/* ============================================
   DESIGN TOKENS
   ============================================ */

:root {
  /* Type scale */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);
  --text-hero: clamp(3rem,     0.5rem  + 7vw,    8rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Fonts */
  --font-body: 'General Sans', 'Helvetica Neue', sans-serif;
  --font-display: 'General Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in: cubic-bezier(0.4, 0, 1, 1);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
}

/* ============================================
   DARK THEME (DEFAULT)
   ============================================ */

:root, [data-theme="dark"] {
  --color-bg: #0c0c0f;
  --color-surface: #141419;
  --color-surface-2: #1a1a22;
  --color-surface-3: #22222d;
  --color-border: rgba(255,255,255,0.08);
  --color-border-strong: rgba(255,255,255,0.15);
  --color-text: #e4e4e7;
  --color-text-muted: #8b8b96;
  --color-text-faint: #55555e;
  --color-primary: #6ee7b7;
  --color-primary-dim: rgba(110, 231, 183, 0.12);
  --color-primary-hover: #86efac;
  --color-accent-2: #93c5fd;
  --color-accent-2-dim: rgba(147, 197, 253, 0.12);
  --color-accent-3: #c4b5fd;
  --color-accent-3-dim: rgba(196, 181, 253, 0.12);
  --color-accent-4: #fbbf24;
  --color-accent-4-dim: rgba(251, 191, 36, 0.12);
  --color-error: #f87171;
  --color-error-dim: rgba(248, 113, 113, 0.12);
  --color-success: #6ee7b7;
  --color-success-dim: rgba(110, 231, 183, 0.12);

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.4);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.5);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.6);

  --glow-primary: 0 0 20px rgba(110, 231, 183, 0.15);
  --glow-accent: 0 0 20px rgba(147, 197, 253, 0.15);
}

[data-theme="light"] {
  --color-bg: #f8f8fa;
  --color-surface: #ffffff;
  --color-surface-2: #f0f0f4;
  --color-surface-3: #e8e8ee;
  --color-border: rgba(0,0,0,0.08);
  --color-border-strong: rgba(0,0,0,0.15);
  --color-text: #1a1a2e;
  --color-text-muted: #6b6b80;
  --color-text-faint: #9b9bb0;
  --color-primary: #059669;
  --color-primary-dim: rgba(5, 150, 105, 0.08);
  --color-primary-hover: #047857;
  --color-accent-2: #2563eb;
  --color-accent-2-dim: rgba(37, 99, 235, 0.08);
  --color-accent-3: #7c3aed;
  --color-accent-3-dim: rgba(124, 58, 237, 0.08);
  --color-accent-4: #d97706;
  --color-accent-4-dim: rgba(217, 119, 6, 0.08);
  --color-error: #dc2626;
  --color-error-dim: rgba(220, 38, 38, 0.08);
  --color-success: #059669;
  --color-success-dim: rgba(5, 150, 105, 0.08);

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);

  --glow-primary: 0 0 20px rgba(5, 150, 105, 0.1);
  --glow-accent: 0 0 20px rgba(37, 99, 235, 0.1);
}

/* ============================================
   PROGRESS BAR
   ============================================ */

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--color-primary);
  z-index: 1000;
  width: 0%;
  transition: width 50ms linear;
}

/* ============================================
   HEADER / NAV
   ============================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: oklch(from var(--color-bg) l c h / 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out);
}

.site-header--hidden { transform: translateY(-100%); }

.nav-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.logo-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
  flex-shrink: 0;
}

.logo-svg { color: var(--color-primary); }

.logo-text {
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  transition: all var(--transition-interactive);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-text);
  background: var(--color-primary-dim);
}

.nav-link.active {
  color: var(--color-primary);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  transition: all var(--transition-interactive);
}

.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

/* ============================================
   HERO
   ============================================ */

.hero {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-16) var(--space-6);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 40% at 20% 80%, var(--color-primary-dim) 0%, transparent 70%),
    radial-gradient(ellipse 50% 50% at 80% 20%, var(--color-accent-2-dim) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-12);
  align-items: center;
  position: relative;
  z-index: 1;
  width: 100%;
}

.hero-text {
  display: flex;
  flex-direction: column;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-primary);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero-title {
  font-size: var(--text-3xl);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text);
}

