem;
  border-left: 2px solid transparent;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 500;
  border-radius: 0 6px 6px 0;
  transition: all 0.18s var(--ease-out);
}
.toc-link:hover, .toc-link.active {
  border-left-color: var(--aws-orange);
  color: var(--text-strong);
  background: var(--surface-tinted);
}

/* ---------- Animation utilities ---------- */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-in { animation: fadeIn 0.5s var(--ease-out); }

@keyframes pulseGlow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255,153,0,0.4); }
  50% { box-shadow: 0 0 0 10px rgba(255,153,0,0); }
}
.pulse-glow { animation: pulseGlow 2.5s infinite; }

/* Anchor scroll offset */
:target { scroll-margin-top: 90px; }
.scroll-mt-24 { scroll-margin-top: 90px; }

/* Section dividers */
.section-divider {
  background: linear-gradient(90deg, transparent, var(--border-strong), transparent);
  height: 1px;
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 12px; height: 12px; }
::-webkit-scrollbar-track { background: var(--surface-soft); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--border-strong), #b6c0cf);
  border-radius: 12px;
  border: 2px solid var(--surface-soft);
}
::-webkit-scrollbar-thumb:hover { background: var(--text-faint); }

/* Search highlight */
mark { background: #fef3c7; color: #92400e; padding: 0 3px; border-radius: 3px; font-weight: 600; }

/* ---------- Print ---------- */
@media print {
  .aws-hero { background: white !important; color: black !important; }
  header, footer, aside, nav { display: none !important; }
  .topic-card, .session-card, .playbook-block { box-shadow: none !important; border: 1px solid #ccc !important; break-inside: avoid; }
  body { background: white; }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}