/**
 * Landing page styles for Ramify (chess-local-learning).
 *
 * Light, neutral-greyscale theme matching https://rbuild.ai (shadcn/ui
 * "neutral" palette). Token names and values below are written to match
 * ../css/theme.css (the app's own design-system stylesheet, read-only
 * reference) exactly, so the marketing page and the app feel like one
 * product even though this file imports nothing and stands alone: no
 * external assets, no build step, system fonts only.
 *
 * Monochrome is the point. The only colour permitted outside the neutral
 * scale is the small --good/--inaccuracy/--blunder set below, used only
 * for real chess move-classification dots, never as decoration. Their
 * values match theme.css's already-verified AA-contrast pairs rather than
 * a plain swatch, so both files show the same shade of "blunder red".
 */

:root {
  color-scheme: light;

  /* ---------------------------------------------------------- surfaces */
  --background: #ffffff;
  --foreground: #0a0a0a;
  --card: #ffffff;
  --card-foreground: #0a0a0a;

  /* ---------------------------------------------------------- actions */
  --primary: #171717;
  --primary-foreground: #fafafa;
  --secondary: #f5f5f5;
  --secondary-foreground: #171717;

  /* ------------------------------------------------------- neutral fill */
  --muted: #f5f5f5;
  --muted-foreground: #737373;
  --accent: #f5f5f5;
  --accent-foreground: #171717;

  /* --------------------------------------------------------- structure */
  --border: #e5e5e5;
  --input: #e5e5e5;
  --ring: #0a0a0a;
  --radius: 0.5rem;
  --radius-sm: calc(var(--radius) - 4px);
  --radius-md: calc(var(--radius) - 2px);
  --radius-lg: var(--radius);
  --radius-xl: calc(var(--radius) + 4px);
  --radius-full: 999px;

  /* ------------------------------------------------------- chess status
   * The one exception to the neutral scale, reserved for small dots and
   * labels on real move-classification data only. good/inaccuracy are
   * one Tailwind step darker than the owner's raw reference swatch so
   * 13-15px label text clears WCAG AA (4.5:1) on white; blunder was
   * already AA at the reference value. Verified: good 5.02:1, inaccuracy
   * 5.02:1, blunder 4.83:1 against #ffffff.
   */
  --good: #15803d;
  --inaccuracy: #b45309;
  --blunder: #dc2626;

  /* ------------------------------------------------------------- fonts */
  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  /* ---------------------------------------------------------- shadows
   * Minimal by design. These two are the only elevation used anywhere.
   */
  --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.04);
  --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.06), 0 1px 2px -1px rgb(0 0 0 / 0.06);

  --max: 1120px;
}

* { box-sizing: border-box; }

html { color-scheme: light; scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

body {
  margin: 0;
  background: var(--background);
  color: var(--foreground);
  font: 16px/1.6 var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; }

/* Body-copy links: underlined, monochrome. No colour accent in this theme. */
a { color: var(--foreground); text-decoration-color: var(--border); text-underline-offset: 3px; }
a:hover { text-decoration-color: currentColor; text-decoration-thickness: 2px; }

/* Consistent, visible keyboard focus everywhere - never remove outline. */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--ring);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

h1, h2, h3 { font-weight: 650; line-height: 1.2; margin: 0 0 .5em; color: var(--foreground); }
h1 { font-size: clamp(28px, 5vw, 46px); letter-spacing: -0.01em; }
h2 { font-size: clamp(22px, 3.4vw, 30px); letter-spacing: -0.01em; }
h3 { font-size: 18px; }
p { margin: 0 0 1em; }
.lede { font-size: 19px; color: var(--muted-foreground); max-width: 62ch; }

.container { max-width: var(--max); margin: 0 auto; padding: 0 22px; }
section { padding: 72px 0; border-bottom: 1px solid var(--border); }
section:last-of-type { border-bottom: none; }

/* Alternating tint bands (white / muted) give the page rhythm using only
   greyscale value, no colour. */
.explorer-section, .privacy-section { background: var(--muted); }

/* --------------------------------------------------------------- skip link */

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  background: var(--primary);
  color: var(--primary-foreground);
  padding: 10px 16px;
  border-radius: var(--radius-md);
  font-weight: 700;
  z-index: 100;
  transition: top .15s ease;
}
.skip-link:focus { top: 12px; }

/* -------------------------------------------------------------- site head */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
@supports not (backdrop-filter: blur(1px)) {
  .site-header { background: var(--background); }
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 14px;
  padding-bottom: 14px;
  flex-wrap: wrap;
}

