/* ═══════════════════════════════════════════════════════════
   SkyDiscover — UC Berkeley Sky Lab
   Professional, polished design system
   Berkeley Blue + California Gold + Modern accents
   ═══════════════════════════════════════════════════════════ */

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

:root {
  /* Berkeley Brand */
  --berkeley-blue:  #002676;
  --berkeley-deep:  #001a5c;
  --cal-gold:       #FDB515;
  --cal-gold-dark:  #C4820E;
  --cal-gold-light: #FECB52;

  /* Surfaces */
  --bg:          #ffffff;
  --bg-subtle:   #f8f9fc;
  --bg-muted:    #eef1f6;
  --bg-card:     #ffffff;
  --bg-code:     #f4f6fa;
  --bg-nav:      rgba(255, 255, 255, 0.92);

  /* Borders */
  --border:      #e2e6ee;
  --border-hover:#c5cbd8;

  /* Text */
  --text:        #0d1117;
  --text-2:      #2d3748;
  --text-3:      #556275;
  --text-muted:  #6b7688;

  /* Semantic */
  --accent:        #003262;
  --accent-hover:  #004a8f;
  --accent-soft:   rgba(0, 50, 98, 0.05);
  --accent-border: rgba(0, 50, 98, 0.12);
  --gold-soft:     rgba(253, 181, 21, 0.07);
  --gold-border:   rgba(253, 181, 21, 0.20);

  /* Palette */
  --blue:   #1d4ed8;
  --green:  #047857;
  --purple: #6d28d9;
  --red:    #b91c1c;
  --teal:   #0d9488;
  --indigo: #4338ca;

  /* Elevation */
  --shadow-xs:   0 1px 2px rgba(0,0,0,0.04);
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md:   0 4px 16px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-lg:   0 12px 32px rgba(0,0,0,0.10), 0 4px 8px rgba(0,0,0,0.05);
  --shadow-xl:   0 20px 48px rgba(0,0,0,0.12), 0 8px 16px rgba(0,0,0,0.06);
  --shadow-gold: 0 4px 20px rgba(253,181,21,0.18);
  --shadow-blue: 0 4px 20px rgba(0,50,98,0.15);

  /* Radii */
  --r-xs:  4px;
  --r-sm:  6px;
  --r-md:  10px;
  --r-lg:  14px;
  --r-xl:  20px;

  /* Layout */
  --max-w:     1200px;
  --content-w: 960px;
  --nav-h:     68px;

  /* Type */
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  color-scheme: light;
}

/* ── Dark Theme ─────────────────────────────────────────── */
[data-theme="dark"] {
  --bg:          #0a0f1e;
  --bg-subtle:   #0e1528;
  --bg-muted:    #141c32;
  --bg-card:     #111a2e;
  --bg-code:     #0f1726;
  --bg-nav:      rgba(10, 15, 30, 0.90);

  --border:      rgba(255,255,255,0.08);
  --border-hover:rgba(255,255,255,0.14);

  --text:        #f1f5f9;
  --text-2:      #c2cad8;
  --text-3:      #8494a7;
  --text-muted:  #7a8a9e;

  --accent:        #004AAE;
  --accent-hover:  #1a6ec7;
  --accent-soft:   rgba(0,74,174,0.10);
  --accent-border: rgba(0,74,174,0.20);
  --gold-soft:     rgba(255,195,27,0.08);
  --gold-border:   rgba(255,195,27,0.18);

  --blue:   #60a5fa;
  --green:  #34d399;
  --purple: #a78bfa;
  --red:    #f87171;
  --teal:   #2dd4bf;
  --indigo: #818cf8;

  --shadow-xs:   0 1px 2px rgba(0,0,0,0.2);
  --shadow-sm:   0 1px 3px rgba(0,0,0,0.3);
  --shadow-md:   0 4px 16px rgba(0,0,0,0.3);
  --shadow-lg:   0 12px 32px rgba(0,0,0,0.35);
  --shadow-xl:   0 20px 48px rgba(0,0,0,0.4);
  --shadow-gold: 0 4px 20px rgba(255,195,27,0.12);
  --shadow-blue: 0 4px 20px rgba(0,74,174,0.15);

  color-scheme: dark;
}

/* ── Base ───────────────────────────────────────────────── */
html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.72;
  overflow-x: hidden;
  transition: background 0.4s ease, color 0.4s ease;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-hover); }
img { max-width: 100%; height: auto; display: block; }
::selection { background: rgba(0,50,98,0.14); }
[data-theme="dark"] ::selection { background: rgba(255,195,27,0.18); }