.hero-accent {
  color: var(--color-primary);
  position: relative;
}

.hero-accent.accent-2 {
  color: var(--color-accent-2);
}

.hero-subtitle {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-top: var(--space-6);
  max-width: 50ch;
  line-height: 1.7;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-8);
  padding: var(--space-3) var(--space-6);
  background: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
  font-size: var(--text-sm);
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: all var(--transition-interactive);
  width: fit-content;
}

.hero-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-primary);
}

/* Hero visual - stack animation */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.stack-visual {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  width: 100%;
  max-width: 380px;
}

.stack-layer {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  opacity: 0;
  transform: translateY(20px);
  animation: stack-enter 0.6s var(--ease-out) forwards;
}

.stack-layer i { width: 20px; height: 20px; flex-shrink: 0; }

.layer-1 { animation-delay: 0.2s; color: var(--color-text-muted); border-color: var(--color-border); }
.layer-2 { animation-delay: 0.4s; color: var(--color-accent-2); border-color: rgba(147, 197, 253, 0.2); background: var(--color-accent-2-dim); }
.layer-3 { animation-delay: 0.6s; color: var(--color-accent-3); border-color: rgba(196, 181, 253, 0.2); background: var(--color-accent-3-dim); }
.layer-4 { animation-delay: 0.8s; color: var(--color-primary); border-color: rgba(110, 231, 183, 0.2); background: var(--color-primary-dim); box-shadow: var(--glow-primary); }

@keyframes stack-enter {
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================
   TIMELINE LINE
   ============================================ */

.timeline-line {
  width: 2px;
  height: 80px;
  background: linear-gradient(to bottom, transparent, var(--color-border-strong), transparent);
  margin: 0 auto;
}

/* ============================================
   ERA SECTIONS
   ============================================ */

.era {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: clamp(var(--space-12), 6vw, var(--space-24)) var(--space-6);
}

.era-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-6);
  margin-bottom: var(--space-10);
}

.era-number {
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-text-faint);
  line-height: 1;
  font-family: var(--font-mono);
  letter-spacing: -0.05em;
  flex-shrink: 0;
  opacity: 0.4;
}

.era-year {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.era-title {
  font-size: var(--text-2xl);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-top: var(--space-1);
}

.era-tagline {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}

.era-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-10);
  align-items: start;
}

.era-explanation p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  line-height: 1.7;
}

.era-explanation p strong {
  color: var(--color-text);
  font-weight: 600;
}

/* Capability cards */
.capability-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.cap-card {
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.cap-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-3);
}

.cap-icon i { width: 18px; height: 18px; }

.cap-card.can .cap-icon,
.cap-card.new-can .cap-icon { color: var(--color-success); }
.cap-card.cannot .cap-icon,
.cap-card.still-cant .cap-icon { color: var(--color-error); }
.cap-card.new-can { border-color: rgba(110, 231, 183, 0.2); background: var(--color-success-dim); }

.cap-card h4 {
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-3);
}

.cap-card ul {
  list-style: none;
  padding: 0;
}

.cap-card li {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  padding: var(--space-1) 0;
  padding-left: var(--space-4);
  position: relative;
}

.cap-card li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  transform: translateY(-50%);
}

.cap-card.can li::before,
.cap-card.new-can li::before { background: var(--color-success); }
.cap-card.cannot li::before,
.cap-card.still-cant li::before { background: var(--color-error); opacity: 0.5; }

/* ============================================
   DEMO BOXES — interactive chat simulators
   ============================================ */

.demo-box {
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border-strong);
  background: var(--color-surface);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.demo-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface-2);
  border-bottom: 1px solid var(--color-border);
}

.demo-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.demo-dot.red { background: #ef4444; }
.demo-dot.yellow { background: #eab308; }
.demo-dot.green { background: #22c55e; }

.demo-label {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  margin-left: var(--space-2);
}

.demo-chat {
  display: flex;
  flex-direction: column;
  height: 400px;
}

.demo-messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.demo-messages::-webkit-scrollbar { width: 4px; }
.demo-messages::-webkit-scrollbar-track { background: transparent; }
.demo-messages::-webkit-scrollbar-thumb { background: var(--color-border-strong); border-radius: 2px; }

/* Message bubbles */
.msg {
  max-width: 85%;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  line-height: 1.6;
  animation: msg-enter 0.3s var(--ease-out);
}

@keyframes msg-enter {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.msg-user {
  align-self: flex-end;
  background: var(--color-primary);
  color: var(--color-bg);
  border-bottom-right-radius: var(--radius-sm);
}

