:root {
  --bg: #0d1117;
  --card: #0f1722;
  --text: #e6edf3;
  --muted: #9aa4b2;
  --accent: #00a2ff;
  --accent-2: #5680ff;
  --chip: #142033;
  --border: #1f2a3a;
  --bg-gradient: linear-gradient(135deg, #0f172a 0%, #0b1220 45%, #0a0f1a 100%);
  --header-bg: rgba(10, 15, 26, 0.75);
  --footer-bg: rgba(10, 15, 26, 0.7);
  /* Theming variables for elements */
  --link-color: #7dc3ff;            /* content links */
  --hover-bg: #111a2a;              /* nav hover bg */
  --hover-fg: #ffffff;              /* nav hover fg */
  --excerpt: #cbd5e1;               /* index excerpt text */
  --chip-fg: #cfe3ff;               /* chip text */
  --chip-border: #20314a;           /* chip border */
  --chip-active-bg: rgba(86,128,255,0.2);
  --chip-active-border: #29406a;
  --chip-active-fg: #eaf3ff;
  --code-bg: #0b1220;               /* code block */
  --code-fg: #e6edf3;
  --embed-bg: #0a0f1a;              /* embeds container */
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: var(--bg-gradient);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
html[data-theme="light"] {
  --text: #0a1020;
  --muted: #3a4755;
  --border: #c5d1dd;
  --chip: #e7f0ff;
  --bg-gradient: linear-gradient(135deg, #f5f8fc 0%, #eef3f8 45%, #e8eff6 100%);
  --header-bg: rgba(255,255,255,0.85);
  --footer-bg: rgba(255,255,255,0.75);
  --link-color: #0f67b1;
  --hover-bg: rgba(0,0,0,0.06);
  --hover-fg: #0a1020;
  --excerpt: #3a4755;
  --chip-fg: #20314a;
  --chip-border: #20314a;
  --chip-active-bg: rgba(0,102,204,0.12);
  --chip-active-border: #6aa3ff;
  --chip-active-fg: #0a1020;
  --code-bg: #f5f7fb;
  --code-fg: #0b1220;
  --embed-bg: #f0f4fa;
}

/* Auto theme follows OS preference */
@media (prefers-color-scheme: light) {
  html[data-theme="auto"] {
    --text: #0a1020;
    --muted: #3a4755;
    --border: #c5d1dd;
    --chip: #e7f0ff;
    --bg-gradient: linear-gradient(135deg, #f5f8fc 0%, #eef3f8 45%, #e8eff6 100%);
    --header-bg: rgba(255,255,255,0.85);
    --footer-bg: rgba(255,255,255,0.75);
    --link-color: #0f67b1;
    --hover-bg: rgba(0,0,0,0.06);
    --hover-fg: #0a1020;
    --excerpt: #3a4755;
    --chip-fg: #20314a;
    --chip-border: #20314a;
    --chip-active-bg: rgba(0,102,204,0.12);
    --chip-active-border: #6aa3ff;
    --chip-active-fg: #0a1020;
    --code-bg: #f5f7fb;
    --code-fg: #0b1220;
    --embed-bg: #f0f4fa;
  }
}

/* Header */
.site-header { position: sticky; top: 0; z-index: 10; background: var(--header-bg); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border); }
.nav { max-width: 1100px; margin: 0 auto; padding: 14px 20px; display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); }
.brand img { height: 28px; width: auto; display: block; }
.brand span { font-weight: 700; letter-spacing: 0.2px; }
.nav-links { display: flex; align-items: center; gap: 12px; }
.nav-links a { color: var(--text); text-decoration: none; font-size: 0.95rem; padding: 8px 12px; border-radius: 8px; transition: background 0.2s ease, color 0.2s ease; }
.nav-links a:hover { background: var(--hover-bg); color: var(--hover-fg); }
.cta { background: linear-gradient(45deg, var(--accent-2), var(--accent)); color: #fff; }

/* Pref controls */
.pref-controls { display: flex; align-items: center; gap: 10px; }
.control-btn { appearance: none; border: 1px solid var(--border); background: transparent; color: var(--text); padding: 6px 10px; border-radius: 8px; cursor: pointer; font: inherit; transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease; }
.control-btn:hover { background: rgba(86,128,255,0.12); border-color: #29406a; }
.control-btn:focus { outline: 2px solid #6aa3ff; outline-offset: 2px; }
.text-resize { display: flex; align-items: center; gap: 8px; }
.text-resize .label { color: var(--muted); font-size: 0.85rem; }
.size-indicator { min-width: 42px; text-align: center; color: var(--muted); font-size: 0.85rem; }