/* ── Progress Bar ───────────────────────────────────────── */
.progress-bar {
  position: fixed; top: 0; left: 0;
  height: 2px; width: 0%;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  z-index: 200; pointer-events: none;
}
[data-theme="dark"] .progress-bar {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}

/* ── Navigation ─────────────────────────────────────────── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: var(--bg-nav);
  backdrop-filter: blur(24px) saturate(1.8);
  -webkit-backdrop-filter: blur(24px) saturate(1.8);
  border-bottom: 1px solid var(--border);
  transition: background 0.4s, border-color 0.4s, box-shadow 0.4s;
}
.nav.nav--scrolled {
  box-shadow: 0 1px 12px rgba(0,0,0,0.06);
}
[data-theme="dark"] .nav.nav--scrolled {
  box-shadow: 0 1px 12px rgba(0,0,0,0.25);
}
.nav-inner {
  max-width: var(--max-w); margin: 0 auto;
  padding: 0 28px; height: 100%;
  display: flex; align-items: center; justify-content: space-between;
}

/* Brand */
.nav-brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--text); transition: opacity 0.2s;
  white-space: nowrap;
}
.nav-brand:hover { opacity: 0.85; color: var(--text); }
.nav-brand img {
  height: 38px; width: 38px;
  object-fit: contain; flex-shrink: 0;
}
.brand-text {
  font-size: 1.35rem; font-weight: 700;
  letter-spacing: -0.02em;
  color: #002676;
}
.brand-text strong {
  font-weight: 700; color: #FDB515;
}
[data-theme="dark"] .brand-text { color: #004AAE; }
[data-theme="dark"] .brand-text strong { color: #FFC31B; }

/* Brand text inside headings */
h1 .brand-text, h2 .brand-text {
  font-size: inherit; font-weight: inherit;
  letter-spacing: inherit;
}
h1 .brand-text strong, h2 .brand-text strong {
  font-weight: inherit;
}

.nav-actions { display: flex; gap: 6px; align-items: center; }

.theme-toggle {
  width: 34px; height: 34px; border-radius: var(--r-sm);
  border: 1px solid var(--border); background: transparent;
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  color: var(--text-3); font-size: 1rem; transition: all 0.2s;
}
.theme-toggle:hover {
  border-color: var(--cal-gold); color: var(--cal-gold); background: var(--gold-soft);
}

.nav-btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 14px; border-radius: var(--r-sm);
  font-size: 0.85rem; font-weight: 600; font-family: var(--sans);
  border: 1px solid var(--border); color: var(--text-2);
  background: transparent; transition: all 0.2s ease;
}
.nav-btn:hover {
  border-color: var(--accent); color: var(--accent); background: var(--accent-soft);
  transform: translateY(-1px);
}
.nav-btn svg { width: 14px; height: 14px; }

/* ── Hero (Blog/Papers) ────────────────────────────────── */
.hero {
  padding: calc(var(--nav-h) + 52px) 32px 44px;
  text-align: center;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: relative;
}
.page-blog .hero {
  background: linear-gradient(160deg, rgba(0,38,118,0.035) 0%, rgba(253,181,21,0.025) 60%, var(--bg) 100%);
  border-bottom: 1px solid var(--border);
}
[data-theme="dark"] .page-blog .hero {
  background: linear-gradient(160deg, rgba(0,74,174,0.12) 0%, rgba(255,195,27,0.04) 60%, var(--bg) 100%);
}
.hero-content {
  max-width: 820px; margin: 0 auto;
}

.hero-badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 12px; border-radius: 20px;
  font-size: 0.7rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.08em;
  background: rgba(0,38,118,0.06); color: #002676;
  border: 1px solid rgba(0,38,118,0.15);
  margin-bottom: 20px;
  text-decoration: none; transition: all 0.2s;
}
.hero-badge:hover {
  background: rgba(0,38,118,0.1); color: #002676;
}
[data-theme="dark"] .hero-badge {
  background: rgba(0,74,174,0.12); color: #004AAE;
  border-color: rgba(0,74,174,0.25);
}

.hero h1 {
  font-size: clamp(2.1rem, 4.8vw, 3rem);
  font-weight: 800; line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--text); margin-bottom: 18px;
  text-wrap: balance;
}

