/* ==========================================================================
   Forest AI Academy — marketing site
   Light forest theme, system fonts, no frameworks (design.md §5)
   Desktop-first full-bleed sections; responsive to small screens.
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-2: #f1f7f3;
  --card: #ffffff;
  --card-2: #f6faf7;
  --line: rgba(12, 34, 23, 0.1);
  --line-strong: rgba(12, 34, 23, 0.16);
  --text: #15271e;
  --muted: #4d6257;
  --accent: #0a7c4a;          /* deep forest green — interactive text & accents */
  --accent-2: #0c9157;        /* hover / gradient partner */
  --mint: #3ddc97;            /* bright mint — decorative + on-dark CTAs */
  --mint-soft: rgba(10, 124, 74, 0.1);
  --amber: #b45309;
  --panel: #0a1b13;           /* dark forest — CTA band + footer */
  --panel-2: #0e2a1c;
  --on-dark: #e9f4ee;
  --on-dark-muted: #8fa799;
  --radius: 16px;
  --shadow: 0 10px 30px rgba(13, 39, 27, 0.07);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.container {
  width: 100%;
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 28px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  border-radius: 0 0 8px 0;
  font-weight: 600;
  z-index: 100;
}
.skip:focus { left: 0; }

/* --- nav ------------------------------------------------------------------ */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  min-height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 17px;
  color: var(--text);
  letter-spacing: -0.01em;
}
.logo:hover { text-decoration: none; }
.logo svg { width: 28px; height: 28px; flex: none; }
.logo .logo-sub { color: var(--muted); font-weight: 500; font-size: 12px; display: block; line-height: 1.1; }

.nav-links {
  display: flex;
  gap: 24px;
  margin-left: 8px;
}
.nav-links a { color: var(--muted); font-size: 15px; font-weight: 500; }
.nav-links a:hover { color: var(--accent); text-decoration: none; }

.nav-cta {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 16px;
}
.nav-signin { color: var(--muted); font-size: 15px; font-weight: 500; }
.nav-signin:hover { color: var(--accent); }

.nav-toggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line-strong);
  color: var(--text);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 18px;
  cursor: pointer;
}

/* --- buttons ---------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 15px;
  font-family: var(--font);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 8px 24px rgba(10, 124, 74, 0.25);
}
.btn-primary:hover { background: var(--accent-2); }

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line-strong);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.btn-sm { padding: 9px 16px; font-size: 14px; border-radius: 10px; }

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

.hero {
  position: relative;
  overflow: hidden;
  padding: 96px 0 84px;
  background:
    radial-gradient(760px 420px at 88% -12%, rgba(10, 124, 74, 0.1), transparent 60%),
    radial-gradient(560px 320px at 4% 108%, rgba(10, 124, 74, 0.06), transparent 60%),
    var(--bg-2);
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--mint-soft);
  border: 1px solid rgba(10, 124, 74, 0.25);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 22px;
}

.hero h1 {
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.1;
  letter-spacing: -0.025em;
  font-weight: 800;
  margin: 0 0 22px;
}

.hero h1 .accent {
  background: linear-gradient(92deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.lead {
  font-size: 18px;
  color: var(--muted);
  max-width: 54ch;
  margin: 0 0 30px;
}

.cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 18px; }

.proof {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 14px;
}
.proof .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); flex: none; }

/* the hero art is a self-contained dark illustration — frame it like a product shot */
.hero-art { position: relative; }
.hero-art::after {
  content: "";
  position: absolute;
  inset: -14px;
  border-radius: 28px;
  background: radial-gradient(closest-side, rgba(10, 124, 74, 0.14), transparent);
  z-index: -1;
}
.hero-art svg {
  border-radius: 22px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 24px 60px -18px rgba(6, 34, 20, 0.55);
}

/* --- sections ----------------------------------------------------------------- */

.section { padding: 88px 0; }
.section.alt { background: var(--bg-2); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }

.section-head { max-width: 680px; margin-bottom: 48px; }

.kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 10px;
}

.section-head h2 {
  font-size: clamp(28px, 3.6vw, 40px);
  letter-spacing: -0.025em;
  line-height: 1.18;
  margin: 0 0 14px;
  font-weight: 800;
}

