/* ─── RESET & BASE ─── */

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

:root {
  /* Surface */
  --bg:          #0a0a0f;
  --bg-raised:   #111118;
  --bg-card:     #16161f;
  --bg-code:     #1a1a24;
  --border:      #24242e;
  --border-dim:  #1c1c26;

  /* Text */
  --fg:          #e4e4ed;
  --fg-muted:    #8888a0;
  --fg-dim:      #55556a;

  /* Accent */
  --accent:      #6c8aff;
  --accent-glow: rgba(108, 138, 255, 0.15);
  --accent-soft: rgba(108, 138, 255, 0.08);

  /* Semantic */
  --cyan:    #5ce0d8;
  --blue:    #6c8aff;
  --yellow:  #f0c050;
  --red:     #f06060;
  --green:   #5cd87a;
  --magenta: #c084fc;

  /* Type scale */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--fg);
  background: var(--bg);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: #93adff; }

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-code);
  padding: 0.15em 0.45em;
  border-radius: 5px;
  color: var(--cyan);
}

img { max-width: 100%; }

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}


/* ─── NAV ─── */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  background: rgba(10, 10, 15, 0.75);
  border-bottom: 1px solid var(--border-dim);
  transition: background 0.3s;
}

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--fg);
  letter-spacing: -0.02em;
}
.nav-logo:hover { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--fg-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--fg); }

.nav-github {
  display: flex;
  align-items: center;
  color: var(--fg-muted) !important;
}
.nav-github:hover { color: var(--fg) !important; }


/* ─── HERO ─── */

.hero {
  position: relative;
  padding: 160px 0 100px;
  text-align: center;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 500px;
  background: radial-gradient(ellipse, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(108, 138, 255, 0.2);
  padding: 6px 18px;
  border-radius: 100px;
  margin-bottom: 32px;
}

.hero-title {
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  color: var(--fg);
  margin-bottom: 24px;
}

.hero-accent {
  background: linear-gradient(135deg, var(--accent), var(--cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--fg-muted);
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: #0a0a0f;
}
.btn-primary:hover {
  background: #93adff;
  color: #0a0a0f;
  transform: translateY(-1px);
  box-shadow: 0 8px 30px rgba(108, 138, 255, 0.3);
}

.btn-ghost {
  background: transparent;
  color: var(--fg-muted);
  border: 1px solid var(--border);
}
.btn-ghost:hover {
  color: var(--fg);
  border-color: var(--fg-dim);
  transform: translateY(-1px);
}

.hero-install {
  display: inline-flex;
  align-items: center;
  gap: 0;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.hero-install code {
  font-size: 0.95rem;
  padding: 10px 20px;
  background: transparent;
  border: none;
  border-radius: 0;
  color: var(--fg-muted);
}

.hero-install .copy-btn {
  border-left: 1px solid var(--border);
  border-radius: 0;
  padding: 10px 14px;
}


/* ─── COPY BUTTON ─── */

.copy-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  color: var(--fg-dim);
  cursor: pointer;
  padding: 6px;
  border-radius: 4px;
  transition: color 0.2s, background 0.2s;
  flex-shrink: 0;
}

.copy-btn:hover {
  color: var(--fg);
  background: rgba(255, 255, 255, 0.06);
}

.copy-btn.copied {
  color: var(--green);
}

/* Inside qs-code blocks: position top-right */
.qs-code {
  position: relative;
}

.qs-code .copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 5px;
  opacity: 0;
  transition: opacity 0.2s, color 0.2s, background 0.2s;
}

.qs-code:hover .copy-btn,
.qs-code .copy-btn.copied {
  opacity: 1;
}


/* ─── SECTIONS ─── */

.section {
  padding: 100px 0;
}

.section-kicker {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--fg);
  margin-bottom: 20px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--fg-muted);
  max-width: 680px;
  line-height: 1.75;
}

.section-problem { text-align: center; }
.section-problem .section-desc {
  margin: 0 auto;
}

em { color: var(--fg); font-style: italic; }


/* ─── PILLARS ─── */

.pillars-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.pillar {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  transition: border-color 0.3s, transform 0.3s;
}

.pillar:hover {
  border-color: rgba(108, 138, 255, 0.3);
  transform: translateY(-2px);
}

.pillar-icon {
  font-size: 1.5rem;
  display: block;
  margin-bottom: 16px;
}

.pillar h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--fg);
}

.pillar p {
  font-size: 0.92rem;
  color: var(--fg-muted);
  line-height: 1.6;
}


/* ─── GIT vs ITHOS ─── */

.contrast-grid {
  display: flex;
  align-items: center;
  gap: 40px;
  justify-content: center;
}

.contrast-col {
  flex: 1;
  max-width: 380px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 40px 32px;
  text-align: center;
}

.contrast-col h3 {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.contrast-git h3 { color: var(--fg-muted); }
.contrast-ithos h3 { color: var(--accent); }