.hero-date {
  font-size: 1rem; color: var(--text-muted); font-weight: 400;
  margin-bottom: 0; letter-spacing: 0.01em;
}

.authors {
  display: flex; flex-wrap: wrap; gap: 2px 10px;
  justify-content: center; margin-top: 12px;
}
.author { font-size: 1.1rem; color: var(--text-3); white-space: nowrap; }
.author a { color: inherit; text-decoration: none; }
.author a:hover { color: #002676; text-decoration: underline; }
[data-theme="dark"] .author a:hover { color: var(--cal-gold); }
.author.lead { color: var(--text-3); font-weight: 400; font-size: 1.1rem; }
.author sup { font-size: 0.5em; color: var(--text-muted); margin-left: 1px; vertical-align: super; }
.affiliations {
  font-size: 1.05rem; color: var(--text-muted); margin-top: 6px;
  letter-spacing: 0.01em;
}

.hero-actions {
  display: flex; gap: 10px; justify-content: center;
  flex-wrap: wrap; margin-top: 22px;
}

/* ── Buttons ────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 22px; border-radius: 8px;
  font-size: 0.95rem; font-weight: 600;
  font-family: var(--sans); cursor: pointer;
  border: none; transition: all 0.25s; text-decoration: none;
  position: relative; overflow: hidden;
}
.btn svg { width: 16px; height: 16px; flex-shrink: 0; }

.btn-primary {
  background: linear-gradient(135deg, var(--berkeley-blue) 0%, #004a8f 100%);
  color: #fff;
  box-shadow: var(--shadow-sm), var(--shadow-blue);
}
.btn-primary:hover {
  background: linear-gradient(135deg, #004a8f 0%, var(--berkeley-deep) 100%);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md), 0 6px 24px rgba(0,50,98,0.2);
}
.btn-primary:active { transform: translateY(0); }
[data-theme="dark"] .btn-primary {
  background: linear-gradient(135deg, var(--cal-gold) 0%, #e5a300 100%);
  color: #0f172a;
  box-shadow: var(--shadow-sm), var(--shadow-gold);
}
[data-theme="dark"] .btn-primary:hover {
  background: linear-gradient(135deg, var(--cal-gold-light) 0%, var(--cal-gold) 100%);
  box-shadow: var(--shadow-md), 0 6px 24px rgba(255,195,27,0.25);
}

.btn-outline {
  background: transparent; color: var(--text-2);
  border: 1.5px solid var(--border-hover);
}
.btn-outline:hover {
  border-color: var(--accent); color: var(--accent);
  background: var(--accent-soft);
  transform: translateY(-2px); box-shadow: var(--shadow-sm);
}
.btn-outline:active { transform: translateY(0); box-shadow: none; }

.btn-ghost {
  background: transparent; color: var(--text-3);
  border: none; padding: 8px 16px;
}
.btn-ghost:hover {
  color: var(--accent); background: var(--accent-soft);
}

/* ── Article ────────────────────────────────────────────── */
.article {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 40px 100px;
  font-size: 1.0625rem;
  color: rgb(55, 53, 47);
}
[data-theme="dark"] .article { color: var(--text-2); }

.article h2 {
  margin-top: 2.4rem; margin-bottom: 12px;
  font-size: clamp(1.8rem, 3.2vw, 2.1rem); font-weight: 700;
  letter-spacing: -0.025em; color: #002676;
  line-height: 1.18;
  scroll-margin-top: 90px;
}
[data-theme="dark"] .article h2 { color: #004AAE; }

.article h3 {
  margin-top: 1.8rem; margin-bottom: 8px;
  font-size: 1.8rem; font-weight: 600;
  color: rgb(37, 36, 33); letter-spacing: -0.02em;
  line-height: 1.28;
  scroll-margin-top: 90px;
}
[data-theme="dark"] .article h3 { color: var(--text); }

/* Category headers */
.category-header {
  margin-top: 40px; margin-bottom: 10px;
  font-size: 1.4rem; font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--text-muted);
  padding: 0 0 10px;
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; gap: 8px;
}
.category-header::before { display: none; }
[data-theme="dark"] .category-header { color: var(--text-3); }

.article p {
  line-height: 1.65; margin-top: 0.6em; margin-bottom: 0.6em;
  overflow-wrap: break-word;
}
[data-theme="dark"] .article p { color: var(--text-2); }
.article strong { color: inherit; font-weight: 600; }

