/* ===== THEME: DARK (default) ===== */
:root {
  --amber: #ffb000;
  --amber-dim: #cc8d00;
  --amber-bright: #ffc940;
  --amber-glow: rgba(255, 176, 0, 0.15);
  --amber-glow-strong: rgba(255, 176, 0, 0.3);
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-card: #141414;
  --bg-card-hover: #1a1a1a;
  --border: #1e1e1e;
  --border-hover: #2a2a2a;
  --text-primary: #e0d0b0;
  --text-secondary: #8a7a60;
  --text-muted: #5a4a30;
  --overlay-bg: rgba(0, 0, 0, 0.8);
  --scanline-opacity: 0.03;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', monospace;
}

/* ===== THEME: LIGHT ===== */
[data-theme="light"] {
  --amber: #b06830;
  --amber-dim: #905528;
  --amber-bright: #c87a40;
  --amber-glow: rgba(176, 104, 48, 0.08);
  --amber-glow-strong: rgba(176, 104, 48, 0.15);
  --bg-primary: #fefefe;
  --bg-secondary: #f5f5f3;
  --bg-card: #efeeeb;
  --bg-card-hover: #e8e7e3;
  --border: #e0ddd8;
  --border-hover: #ccc8c0;
  --text-primary: #1e1a16;
  --text-secondary: #605850;
  --text-muted: #999590;
  --overlay-bg: rgba(254, 254, 254, 0.9);
  --scanline-opacity: 0;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-mono);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  font-size: 14px;
  overflow-x: hidden;
  transition: background 0.3s, color 0.3s;
}

/* CRT scanline overlay */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(0,0,0,var(--scanline-opacity)) 2px, rgba(0,0,0,var(--scanline-opacity)) 4px);
  pointer-events: none;
  z-index: 9999;
}

::selection { background: var(--amber); color: var(--bg-primary); }

a { color: var(--amber); text-decoration: none; transition: all 0.2s; }
a:hover { color: var(--amber-bright); text-shadow: 0 0 8px var(--amber-glow-strong); }

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== NAVBAR ===== */
.navbar {
  position: fixed;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  background: var(--overlay-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 8px;
  display: flex;
  align-items: center;
  gap: 2px;
  transition: border-color 0.3s, background 0.3s;
}
.navbar:hover { border-color: var(--border-hover); }
.navbar a, .navbar button {
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 999px;
  transition: all 0.25s;
  letter-spacing: 0.5px;
  text-transform: lowercase;
  white-space: nowrap;
  background: none;
  border: none;
  cursor: pointer;
}
.navbar a:hover, .navbar button:hover {
  color: var(--amber);
  background: var(--amber-glow);
  text-shadow: none;
}
.navbar a.active {
  color: var(--bg-primary);
  background: var(--amber);
  font-weight: 600;
}
.navbar .nav-sep {
  width: 1px;
  height: 16px;
  background: var(--border);
  flex-shrink: 0;
}

/* ===== SECTION LABEL ===== */
.section-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--text-muted);
  margin-bottom: 32px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.section-label::before { content: '>'; color: var(--amber-dim); }
.section-label::after { content: ''; flex: 1; height: 1px; background: var(--border); }

/* ===== CLICKABLE TAGS ===== */
.tag-link {
  display: inline-block;
  font-size: 10px;
  padding: 2px 8px;
  background: var(--amber-glow);
  color: var(--amber-dim);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1px solid transparent;
  text-decoration: none;
}
.tag-link:hover {
  border-color: var(--amber-dim);
  color: var(--amber);
  background: var(--amber-glow-strong);
  text-shadow: none;
}
.tag-link.active {
  border-color: var(--amber);
  color: var(--amber);
  background: var(--amber-glow-strong);
}

/* Tag filter bar */
.tag-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 24px;
  align-items: center;
}
.tag-filter-bar .filter-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-right: 4px;
}
.tag-clear {
  font-size: 10px;
  color: var(--text-muted);
  cursor: pointer;
  padding: 2px 8px;
  border: 1px dashed var(--border);
  border-radius: 4px;
  background: none;
  font-family: var(--font-mono);
  transition: all 0.2s;
}
.tag-clear:hover {
  border-color: var(--amber-dim);
  color: var(--amber);
}

/* ===== SEARCH OVERLAY ===== */
.search-overlay {
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: var(--overlay-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  display: none;
  justify-content: center;
  padding-top: 15vh;
}
.search-overlay.open { display: flex; }

.search-box {
  width: 100%;
  max-width: 600px;
  padding: 0 24px;
}
.search-input-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 8px;
}
.search-input-wrap .search-icon {
  color: var(--amber-dim);
  font-size: 14px;
  flex-shrink: 0;
}
.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-family: var(--font-mono);
  font-size: 15px;
  caret-color: var(--amber);
}
.search-input::placeholder { color: var(--text-muted); }
.search-hint {
  font-size: 10px;
  color: var(--text-muted);
  text-align: right;
  padding: 4px 8px;
}
.search-hint kbd {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 10px;
}