.contrast-records {
  font-size: 1.1rem;
  margin-bottom: 12px;
  color: var(--fg);
}

.contrast-records strong {
  color: var(--cyan);
}

.contrast-detail {
  font-size: 0.9rem;
  color: var(--fg-dim);
  line-height: 1.6;
}

.contrast-divider {
  display: flex;
  align-items: center;
  justify-content: center;
}

.contrast-plus {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--fg-dim);
}


/* ─── HOW / STEPS ─── */

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 48px;
}

.step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px;
  transition: border-color 0.3s, transform 0.3s;
}

.step:hover {
  border-color: rgba(108, 138, 255, 0.3);
  transform: translateY(-2px);
}

.step-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  display: block;
  margin-bottom: 16px;
}

.step h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.step p {
  font-size: 0.92rem;
  color: var(--fg-muted);
  line-height: 1.6;
}


/* ─── TERMINAL ─── */

.terminal {
  max-width: 720px;
  margin: 48px auto 0;
  border-radius: 12px;
  border: 1px solid var(--border);
  overflow: hidden;
  background: #0d0d14;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 12px 16px;
  background: var(--bg-raised);
  border-bottom: 1px solid var(--border);
}

.terminal-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.terminal-dot-red    { background: #ff5f56; }
.terminal-dot-yellow { background: #ffbd2e; }
.terminal-dot-green  { background: #27c93f; }

.terminal-title {
  flex: 1;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--fg-dim);
  margin-right: 36px;
}

.terminal-body {
  padding: 20px 24px;
  overflow-x: auto;
}

.terminal-body pre {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--fg);
  white-space: pre;
}

/* Terminal syntax colors */
.t-prompt { color: var(--green); }
.t-cmd    { color: var(--fg); font-weight: 500; }
.t-date   { color: var(--fg); font-weight: 700; }
.t-icon   { }
.t-dim    { color: var(--fg-dim); }
.t-sep    { color: #2a2a38; }

.t-type-decision   { color: var(--cyan); font-weight: 600; }
.t-type-lesson     { color: var(--yellow); font-weight: 600; }
.t-type-regression { color: var(--red); font-weight: 600; }
.t-type-session    { color: var(--blue); font-weight: 600; }


/* ─── STRUCTURE ─── */

.section-structure { text-align: center; }

.structure-block {
  display: inline-block;
  text-align: left;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 36px;
  margin-top: 36px;
}

.structure-block pre {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--fg);
}

.s-dir     { color: var(--accent); font-weight: 600; }
.s-comment { color: var(--fg-dim); }


/* ─── QUICK START ─── */

.qs-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-top: 48px;
}

.qs-step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px;
}

.qs-step h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.qs-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid rgba(108, 138, 255, 0.2);
  border-radius: 8px;
}

.qs-code {
  background: #0d0d14;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  margin-bottom: 14px;
  overflow-x: auto;
}

.qs-code pre {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--fg);
}

.qs-code-json pre {
  color: var(--fg-muted);
}

.qs-step > p {
  font-size: 0.9rem;
  color: var(--fg-muted);
  line-height: 1.6;
}


/* ─── COMMANDS TABLE ─── */

.commands-table-wrap {
  margin-top: 36px;
  overflow-x: auto;
}

.commands-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

.commands-table th {
  text-align: left;
  font-weight: 600;
  color: var(--fg-muted);
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.commands-table td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border-dim);
  color: var(--fg-muted);
}

.commands-table td:first-child {
  white-space: nowrap;
}

.commands-table td code {
  font-size: 0.85rem;
  padding: 3px 8px;
}

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

.commands-table tr:hover td {
  background: var(--accent-soft);
}


/* ─── ARCHITECTURE ─── */

.arch-diagram {
  text-align: center;
  margin: 36px 0 48px;
}

.arch-diagram pre {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--fg-dim);
}

.a-cli  { color: var(--cyan); font-weight: 600; }
.a-mcp  { color: var(--yellow); font-weight: 600; }
.a-core { color: var(--accent); font-weight: 700; }
.a-fs   { color: var(--fg-muted); }

.arch-packages {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.arch-pkg {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
}

.arch-pkg h4 {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.arch-pkg p {
  font-size: 0.88rem;
  color: var(--fg-muted);
  line-height: 1.6;
}


/* ─── PRINCIPLES ─── */

.principles-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-top: 24px;
}

.principle {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  padding: 24px;
  border-radius: 10px;
  transition: background 0.2s;
}

.principle:hover {
  background: var(--accent-soft);
}

.principle-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
  padding-top: 2px;
}

.principle h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.principle p {
  font-size: 0.9rem;
  color: var(--fg-muted);
}


/* ─── FOOTER ─── */

.footer {
  padding: 80px 0 40px;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand {
  max-width: 340px;
}

.footer-logo {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--fg);
  display: block;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--fg-dim);
  line-height: 1.6;
}

.footer-links {
  display: flex;
  gap: 64px;
}

.footer-col h4 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--fg-muted);
  margin-bottom: 16px;
}