.article ul, .article ol { padding-left: 1.7em; margin-block-start: 0.6em; margin-block-end: 0.6em; }
.article li {
  line-height: 1.65; margin-bottom: 4px;
  padding-left: 0.1em;
}
[data-theme="dark"] .article li { color: var(--text-2); }
.article li strong { color: inherit; }
.article li::marker { color: rgb(55, 53, 47); }
[data-theme="dark"] .article li::marker { color: var(--text-3); }

.article code {
  font-family: var(--mono); font-size: 85%;
  padding: 0.2em 0.4em; border-radius: 3px;
  background: rgba(135, 131, 120, 0.15); color: #eb5757;
  border: none; font-weight: 400;
}
[data-theme="dark"] .article code {
  background: rgba(255,255,255,0.08); color: #FF9080;
}
.code-block code, .code-toggle code {
  background: none; color: inherit;
  padding: 0; border-radius: 0; font-size: inherit;
}

.article a {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-hover);
}
.article a:hover { text-decoration-color: var(--accent); }

/* ── Callout ────────────────────────────────────────────── */
.callout {
  padding: 1rem 1.25rem;
  border-radius: 10px;
  margin: 1.5em 0;
  background: rgb(255, 253, 243);
  border: none;
  border-left: 4px solid rgba(220, 180, 40, 0.4);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.03);
  transition: background 0.3s;
}
[data-theme="dark"] .callout {
  background: rgba(255, 195, 27, 0.13);
  border-left: 4px solid rgba(255, 195, 27, 0.35);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
}
.callout p { margin: 0; font-size: 1.0625rem; line-height: 1.65; color: rgb(30, 28, 25); }
[data-theme="dark"] .callout p { color: #e8d9a8; }
.callout p + p { margin-top: 0.5em; }
.callout ul { margin-block-start: 0.5em; margin-block-end: 0; padding-left: 1.7em; }
.callout li { font-size: 1.0625rem; line-height: 1.65; margin-bottom: 5px; color: rgb(30, 28, 25); }
[data-theme="dark"] .callout li { color: #e8d9a8; }
.callout strong { font-weight: 700; color: rgb(10, 9, 7); }
[data-theme="dark"] .callout strong { color: #FFC31B; }

.callout--blue {
  background: rgba(0, 124, 215, 0.094);
}
[data-theme="dark"] .callout--blue {
  background: rgba(96,165,250,0.1);
}
.callout--red {
  background: rgba(223, 22, 0, 0.094);
}
[data-theme="dark"] .callout--red {
  background: rgba(248,113,113,0.1);
}

/* ── Table of Contents Sidebar ──────────────────────────── */
.toc {
  display: none;
}
@media (min-width: 1340px) {
  .toc {
    display: block;
    position: fixed;
    top: 120px;
    left: calc(50% - 620px);
    width: 170px;
    z-index: 50;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
  }
  .toc.visible {
    opacity: 1;
    pointer-events: auto;
  }
  .toc ul {
    list-style: none;
    margin: 0;
    padding: 0;
    border-left: 1.5px solid var(--border);
  }
  .toc li {
    margin: 0;
  }
  .toc ul ul {
    border-left: none;
    padding: 0;
    margin: 0;
  }
  .toc ul ul a {
    padding-left: 24px;
    font-size: 0.72rem;
    font-weight: 400;
    opacity: 0.75;
  }
  .toc ul ul a:hover { opacity: 1; }
  .toc ul ul a.active { opacity: 1; }
  .toc a {
    display: block;
    padding: 5px 0 5px 14px;
    font-size: 0.78rem;
    font-weight: 450;
    color: var(--text-muted);
    text-decoration: none;
    line-height: 1.35;
    transition: color 0.15s, border-color 0.15s;
    border-left: 2px solid transparent;
    margin-left: -1.5px;
  }
  .toc a:hover {
    color: var(--text);
  }
  .toc a.active {
    color: #002676;
    font-weight: 600;
    border-left-color: #002676;
  }
  [data-theme="dark"] .toc a.active {
    color: #FDB515;
    border-left-color: #FDB515;
  }
  .page-blog .article {
    margin-left: calc(50% - 390px);
    margin-right: auto;
  }
}

