/* ===== CSS Custom Properties ===== */
:root {
  --color-bg: #fafbfc;
  --color-bg-alt: #f1f5f9;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-accent: #2563EB;
  --color-accent-hover: #1D4ED8;
  --color-accent-subtle: #eff6ff;
  --color-success: #059669;
  --color-accent-shadow: rgba(37, 99, 235, 0.3);
  --color-accent-shadow-hover: rgba(37, 99, 235, 0.4);
  --color-footer-bg: #0f172a;
  --color-footer-text: #cbd5e1;
  --color-footer-text-muted: #64748b;

  --font-sans: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.08);

  --max-width: 1200px;
  --nav-height: 64px;
}

/* ===== Dark Mode ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f172a;
    --color-bg-alt: #1e293b;
    --color-surface: #1e293b;
    --color-border: #334155;
    --color-text: #f1f5f9;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    --color-accent: #3b82f6;
    --color-accent-hover: #60a5fa;
    --color-accent-subtle: #1e3a5f;
    --color-accent-shadow: rgba(59, 130, 246, 0.3);
    --color-accent-shadow-hover: rgba(59, 130, 246, 0.4);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
  }
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

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

/* ===== Nav ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav-inner {
  max-width: var(--max-width);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.logo svg {
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: color 0.15s, background-color 0.15s;
}

.nav-links a:hover {
  color: var(--color-text);
  background: var(--color-bg-alt);
}

/* ===== Hero ===== */
.hero {
  padding: 80px 24px 96px;
  text-align: center;
}

.hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.hero-title {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--color-text);
}

.hero-highlight {
  color: var(--color-accent);
}

.hero-sub {
  margin-top: 24px;
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero-cta {
  margin-top: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-sans);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background-color 0.15s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--color-accent);
  color: #ffffff;
  box-shadow: 0 2px 8px var(--color-accent-shadow);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 4px 16px var(--color-accent-shadow-hover);
}

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

.btn-secondary:hover {
  background: var(--color-bg-alt);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

/* ===== Section ===== */
.section {
  padding: 80px 24px;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}

.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.section-desc {
  margin-top: 12px;
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--color-text-secondary);
}

/* ===== Product Grid ===== */
.product-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.product-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  display: flex;
  flex-direction: column;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.product-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent);
}

.product-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.product-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.product-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-bottom: 16px;
}

.product-features {
  list-style: none;
  margin-bottom: 24px;
}

.product-features li {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  padding: 4px 0;
  padding-left: 20px;
  position: relative;
}

.product-features li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
}

.product-link {
  margin-top: auto;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-accent);
  transition: gap 0.2s;
}

.product-link:hover {
  text-decoration: underline;
}

/* ===== Agent Grid ===== */
.agent-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 12px;
}

.agent-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.agent-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.agent-provider {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

/* ===== Features Grid ===== */
.features-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px 24px;
}

.feature-item {
  padding: 8px 0;
}

.feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
}

.feature-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.feature-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
  max-width: 320px;
}

/* ===== FAQ ===== */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  padding: 20px 24px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question::after {
  content: "+";
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--color-text-muted);
  transition: transform 0.2s;
  flex-shrink: 0;
  margin-left: 12px;
}

details[open] .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 24px 20px;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ===== CTA Section ===== */
.cta-section {
  padding: 96px 24px;
  text-align: center;
  background: var(--color-accent);
  color: #ffffff;
}

.cta-inner {
  max-width: 560px;
  margin: 0 auto;
}

.cta-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.cta-desc {
  margin-top: 16px;
  font-size: 1.1rem;
  opacity: 0.85;
  line-height: 1.6;
}

.cta-section .btn-primary {
  margin-top: 32px;
  background: #ffffff;
  color: var(--color-accent);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.cta-section .btn-primary:hover {
  background: #f0f5ff;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.2);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
  padding: 64px 24px 32px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 48px;
}

.footer-tagline {
  margin-top: 12px;
  font-size: 0.9rem;
  color: var(--color-footer-text-muted);
}

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

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col-title {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-footer-text-muted);
  margin-bottom: 4px;
}

.footer-col a {
  font-size: 0.9rem;
  color: var(--color-footer-text);
  transition: color 0.15s;
}

.footer-col a:hover {
  color: #ffffff;
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 48px auto 0;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.85rem;
  color: var(--color-footer-text-muted);
}

/* ===== Launcher ===== */
.launcher-cli {
  max-width: var(--max-width);
  margin: 0 auto 56px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.cli-header {
  padding-top: 8px;
}

.cli-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.cli-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.cli-code {
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
}

.cli-prompt {
  color: var(--color-accent);
  user-select: none;
}

.cli-comment {
  color: var(--color-text-muted);
}

.cli-demo {
  margin-top: 0;
}

.cli-tabs + .cli-demo {
  margin-top: 16px;
}

/* Launcher Features */
.launcher-features {
  max-width: var(--max-width);
  margin: 0 auto 56px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.launcher-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: box-shadow 0.2s, border-color 0.2s;
}

.launcher-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent);
}

.launcher-card-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-accent-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
}

.launcher-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.launcher-card-desc {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* Launcher Platforms */
.launcher-platforms {
  max-width: var(--max-width);
  margin: 0 auto 48px;
  text-align: center;
}

.platforms-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.platforms-desc {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}

.platforms-list {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.platform-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 20px 32px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  min-width: 140px;
}

.platform-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--color-text);
}

.platform-arch {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.platforms-note {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 16px;
}

.platforms-note code {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: var(--color-bg-alt);
  padding: 2px 8px;
  border-radius: 4px;
}

/* Launcher CTA */
.launcher-cta {
  text-align: center;
  padding-top: 16px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  .hero {
    padding: 56px 20px 64px;
  }

  .hero-title {
    font-size: 2rem;
  }

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

  .hero-cta {
    flex-direction: column;
    gap: 12px;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .section {
    padding: 56px 20px;
  }

  .section-header {
    margin-bottom: 40px;
  }

  .product-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .product-card {
    padding: 24px;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .agent-grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-links {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .nav-links a {
    padding: 6px 12px;
    font-size: 0.85rem;
  }

  .logo span {
    font-size: 1.1rem;
  }

  .agent-grid {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .agent-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
    padding: 12px 16px;
  }

  .launcher-cli {
    grid-template-columns: 1fr;
  }

  .platforms-list {
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }

  .footer-links {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}