.footer-col a {
  display: block;
  font-size: 0.88rem;
  color: var(--fg-dim);
  padding: 4px 0;
  transition: color 0.2s;
}
.footer-col a:hover { color: var(--fg); }

.footer-bottom {
  border-top: 1px solid var(--border-dim);
  padding-top: 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: var(--fg-dim);
}


/* ─── FADE-IN ANIMATIONS ─── */

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}


/* ─── RESPONSIVE ─── */

/* Tablet — 1024px */
@media (max-width: 1024px) {
  .pillars-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .steps-grid,
  .qs-steps,
  .arch-packages {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .hero { padding: 140px 0 80px; }

  .section { padding: 72px 0; }

  .arch-diagram pre { font-size: 0.75rem; }
}

/* Large mobile — 768px */
@media (max-width: 768px) {
  .container { padding: 0 20px; }

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

  .contrast-grid {
    flex-direction: column;
    gap: 16px;
  }

  .contrast-divider { transform: rotate(90deg); }
  .contrast-col { max-width: 100%; }

  .hero {
    padding: 110px 0 56px;
  }

  .hero-title {
    font-size: clamp(1.6rem, 6vw, 2.4rem);
  }

  .hero-sub {
    font-size: 1rem;
  }

  .hero-sub br { display: none; }

  .hero-actions {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }

  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
    padding: 14px 28px;
    min-height: 48px;
  }

  .section { padding: 56px 0; }

  .section-title {
    font-size: clamp(1.3rem, 5vw, 1.8rem);
  }

  .terminal-body {
    padding: 16px;
  }

  .terminal-body pre {
    font-size: 0.72rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .terminal {
    margin-top: 32px;
    border-radius: 10px;
  }

  .structure-block {
    padding: 20px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    width: 100%;
    display: block;
  }

  .structure-block pre {
    font-size: 0.78rem;
    min-width: max-content;
  }

  .arch-diagram {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .arch-diagram pre {
    font-size: 0.65rem;
    min-width: max-content;
  }

  .commands-table td:first-child {
    white-space: normal;
  }

  .commands-table th,
  .commands-table td {
    padding: 10px 12px;
    font-size: 0.85rem;
  }

  .footer-inner {
    flex-direction: column;
    gap: 32px;
  }

  .footer-links { gap: 40px; }
  .footer { padding: 56px 0 32px; }

  .nav-links a:not(.nav-github) {
    display: none;
  }

  .nav-inner { height: 52px; }

  /* Touch-friendly tap targets */
  .nav-github svg { width: 24px; height: 24px; }

  .principle {
    padding: 18px 16px;
    gap: 16px;
  }

  .qs-code {
    padding: 12px 14px;
  }

  .qs-code pre {
    font-size: 0.78rem;
  }
}

/* Small mobile — 480px */
@media (max-width: 480px) {
  .container { padding: 0 16px; }

  .hero {
    padding: 100px 0 48px;
  }

  .hero-badge {
    font-size: 0.7rem;
    padding: 5px 14px;
    margin-bottom: 24px;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-sub {
    font-size: 0.92rem;
    margin-bottom: 32px;
  }

  .hero-install code {
    font-size: 0.82rem;
    padding: 8px 16px;
  }

  .section { padding: 44px 0; }

  .section-kicker { font-size: 0.72rem; }

  .section-title {
    font-size: 1.25rem;
  }

  .section-desc {
    font-size: 0.95rem;
  }

  .pillar {
    padding: 24px 20px;
  }

  .pillar h3 { font-size: 1rem; }
  .pillar p { font-size: 0.88rem; }

  .step { padding: 24px 20px; }
  .step h3 { font-size: 1.05rem; }
  .step p { font-size: 0.88rem; }

  .contrast-col { padding: 28px 20px; }
  .contrast-records { font-size: 1rem; }
  .contrast-detail { font-size: 0.85rem; }

  .terminal-body pre {
    font-size: 0.65rem;
  }

  .terminal-bar { padding: 10px 12px; }
  .terminal-dot { width: 10px; height: 10px; }

  .qs-step {
    padding: 22px 18px;
  }

  .qs-step h3 { font-size: 1rem; }
  .qs-step > p { font-size: 0.85rem; }

  .arch-pkg { padding: 20px 18px; }

  .principle h3 { font-size: 0.95rem; }
  .principle p { font-size: 0.85rem; }

  .principle-num { font-size: 0.78rem; }

  .footer-links {
    flex-direction: column;
    gap: 28px;
  }

  .footer-brand { max-width: 100%; }

  .footer-logo { font-size: 1.1rem; }
  .footer-brand p { font-size: 0.85rem; }
}

/* Respect reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  .fade-in {
    opacity: 1;
    transform: none;
    transition: none;
  }

  html { scroll-behavior: auto; }

  .pillar,
  .step,
  .btn-primary,
  .btn-ghost {
    transition: none;
  }
}