/* ── Tags ───────────────────────────────────────────────── */
.tag {
  display: inline-block; padding: 3px 10px; border-radius: 5px;
  font-size: 0.76rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.05em;
}
.tag--accent  { background: var(--accent-soft); color: var(--accent); border: 1px solid var(--accent-border); }
.tag--blue    { background: rgba(29,78,216,0.06); color: var(--blue); border: 1px solid rgba(29,78,216,0.12); }
.tag--green   { background: rgba(4,120,87,0.06); color: var(--green); border: 1px solid rgba(4,120,87,0.12); }
.tag--purple  { background: rgba(109,40,217,0.06); color: var(--purple); border: 1px solid rgba(109,40,217,0.12); }
.tag--red     { background: rgba(185,28,28,0.06); color: var(--red); border: 1px solid rgba(185,28,28,0.12); }
.tag--gold    { background: var(--gold-soft); color: var(--cal-gold-dark); border: 1px solid var(--gold-border); }

[data-theme="dark"] .tag--accent { background: var(--gold-soft); color: var(--cal-gold); border-color: var(--gold-border); }
[data-theme="dark"] .tag--blue   { background: rgba(96,165,250,0.08); color: var(--blue); border-color: rgba(96,165,250,0.15); }
[data-theme="dark"] .tag--green  { background: rgba(52,211,153,0.08); color: var(--green); border-color: rgba(52,211,153,0.15); }
[data-theme="dark"] .tag--purple { background: rgba(167,139,250,0.08); color: var(--purple); border-color: rgba(167,139,250,0.15); }
[data-theme="dark"] .tag--red    { background: rgba(248,113,113,0.08); color: var(--red); border-color: rgba(248,113,113,0.15); }
[data-theme="dark"] .tag--gold   { color: var(--cal-gold); }

/* ── Figures ────────────────────────────────────────────── */
.figure {
  margin: 36px auto; border-radius: 8px;
  overflow: hidden; max-width: 75%;
}

.figure__img {
  display: flex; align-items: center; justify-content: center;
}
.figure__img img {
  border-radius: 6px; max-width: 100%; height: auto;
  box-shadow: 0 1px 6px rgba(0,0,0,0.06);
  border: 1px solid var(--border);
}
[data-theme="dark"] .figure__img img { box-shadow: 0 2px 8px rgba(0,0,0,0.22); }
.figure__img--flush { padding: 0; }
.figure__img--flush img { border-radius: 0; }

.figure__caption {
  font-size: 85%; color: var(--text-muted);
  text-align: center; padding: 8px 16px 0;
  line-height: 1.4; opacity: 0.7;
  max-width: 100%;
}
.figure__caption strong { font-weight: 600; }

/* Table figures */
.figure--table { max-width: 100%; }
.figure--table .figure__img img {
  border-radius: 4px; border: 1px solid var(--border);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
[data-theme="dark"] .figure--table .figure__img img { box-shadow: 0 2px 10px rgba(0,0,0,0.2); }

/* Case study figures */
.cs-figure { max-width: 70%; margin: 16px auto; }
.cs-figure .figure__img img { max-width: 100%; height: auto; }

/* ── Case Studies ───────────────────────────────────────── */
.case-study {
  margin: 22px 0; padding: 24px;
  border-radius: var(--r-lg); border: 1px solid var(--border);
  background: var(--bg-card); box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, transform 0.3s, border-color 0.3s;
}
.case-study:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-hover);
  transform: translateY(-2px);
}
.case-study { font-size: 1.0625rem; color: rgb(55, 53, 47); line-height: 1.65; }
.case-study p { font-size: 1.0625rem; color: rgb(55, 53, 47); line-height: 1.65; margin-top: 0.6em; margin-bottom: 0.6em; }
[data-theme="dark"] .case-study { color: var(--text-2); }
[data-theme="dark"] .case-study p { color: var(--text-2); }
.case-study h3 { margin-top: 8px; margin-bottom: 10px; font-size: 1.35rem; }
details.case-study { cursor: default; }
details.case-study > summary {
  font-size: 1.35rem; font-weight: 600;
  color: rgb(37, 36, 33); letter-spacing: -0.015em;
  cursor: pointer; list-style: none;
  display: flex; align-items: center; gap: 10px;
  margin-bottom: 10px;
}
details.case-study > summary::-webkit-details-marker { display: none; }
details.case-study > summary::before {
  content: '';
  display: inline-block; width: 0; height: 0;
  border-left: 6px solid var(--cal-gold);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  transition: transform 0.2s; flex-shrink: 0;
}
details.case-study[open] > summary::before { transform: rotate(90deg); }
[data-theme="dark"] details.case-study > summary { color: var(--text); }