.search-results {
  max-height: 50vh;
  overflow-y: auto;
  margin-top: 8px;
}
.search-result {
  display: block;
  padding: 14px 20px;
  border-bottom: 1px dashed var(--border);
  transition: all 0.15s;
  text-decoration: none;
}
.search-result:hover {
  background: var(--amber-glow);
  padding-left: 28px;
  text-shadow: none;
}
.search-result-type {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--amber-dim);
  margin-bottom: 2px;
}
.search-result-title {
  font-size: 13px;
  color: var(--text-primary);
  font-weight: 500;
}
.search-result-snippet {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 2px;
}
.search-empty {
  padding: 32px 20px;
  text-align: center;
  color: var(--text-muted);
  font-size: 12px;
}

/* ===== TOPBAR (blog pages) ===== */
.topbar {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 48px;
}
.topbar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.topbar-brand { font-size: 13px; color: var(--text-muted); }
.topbar-brand a { color: var(--amber-dim); }
.topbar-nav { display: flex; gap: 16px; align-items: center; }
.topbar-nav a, .topbar-nav button {
  font-size: 12px;
  color: var(--text-secondary);
  letter-spacing: 0.5px;
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-mono);
  padding: 0;
  transition: all 0.2s;
}
.topbar-nav button:hover, .topbar-nav a:hover { color: var(--amber); }

/* ===== FOOTER ===== */
footer {
  padding: 40px 0;
  text-align: center;
  font-size: 11px;
  color: var(--text-muted);
}
footer .amber { color: var(--amber-dim); }

/* ===== THEME TOGGLE ICON ===== */
.theme-toggle-btn { display: flex; align-items: center; justify-content: center; }
/* Dark mode (default): show sun icon to switch to light */
.theme-toggle-btn .icon-sun { display: block; }
.theme-toggle-btn .icon-moon { display: none; }
[data-theme="light"] .theme-toggle-btn .icon-sun { display: none; }
[data-theme="light"] .theme-toggle-btn .icon-moon { display: block; }

/* ===== BIBTEX COPY BUTTON ===== */
.bib-btn {
  font-size: 11px; color: var(--text-muted); cursor: pointer;
  border-bottom: 1px dashed var(--text-muted); padding-bottom: 1px;
  background: none; border-top: none; border-left: none; border-right: none;
  font-family: var(--font-mono); transition: all 0.2s; margin-right: 12px;
}
.bib-btn:hover { color: var(--amber); border-bottom-color: var(--amber); }
.bib-btn.copied { color: var(--amber); border-bottom-color: var(--amber); }

/* ===== SEVERANCE TOGGLE ===== */
.sev-toggle {
  display: flex; align-items: center; gap: 8px; cursor: pointer; user-select: none;
}
.sev-label {
  font-size: 9px; letter-spacing: 1px; text-transform: uppercase;
  color: var(--text-muted); transition: color 0.3s;
}
.sev-label.active { color: var(--amber); }
.sev-switch {
  width: 32px; height: 16px; border-radius: 999px; position: relative;
  background: var(--bg-card); border: 1px solid var(--border);
  transition: all 0.3s; flex-shrink: 0;
}
.sev-switch::after {
  content: ''; position: absolute; top: 2px; left: 2px;
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--amber-dim); transition: all 0.3s;
}
.sev-toggle.outie .sev-switch::after { left: 18px; background: var(--amber); }
.sev-toggle.outie .sev-switch {
  border-color: var(--amber-dim); box-shadow: 0 0 8px var(--amber-glow);
}

/* ===== SHARED PAGE STYLES ===== */
.page-header { margin-bottom: 48px; }
.page-header h1 {
  font-size: 11px; text-transform: uppercase; letter-spacing: 3px;
  color: var(--text-muted); font-weight: 400; display: flex; align-items: center; gap: 12px;
}
.page-header h1::before { content: '>'; color: var(--amber-dim); }
.page-header h1::after { content: ''; flex: 1; height: 1px; background: var(--border); }

.page-section { margin-bottom: 48px; }

/* Section toggle (view all / show less) */
.section-toggle { margin-top: 24px; font-size: 12px; }
.section-toggle button {
  background: none; border: 1px solid var(--border); color: var(--text-muted);
  font-family: var(--font-mono); font-size: 11px; padding: 6px 16px;
  border-radius: 999px; cursor: pointer; transition: all 0.25s;
}
.section-toggle button:hover {
  border-color: var(--amber-dim); color: var(--amber); background: var(--amber-glow);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 640px) {
  .navbar {
    top: auto;
    bottom: 16px;
    padding: 4px 6px;
    max-width: calc(100vw - 32px);
    overflow-x: auto;
  }
  .navbar a, .navbar button { font-size: 11px; padding: 6px 12px; }
  html { scroll-padding-top: 20px; }
  .search-overlay { padding-top: 8vh; }
}