/* ============================================================
   Claude Design System — Shared Theme
   For Xiong Zifeng's Digital Garden
   ============================================================
   Design inspiration: Anthropic Claude (claude.ai)
   Warm, editorial, unhurried, quietly intellectual.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Noto+Serif+CJK+SC:wght@400;500;600;700&display=swap');

/* ===== CSS Custom Properties (Design Tokens) ===== */
:root {
  /* --- Warm Palette (no cool grays) --- */
  --claude-parchment:    #f5f4ed;
  --claude-ivory:        #faf9f5;
  --claude-white:        #ffffff;
  --claude-warm-sand:    #e8e6dc;
  --claude-border-cream: #f0eee6;
  --claude-border-warm:  #e8e6dc;

  --claude-near-black:   #141413;
  --claude-dark-surface: #30302e;
  --claude-charcoal:     #4d4c48;
  --claude-olive-gray:   #5e5d59;
  --claude-stone-gray:   #87867f;
  --claude-warm-silver:  #b0aea5;
  --claude-dark-warm:    #3d3d3a;

  --claude-terracotta:   #c96442;
  --claude-coral:        #d97757;
  --claude-error:        #b53333;
  --claude-focus:        #3898ec;

  /* --- Semantic Aliases --- */
  --bg-page:             var(--claude-parchment);
  --bg-card:             var(--claude-ivory);
  --bg-elevated:         var(--claude-white);
  --text-primary:        var(--claude-near-black);
  --text-secondary:      var(--claude-olive-gray);
  --text-tertiary:       var(--claude-stone-gray);
  --text-on-dark:        var(--claude-warm-silver);
  --accent:              var(--claude-terracotta);
  --accent-hover:        #b8503a;
  --border-subtle:       var(--claude-border-cream);
  --border-prominent:    var(--claude-border-warm);

  /* --- Typography --- */
  --font-serif:          'Noto Serif CJK SC', Georgia, 'Songti SC', serif;
  --font-sans:           'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
  --font-mono:           'JetBrains Mono', 'SF Mono', ui-monospace, monospace;

  /* --- Spacing --- */
  --space-xs:  4px;
  --space-sm:  8px;
  --space-md:  16px;
  --space-lg:  24px;
  --space-xl:  32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 80px;

  /* --- Border Radius --- */
  --radius-sm:   4px;
  --radius-md:   8px;
  --radius-lg:   12px;
  --radius-xl:   16px;
  --radius-2xl:  24px;
  --radius-3xl:  32px;
  --radius-full: 100px;

  /* --- Shadows --- */
  --shadow-ring:     0px 0px 0px 1px var(--claude-border-cream);
  --shadow-ring-warm: 0px 0px 0px 1px var(--claude-border-warm);
  --shadow-whisper:  rgba(0,0,0,0.04) 0px 4px 24px;
  --shadow-elevated: rgba(0,0,0,0.06) 0px 8px 32px;
  --shadow-card:     0px 0px 0px 1px rgba(0,0,0,0.04), rgba(0,0,0,0.03) 0px 4px 16px;

  /* --- Container --- */
  --container-max: 1100px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  background: var(--bg-page);
  color: var(--text-primary);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Background Layers ===== */
.bg-glow {
  position: fixed;
  pointer-events: none;
  z-index: 0;
}
.bg-glow--tl {
  top: -12%;
  left: -8%;
  width: 600px;
  height: 600px;
  background: radial-gradient(ellipse, rgba(201,100,66,0.07) 0%, transparent 65%);
}
.bg-glow--br {
  bottom: -8%;
  right: -5%;
  width: 500px;
  height: 500px;
  background: radial-gradient(ellipse, rgba(90,89,89,0.04) 0%, transparent 65%);
}

/* ===== Container ===== */
.container {
  position: relative;
  z-index: 1;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* ===== Top Navigation ===== */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 200;
  background: rgba(245,244,237,0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0 var(--space-xl);
}
.top-nav__inner {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 0;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding: 10px 0;
}
.top-nav__inner::-webkit-scrollbar { display: none; }

.top-nav__home {
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-primary);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  padding: 6px 12px;
  margin-right: 4px;
  border-radius: var(--radius-md);
  transition: all 0.2s;
}
.top-nav__home:hover {
  background: rgba(201,100,66,0.06);
}

.top-nav__divider {
  width: 1px;
  height: 18px;
  background: rgba(0,0,0,0.06);
  margin: 0 4px;
  flex-shrink: 0;
}

.top-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
  flex-shrink: 0;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: var(--radius-md);
  transition: all 0.2s;
  letter-spacing: 0.02em;
}
.top-nav__link:hover {
  background: rgba(201,100,66,0.06);
  color: var(--accent);
}

.top-nav__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: var(--space-3xl) 0 var(--space-lg);
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(201,100,66,0.2);
  padding: 5px 18px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-lg);
  background: rgba(255,253,249,0.5);
}

.hero__badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: dotPulse 2.5s ease-in-out infinite;
}
@keyframes dotPulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}

.hero__title {
  font-family: var(--font-serif);
  font-size: 3.2rem;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
}

.hero__subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  letter-spacing: 0.15em;
  font-weight: 400;
}

/* ===== Section Block ===== */
.section {
  max-width: 780px;
  margin: 0 auto var(--space-2xl);
}

/* ===== Founding Story ===== */
.story {
  max-width: 720px;
  margin: 0 auto var(--space-2xl);
  padding: var(--space-xl) var(--space-xl);
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  position: relative;
}

.story::before {
  content: '';
  position: absolute;
  top: 0;
  left: var(--space-xl);
  right: var(--space-xl);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201,100,66,0.12), transparent);
}