.msg-ai {
  align-self: flex-start;
  background: var(--color-surface-2);
  color: var(--color-text);
  border-bottom-left-radius: var(--radius-sm);
}

.msg-system {
  align-self: center;
  background: none;
  border: 1px dashed var(--color-border-strong);
  color: var(--color-text-faint);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  text-align: center;
  max-width: 95%;
}

/* Tool call message */
.msg-tool {
  align-self: flex-start;
  background: var(--color-accent-2-dim);
  border: 1px solid rgba(147, 197, 253, 0.2);
  color: var(--color-accent-2);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  border-bottom-left-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.msg-tool .tool-spinner {
  width: 14px;
  height: 14px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.msg-tool.done {
  opacity: 0.6;
}

.msg-tool.done .tool-spinner {
  animation: none;
  border: none;
}

.msg-tool.done::after {
  content: ' ✓';
}

/* Typing indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: var(--space-3) var(--space-4);
  align-self: flex-start;
}

.typing-indicator span {
  width: 6px;
  height: 6px;
  background: var(--color-text-faint);
  border-radius: 50%;
  animation: typing-bounce 1.2s ease-in-out infinite;
}

.typing-indicator span:nth-child(2) { animation-delay: 0.15s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.3s; }

@keyframes typing-bounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-6px); }
}

/* Input row */
.demo-input-row {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--color-border);
}

.demo-input {
  flex: 1;
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  color: var(--color-text);
  outline: none;
}

.demo-input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px var(--color-primary-dim);
}

.demo-input::placeholder { color: var(--color-text-faint); }

.demo-send {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--color-primary);
  color: var(--color-bg);
  transition: all var(--transition-interactive);
}

.demo-send:hover {
  transform: translateY(-1px);
  box-shadow: var(--glow-primary);
}

/* Suggestions */
.demo-suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--color-border);
}

.suggestion-btn {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-interactive);
  white-space: nowrap;
}

.suggestion-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-dim);
}

/* ============================================
   ARCHITECTURE DIAGRAM (Era 2)
   ============================================ */

.architecture-diagram {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6);
  margin: var(--space-6) 0;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  overflow-x: auto;
  flex-wrap: wrap;
  justify-content: center;
}

.arch-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  min-width: 80px;
}

.arch-node i { width: 24px; height: 24px; }
.arch-node span { font-size: var(--text-xs); font-weight: 500; }

.user-node { color: var(--color-text); }
.model-node { color: var(--color-accent-2); border-color: rgba(147, 197, 253, 0.3); background: var(--color-accent-2-dim); }
.response-node { color: var(--color-primary); border-color: rgba(110, 231, 183, 0.3); background: var(--color-primary-dim); }

.arch-arrow {
  color: var(--color-text-faint);
}

.arch-arrow i { width: 20px; height: 20px; }

.arch-arrow.reverse { transform: scaleX(-1); }

.arch-tools {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.arch-tool {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-accent-3);
  background: var(--color-accent-3-dim);
  border-radius: var(--radius-md);
  border: 1px solid rgba(196, 181, 253, 0.2);
}

.arch-tool i { width: 14px; height: 14px; }

/* ============================================
   ORCHESTRATION DEMO (Era 3)
   ============================================ */

.orchestration-demo {
  margin-top: var(--space-8);
  padding: var(--space-6);
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
}

.orch-prompt {
  margin-bottom: var(--space-6);
}

.orch-label {
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.orch-prompt p {
  font-size: var(--text-sm);
  color: var(--color-text);
  margin-top: var(--space-2);
  font-style: italic;
}

.orch-tree {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
}

.orch-node {
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
  transition: all 0.4s var(--ease-out);
}

.orch-node-inner {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.orch-node-inner i { width: 18px; height: 18px; }

.orch-node-inner span {
  font-size: var(--text-sm);
  font-weight: 500;
}

.orch-status {
  font-size: var(--text-xs) !important;
  font-family: var(--font-mono);
  color: var(--color-text-faint) !important;
  font-weight: 400 !important;
}

.orch-node.primary {
  border-color: rgba(147, 197, 253, 0.3);
  color: var(--color-accent-2);
}

.orch-node.primary.active {
  background: var(--color-accent-2-dim);
  box-shadow: var(--glow-accent);
}

.orch-branches {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
  width: 100%;
}