.section-head p { color: var(--muted); font-size: 17.5px; margin: 0; }

/* --- pillars -------------------------------------------------------------------- */

.pillars {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pillar-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.pillar-card:hover { transform: translateY(-4px); border-color: rgba(10, 124, 74, 0.35); box-shadow: 0 16px 40px rgba(13, 39, 27, 0.1); }

.pillar-icon {
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: var(--mint-soft);
  border: 1px solid rgba(10, 124, 74, 0.22);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
}
.pillar-icon svg { width: 22px; height: 22px; stroke: var(--accent); fill: none; stroke-width: 1.8; }

.pillar-card h3 { margin: 0 0 8px; font-size: 17.5px; font-weight: 700; letter-spacing: -0.01em; }
.pillar-card p { margin: 0; color: var(--muted); font-size: 14.5px; }

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

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  counter-reset: step;
}

.step {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
}

.step-num {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  font-size: 15px;
  margin-bottom: 16px;
}

.step h3 { margin: 0 0 8px; font-size: 17.5px; font-weight: 700; }
.step p { margin: 0; color: var(--muted); font-size: 14.5px; }

/* --- courses ------------------------------------------------------------------------ */

.courses {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.course-card {
  display: flex;
  flex-direction: column;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.course-card:hover { transform: translateY(-4px); border-color: rgba(10, 124, 74, 0.35); box-shadow: 0 16px 40px rgba(13, 39, 27, 0.1); }

/* course covers stay dark — like cover art against the light UI */
.course-thumb {
  height: 148px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.course-thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(120% 90% at 50% 0%, rgba(61, 220, 151, 0.14), transparent 55%);
}
.course-thumb svg { width: 46px; height: 46px; opacity: 0.95; position: relative; }
.thumb-a { background: linear-gradient(135deg, #0d3b27, #0e5c31); }
.thumb-b { background: linear-gradient(135deg, #0d3a45, #0e5a63); }
.thumb-c { background: linear-gradient(135deg, #3c3512, #574a16); }

.course-body { padding: 22px 22px 24px; display: flex; flex-direction: column; gap: 8px; flex: 1; }

.course-meta { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--muted); }
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--mint-soft);
  color: var(--accent);
  border: 1px solid rgba(10, 124, 74, 0.22);
}
.badge-free { background: rgba(180, 83, 9, 0.1); color: var(--amber); border-color: rgba(180, 83, 9, 0.24); }

.course-body h3 { margin: 0; font-size: 17.5px; font-weight: 700; letter-spacing: -0.01em; }
.course-body p { margin: 0; color: var(--muted); font-size: 14.5px; flex: 1; }

.course-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 10px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
}
.price { font-weight: 800; font-size: 18px; }
.price small { color: var(--muted); font-weight: 500; font-size: 13px; }
.course-link { font-weight: 600; font-size: 14.5px; white-space: nowrap; }

/* --- coaching ------------------------------------------------------------------------ */

.coach {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}

.coach-points { list-style: none; margin: 20px 0 28px; padding: 0; display: grid; gap: 12px; }
.coach-points li { display: flex; gap: 12px; color: var(--muted); font-size: 15.5px; }
.coach-points .check {
  flex: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--mint-soft);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 800;
  margin-top: 2px;
}

.coach-card {
  background: linear-gradient(160deg, var(--card), var(--bg-2));
  border: 1px solid rgba(10, 124, 74, 0.28);
  border-radius: var(--radius);
  padding: 32px 30px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.coach-card::before {
  content: "";
  position: absolute;
  inset: -40% -20% auto auto;
  width: 240px;
  height: 240px;
  background: radial-gradient(closest-side, rgba(10, 124, 74, 0.12), transparent);
}
.coach-card h3 { margin: 0 0 6px; font-size: 21px; }
.coach-card .coach-sub { color: var(--accent); font-size: 14px; font-weight: 600; margin: 0 0 18px; }
.coach-card ul { margin: 0 0 22px; padding: 0; list-style: none; display: grid; gap: 10px; color: var(--muted); font-size: 14.5px; }
.coach-card ul li::before { content: "— "; color: var(--accent); }

