/* ---------- base colors ---------- */
:root {
  --bg: #0b0b0c;
  --bg-elev: #131316;
  --text: #e6e6e6;
  --muted: #a8a8ad;
  --link: #7aa2ff;
  --border: #222229;
  --btn-bg: #1e1e24;
  --btn-text: #e6e6e6;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #fafafa;
    --bg-elev: #ffffff;
    --text: #333333;
    --muted: #5a5a5a;
    --link: #1e40af;
    --border: #e5e7eb;
    --btn-bg: #111827;
    --btn-text: #ffffff;
  }
}


/* ---------- layout ---------- */
html[data-theme="dark"],
html[data-theme="light"] {
  background: var(--bg);
  color: var(--text);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.6;
  display: flex;
  min-height: 100vh;
}

.layout {
  display: flex;
  width: 100%;
}

/* ---------- sidebar ---------- */
.sidebar {
  width: 240px;
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  padding: 30px 20px;
  position: sticky;
  top: 0;
  height: 100vh;
}

.sidebar h2 {
  margin-top: 0;
  color: var(--text);
  font-size: 20px;
}

.sidebar a {
  display: block;
  padding: 8px 0;
  color: var(--text);
  text-decoration: none;
  font-size: 16px;
}

.sidebar a:hover {
  color: var(--link);
}

/* ---------- main content ---------- */
.content {
  flex: 1;
  padding: 40px 60px;
  margin-left: 40px;
}

.content-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
  margin-bottom: 30px;
}

/* ---------- theme toggle button ---------- */
#theme-toggle {
  font-size: 18px;
  padding: 8px 12px;
  background: var(--btn-bg);
  color: var(--btn-text);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
}

/* ---------- section spacing ---------- */
section {
  margin-bottom: 60px;
}

section h2 {
  margin-top: 0;
  color: var(--text);
  opacity: 0.85;
}

section p {
  color: var(--muted);
  margin-top: 6px;
}