/* ===== Variables ===== */
:root {
  --color-bg: #0f0f12;
  --color-surface: #18181c;
  --color-surface-elevated: #222228;
  --color-text: #f4f4f5;
  --color-text-muted: #a1a1aa;
  --color-accent: #22c55e;
  --color-accent-hover: #16a34a;
  --color-border: #27272a;
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Outfit', var(--font-sans);
  --radius: 12px;
  --radius-lg: 16px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  color: var(--color-accent-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 15, 18, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 64px;
  flex-wrap: wrap;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-left: auto;
}

.logo {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: var(--color-text-muted);
  font-size: 0.9375rem;
  font-weight: 500;
}

.nav a:hover {
  color: var(--color-text);
}

.lang-switcher {
  position: relative;
  flex-shrink: 0;
}

.lang-switcher__trigger {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
}

.lang-switcher__trigger::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 5px solid var(--color-text-muted);
  margin-left: 2px;
}

.lang-switcher__trigger:hover,
.lang-switcher.is-open .lang-switcher__trigger {
  border-color: rgba(34, 197, 94, 0.4);
  background: var(--color-surface);
}

.lang-switcher__panel {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 140px;
  margin: 0;
  padding: 6px;
  list-style: none;
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
  z-index: 200;
}

.lang-switcher.is-open .lang-switcher__panel {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-switcher__panel li {
  margin: 0;
}

.lang-switcher__option {
  display: block;
  width: 100%;
  padding: 10px 12px;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  text-align: left;
  color: var(--color-text-muted);
  background: transparent;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.lang-switcher__option:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

.lang-switcher__option.is-active {
  color: var(--color-accent);
  background: rgba(34, 197, 94, 0.1);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform 0.1s ease, border-color var(--transition), color var(--transition);
}

.btn-primary {
  background: var(--color-accent);
  color: #0a0a0a;
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  color: #0a0a0a;
}

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

.btn-ghost:hover {
  border-color: rgba(34, 197, 94, 0.4);
  color: var(--color-text);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  align-items: center;
}

.hero {
  padding: 80px 0 120px;
  text-align: center;
}

.badge {
  display: inline-block;
  padding: 6px 14px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-accent);
  background: rgba(34, 197, 94, 0.12);
  border-radius: 999px;
  margin-bottom: 24px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 0 0 20px;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto 32px;
  line-height: 1.65;
}

.hero-visual {
  margin-top: 56px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-visual img {
  width: 100%;
  background: var(--color-surface);
}

.section {
  padding: 80px 0;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
  text-align: center;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  margin: 0 0 16px;
  text-align: center;
}

.section-desc {
  font-size: 1rem;
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto 48px;
  text-align: center;
  line-height: 1.65;
}

.features {
  background: var(--color-surface);
}

.feature-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

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

.feature-card:hover {
  border-color: rgba(34, 197, 94, 0.3);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.feature-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  border-radius: var(--radius);
  background: rgba(34, 197, 94, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.35rem;
  line-height: 1;
}

.feature-card h3 {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  margin: 0 0 8px;
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.6;
}

.spec-block {
  margin-top: 56px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.spec-block .section-subtitle {
  margin-bottom: 8px;
}

.spec-list {
  margin: 0;
  padding: 0 0 0 1.25rem;
  list-style: disc;
  color: var(--color-text-muted);
}

.spec-list li {
  margin-bottom: 12px;
  line-height: 1.6;
  font-size: 0.9375rem;
}

.spec-list li:last-child {
  margin-bottom: 0;
}

.toolkit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.tool-item {
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: border-color var(--transition);
}

.tool-item:hover {
  border-color: rgba(34, 197, 94, 0.25);
}

.tool-icon {
  font-size: 1.75rem;
  display: block;
  margin-bottom: 12px;
}

.tool-item h4 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 6px;
}

.tool-item p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin: 0;
  line-height: 1.55;
}

.discover {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.discover-body {
  max-width: 720px;
  margin: 0 auto;
}

.discover-body p {
  font-size: 1rem;
  color: var(--color-text-muted);
  line-height: 1.75;
  margin: 0 0 1rem;
}

.discover-body p:last-child {
  margin-bottom: 0;
}

.advantage {
  background: var(--color-surface);
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
}

.stat {
  text-align: center;
  padding: 24px 16px;
  background: var(--color-surface-elevated);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}

.stat-value {
  display: block;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.cta {
  padding: 80px 0 100px;
}

.cta-visual {
  max-width: 700px;
  margin: 40px auto 24px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.cta-visual img {
  width: 100%;
  background: var(--color-surface);
}

.cta-note {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  text-align: center;
  margin: 0 0 28px;
}

.btn-play {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  color: #0a0a0a;
  background: var(--color-text);
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform 0.1s ease;
}

.btn-play:hover {
  background: #e4e4e7;
  color: #0a0a0a;
}

.btn-play svg {
  flex-shrink: 0;
}

.play-wrap {
  text-align: center;
}

.footer {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
}

.footer-inner {
  text-align: center;
}

.footer-brand {
  margin-bottom: 16px;
}

.footer-brand .logo {
  display: block;
  font-size: 1.125rem;
  margin-bottom: 4px;
}

.tagline {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.copyright {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin: 0;
}

.hero-visual img,
.cta-visual img {
  background: linear-gradient(135deg, var(--color-surface-elevated) 0%, var(--color-surface) 100%);
}

@media (max-width: 768px) {
  .header-inner {
    height: auto;
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .header-right {
    width: 100%;
    justify-content: space-between;
    margin-left: 0;
  }

  .nav {
    gap: 16px;
    flex-wrap: wrap;
  }

  .hero {
    padding: 48px 0 80px;
  }

  .section {
    padding: 56px 0;
  }

  .feature-cards,
  .toolkit-grid {
    grid-template-columns: 1fr;
  }

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