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

.faq { max-width: 760px; }
.faq details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 4px 20px;
  margin-bottom: 10px;
  transition: border-color 0.2s ease;
}
.faq details[open] { border-color: rgba(10, 124, 74, 0.4); }
.faq summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  font-weight: 600;
  font-size: 15.5px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary .chev { flex: none; transition: transform 0.2s ease; color: var(--accent); }
.faq details[open] summary .chev { transform: rotate(45deg); }
.faq details p { margin: 0 0 18px; color: var(--muted); font-size: 15px; }

/* --- cta band ------------------------------------------------------------------------ */

.cta-band {
  background:
    radial-gradient(700px 340px at 50% 0%, rgba(61, 220, 151, 0.16), transparent 62%),
    linear-gradient(180deg, var(--panel-2), var(--panel));
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
  padding: 96px 0;
}
.cta-band h2 {
  font-size: clamp(28px, 4vw, 42px);
  letter-spacing: -0.02em;
  line-height: 1.18;
  max-width: 22ch;
  margin: 0 auto 16px;
  font-weight: 800;
  color: var(--on-dark);
}
.cta-band p { color: var(--on-dark-muted); margin: 0 0 30px; font-size: 17.5px; }
.cta-band .btn-primary {
  background: var(--mint);
  color: #062318;
  box-shadow: 0 10px 34px rgba(61, 220, 151, 0.3);
}
.cta-band .btn-primary:hover { background: #57e6aa; }

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

.footer {
  padding: 64px 0 44px;
  background: linear-gradient(180deg, var(--panel), #07160f);
  color: var(--on-dark-muted);
}
.footer a { color: var(--on-dark); }

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand .logo { color: var(--on-dark); }
.footer-brand p { color: var(--on-dark-muted); font-size: 14px; max-width: 34ch; margin: 12px 0 0; }

.footer h4 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--on-dark-muted);
  margin: 0 0 14px;
}
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.footer ul a { color: var(--on-dark); font-size: 14.5px; opacity: 0.85; }
.footer ul a:hover { opacity: 1; text-decoration: none; color: var(--mint); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 26px;
  color: var(--on-dark-muted);
  font-size: 13.5px;
}
.lang-switch { display: flex; gap: 8px; }
.lang-switch a { color: var(--on-dark-muted); font-size: 13.5px; }
.lang-switch a:hover { color: var(--on-dark); text-decoration: none; }
.lang-switch a[aria-current] { color: var(--mint); font-weight: 700; }

/* --- legal pages ------------------------------------------------------------------------ */

.legal { padding: 64px 0 88px; }
.legal h1 { font-size: 34px; letter-spacing: -0.02em; margin: 0 0 6px; color: var(--text); }
.legal .updated { color: var(--muted); font-size: 14px; margin: 0 0 40px; }
.legal article { max-width: 72ch; }
.legal h2 { font-size: 20px; margin: 32px 0 10px; letter-spacing: -0.01em; }
.legal p, .legal li { color: var(--muted); font-size: 15.5px; }
.legal ul { padding-left: 22px; }
.legal .note {
  background: var(--mint-soft);
  border: 1px solid rgba(10, 124, 74, 0.22);
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 14px;
  color: var(--accent);
}

/* --- responsive ------------------------------------------------------------------------ */

@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }
  .hero-art { max-width: 480px; margin: 0 auto; }
  .pillars { grid-template-columns: repeat(2, 1fr); }
  .courses { grid-template-columns: 1fr 1fr; }
  .coach { grid-template-columns: 1fr; gap: 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .container { padding: 0 20px; }
  .nav-links {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 12px 24px rgba(13, 39, 27, 0.08);
    flex-direction: column;
    gap: 0;
    padding: 8px 20px 16px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 0; }
  .nav-toggle { display: block; }
  .nav-signin { display: none; }
  .pillars { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .courses { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 56px; }
  .section { padding: 64px 0; }
  .cta-band { padding: 72px 0; }
}