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

:root {
  --font: 'Segoe UI Variable', 'Segoe UI', 'Yu Gothic UI', 'Malgun Gothic', 'Microsoft YaHei UI', -apple-system, system-ui, sans-serif;
  --radius-card: 12px;
  --radius-btn: 8px;
}

[data-theme="dark"] {
  --bg: #1A1612;
  --surface: #261F19;
  --surface-hover: #2E2520;
  --border: #382D24;
  --border-subtle: #302720;
  --accent: #CC7744;
  --accent-hover: #D49B6A;
  --accent-pressed: #A0613A;
  --text: #EEDDD0;
  --text-secondary: #9E8878;
  --text-tertiary: #907E72;
}

[data-theme="light"] {
  --bg: #FFF7F0;
  --surface: #EEE0D2;
  --surface-hover: #F5EAE0;
  --border: #D8C8B8;
  --border-subtle: #D8C8B8;
  --accent: #9E5528;
  --accent-hover: #B86838;
  --accent-pressed: #905020;
  --text: #382820;
  --text-secondary: #7D6452;
  --text-tertiary: #7D6B5D;
}

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

body {
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 2px; }

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

.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  background: var(--accent);
  color: var(--bg);
  padding: 8px 16px;
  border-radius: var(--radius-btn);
  z-index: 100;
  font-weight: 600;
}

.skip-link:focus { top: 16px; }

.container { max-width: 960px; margin: 0 auto; padding: 0 24px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border-subtle);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 56px;
  padding: 12px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.brand-icon { border-radius: 6px; }

.brand-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.02em;
}

.site-controls {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 18px;
  flex: 1;
  flex-wrap: wrap;
}

.nav-links,
.locale-links {
  list-style: none;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
}

.nav-links { gap: 24px; }

.nav-links a {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

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

.locale-links { gap: 12px; }

.locale-links a {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
}

.locale-links a[aria-current="page"] { color: var(--text); }
.locale-links a:hover { color: var(--text); }

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-btn);
  padding: 6px 8px;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.theme-toggle:hover { color: var(--text); border-color: var(--accent); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: none; }

.hero { padding: 80px 0 64px; }

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 48px;
  align-items: center;
}

.hero-text h1 {
  font-size: 40px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 520px;
  margin-bottom: 32px;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--accent);
  color: var(--bg);
  font-size: 15px;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-btn);
  border: none;
  cursor: pointer;
}

.cta-button:hover { background: var(--accent-hover); color: var(--bg); }
.cta-button:active { background: var(--accent-pressed); }
.cta-button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.hero-platform {
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.mockup-frame {
  width: 280px;
  height: 280px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  display: flex;
  align-items: center;
  justify-content: center;
}

.mockup-timer {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.mockup-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--accent);
  text-transform: uppercase;
}

.mockup-time {
  font-size: 56px;
  font-weight: 600;
  line-height: 1;
  color: var(--text);
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.mockup-session {
  font-size: 12px;
  color: var(--text-tertiary);
}

.mockup-progress {
  width: 160px;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-top: 4px;
}

.mockup-bar {
  width: 55%;
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
}

.features {
  padding: 64px 0;
  border-top: 1px solid var(--border-subtle);
}

.features h2 {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

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

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 28px;
}

.feature-card:hover { background: var(--surface-hover); }

.feature-card h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.why {
  padding: 64px 0;
  border-top: 1px solid var(--border-subtle);
}

.why h2 {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 28px;
}

.why-content p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
  max-width: 680px;
}

.why-content strong { color: var(--text); font-weight: 600; }

.download {
  padding: 64px 0;
  border-top: 1px solid var(--border-subtle);
}

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

.download h2 {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 24px;
}

.download-cta { margin-bottom: 8px; }

.sys-reqs {
  display: inline-grid;
  grid-template-columns: auto auto;
  gap: 4px 24px;
  text-align: left;
  margin-top: 28px;
  font-size: 13px;
}

.sys-reqs dt {
  color: var(--text-tertiary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 11px;
  align-self: center;
}

.sys-reqs dd { color: var(--text-secondary); }

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 24px 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--text-tertiary);
  gap: 12px;
}

.footer-brand a { color: var(--text-tertiary); }
.footer-brand a:hover { color: var(--text-secondary); }

.footer-inner nav a { color: var(--text-tertiary); }
.footer-inner nav a:hover { color: var(--text-secondary); }

:lang(ja) .hero-text h1,
:lang(ko) .hero-text h1,
:lang(zh-Hans) .hero-text h1 {
  letter-spacing: 0;
  line-height: 1.25;
}

:lang(ja) .nav-links a,
:lang(ko) .nav-links a,
:lang(zh-Hans) .nav-links a,
:lang(ja) .features h2,
:lang(ko) .features h2,
:lang(zh-Hans) .features h2 {
  letter-spacing: 0.08em;
}

@media (max-width: 860px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-controls {
    width: 100%;
    justify-content: space-between;
  }
}

@media (max-width: 720px) {
  .hero { padding: 48px 0 40px; }

  .hero-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-visual { display: flex; justify-content: center; }

  .hero-text h1 { font-size: 28px; }

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

  .nav-links { gap: 16px; }

  .nav-links a,
  .locale-links a { font-size: 12px; }

  .footer-inner { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 560px) {
  .site-controls {
    flex-direction: column;
    align-items: flex-start;
  }

  .theme-toggle { margin-top: 4px; }
}

@media (max-width: 480px) {
  .hero-text h1 { font-size: 24px; }
  .hero-sub { font-size: 14px; }
  .container { padding: 0 16px; }
  .nav-links,
  .locale-links { gap: 12px; }
  .mockup-frame {
    width: min(280px, 100%);
    height: 260px;
  }
}