/* ============================================================
   Aether — design tokens (DESIGN.md §2–§4)
   Dark black & white mono aesthetic · jcode.sh discipline
   ============================================================ */

:root {
  /* Surface — dark, borders-only depth */
  --surface-primary: #0A0A0A;
  --surface-secondary: #111111;
  --surface-elevated: #161616;
  /* Text */
  --text-primary: #F5F5F5;
  --text-secondary: #A3A3A3;
  --text-tertiary: #6B6B6B;
  /* Border */
  --border-default: #2E2E2E;
  --border-subtle: #1F1F1F;
  /* Accent — black & white: accent is paper, not color */
  --accent-primary: #F5F5F5;
  --accent-hover: #FFFFFF;
  /* Status — monochrome grays */
  --status-success: #F5F5F5;
  --status-error: #A3A3A3;
  /* Spacing */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  /* Type scale */
  --text-display: clamp(2.25rem, 6vw, 3.5rem);
  --text-h1: 1.75rem;
  --text-h2: 1.25rem;
  --text-body-lg: 1.0625rem;
  --text-body: 0.9375rem;
  --text-body-sm: 0.8125rem;
  --text-caption: 0.75rem;
  --text-overline: 0.6875rem;
  /* Motion */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  /* Layout */
  --content-width: 1080px;
  --radius: 8px;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@font-face {
  font-family: "JetBrains Mono";
  src: url("/fonts/jetbrains-mono-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("/fonts/jetbrains-mono-700.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

/* ============================================================
   Base
   ============================================================ */

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

:root { color-scheme: dark; }

html {
  scroll-padding-top: 96px;
}

::selection {
  background: var(--text-primary);
  color: var(--surface-primary);
}

body {
  margin: 0;
  background: var(--surface-primary);
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; }

a { color: var(--text-secondary); text-decoration: none; transition: color 150ms var(--ease-out); }
a:hover { color: var(--text-primary); }
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--text-primary);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--text-primary);
  color: var(--surface-primary);
  padding: var(--space-2) var(--space-4);
  font-weight: 700;
}
.skip-link:focus { left: 0; }

.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;
}

/* ============================================================
   Nav
   ============================================================ */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(22, 22, 22, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-subtle);
}

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

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--text-primary);
  font-weight: 700;
}
.brand:hover { color: var(--text-primary); }
.brand-mark { flex: none; }
.brand-name { font-size: var(--text-body); letter-spacing: 0.02em; }
.brand-accent { color: var(--text-primary); }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  font-size: var(--text-body-sm);
}

.nav-links a[aria-current="page"] { color: var(--text-primary); }

.nav-cta {
  color: var(--text-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  padding: var(--space-1) var(--space-3);
  transition: border-color 150ms var(--ease-out), color 150ms var(--ease-out);
}
.nav-cta:hover { border-color: var(--text-primary); }

/* ============================================================
   Hero
   ============================================================ */

.hero {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-20) var(--space-6) var(--space-12);
  text-align: center;
}

.overline {
  font-size: var(--text-overline);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin: 0 0 var(--space-4);
}

.hero h1 {
  font-size: var(--text-display);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-6);
}

.lead {
  font-size: var(--text-body-lg);
  color: var(--text-secondary);
  max-width: 46rem;
  margin: 0 auto var(--space-12);
}

/* Install command */
.install { max-width: 46rem; margin: 0 auto var(--space-8); }

.install-row {
  display: flex;
  align-items: stretch;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-elevated);
  overflow: hidden;
  transition: border-color 150ms var(--ease-out);
}
.install-row.copied { border-color: var(--text-primary); }

.install-code {
  flex: 1;
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-body);
  color: var(--text-primary);
  text-align: left;
  user-select: all;
  overflow-x: auto;
  white-space: nowrap;
}

.copy-btn {
  flex: none;
  display: grid;
  place-items: center;
  width: 48px;
  border: none;
  border-left: 1px solid var(--border-default);
  background: var(--surface-secondary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: color 150ms var(--ease-out), background-color 150ms var(--ease-out);
}
.copy-btn:hover { color: var(--text-primary); background: var(--surface-elevated); }
.copy-btn:active { background: var(--surface-secondary); }

.icon-check { display: none; }
.install-row.copied .icon-copy { display: none; }
.install-row.copied .icon-check { display: block; color: var(--text-primary); }

.install-meta {
  margin: var(--space-3) 0 0;
  font-size: var(--text-body-sm);
  color: var(--text-tertiary);
}