/* ── Paragraph Toggle (Problem/Result expand) ──────────── */
details.para-toggle {
  margin: 0.6em 0;
}
details.para-toggle summary {
  font-size: 1.0625rem; font-weight: 400; color: rgb(55, 53, 47); line-height: 1.65;
  cursor: pointer; list-style: none;
  display: block;
}
details.para-toggle summary::-webkit-details-marker { display: none; }
details.para-toggle summary::marker { content: ''; display: none; }
details.para-toggle summary > strong:first-child::before {
  content: '▶'; font-size: 0.55em; color: var(--cal-gold-dark);
  margin-right: 5px; vertical-align: 0.15em;
  display: inline-block; transition: transform 0.2s;
}
details.para-toggle[open] summary > strong:first-child::before {
  transform: rotate(90deg);
}
details.para-toggle p {
  font-size: 1.0625rem; color: rgb(55, 53, 47); line-height: 1.65;
  margin-top: 0.5em; margin-bottom: 0.5em;
}
[data-theme="dark"] details.para-toggle summary { color: var(--text-2); }
[data-theme="dark"] details.para-toggle p { color: var(--text-2); }
[data-theme="dark"] details.para-toggle summary > strong:first-child::before { color: var(--accent); }

.metric {
  display: inline-flex; align-items: baseline; gap: 10px;
  padding: 8px 14px; border-radius: var(--r-sm);
  background: rgba(4,120,87,0.05); border: 1px solid rgba(4,120,87,0.10);
  margin: 12px 0 6px;
}
[data-theme="dark"] .metric {
  background: rgba(52,211,153,0.06); border-color: rgba(52,211,153,0.12);
}
.metric__value {
  font-size: 1.15rem; font-weight: 700; color: var(--green);
  letter-spacing: -0.01em;
}
.metric__label { font-size: 0.85rem; color: var(--text-3); font-weight: 500; }

/* ── Code Block ─────────────────────────────────────────── */
.code-block {
  margin: 24px 0; border-radius: 8px;
  overflow: hidden; border: 1px solid var(--border);
  background: #F7F6F3; position: relative;
  box-shadow: none;
}
[data-theme="dark"] .code-block { background: var(--bg-code); }
.code-block::before {
  content: var(--code-label, 'python'); position: absolute; top: 0; right: 0;
  padding: 4px 12px; font-size: 0.58rem; font-weight: 700;
  font-family: var(--mono); color: var(--text-muted);
  text-transform: uppercase; letter-spacing: 0.07em;
  background: rgba(0,0,0,0.04); border-bottom-left-radius: 5px;
}
[data-theme="dark"] .code-block::before { background: rgba(255,255,255,0.05); }
.code-block pre {
  padding: 22px 24px; font-family: var(--mono);
  font-size: 0.87rem; line-height: 1.75;
  overflow-x: auto; color: var(--text-2);
}
.code-block .copy-btn {
  position: absolute; top: 0; left: 0;
  padding: 5px 14px; font-size: 0.6rem; font-weight: 700;
  font-family: var(--mono); color: var(--text-muted);
  background: var(--border); border: none; cursor: pointer;
  border-bottom-right-radius: var(--r-sm);
  transition: all 0.2s; letter-spacing: 0.06em;
}
.code-block .copy-btn:hover { color: var(--accent); background: var(--bg-muted); }
[data-theme="dark"] .code-block .copy-btn { background: rgba(255,255,255,0.06); }
.code-block .copy-btn.copied { color: var(--green); }