/* Hero */
.hero { max-width: 1100px; margin: 24px auto 8px; padding: 24px 20px 8px; }
.eyebrow { color: var(--muted); font-size: 0.9rem; letter-spacing: 0.08em; text-transform: uppercase; }
.title { font-size: clamp(1.8rem, 3.5vw, 2.6rem); margin: 6px 0 8px; font-weight: 700; }
.subtitle { color: var(--muted); font-size: 1rem; max-width: 800px; }

/* Index content */
.content { max-width: 1100px; margin: 8px auto 40px; padding: 0 20px 40px; width: 100%; }
.posts { display: grid; grid-template-columns: repeat(12, 1fr); gap: 18px; }
.post-card { grid-column: span 12; background: radial-gradient(1200px 400px at -10% -20%, rgba(86,128,255,0.06), transparent 45%), linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0)); border: 1px solid var(--border); border-radius: 14px; padding: 18px; position: relative; overflow: hidden; transition: transform 0.15s ease, border-color 0.2s ease, box-shadow 0.2s ease; }
.post-card:hover { transform: translateY(-2px); border-color: #29406a; box-shadow: 0 8px 32px rgba(0,0,0,0.35); }
@media (min-width: 720px) { .post-card { grid-column: span 6; } }
.post-title { margin: 0 0 8px; font-size: 1.2rem; }
.post-title a { color: var(--text); text-decoration: none; }
.post-title a:hover { text-decoration: underline; }
.meta { color: var(--muted); font-size: 0.85rem; margin-bottom: 8px; display: flex; gap: 12px; align-items: center; }
.excerpt { color: var(--excerpt); line-height: 1.55; font-size: 0.98rem; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.chip { background: var(--chip); color: var(--chip-fg); border: 1px solid var(--chip-border); padding: 4px 10px; border-radius: 999px; font-size: 0.8rem; }
/* Active tag state */
.chip.active { background: var(--chip-active-bg); border-color: var(--chip-active-border); color: var(--chip-active-fg); }

/* Post page */
.post { max-width: 820px; margin: 24px auto 64px; padding: 0 20px; }
.post .post-header { margin-bottom: 16px; }
.post .post-title { font-size: clamp(1.8rem, 3vw, 2.4rem); margin: 8px 0; }
.post .post-meta { color: var(--muted); font-size: 0.9rem; display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.post .cover { margin: 16px 0 20px; border-radius: 12px; overflow: hidden; border: 1px solid var(--border); }
.post .cover img { display: block; width: 100%; height: auto; }
.post .tags { margin: 12px 0 24px; }
.post .tags .chip { margin-right: 8px; }

/* Markdown content */
.post-content { color: var(--text); line-height: 1.7; font-size: 1.05rem; }
.post-content a { color: var(--link-color); text-decoration: underline; text-underline-offset: 2px; }
.post-content h2, .post-content h3, .post-content h4 { margin-top: 1.6em; }
.post-content img { max-width: 100%; height: auto; border-radius: 10px; border: 1px solid var(--border); }
.post-content figure { margin: 1.25rem 0; }
.post-content figcaption { color: var(--muted); font-size: 0.9rem; text-align: center; margin-top: 6px; }
.post-content pre { background: var(--code-bg); color: var(--code-fg); padding: 14px; border-radius: 10px; overflow: auto; border: 1px solid var(--border); }

/* Embeds */
.embed { margin: 16px 0 20px; border-radius: 12px; overflow: hidden; border: 1px solid var(--border); background: var(--embed-bg); }
.embed iframe { width: 100%; height: 166px; display: block; border: 0; }

/* Footer */
footer { margin-top: auto; border-top: 1px solid var(--border); background: var(--footer-bg); }
.footer-inner { max-width: 1100px; margin: 0 auto; padding: 18px 20px; color: var(--muted); font-size: 0.92rem; text-align: center; }
.footer-inner a { color: #5a7397; text-decoration: none; }
.footer-inner a:hover { text-decoration: underline; }