/* ============================================================
   Terminal demo
   ============================================================ */

.terminal-wrap {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-8) var(--space-6) var(--space-20);
}

.terminal {
  max-width: 720px;
  margin: 0 auto;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-secondary);
  overflow: hidden;
  animation: rise 500ms var(--ease-out) both;
}

.terminal-bar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--surface-elevated);
}

.dot { width: 11px; height: 11px; border-radius: 50%; border: 1px solid var(--border-default); }
.dot-red { background: var(--surface-primary); }
.dot-yellow { background: var(--surface-secondary); }
.dot-green { background: var(--text-tertiary); }

.terminal-path {
  margin-left: var(--space-2);
  font-size: var(--text-caption);
  color: var(--text-tertiary);
}

.terminal-body {
  margin: 0;
  padding: var(--space-6);
  font-family: var(--font-mono);
  font-size: var(--text-body-sm);
  line-height: 1.7;
  color: var(--text-primary);
  overflow-x: auto;
  max-height: 420px;
}

.terminal-gif {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1150 / 640;
  background: var(--surface-secondary);
  object-fit: cover;
}

.t-dim { color: var(--text-tertiary); }
.t-prompt { color: var(--text-primary); font-weight: 700; }
.t-sys { color: var(--text-primary); font-weight: 700; }
.t-plain { color: var(--text-secondary); }
.t-cursor {
  display: inline-block;
  width: 0.6em;
  background: var(--text-primary);
  color: transparent;
  animation: blink 1.2s steps(2, start) infinite;
}

@keyframes blink { to { visibility: hidden; } }
@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   Quick start (install & usage)
   ============================================================ */

.quickstart {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-20);
}

.quickstart .overline { margin-bottom: var(--space-2); }

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(20rem, 100%), 1fr));
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.step {
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-secondary);
  padding: var(--space-6);
}

.step-head {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  margin: 0 0 var(--space-4);
}

.step-num {
  font-size: var(--text-overline);
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--text-tertiary);
}

.step-title {
  font-size: var(--text-h2);
  font-weight: 700;
  margin: 0;
}

.step p {
  margin: 0 0 var(--space-4);
  font-size: var(--text-body-sm);
  color: var(--text-secondary);
}

.step-code {
  display: block;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-elevated);
  padding: var(--space-3) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-body-sm);
  color: var(--text-primary);
  overflow-x: auto;
  white-space: nowrap;
  user-select: all;
}

.step-code.multi { white-space: pre; }

.step-code .c-comment { color: var(--text-tertiary); }
.step-code .c-cmd { color: var(--text-primary); font-weight: 700; }

/* ============================================================
   Features
   ============================================================ */

.features {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-20);
}

.features .overline { margin-bottom: var(--space-2); }

.section-title {
  font-size: var(--text-h1);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 var(--space-12);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(18rem, 100%), 1fr));
  gap: var(--space-6);
}

.feature-card {
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-secondary);
  padding: var(--space-6);
  transition: border-color 150ms var(--ease-out), transform 150ms var(--ease-out);
}
.feature-card:hover {
  border-color: var(--text-primary);
  transform: translateY(-2px);
}

.feature-label {
  margin: 0 0 var(--space-3);
  font-size: var(--text-overline);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.feature-card h3 {
  font-size: var(--text-h2);
  font-weight: 700;
  margin: 0 0 var(--space-2);
}

.feature-card p:last-child {
  margin: 0;
  font-size: var(--text-body-sm);
  color: var(--text-secondary);
}

/* ============================================================
   Footer
   ============================================================ */

.footer {
  border-top: 1px solid var(--border-subtle);
  background: var(--surface-elevated);
}

.footer-grid {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-12) var(--space-6) var(--space-8);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-8);
}

.footer-tagline {
  margin: var(--space-3) 0 0;
  font-size: var(--text-body-sm);
  color: var(--text-secondary);
  max-width: 26rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  font-size: var(--text-body-sm);
}

.footer-status {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-8);
  font-size: var(--text-caption);
  color: var(--text-tertiary);
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 768px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-6); }
  .hero { padding-top: var(--space-16); }
}

@media (max-width: 480px) {
  .terminal-body { padding: var(--space-4); }
  .feature-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
}

/* ============================================================
   Reduced motion
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .terminal { animation: none; }
  .t-cursor { animation: none; visibility: hidden; }
  .feature-card, a, .copy-btn { transition: none; }
}

