:root {
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --bg: #ffffff;
  --bg-alt: #f5f5f7;
  --accent: #ff6b35;
  --border: #e5e5ea;
  --page-pad: 20px;
  --max-width: 100%;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.7;
  padding-left: max(var(--page-pad), env(safe-area-inset-left));
  padding-right: max(var(--page-pad), env(safe-area-inset-right));
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 0 80px;
}

header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

header .meta {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

header .meta span + span::before {
  content: "·";
  margin: 0 8px;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 36px;
  margin-bottom: 12px;
}

h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
}

p {
  margin-bottom: 12px;
}

ul, ol {
  margin-bottom: 12px;
  padding-left: 1.5em;
}

li {
  margin-bottom: 6px;
}

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

a:hover {
  text-decoration: underline;
}

.lang-switcher {
  display: flex;
  gap: 12px;
  margin-top: 12px;
}

.lang-switcher a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding: 4px 12px;
  border-radius: 16px;
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.lang-switcher a:hover,
.lang-switcher a.active {
  color: var(--accent);
  border-color: var(--accent);
  text-decoration: none;
}

.footer-nav {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-nav a {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.highlight-box {
  background: var(--bg-alt);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 16px 0;
}

@media (max-width: 480px) {
  .container {
    padding: 32px 0 60px;
  }
  header h1 {
    font-size: 1.5rem;
  }
}

@media (min-width: 768px) {
  :root {
    --page-pad: 48px;
  }

  html {
    font-size: 17px;
  }

  header h1 {
    font-size: 2rem;
  }
}

@media (min-width: 1024px) {
  :root {
    --page-pad: clamp(48px, 6vw, 96px);
    --max-width: 1200px;
  }
}