.orch-branch {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
}

.orch-connector {
  width: 2px;
  height: 24px;
  background: var(--color-border);
  transition: background 0.4s var(--ease-out);
}

.orch-branch.active .orch-connector {
  background: var(--color-primary);
}

.orch-node.sub {
  color: var(--color-text-muted);
  width: 100%;
}

.orch-node.sub .orch-node-inner {
  flex-direction: column;
  text-align: center;
}

.orch-node.sub.active {
  color: var(--color-primary);
  border-color: rgba(110, 231, 183, 0.3);
  background: var(--color-primary-dim);
}

.orch-node.sub.complete {
  color: var(--color-success);
  border-color: rgba(110, 231, 183, 0.4);
}

.orch-run-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  margin: var(--space-6) auto 0;
  padding: var(--space-3) var(--space-6);
  background: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
  font-size: var(--text-sm);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.orch-run-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-primary);
}

.orch-run-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* ============================================
   OS FEATURES (Era 4)
   ============================================ */

.os-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.os-feature {
  padding: var(--space-5);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  transition: all var(--transition-interactive);
}

.os-feature:hover {
  border-color: var(--color-border-strong);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.os-feature-icon {
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.os-feature-icon i { width: 22px; height: 22px; }

.os-feature h4 {
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-2);
}

.os-feature p {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* OS Demo */
.os-demo {
  margin-top: var(--space-8);
}

.os-demo-content {
  padding: var(--space-4);
  min-height: 350px;
  display: flex;
  flex-direction: column;
}

.os-command-list {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.os-command-list::-webkit-scrollbar { width: 4px; }
.os-command-list::-webkit-scrollbar-track { background: transparent; }
.os-command-list::-webkit-scrollbar-thumb { background: var(--color-border-strong); border-radius: 2px; }

.os-cmd-entry {
  animation: msg-enter 0.3s var(--ease-out);
}

.os-cmd-user {
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-family: var(--font-mono);
  margin-bottom: var(--space-2);
}

.os-cmd-user::before {
  content: '> ';
  color: var(--color-text-faint);
}

.os-cmd-steps {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding-left: var(--space-4);
  border-left: 2px solid var(--color-border);
}

.os-step {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  opacity: 0;
  animation: step-enter 0.3s var(--ease-out) forwards;
}

@keyframes step-enter {
  from { opacity: 0; transform: translateX(-8px); }
  to { opacity: 1; transform: translateX(0); }
}

.os-step .step-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.os-step.pending .step-icon { color: var(--color-text-faint); }
.os-step.running .step-icon { color: var(--color-accent-2); }
.os-step.done .step-icon { color: var(--color-success); }

.os-step .step-spinner {
  width: 14px;
  height: 14px;
  border: 2px solid var(--color-accent-2);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}

.os-demo-suggestions {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.os-cmd-btn {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-interactive);
}

.os-cmd-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-dim);
}

/* ============================================
   KEY INSIGHT BOXES
   ============================================ */

.era-key-insight {
  display: flex;
  gap: var(--space-4);
  margin-top: var(--space-10);
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  background: var(--color-primary-dim);
  border: 1px solid rgba(110, 231, 183, 0.15);
}

.insight-icon {
  color: var(--color-primary);
  flex-shrink: 0;
}

.insight-icon i { width: 22px; height: 22px; }

.insight-text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

.insight-text strong {
  color: var(--color-text);
}

.insight-text em {
  color: var(--color-primary);
  font-style: normal;
  font-weight: 600;
}

/* ============================================
   TRANSITIONS BETWEEN ERAS
   ============================================ */

.transition-section {
  padding: var(--space-12) var(--space-6);
}

.transition-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  text-align: center;
}

.transition-arrow {
  color: var(--color-primary);
  animation: bounce-down 2s ease-in-out infinite;
}

.transition-arrow i { width: 32px; height: 32px; }

@keyframes bounce-down {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

.transition-text {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 40ch;
}

.transition-text strong {
  color: var(--color-text);
}

/* ============================================
   FUTURE SECTION (Era 5)
   ============================================ */

.future-timeline {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
  margin-top: var(--space-6);
}

.future-item {
  display: flex;
  gap: var(--space-5);
  align-items: flex-start;
}

.future-marker {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 4px;
  position: relative;
}

.future-marker::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 40px;
  background: var(--color-border);
}

