/* ─── reset ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ─── tokens ─────────────────────────────────────────── */
:root {
  color-scheme: light;
  --ink:       #1a1a18;
  --ink-2:     #4a4a46;
  --ink-3:     #8a8a84;
  --ink-4:     #c0bfb8;
  --paper:     #f7f5f0;
  --paper-2:   #f0ede6;
  --accent:    #2a4a8c;
  --accent-2:  #1a3060;
  --mono:      'DM Mono', 'Courier New', monospace;
  --serif:     'EB Garamond', Georgia, serif;
  --border:    rgba(26, 26, 24, 0.12);
  --border-md: rgba(26, 26, 24, 0.20);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    color-scheme: dark;
    --ink:       #e8e6df;
    --ink-2:     #a8a69e;
    --ink-3:     #6a6860;
    --ink-4:     #3a3830;
    --paper:     #141412;
    --paper-2:   #1e1c1a;
    --accent:    #7a9cd8;
    --accent-2:  #a0bae8;
    --border:    rgba(232, 230, 223, 0.10);
    --border-md: rgba(232, 230, 223, 0.18);
  }
}

html[data-theme="light"] {
  color-scheme: light;
  --ink:       #1a1a18;
  --ink-2:     #4a4a46;
  --ink-3:     #8a8a84;
  --ink-4:     #c0bfb8;
  --paper:     #f7f5f0;
  --paper-2:   #f0ede6;
  --accent:    #2a4a8c;
  --accent-2:  #1a3060;
  --border:    rgba(26, 26, 24, 0.12);
  --border-md: rgba(26, 26, 24, 0.20);
}

html[data-theme="dark"] {
  color-scheme: dark;
  --ink:       #e8e6df;
  --ink-2:     #a8a69e;
  --ink-3:     #6a6860;
  --ink-4:     #3a3830;
  --paper:     #141412;
  --paper-2:   #1e1c1a;
  --accent:    #7a9cd8;
  --accent-2:  #a0bae8;
  --border:    rgba(232, 230, 223, 0.10);
  --border-md: rgba(232, 230, 223, 0.18);
}

/* ─── base ───────────────────────────────────────────── */
html { font-size: 18px; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--serif);
  background: var(--paper);
  color: var(--ink);
  line-height: 1.7;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-2); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }

strong { font-weight: 500; }

/* ─── layout ─────────────────────────────────────────── */
.site {
  max-width: 660px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
}

/* ─── nav ────────────────────────────────────────────── */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 2rem;
  margin-bottom: 3rem;
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  font-family: var(--serif);
  font-size: 1rem;
  font-weight: 400;
  font-style: italic;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.nav-logo:hover { text-decoration: none; color: var(--ink); }
.nav-logo span { color: var(--ink-3); font-style: normal; }

.nav-end {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; }
.nav-links a.active { color: var(--ink); }

.nav-theme.theme-toggle-wrap {
  gap: 0.35rem;
}

.nav-theme .theme-toggle-hint {
  font-size: 0.58rem;
}

.nav-theme .theme-toggle {
  width: 2.5rem;
  height: 1.35rem;
}

.nav-theme .theme-toggle-thumb {
  width: 0.95rem;
  height: 0.95rem;
}

.nav-theme .theme-toggle[aria-checked="true"] .theme-toggle-thumb {
  transform: translateX(1.12rem);
}

/* ─── home ───────────────────────────────────────────── */
.home-main { display: flex; flex-direction: column; gap: 3.5rem; }

.home-intro h1 {
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.tagline {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  letter-spacing: 0.03em;
  margin-bottom: 1.25rem;
}

.bio {
  font-size: 0.95rem;
  color: var(--ink-2);
  max-width: 540px;
  margin-bottom: 1.5rem;
  line-height: 1.75;
}

.home-links {
  display: flex;
  gap: 1.5rem;
}

.home-links a {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}
.home-links a:hover { color: var(--accent); text-decoration: none; }

.section-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}

/* ─── page headers ───────────────────────────────────── */
.page-title {
  font-size: 1.6rem;
  font-weight: 400;
  font-style: italic;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
}

.page-desc {
  font-size: 0.9rem;
  color: var(--ink-2);
  max-width: 520px;
  margin-bottom: 3rem;
  line-height: 1.75;
}

/* ─── category ───────────────────────────────────────── */
.category { margin-bottom: 2.5rem; }

.category-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-4);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

/* ─── note rows ──────────────────────────────────────── */
.note-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background 0.1s;
}

.note-row.plain { cursor: default; }

a.note-row {
  color: inherit;
}

a.note-row:hover {
  text-decoration: none;
}

.note-row:hover:not(.plain) .note-title { color: var(--accent); }

.note-text {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  min-width: 0;
}

.note-title {
  font-family: var(--serif);
  font-size: 0.95rem;
  color: var(--ink);
  transition: color 0.15s;
}

.note-sub {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-3);
  letter-spacing: 0.01em;
  line-height: 1.5;
}

.note-tag {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: var(--ink-3);
  border: 1px solid var(--border-md);
  padding: 2px 8px;
  border-radius: 20px;
  white-space: nowrap;
  flex-shrink: 0;
  letter-spacing: 0.03em;
}