/* ============================================================
   Install tabs (opencode.ai pattern — ARIA tablist)
   ============================================================ */

.install-tabs {
  display: flex;
  justify-content: center;
  gap: var(--space-1);
  margin-bottom: var(--space-2);
}

.install-tab {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  padding: var(--space-1) var(--space-3);
  cursor: pointer;
  transition: color 150ms var(--ease-out), background-color 150ms var(--ease-out), border-color 150ms var(--ease-out);
}
.install-tab:hover { color: var(--text-primary); border-color: var(--text-primary); }
.install-tab[aria-selected="true"] {
  background: var(--text-primary);
  color: var(--surface-primary);
  border-color: var(--text-primary);
}

.install-panel { flex: 1; min-width: 0; display: flex; }
.install-panel[hidden] { display: none; }
.install-code { min-width: 0; }

/* ============================================================
   Platform download buttons (jcode.sh pattern)
   ============================================================ */

.platforms {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-3);
  margin: var(--space-4) 0 0;
}

.platform-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-body-sm);
  font-weight: 700;
  color: var(--text-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  padding: var(--space-2) var(--space-4);
  transition: border-color 150ms var(--ease-out), background-color 150ms var(--ease-out);
}
.platform-btn:hover { border-color: var(--text-primary); background: var(--surface-elevated); }

.platform-note {
  margin: var(--space-3) 0 0;
  font-size: var(--text-caption);
  color: var(--text-tertiary);
}

/* ============================================================
   Stats strip (opencode.ai / jcode.sh hard-numbers pattern)
   ============================================================ */

.stats {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-20);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  margin: 0;
}

.stat {
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-secondary);
  padding: var(--space-6);
  text-align: center;
}

.stat-value {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0 0 var(--space-2);
}

.stat-label {
  margin: 0;
  font-size: var(--text-body-sm);
  color: var(--text-secondary);
}

.stat-note {
  margin: var(--space-4) 0 0;
  text-align: center;
  font-size: var(--text-caption);
  color: var(--text-tertiary);
}

/* ============================================================
   FAQ accordion (opencode.ai pattern — native <details>)
   ============================================================ */

.faq {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-20);
}

.faq .overline { margin-bottom: var(--space-2); }

.faq-list {
  margin-top: var(--space-12);
  display: grid;
  gap: var(--space-3);
}

.faq-item {
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  background: var(--surface-secondary);
}

.faq-item summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-6);
  cursor: pointer;
  list-style: none;
  font-weight: 700;
  font-size: var(--text-body);
  color: var(--text-primary);
}
.faq-item summary::-webkit-details-marker { display: none; }

.faq-mark {
  flex: none;
  font-size: var(--text-h2);
  font-weight: 700;
  line-height: 1;
  color: var(--text-secondary);
  transition: transform 200ms var(--ease-out);
}
.faq-item[open] .faq-mark { transform: rotate(45deg); }
.faq-item[open] summary { border-bottom: 1px solid var(--border-subtle); }

.faq-item p {
  margin: 0;
  padding: var(--space-4) var(--space-6) var(--space-6);
  font-size: var(--text-body-sm);
  color: var(--text-secondary);
}
.faq-item a {
  color: var(--text-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ============================================================
   Comparison table (jcode.sh pattern)
   ============================================================ */

.compare {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-6) var(--space-20);
}

.compare .overline { margin-bottom: var(--space-2); }

.table-wrap {
  margin-top: var(--space-12);
  border: 1px solid var(--border-default);
  border-radius: var(--radius);
  overflow-x: auto;
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-body-sm);
  background: var(--surface-primary);
}

.compare-table th,
.compare-table td {
  text-align: left;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-subtle);
  vertical-align: top;
}

.compare-table thead th {
  font-size: var(--text-overline);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-secondary);
  background: var(--surface-secondary);
}

.compare-table tbody tr:last-child th,
.compare-table tbody tr:last-child td { border-bottom: none; }

.compare-table tbody th {
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
}

.compare-table td { color: var(--text-secondary); }
.compare-table td strong { color: var(--text-primary); }

.compare-note {
  margin: var(--space-4) 0 0;
  font-size: var(--text-caption);
  color: var(--text-tertiary);
}

/* ============================================================
   Responsive additions
   ============================================================ */

@media (max-width: 768px) {
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .stat-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   Reduced-motion additions
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  .install-tab, .platform-btn, .faq-mark { transition: none; }
}