/* ── CTA ────────────────────────────────────────────────── */
.cta {
  margin: 48px auto 0; padding: 36px 32px;
  max-width: 720px;
  border-radius: var(--r-lg); text-align: center;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-top: 3px solid var(--cal-gold);
  position: relative; overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.cta::before { display: none; }
[data-theme="dark"] .cta {
  background: var(--bg-card); border: 1px solid var(--border);
}
.cta h3 {
  font-size: 1.2rem; font-weight: 700;
  margin-bottom: 8px; color: var(--text); position: relative;
}
[data-theme="dark"] .cta h3 { color: var(--cal-gold); }
.cta p {
  font-size: 0.98rem; color: var(--text-2);
  margin-bottom: 16px; position: relative;
}
[data-theme="dark"] .cta p { color: var(--text-2); }
.cta .btn-primary {
  background: linear-gradient(135deg, var(--berkeley-blue), #004a8f);
  color: #fff; font-weight: 700; box-shadow: var(--shadow-sm);
}
.cta .btn-primary:hover {
  background: linear-gradient(135deg, #004a8f, var(--berkeley-deep));
  box-shadow: var(--shadow-md); transform: translateY(-1px);
}
[data-theme="dark"] .cta .btn-primary {
  background: linear-gradient(135deg, var(--cal-gold), #e5a300);
  color: #0f172a;
}

/* CTA List */
.cta-list {
  text-align: left; display: inline-block;
  list-style: none; padding-left: 0;
  font-size: 1.0rem; line-height: 1.8;
  margin-bottom: 18px;
}
.cta-list li {
  color: var(--text-2);
  margin-bottom: 5px; padding-left: 18px; position: relative;
}
.cta-list li::before {
  content: '\2022'; position: absolute; left: 0;
  color: var(--cal-gold-dark); font-weight: 700;
}
.cta-list li strong { color: var(--text); font-weight: 700; }
[data-theme="dark"] .cta-list li { color: var(--text-2); }
[data-theme="dark"] .cta-list li strong { color: var(--cal-gold); }

/* ── Collapsible Code Sections ──────────────────────────── */
details.code-toggle {
  margin: 16px 0; border-radius: var(--r-md);
  border: 1px solid var(--border); overflow: hidden;
  box-shadow: 0 1px 2px rgba(0,0,0,0.03);
}
details.code-toggle summary {
  padding: 12px 18px; cursor: pointer;
  font-size: 0.94rem; font-weight: 600; color: var(--text-2);
  background: var(--bg-subtle); user-select: none;
  display: flex; align-items: center; gap: 8px;
  transition: background 0.2s;
  list-style: none;
}
details.code-toggle summary::-webkit-details-marker { display: none; }
details.code-toggle summary::before {
  content: ''; display: inline-block;
  width: 0; height: 0;
  border-left: 5px solid var(--text-3); border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  transition: transform 0.2s;
}
details.code-toggle[open] summary::before { transform: rotate(90deg); }
details.code-toggle summary:hover { background: var(--bg-muted); }
details.code-toggle .code-inner {
  padding: 0; border-top: 1px solid var(--border);
}
details.code-toggle pre {
  padding: 18px 20px; font-family: var(--mono);
  font-size: 0.86rem; line-height: 1.7;
  overflow-x: auto; color: var(--text-2);
  background: var(--bg-code); margin: 0;
  max-height: 500px;
}

/* ── Video ──────────────────────────────────────────────── */
.video-container {
  margin: 20px auto; border-radius: var(--r-lg);
  overflow: hidden; border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  max-width: 800px;
}
.video-container video {
  width: 100%; height: auto; display: block;
}

/* ── GIF Animation ──────────────────────────────────────── */
.gif-container {
  margin: 36px auto; border-radius: 8px;
  overflow: hidden; max-width: 75%;
}
.gif-container img {
  border-radius: 6px; max-width: 100%; height: auto; display: block;
  box-shadow: 0 1px 6px rgba(0,0,0,0.06);
  border: 1px solid var(--border);
}
[data-theme="dark"] .gif-container img { box-shadow: 0 2px 8px rgba(0,0,0,0.22); }
.gif-caption {
  font-size: 85%; color: var(--text-muted);
  text-align: center; padding: 8px 16px 0;
  line-height: 1.4; opacity: 0.7;
}

/* ── Acknowledgments ────────────────────────────────────── */
.acknowledgments {
  margin-top: 36px; font-size: 0.88rem;
  color: var(--text-muted); text-align: center; line-height: 1.6;
}