/* ─── about ──────────────────────────────────────────── */
.about-body {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  font-size: 0.97rem;
  color: var(--ink);
  line-height: 1.8;
  max-width: 540px;
}

.about-links {
  display: flex;
  gap: 1.5rem;
  margin-top: 0.5rem;
}

.about-links a {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  letter-spacing: 0.02em;
}
.about-links a:hover { color: var(--accent); text-decoration: none; }

/* ─── research ───────────────────────────────────────── */
.paper-row {
  display: flex;
  gap: 1rem;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--border);
}

.paper-meta {
  flex-shrink: 0;
  width: 56px;
  padding-top: 2px;
}

.paper-year {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-4);
  letter-spacing: 0.04em;
}

.paper-tag-pill {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: var(--ink-3);
  border: 1px solid var(--border-md);
  padding: 2px 7px;
  border-radius: 20px;
  white-space: nowrap;
  display: inline-block;
}

.paper-body { flex: 1; min-width: 0; }

.paper-title {
  font-family: var(--serif);
  font-size: 0.97rem;
  color: var(--ink);
  display: block;
  margin-bottom: 0.2rem;
}

.paper-title-plain {
  font-family: var(--serif);
  font-size: 0.97rem;
  color: var(--ink);
  display: block;
  margin-bottom: 0.2rem;
}

.paper-authors, .paper-venue {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-3);
  letter-spacing: 0.01em;
  margin-bottom: 0.15rem;
}

.paper-abstract {
  font-size: 0.85rem;
  color: var(--ink-2);
  margin-top: 0.4rem;
  line-height: 1.65;
}

/* ─── post ───────────────────────────────────────────── */
.post-main { max-width: 600px; }

.post-back {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-3);
  margin-bottom: 1.5rem;
}

.post-back a { color: var(--ink-3); }
.post-back a:hover { color: var(--ink); text-decoration: none; }

.post-title {
  font-size: 1.6rem;
  font-weight: 400;
  font-style: italic;
  letter-spacing: -0.02em;
  margin-bottom: 0.3rem;
}

.post-subtitle {
  font-size: 1rem;
  color: var(--ink-2);
  margin-bottom: 0.75rem;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-3);
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.dot { color: var(--ink-4); }

.post-body {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  font-size: 0.97rem;
  line-height: 1.82;
}

.post-body h2 {
  font-size: 1.05rem;
  font-weight: 500;
  font-style: italic;
  letter-spacing: -0.01em;
  margin-top: 0.5rem;
}

.post-body pre {
  font-family: var(--mono);
  font-size: 0.78rem;
  background: var(--paper-2);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.9rem 1rem;
  overflow-x: auto;
  color: var(--ink-2);
  line-height: 1.6;
}

.post-body code {
  font-family: var(--mono);
  font-size: 0.82rem;
  background: var(--paper-2);
  padding: 1px 5px;
  border-radius: 3px;
}

.post-body pre code { background: none; padding: 0; }

.post-note {
  font-size: 0.85rem;
  color: var(--ink-3);
  font-style: italic;
  border-left: 2px solid var(--border-md);
  padding-left: 0.75rem;
  margin-top: 0.5rem;
}

/* ─── footer ─────────────────────────────────────────── */
footer {
  margin-top: 5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

footer p {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-4);
  letter-spacing: 0.03em;
}

footer p a { color: var(--ink-3); }
footer p a:hover { color: var(--accent); text-decoration: none; }

.theme-toggle-wrap {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.theme-toggle-hint {
  font-family: var(--mono);
  font-size: 0.62rem;
  font-weight: 500;
  color: var(--ink-3);
  letter-spacing: 0.03em;
  user-select: none;
}

.theme-toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  width: 2.75rem;
  height: 1.45rem;
  padding: 3px;
  border: 1px solid var(--border-md);
  border-radius: 999px;
  background: var(--paper-2);
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.theme-toggle:hover {
  border-color: var(--ink-4);
}

.theme-toggle-thumb {
  display: block;
  width: 1.05rem;
  height: 1.05rem;
  border-radius: 50%;
  background: var(--ink-3);
  transition: transform 0.2s ease, background 0.2s ease;
  transform: translateX(0);
}

.theme-toggle[aria-checked="true"] .theme-toggle-thumb {
  transform: translateX(1.22rem);
  background: var(--accent);
}

.theme-toggle:focus {
  outline: none;
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--ink-4);
  letter-spacing: 0.03em;
}
.footer-links a:hover { color: var(--ink-3); text-decoration: none; }

/* ─── responsive ─────────────────────────────────────── */
@media (max-width: 500px) {
  nav { flex-direction: column; gap: 0.75rem; align-items: flex-start; }
  .nav-end { width: 100%; justify-content: space-between; align-items: center; }
  .paper-row { flex-direction: column; gap: 0.3rem; }
  .paper-meta { width: auto; }
  footer { flex-direction: column; gap: 0.75rem; align-items: flex-start; }
  .home-links { flex-wrap: wrap; gap: 1rem; }
}

/* ─── fade-in on load ────────────────────────────────── */
.site {
  animation: fadein 0.4s ease both;
}

@keyframes fadein {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}