:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --text: #1c1e21;
  --muted: #5f6368;
  --border: #e4e4e0;
  --code-bg: #f2f2ee;
  --brand: #3b5bdb;
  --notice: #fff6db;
  --notice-border: #f0d78c;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
html { color-scheme: light; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 "Spectral", Georgia, serif;
}
a { color: var(--brand); }
img { max-width: 100%; height: auto; border-radius: 0; }
code, pre { font-family: "JetBrains Mono", ui-monospace, monospace; font-size: 0.9em; }
:not(pre) > code { background: var(--code-bg); padding: 0.1em 0.35em; border-radius: 0; }
pre, .highlight pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 0;
  overflow-x: auto;
}

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.wrap.narrow { max-width: 740px; }

/* Header */
.site-header { border-bottom: 1px solid var(--border); background: var(--surface); position: sticky; top: 0; z-index: 10; }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; padding-top: 0.8rem; padding-bottom: 0.8rem; }
.brand { font-weight: 700; color: var(--text); text-decoration: none; }
.brand-mark { font-family: "JetBrains Mono", monospace; color: var(--brand); }
nav { display: flex; gap: 1.2rem; flex-wrap: wrap; }
nav a { color: var(--muted); text-decoration: none; font-weight: 500; font-size: 0.95rem; }
nav a:hover, nav a.active { color: var(--text); }

/* Hero */
.hero, .course-hero { padding: 4rem 0 2.5rem; }
.course-hero { border-bottom: 4px solid var(--accent); background: linear-gradient(180deg, color-mix(in srgb, var(--accent) 10%, transparent), transparent); margin-bottom: 2rem; }
.eyebrow { text-transform: uppercase; letter-spacing: 0.08em; font-size: 0.78rem; font-weight: 600; color: var(--muted); margin: 0 0 0.5rem; }
h1 { font-size: clamp(1.9rem, 4.5vw, 2.8rem); line-height: 1.15; margin: 0 0 1rem; letter-spacing: -0.02em; }
.lead { font-size: 1.15rem; color: var(--muted); max-width: 680px; margin: 0; }

/* Course cards */
.course-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.25rem; margin-bottom: 3rem; }
.course-card {
  display: block; text-decoration: none; color: var(--text);
  background: var(--surface); border: 1px solid var(--border); border-top: 5px solid var(--accent);
  border-radius: 0; padding: 1.5rem; transition: transform .15s, box-shadow .15s;
}
.course-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.course-card h2 { margin: 0 0 0.4rem; color: var(--accent); }
.course-card p { margin: 0 0 1rem; color: var(--muted); }
.count { font-weight: 600; font-size: 0.9rem; }

.section-title { font-size: 1.35rem; margin: 0 0 1.25rem; }

/* Post grid */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 1.25rem; margin-bottom: 4rem; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 0; overflow: hidden; transition: transform .15s, box-shadow .15s; }
.card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.card-link { display: flex; flex-direction: column; height: 100%; color: inherit; text-decoration: none; }
.card-banner {
  position: relative; aspect-ratio: 16 / 9; background: var(--code-bg);
  border-bottom: 3px solid var(--accent);
}
.card-banner img { display: block; width: 100%; height: 100%; object-fit: cover; }
.card-labels { position: absolute; inset: 0.7rem 0.7rem auto; display: flex; justify-content: space-between; align-items: flex-start; }
.card-course { background: var(--accent); color: #fff; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; padding: 0.15rem 0.5rem; }
.badge { background: rgba(255,255,255,.9); color: #333; font-size: 0.72rem; font-weight: 600; padding: 0.15rem 0.5rem; border-radius: 0; }
.card-body { padding: 1.1rem 1.2rem 1.3rem; }
.card-body h3 { margin: 0 0 0.25rem; font-size: 1.1rem; line-height: 1.3; }
.card-body p { margin: 0 0 0.6rem; font-size: 0.93rem; }
.meta { color: var(--muted); font-size: 0.88rem; }

.tags { list-style: none; padding: 0; margin: 0.5rem 0 0; display: flex; flex-wrap: wrap; gap: 0.35rem; }
.tags li { font-size: 0.75rem; font-family: "JetBrains Mono", monospace; background: var(--code-bg); padding: 0.1rem 0.5rem; border-radius: 0; color: var(--muted); }

.empty { color: var(--muted); padding: 2rem 0 4rem; }

/* Post page */
.post-hero { padding: 3rem 0 2rem; border-bottom: 4px solid var(--accent); background: linear-gradient(180deg, color-mix(in srgb, var(--accent) 10%, transparent), transparent); margin-bottom: 2rem; }
.back { display: inline-block; margin-bottom: 1rem; font-size: 0.9rem; text-decoration: none; color: var(--accent); font-weight: 500; }
.links { display: flex; gap: 1rem; margin-top: 1rem; }
.links a { font-weight: 600; font-size: 0.92rem; }
.post-content { padding-bottom: 4rem; }
.post-content h2 { margin-top: 2.2rem; font-size: 1.45rem; }
.post-content h3 { margin-top: 1.6rem; }
.notice { background: var(--notice); border: 1px solid var(--notice-border); border-radius: 0; padding: 0.9rem 1.1rem; margin-bottom: 2rem; font-size: 0.95rem; }
.figure-placeholder {
  border: 2px dashed var(--border); border-radius: 0; padding: 3rem 1rem; text-align: center;
  color: var(--muted); font-size: 0.92rem; margin: 1.5rem 0; background: var(--surface);
}

/* Generic page */
.page { padding: 3rem 16px 4rem; }
table { border-collapse: collapse; width: 100%; margin: 1rem 0; font-size: 0.93rem; display: block; overflow-x: auto; }
th, td { border: 1px solid var(--border); padding: 0.5rem 0.75rem; text-align: left; }
th { background: var(--code-bg); }

.site-footer { border-top: 1px solid var(--border); padding: 1.5rem 0; color: var(--muted); font-size: 0.88rem; }
.site-footer p { margin: 0; }

.post-cover { margin: 0 0 2rem; }
.post-cover img { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.post-cover figcaption { font-size: 0.8rem; color: var(--muted); margin-top: 0.4rem; font-style: italic; }
.post-cover figcaption a { color: inherit; }