:root {
  color-scheme: light;

  --bg: #ffffff;
  --bg-subtle: #f5f5f6;
  --surface: #ffffff;
  --border: #e4e4e7;
  --border-strong: #a1a1aa;
  --glow: rgba(0, 0, 0, 0.05);

  --glass-bg: rgba(255, 255, 255, 0.62);
  --glass-fill: rgba(0, 0, 0, 0.045);
  --glass-fill-hover: rgba(0, 0, 0, 0.09);
  --glass-border: rgba(0, 0, 0, 0.1);
  --glass-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
  --glass-blur: saturate(160%) blur(16px);

  --text: #09090b;
  --text-soft: #3f3f46;
  --muted: #71717a;

  --accent: #09090b;
  --on-accent: #ffffff;

  --radius: 12px;
  --radius-sm: 8px;

  --sidebar-width: 280px;
  --content-width: 820px;

  --font-body: Inter, "Segoe UI", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", SFMono-Regular, Menlo, Consolas, monospace;
}

:root[data-theme="dark"] {
  color-scheme: dark;

  --bg: #141518;
  --bg-subtle: #1c1e22;
  --surface: #1a1c20;
  --border: #2d3036;
  --border-strong: #6b6f78;
  --glow: rgba(255, 255, 255, 0.07);

  --text: #ffffff;
  --text-soft: #d3d5da;
  --muted: #9a9ea8;

  --accent: #ffffff;
  --on-accent: #141518;

  --glass-bg: rgba(34, 37, 42, 0.55);
  --glass-fill: rgba(255, 255, 255, 0.06);
  --glass-fill-hover: rgba(255, 255, 255, 0.12);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}

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

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-soft);
  background-color: var(--bg);
  background-image:
    radial-gradient(60rem 40rem at 85% -10%, var(--glow), transparent 60%),
    radial-gradient(50rem 35rem at -10% 110%, var(--glow), transparent 60%);
  background-attachment: fixed;
  transition: background-color 0.2s, color 0.2s;
}

::selection {
  color: var(--bg);
  background: var(--text);
}

h1,
h2,
h3 {
  margin: 0 0 16px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
}

@supports (background-clip: text) or (-webkit-background-clip: text) {
  h1 {
    background-image: linear-gradient(180deg, var(--text) 35%, var(--muted));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
  }
}

h2 {
  margin-top: 48px;
  font-size: 1.5rem;
}

h3 {
  font-size: 1.05rem;
}

p {
  margin: 0 0 20px;
}

strong {
  color: var(--text);
}

a {
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: var(--border-strong);
  text-underline-offset: 3px;
}

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

:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 3px;
}

ul,
ol {
  margin: 0 0 20px;
  padding-left: 24px;
}

hr {
  margin: 40px 0 20px;
  border: 0;
  border-top: 1px solid var(--border);
}

code {
  padding: 2px 6px;
  font-family: var(--font-mono);
  font-size: 0.85em;
  color: var(--text);
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: 6px;
}

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

.tone-b {
  color: var(--muted);
}

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