.story__label {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(201,100,66,0.18);
  padding: 4px 14px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-lg);
  background: rgba(255,253,249,0.4);
}

.story__heading {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.35;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
}

.story__body {
  margin-bottom: var(--space-md);
}

.story__body p {
  font-size: 0.97rem;
  line-height: 2;
  color: var(--text-secondary);
  text-indent: 2em;
  margin-bottom: var(--space-sm);
}

.story__highlight {
  font-weight: 500;
  color: var(--text-primary);
  background: linear-gradient(180deg, transparent 58%, rgba(201,100,66,0.08) 58%);
}

.story__metaphor {
  display: block;
  text-align: center;
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--accent);
  opacity: 0.8;
  letter-spacing: 0.04em;
  padding: var(--space-md) 0;
  border-top: 1px dashed rgba(201,100,66,0.12);
  border-bottom: 1px dashed rgba(201,100,66,0.12);
  margin: var(--space-lg) 0;
  line-height: 1.8;
}

.story__action {
  font-size: 0.95rem;
  line-height: 1.95;
  color: var(--text-secondary);
  text-indent: 2em;
  margin-bottom: var(--space-sm);
}

.story__divider {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}
.story__divider-line {
  width: 36px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201,100,66,0.15), transparent);
}
.story__divider-dot {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0.2;
}

/* ===== Card Grid ===== */
.garden {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
  padding-bottom: var(--space-3xl);
}

.garden-card {
  position: relative;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-xl) var(--space-xl);
  text-decoration: none;
  color: var(--text-primary);
  box-shadow: 0px 0px 0px 1px rgba(0,0,0,0.04), rgba(0,0,0,0.02) 0px 2px 8px;
  transition: all 0.3s cubic-bezier(0.23, 1, 0.32, 1);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  overflow: hidden;
  cursor: pointer;
}

/* Top accent line */
.garden-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: var(--space-lg);
  right: var(--space-lg);
  height: 2px;
  border-radius: 0 0 2px 2px;
  opacity: 0.35;
  transition: all 0.3s ease;
}

.garden-card:hover {
  transform: translateY(-3px);
  box-shadow: 0px 0px 0px 1px rgba(201,100,66,0.08), rgba(0,0,0,0.05) 0px 8px 32px;
  background: var(--claude-white);
}
.garden-card:hover::after {
  left: 0;
  right: 0;
  opacity: 0.7;
}
.garden-card:active {
  transform: translateY(-1px);
}

/* Icon circle */
.garden-card__icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-weight: 600;
  position: relative;
  z-index: 1;
}

/* Card label */
.garden-card__label {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  position: relative;
  z-index: 1;
  margin-top: var(--space-sm);
}

/* Card title */
.garden-card__title {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 600;
  line-height: 1.2;
  color: var(--text-primary);
  position: relative;
  z-index: 1;
}

/* Card description */
.garden-card__desc {
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--text-secondary);
  position: relative;
  z-index: 1;
}

/* Card arrow */
.garden-card__arrow {
  position: absolute;
  top: var(--space-lg);
  right: var(--space-xl);
  font-size: 1rem;
  color: rgba(0,0,0,0.06);
  transition: all 0.3s ease;
  z-index: 1;
  font-weight: 300;
}
.garden-card:hover .garden-card__arrow {
  color: var(--accent);
  transform: translate(4px, -4px);
}

/* Card glow */
.garden-card__glow {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.4s ease;
  border-radius: var(--radius-lg);
}
.garden-card:hover .garden-card__glow {
  opacity: 1;
}

/* ===== Card accent colors (Claude warm palette variations) ===== */
.garden-card:nth-child(1)::after { background: var(--claude-terracotta); }
.garden-card:nth-child(2)::after { background: var(--claude-olive-gray); }
.garden-card:nth-child(3)::after { background: var(--claude-coral); }
.garden-card:nth-child(4)::after { background: var(--claude-stone-gray); }
.garden-card:nth-child(5)::after { background: #8a7a5a; }
.garden-card:nth-child(6)::after { background: var(--claude-olive-gray); }
.garden-card:nth-child(7)::after { background: #a85d6f; }
.garden-card:nth-child(8)::after { background: #7a5c8a; }

/* ===== Footer ===== */
.site-footer {
  text-align: center;
  padding: 0 0 var(--space-2xl);
  font-size: 0.72rem;
  color: var(--text-tertiary);
  letter-spacing: 0.1em;
  position: relative;
  z-index: 1;
}

.site-footer::before {
  content: '';
  display: block;
  width: 40px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201,100,66,0.15), transparent);
  margin: 0 auto var(--space-sm);
}

/* ===== Responsive ===== */
@media (max-width: 700px) {
  .container { padding: 0 var(--space-md); }
  .top-nav { padding: 0 var(--space-md); }
  .top-nav__link { font-size: 0.72rem; padding: 5px 10px; }
  .top-nav__home { font-size: 0.76rem; padding: 5px 8px; }

  .hero { padding: var(--space-xl) 0 var(--space-md); }
  .hero__title { font-size: 2rem; }
  .hero__subtitle { font-size: 0.88rem; }

  .story { padding: var(--space-lg); }
  .story__heading { font-size: 1.2rem; }
  .story__body p,
  .story__action { font-size: 0.88rem; text-indent: 1.6em; }
  .story__metaphor { font-size: 0.95rem; }

  .garden { grid-template-columns: 1fr; gap: var(--space-md); padding-bottom: var(--space-2xl); }
  .garden-card { padding: var(--space-lg); }
  .garden-card__title { font-size: 1.2rem; }
  .garden-card__desc { font-size: 0.85rem; }
}

@media (min-width: 1400px) {
  .garden { grid-template-columns: repeat(3, 1fr); }
}

/* ===== Utility ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}