.wordmark { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--foreground); }
.wordmark-icon { flex: 0 0 auto; display: block; }
.wordmark .mark { font-size: 22px; font-weight: 800; letter-spacing: -0.02em; color: var(--foreground); }
.wordmark .strap { font-size: 13px; color: var(--muted-foreground); align-self: baseline; }
.wordmark:hover .mark { text-decoration: underline; text-underline-offset: 3px; }

.site-nav ul { list-style: none; display: flex; gap: 4px; margin: 0; padding: 0; flex-wrap: wrap; align-items: center; }
.site-nav a {
  display: inline-block;
  padding: 8px 12px;
  border-radius: var(--radius-md);
  color: var(--muted-foreground);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
}
.site-nav a:hover { color: var(--foreground); background: var(--muted); }
.site-nav a.cta { color: var(--primary-foreground); background: var(--primary); }
.site-nav a.cta:hover { filter: brightness(1.25); color: var(--primary-foreground); background: var(--primary); }

/* -------------------------------------------------------------------- hero */

.hero { padding-top: 56px; }
.hero .container {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 48px;
  align-items: center;
}
@media (max-width: 860px) {
  .hero .container { grid-template-columns: 1fr; }
  .hero-art { order: -1; }
}

.hero h1 { margin-bottom: .4em; }
.hero .sub-line { font-size: 18px; color: var(--muted-foreground); max-width: 58ch; }
.hero .sub-line strong { color: var(--foreground); }

.cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin: 26px 0 14px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: var(--radius-md);
  padding: 13px 20px;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid var(--border);
  cursor: pointer;
}
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-foreground); }
.btn.primary:hover { filter: brightness(1.25); }
.btn.ghost { background: transparent; color: var(--foreground); }
.btn.ghost:hover { background: var(--accent); border-color: var(--foreground); }

.microcopy { font-size: 13px; color: var(--muted-foreground); }
.microcopy .sep { margin: 0 8px; opacity: .5; }

.hero-art { display: flex; align-items: center; justify-content: center; }
.hero-art svg { width: 100%; height: auto; }

/* ----------------------------------------------------------------- badges */

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font: 700 12px/1 var(--font-mono);
  padding: 7px 12px;
  border-radius: var(--radius-full);
  background: var(--primary);
  color: var(--primary-foreground);
}

/* ------------------------------------------------------------------ prose */

.prose-section .container { max-width: 860px; }
.prose-section p { font-size: 17px; color: var(--foreground); }
.prose-section p.muted { color: var(--muted-foreground); }

/* -------------------------------------------------------------- how-steps */

.steps {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  counter-reset: step;
}
@media (max-width: 900px) {
  .steps { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; }
}
.steps li {
  counter-increment: step;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xs);
  padding: 20px 18px;
  position: relative;
}
.steps li::before {
  content: counter(step);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--primary-foreground);
  font: 800 14px/1 var(--font-mono);
  margin-bottom: 14px;
}
.steps h3 { margin-bottom: 6px; }
.steps p { color: var(--muted-foreground); font-size: 14.5px; margin-bottom: 0; }
.steps-loop {
  margin-top: 18px;
  color: var(--muted-foreground);
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.steps-loop .loop-icon { flex: 0 0 auto; color: var(--foreground); }

/* -------------------------------------------------------------------- jobs */

.jobs {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
@media (max-width: 800px) {
  .jobs { grid-template-columns: 1fr; }
}
.jobs li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xs);
  padding: 24px 22px;
}
.jobs .job-kicker {
  display: inline-block;
  font: 800 12px/1 var(--font-mono);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--primary-foreground);
  background: var(--primary);
  border-radius: var(--radius-full);
  padding: 6px 10px;
  margin-bottom: 14px;
}
.jobs h3 { margin-bottom: 8px; }
.jobs p { color: var(--muted-foreground); font-size: 15px; margin-bottom: 0; }

/* Small, restrained move-classification legend, real product data only -
   see public/js/analysis.js MOVE_CLASS. Dots are graphical (3:1 checked),
   labels stay in the default text colour so they always pass AA on their
   own regardless of the dot colour. */
.class-legend { list-style: none; display: flex; gap: 16px; flex-wrap: wrap; margin: 16px 0 0; padding: 0; font-size: 13px; color: var(--muted-foreground); }
.class-legend li { display: flex; align-items: center; gap: 7px; }
.class-legend .dot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; flex: 0 0 auto; }
.class-legend .dot-good { background: var(--good); }
.class-legend .dot-inaccuracy { background: var(--inaccuracy); }
.class-legend .dot-blunder { background: var(--blunder); }