.future-item:last-child .future-marker::after { display: none; }

.future-marker.near { background: var(--color-primary); box-shadow: 0 0 12px rgba(110, 231, 183, 0.3); }
.future-marker.mid { background: var(--color-accent-2); box-shadow: 0 0 12px rgba(147, 197, 253, 0.3); }
.future-marker.far { background: var(--color-accent-3); box-shadow: 0 0 12px rgba(196, 181, 253, 0.3); }

.future-content h4 {
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-2);
}

.future-content p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ============================================
   SPEED SECTION
   ============================================ */

.speed-section {
  padding: clamp(var(--space-16), 8vw, var(--space-32)) var(--space-6);
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.speed-inner {
  max-width: var(--content-default);
  margin: 0 auto;
  text-align: center;
}

.speed-title {
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-10);
}

.speed-timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  text-align: left;
  max-width: 600px;
  margin: 0 auto;
}

.speed-item {
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  border-left: 2px solid var(--color-border);
  padding-left: var(--space-6);
  position: relative;
}

.speed-item::before {
  content: '';
  position: absolute;
  left: -5px;
  top: var(--space-4);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-primary);
}

.speed-year {
  font-size: var(--text-sm);
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--color-primary);
}

.speed-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.speed-punchline {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-top: var(--space-10);
  letter-spacing: -0.02em;
}

/* ============================================
   COMPARISON TABLE
   ============================================ */

.comparison-section {
  padding: clamp(var(--space-12), 6vw, var(--space-24)) var(--space-6);
  max-width: var(--content-wide);
  margin: 0 auto;
}

.comparison-title {
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-8);
  text-align: center;
}

.comparison-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
}

.comparison-table {
  min-width: 600px;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-3) var(--space-5);
  text-align: center;
  font-size: var(--text-sm);
  border-bottom: 1px solid var(--color-border);
}

.comparison-table th {
  font-weight: 600;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  background: var(--color-surface-2);
}

.comparison-table th:first-child { text-align: left; }

.row-label {
  text-align: left !important;
  font-weight: 500;
  color: var(--color-text);
}

.comparison-table tbody tr:last-child td { border-bottom: none; }

.icon-yes { width: 18px; height: 18px; color: var(--color-success); margin: 0 auto; }
.icon-no { width: 18px; height: 18px; color: var(--color-error); opacity: 0.4; margin: 0 auto; }
.icon-partial { width: 18px; height: 18px; color: var(--color-accent-4); margin: 0 auto; }

/* ============================================
   FOOTER
   ============================================ */

.site-footer {
  padding: var(--space-12) var(--space-6);
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  text-align: center;
}

.footer-text {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.footer-link {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
  transition: color var(--transition-interactive);
}

.footer-link:hover {
  color: var(--color-primary);
}

/* ============================================
   SCROLL REVEAL
   ============================================ */

.fade-in {
  opacity: 1;
}

@supports (animation-timeline: scroll()) {
  .fade-in {
    opacity: 0;
    animation: reveal-fade linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 100%;
  }
}

@keyframes reveal-fade {
  to { opacity: 1; }
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 900px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-subtitle { margin-left: auto; margin-right: auto; }

  .hero-visual { order: -1; }

  .stack-visual { max-width: 320px; margin: 0 auto; }

  .era-content {
    grid-template-columns: 1fr;
  }

  .capability-grid {
    grid-template-columns: 1fr;
  }

  .os-features {
    grid-template-columns: 1fr;
  }

  .orch-branches {
    grid-template-columns: 1fr 1fr;
  }

  .nav-links {
    display: none;
  }

  .era-header {
    flex-direction: column;
    gap: var(--space-3);
  }

  .architecture-diagram {
    flex-direction: column;
    gap: var(--space-4);
  }

  .arch-arrow {
    transform: rotate(90deg);
  }

  .arch-arrow.reverse {
    transform: rotate(90deg) scaleX(-1);
  }

  .os-demo-suggestions {
    flex-direction: column;
  }

  .comparison-table-wrap {
    margin: 0 calc(-1 * var(--space-6));
    border-radius: 0;
    border-left: none;
    border-right: none;
  }
}

@media (max-width: 600px) {
  .orch-branches {
    grid-template-columns: 1fr;
  }

  .hero-title {
    font-size: var(--text-2xl);
  }

  .speed-item {
    grid-template-columns: 1fr;
    gap: var(--space-1);
  }
}