/* r.sanyulabs — Silicon Valley personal-site grammar
   Quiet type, long line-height, almost no chrome.
   References: collison.com · sivers.org · paulgraham.com restraint */

:root {
  --bg: #faf9f7;
  --bg-elev: #ffffff;
  --ink: #1a1917;
  --ink-2: #3d3a36;
  --muted: #6b6560;
  --line: #e8e4de;
  --accent: #1f4b3a;
  --accent-soft: #e8f0ec;
  --warm: #8b5a2b;
  --max: 42rem;
  --wide: 56rem;
  --serif: "Iowan Old Style", "Palatino Linotype", "Songti SC", "Noto Serif SC", Georgia, serif;
  --sans: "Inter", "SF Pro Text", "PingFang SC", "Helvetica Neue", system-ui, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", ui-monospace, monospace;
}

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

html {
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.65;
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
a:hover {
  color: var(--ink);
}

.wrap {
  width: min(var(--wide), calc(100% - 2.5rem));
  margin: 0 auto;
}

/* ——— Nav ——— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  border-bottom-color: var(--line);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
}
.brand {
  font-family: var(--serif);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -0.02em;
}
.brand span {
  color: var(--muted);
  font-weight: 400;
  font-size: 0.85rem;
  margin-left: 0.4rem;
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.2rem 1.1rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
}
.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--ink);
}

/* ——— Hero / home ——— */
.hero {
  padding: 4.5rem 0 3rem;
  border-bottom: 1px solid var(--line);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 2.5rem;
  align-items: end;
}
.kicker {
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--warm);
  font-weight: 600;
  margin: 0 0 1rem;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  font-weight: 600;
  margin: 0 0 1.25rem;
}
.hero .lede {
  font-size: 1.12rem;
  color: var(--ink-2);
  max-width: 36rem;
  margin: 0 0 1.75rem;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.7rem 1.15rem;
  border-radius: 999px;
  font-size: 0.92rem;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  text-decoration: none;
  transition: transform 0.15s ease, background 0.15s ease;
}
.btn:hover {
  transform: translateY(-1px);
  color: #fff;
}
.btn-ghost {
  background: transparent;
  color: var(--ink);
}
.btn-ghost:hover {
  background: var(--bg-elev);
  color: var(--ink);
}
.portrait {
  justify-self: end;
  width: min(220px, 100%);
  aspect-ratio: 1;
  border-radius: 50%;
  overflow: hidden;
  border: 1px solid var(--line);
  box-shadow: 0 18px 50px rgba(26, 25, 23, 0.08);
}
.portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: grayscale(8%);
}

/* ——— Sections ——— */
section {
  padding: 3.25rem 0;
  border-bottom: 1px solid var(--line);
}
section:last-of-type {
  border-bottom: none;
}
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
}
.section-head h2 {
  font-family: var(--serif);
  font-size: 1.55rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0;
}
.section-head a {
  font-size: 0.88rem;
  color: var(--muted);
  text-decoration: none;
}
.section-head a:hover {
  color: var(--accent);
}

.prose-narrow {
  max-width: var(--max);
}

/* ——— Cards ——— */
.card-list {
  display: grid;
  gap: 0.85rem;
}
.card {
  display: block;
  padding: 1.15rem 1.25rem;
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 12px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.card:hover {
  border-color: #cfc8be;
  box-shadow: 0 10px 30px rgba(26, 25, 23, 0.05);
  color: inherit;
}
.card .meta {
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}
.card h3 {
  font-family: var(--serif);
  font-size: 1.15rem;
  margin: 0 0 0.35rem;
  letter-spacing: -0.015em;
}
.card p {
  margin: 0;
  color: var(--ink-2);
  font-size: 0.95rem;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 0;
}
.pill {
  font-size: 0.8rem;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

/* ——— About principles ——— */
.principles {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}
.principle {
  padding: 1.1rem 0;
  border-top: 1px solid var(--line);
}
.principle:last-child {
  border-bottom: 1px solid var(--line);
}
.principle strong {
  display: block;
  font-family: var(--serif);
  font-size: 1.05rem;
  margin-bottom: 0.25rem;
}
.principle p {
  margin: 0;
  color: var(--ink-2);
}

