:root {
  --background: #f3ebdd;
  --panel: #faf4ea;
  --panel-muted: #f0e4d1;
  --card: #fff9f0;
  --text: #1e2420;
  --text-muted: #6e695f;
  --accent: #556b59;
  --accent-strong: #3a4d40;
  --border: rgba(71, 68, 61, 0.14);
  --warning: #c88a3d;
  --success: #4d7460;
  --shadow: rgba(56, 45, 27, 0.16);
  --focus-glow: rgba(233, 196, 126, 0.3);
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #171714;
    --panel: #1e1f1b;
    --panel-muted: #2a2c27;
    --card: #242620;
    --text: #f4e8d7;
    --text-muted: #c4b5a1;
    --accent: #8aa183;
    --accent-strong: #b6c5b0;
    --border: rgba(255, 245, 232, 0.1);
    --warning: #c99a57;
    --success: #7ca592;
    --shadow: rgba(0, 0, 0, 0.35);
    --focus-glow: rgba(170, 128, 70, 0.24);
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont,
    'Segoe UI', sans-serif;
  background-color: var(--background);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 18px;
}

header {
  background-color: var(--panel);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.logo img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.logo span {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

nav ul {
  display: flex;
  list-style: none;
  gap: 24px;
  align-items: center;
}

nav a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  font-size: 14px;
  transition: opacity 0.2s;
}

nav a:hover {
  opacity: 0.7;
}

.lang-switch {
  display: flex;
  gap: 8px;
}

.lang-switch a {
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  background-color: var(--panel-muted);
  color: var(--text-muted);
  text-decoration: none;
}

.lang-switch a:hover {
  opacity: 0.8;
}

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

.hero h1 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text);
}

.hero p {
  font-size: clamp(16px, 2vw, 20px);
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 32px;
}

.hero-icon {
  width: 80px;
  height: 80px;
  border-radius: 20px;
  margin-bottom: 24px;
}

.cta-button {
  display: inline-block;
  background-color: var(--accent-strong);
  color: #fff7ed;
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 16px;
  text-decoration: none;
  transition: transform 0.2s, opacity 0.2s;
}

.cta-button:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}

.section {
  padding: 60px 0;
}

.section-title {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text);
}

.section-subtitle {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 32px;
}

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

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px var(--shadow);
}

.feature-icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
  color: var(--accent-strong);
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.feature-card p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

.screenshots-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-top: 32px;
}

.screenshot-placeholder {
  background-color: var(--panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  aspect-ratio: 9/16;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 14px;
}

.download-section {
  background-color: var(--panel);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
  padding: 80px 0;
}

.download-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 32px;
}

.download-btn {
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 24px;
  text-decoration: none;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 12px;
  transition: transform 0.2s, opacity 0.2s;
  opacity: 0.5;
  cursor: not-allowed;
}

.download-btn:hover {
  transform: translateY(-2px);
}

.download-btn svg {
  width: 24px;
  height: 24px;
  color: var(--text-muted);
}

.download-btn span {
  font-weight: 600;
  font-size: 14px;
}

.contact-section {
  padding: 60px 0;
  text-align: center;
}

.contact-email {
  display: inline-block;
  background-color: var(--panel-muted);
  color: var(--text);
  padding: 14px 24px;
  border-radius: 999px;
  font-weight: 500;
  font-size: 15px;
  text-decoration: none;
  transition: transform 0.2s, opacity 0.2s;
  margin-top: 24px;
}

.contact-email:hover {
  transform: translateY(-2px);
  opacity: 0.8;
}

footer {
  background-color: var(--panel);
  border-top: 1px solid var(--border);
  padding: 40px 0;
  text-align: center;
}

footer p {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 8px;
}

footer nav {
  margin-top: 16px;
}

footer nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  margin: 0 12px;
  transition: opacity 0.2s;
}

footer nav a:hover {
  opacity: 0.7;
}

@media (max-width: 768px) {
  nav ul {
    gap: 16px;
  }

  .hero {
    padding: 60px 0;
  }

  .section {
    padding: 40px 0;
  }

  .download-section {
    padding: 60px 0;
  }
}

@media (max-width: 480px) {
  nav ul {
    gap: 12px;
  }

  nav a {
    font-size: 13px;
  }

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