/**
 * CatFGS AI Landing — 樣式表
 * Version: 1.0.3
 */

:root {
  --bg-deep: #0c1222;
  --bg-card: #141c2f;
  --bg-elevated: #1a2540;
  --text: #e8edf5;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.12);
  --accent-warm: #fbbf24;
  --border: rgba(148, 163, 184, 0.15);
  --font-sans: "DM Sans", "Noto Sans TC", system-ui, sans-serif;
  --font-display: "Outfit", "Noto Sans TC", system-ui, sans-serif;
  --radius: 14px;
  --max: 1100px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg-deep);
  background-image:
    radial-gradient(ellipse 120% 80% at 50% -30%, rgba(56, 189, 248, 0.18), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(251, 191, 36, 0.06), transparent);
  min-height: 100vh;
}

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

a:hover {
  text-decoration: underline;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: 0.75rem 1rem;
  background: var(--accent);
  color: var(--bg-deep);
  font-weight: 600;
  z-index: 100;
}

.skip-link:focus {
  left: 0.5rem;
  top: 0.5rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(12px);
  background: rgba(12, 18, 34, 0.85);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), #0ea5e9);
  display: grid;
  place-items: center;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--text);
  text-decoration: none;
}

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.hero {
  padding: 3.5rem 0 3rem;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 1.25rem;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 2.85rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin: 0 0 1rem;
}

.hero-lead {
  max-width: 36rem;
  margin: 0 auto 2rem;
  color: var(--text-muted);
  font-size: 1.1rem;
}

.hero-cta {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.35rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #0284c7);
  color: var(--bg-deep);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(56, 189, 248, 0.35);
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  background: var(--bg-elevated);
  text-decoration: none;
}

section {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border);
}

section h2 {
  font-family: var(--font-display);
  font-size: 1.65rem;
  font-weight: 700;
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.section-intro {
  color: var(--text-muted);
  max-width: 42rem;
  margin-bottom: 1.75rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.35rem 1.5rem;
}

.card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
  color: var(--accent);
}

.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.98rem;
}

.pipeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}

@media (min-width: 768px) {
  .pipeline {
    flex-direction: row;
    align-items: stretch;
  }
}

.pipeline-step {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.35rem 1.25rem;
  position: relative;
}

@media (min-width: 768px) {
  .pipeline-step:not(:last-child)::after {
    content: "→";
    position: absolute;
    right: -0.65rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent);
    font-weight: 700;
    z-index: 1;
    background: var(--bg-deep);
    padding: 0 0.15rem;
  }
}

.pipeline-step:first-child {
  border-radius: var(--radius) var(--radius) 0 0;
}

.pipeline-step:last-child {
  border-radius: 0 0 var(--radius) var(--radius);
}

@media (min-width: 768px) {
  .pipeline-step:first-child {
    border-radius: var(--radius) 0 0 var(--radius);
  }
  .pipeline-step:last-child {
    border-radius: 0 var(--radius) var(--radius) 0;
  }
  .pipeline-step:not(:first-child) {
    border-left: none;
  }
}

.pipeline-step .step-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent-warm);
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.pipeline-step h3 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
}

.pipeline-step p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.au-list {
  margin: 1.25rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.65rem;
}

.au-list li {
  display: flex;
  gap: 0.75rem;
  align-items: baseline;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.au-list strong {
  color: var(--text);
  font-variant-numeric: tabular-nums;
  min-width: 2.5rem;
}

.privacy-block {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
}

.privacy-block h3 {
  font-size: 1rem;
  margin: 1.25rem 0 0.5rem;
  color: var(--text);
}

.privacy-block h3:first-child {
  margin-top: 0;
}

.privacy-block p,
.privacy-block ul {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0 0 0.75rem;
}

.privacy-block ul {
  padding-left: 1.25rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.88rem;
}

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

.disclaimer {
  margin-top: 1rem;
  max-width: 36rem;
  margin-left: auto;
  margin-right: auto;
  font-size: 0.82rem;
  opacity: 0.9;
}

.subsection-title {
  margin-top: 2rem;
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
  font-family: var(--font-display);
  color: var(--text);
}