/* ——— Article ——— */
.article-header {
  padding: 3rem 0 1.5rem;
  max-width: var(--max);
}
.article-header .meta {
  color: var(--muted);
  font-size: 0.88rem;
  margin-bottom: 0.75rem;
}
.article-header h1 {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -0.025em;
  margin: 0 0 1rem;
}
.article-header .summary {
  color: var(--ink-2);
  font-size: 1.05rem;
  margin: 0;
}
.article-body {
  max-width: var(--max);
  padding: 0 0 4rem;
  font-family: var(--serif);
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--ink-2);
}
.article-body h2,
.article-body h3 {
  font-family: var(--serif);
  color: var(--ink);
  letter-spacing: -0.02em;
  margin-top: 2rem;
}
.article-body h2 {
  font-size: 1.35rem;
}
.article-body h3 {
  font-size: 1.15rem;
}
.article-body p {
  margin: 0 0 1.1rem;
}
.article-body ul,
.article-body ol {
  margin: 0 0 1.1rem;
  padding-left: 1.3rem;
}
.article-body li {
  margin-bottom: 0.35rem;
}
.article-body blockquote {
  margin: 1.5rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 3px solid var(--accent);
  color: var(--ink);
  font-style: italic;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--sans);
  font-size: 0.88rem;
  margin: 1.25rem 0;
}
.article-body th,
.article-body td {
  border: 1px solid var(--line);
  padding: 0.5rem 0.65rem;
  text-align: left;
  vertical-align: top;
}
.article-body th {
  background: #f3f0eb;
}
.article-body code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: #f1eee8;
  padding: 0.1em 0.35em;
  border-radius: 4px;
}
.article-body pre {
  overflow: auto;
  background: #1a1917;
  color: #f5f2ec;
  padding: 1rem 1.1rem;
  border-radius: 10px;
  font-size: 0.85rem;
}
.article-body pre code {
  background: none;
  color: inherit;
  padding: 0;
}
.article-body hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 2rem 0;
}
.back-link {
  display: inline-block;
  margin-bottom: 1rem;
  font-family: var(--sans);
  font-size: 0.9rem;
  color: var(--muted);
  text-decoration: none;
}
.back-link:hover {
  color: var(--accent);
}

/* ——— Guestbook ——— */
.form {
  max-width: 28rem;
  display: grid;
  gap: 1rem;
}
.field label {
  display: block;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}
.field input,
.field textarea {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--bg-elev);
  border-radius: 10px;
  padding: 0.75rem 0.9rem;
  font: inherit;
  color: var(--ink);
}
.field input:focus,
.field textarea:focus {
  outline: 2px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-color: var(--accent);
}
.form-note {
  font-size: 0.85rem;
  color: var(--muted);
}
.form-status {
  min-height: 1.4rem;
  font-size: 0.9rem;
}
.form-status.ok {
  color: var(--accent);
}
.form-status.err {
  color: #9b2c2c;
}

/* ——— Footer ——— */
.site-footer {
  padding: 2.5rem 0 3rem;
  color: var(--muted);
  font-size: 0.85rem;
}
.site-footer .inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  border-top: 1px solid var(--line);
  padding-top: 1.5rem;
}
.site-footer a {
  color: var(--muted);
  text-decoration: none;
}
.site-footer a:hover {
  color: var(--ink);
}

/* ——— Lyceum special ——— */
.lyceum-banner {
  background: linear-gradient(145deg, #10241c 0%, #1f4b3a 55%, #2d5a45 100%);
  color: #f4f7f5;
  border-radius: 18px;
  padding: 2rem 2.1rem;
  margin: 1rem 0 2rem;
}
.lyceum-banner h1 {
  font-family: var(--serif);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  margin: 0 0 0.6rem;
  letter-spacing: -0.02em;
}
.lyceum-banner p {
  margin: 0;
  opacity: 0.9;
  max-width: 36rem;
}
.greek {
  font-family: var(--serif);
  letter-spacing: 0.04em;
  opacity: 0.75;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

@media (max-width: 800px) {
  html {
    font-size: 16px;
  }
  .hero-grid,
  .grid-2 {
    grid-template-columns: 1fr;
  }
  .portrait {
    justify-self: start;
    width: 140px;
  }
  .hero {
    padding-top: 2.5rem;
  }
  .nav {
    flex-direction: column;
    align-items: flex-start;
  }
}