/* --------------------------------------------------------------- explorer */

.explorer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 40px;
  align-items: start;
  margin-top: 30px;
}
@media (max-width: 900px) {
  .explorer-grid { grid-template-columns: 1fr; }
}

.explorer-demo {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  padding: 20px;
}
.explorer-demo .demo-label {
  font: 700 12px/1 var(--font-mono);
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--muted-foreground);
  margin-bottom: 12px;
}
.demo-position { font: 14px/1.5 var(--font-mono); color: var(--muted-foreground); margin-bottom: 14px; }
.demo-position strong { color: var(--foreground); }

.variation-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.variation-list li {
  display: grid;
  grid-template-columns: 64px 1fr auto;
  gap: 10px;
  align-items: baseline;
  background: var(--muted);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  font-size: 14px;
}
.variation-list .san { font: 700 14px/1 var(--font-mono); color: var(--foreground); }
.variation-list .name { color: var(--foreground); }
.variation-list .name .eco { color: var(--muted-foreground); font: 12px/1 var(--font-mono); margin-left: 6px; }
.variation-list .share { color: var(--muted-foreground); font: 12px/1 var(--font-mono); text-align: right; white-space: nowrap; }
.variation-list li.novelty { border-style: dashed; background: var(--card); }
.variation-list li.novelty .name { color: var(--muted-foreground); font-style: italic; }
.variation-list li.is-main { background: var(--card); border-color: var(--foreground); border-width: 1.5px; }

@media (max-width: 480px) {
  .variation-list li { grid-template-columns: 1fr; gap: 4px; }
  .variation-list .share { text-align: left; }
}

.explorer-copy .stat-row { display: flex; gap: 22px; flex-wrap: wrap; margin: 22px 0; }
.explorer-copy .stat b { display: block; font: 800 26px/1.1 var(--font-mono); color: var(--foreground); }
.explorer-copy .stat span { font-size: 13px; color: var(--muted-foreground); }

/* ------------------------------------------------------------- comparison */

.compare-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 34px; }
@media (max-width: 760px) { .compare-grid { grid-template-columns: 1fr; } }
.compare-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xs);
  padding: 22px;
}
.compare-card h3 { color: var(--muted-foreground); font-size: 14px; text-transform: uppercase; letter-spacing: .05em; margin-bottom: 12px; }
.compare-card p { font-size: 15px; margin-bottom: 0; }
.compare-close { margin-top: 26px; font-size: 17px; }
.compare-close strong { color: var(--foreground); }

/* --------------------------------------------------------------- privacy */

.privacy-section .container { max-width: 860px; }
.privacy-list { list-style: none; margin: 26px 0 0; padding: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
@media (max-width: 640px) { .privacy-list { grid-template-columns: 1fr; } }
.privacy-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs);
  padding: 14px 16px;
  font-size: 14.5px;
}
.privacy-list .icon { flex: 0 0 auto; color: var(--foreground); margin-top: 2px; }

/* -------------------------------------------------------------------- faq */

.faq-list { margin-top: 30px; display: flex; flex-direction: column; gap: 10px; }
.faq-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
}
.faq-item summary {
  cursor: pointer;
  padding: 16px 18px;
  font-weight: 650;
  font-size: 16px;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary .chevron { flex: 0 0 auto; transition: transform .15s ease; color: var(--muted-foreground); }
.faq-item[open] summary .chevron { transform: rotate(90deg); }
.faq-item summary:hover { background: var(--muted); }
.faq-item .faq-answer { padding: 0 18px 18px; color: var(--muted-foreground); font-size: 15px; max-width: 72ch; }
.faq-item .faq-answer p { margin-bottom: 0; }

/* ---------------------------------------------------------------- footer */

.site-footer { padding: 40px 0 60px; }
.site-footer .container { display: flex; flex-direction: column; gap: 14px; }
.footer-links { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.footer-links a { color: var(--foreground); font-weight: 650; text-decoration: none; }
.footer-links a:hover { text-decoration: underline; text-underline-offset: 3px; }
.footer-credits { color: var(--muted-foreground); font-size: 13px; max-width: 80ch; }
.footer-credits a { color: var(--muted-foreground); text-decoration-color: var(--border); }
.footer-credits a:hover { color: var(--foreground); text-decoration-color: currentColor; }
.footer-note { color: var(--muted-foreground); font-size: 12.5px; }

/* ------------------------------------------------------------ misc utils */

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; border: 0; padding: 0;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  overflow: hidden;
  white-space: nowrap;
}