/* ── Footer ─────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  background: var(--bg-subtle);
  transition: background 0.4s;
}
.footer__bar {
  width: 100%; height: 3px;
  background: linear-gradient(90deg, var(--berkeley-blue) 0%, var(--cal-gold) 50%, var(--cal-gold-light) 100%);
}
[data-theme="dark"] .footer__bar {
  background: linear-gradient(90deg, #1e3a5f 0%, var(--cal-gold) 50%, var(--cal-gold-light) 100%);
}
.footer__inner {
  max-width: var(--max-w); margin: 0 auto;
  padding: 24px 28px;
  display: flex; justify-content: space-between;
  align-items: center; flex-wrap: wrap; gap: 12px;
}
.footer__left { font-size: 0.88rem; color: var(--text-muted); }
.footer__left a { color: var(--text-muted); }
.footer__left a:hover { color: var(--accent); }
.footer__right { display: flex; gap: 20px; }
.footer__right a {
  font-size: 0.88rem; color: var(--text-muted); transition: color 0.2s;
  font-weight: 500;
}
.footer__right a:hover { color: var(--accent); }

/* ── Scroll Reveal ──────────────────────────────────────── */
.reveal {
  opacity: 0; transform: translateY(18px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

.reveal-stagger > .reveal:nth-child(1) { transition-delay: 0s; }
.reveal-stagger > .reveal:nth-child(2) { transition-delay: 0.06s; }
.reveal-stagger > .reveal:nth-child(3) { transition-delay: 0.06s; }
.reveal-stagger > .reveal:nth-child(4) { transition-delay: 0.12s; }
.reveal-stagger > .reveal:nth-child(5) { transition-delay: 0.18s; }

/* ── Focus ──────────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--cal-gold);
  outline-offset: 2px;
  border-radius: 3px;
}
[data-theme="dark"] :focus-visible { outline-color: var(--cal-gold); }

/* ── Papers Page ───────────────────────────────────────── */
.papers-hero {
  padding: calc(var(--nav-h) + 48px) 24px 40px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-subtle) 0%, var(--bg) 100%);
  border-bottom: 1px solid var(--border);
}
.papers-hero h1 {
  font-size: clamp(1.7rem, 3.4vw, 2.25rem);
  font-weight: 800; letter-spacing: -0.03em;
  color: var(--text); margin-bottom: 6px;
}
.papers-hero h1::after {
  content: ''; display: block;
  width: 80px; height: 3px; margin: 12px auto 0;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  border-radius: 2px;
}
[data-theme="dark"] .papers-hero h1::after {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}
.papers-hero p { font-size: 1.04rem; color: var(--text-3); }

.papers-grid {
  max-width: var(--content-w);
  margin: 0 auto;
  padding: 24px 24px 48px;
  display: flex; flex-direction: column; gap: 20px;
}

.paper-card {
  display: flex; gap: 24px;
  padding: 28px; border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, border-color 0.3s, transform 0.3s;
  border-left: 3px solid var(--cal-gold);
}
.paper-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-hover);
  border-left-color: var(--cal-gold);
  transform: translateY(-2px);
}

.paper-thumb {
  flex-shrink: 0; width: 340px; height: 260px;
  border-radius: var(--r-md); overflow: hidden;
  border: 1px solid var(--border);
  background: #fff;
  display: flex; align-items: center; justify-content: center;
  padding: 10px;
}
[data-theme="dark"] .paper-thumb { background: rgba(255,255,255,0.06); }
.paper-thumb img {
  width: 100%; height: 100%;
  object-fit: contain;
  border-radius: 4px;
}

.paper-body { flex: 1; min-width: 0; }
.paper-body h2 {
  font-size: 1.28rem; font-weight: 800;
  letter-spacing: -0.02em; color: var(--text);
  margin-bottom: 6px; line-height: 1.3;
}
.paper-authors {
  font-size: 0.9rem; color: var(--text-3);
  line-height: 1.5; margin-bottom: 10px;
}

.paper-abstract {
  margin: 10px 0 14px; border-radius: var(--r-sm);
  border: 1px solid var(--border); overflow: hidden;
}
.paper-abstract summary {
  padding: 8px 14px; cursor: pointer;
  font-size: 0.9rem; font-weight: 600; color: var(--text-2);
  background: var(--bg-subtle); user-select: none;
  display: flex; align-items: center; gap: 6px;
  list-style: none; transition: background 0.2s;
}
.paper-abstract summary::-webkit-details-marker { display: none; }
.paper-abstract summary::before {
  content: ''; display: inline-block;
  width: 0; height: 0;
  border-left: 5px solid var(--text-3);
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  transition: transform 0.2s;
}
.paper-abstract[open] summary::before { transform: rotate(90deg); }
.paper-abstract summary:hover { background: var(--bg-muted); }
.paper-abstract .abstract-text {
  padding: 14px 18px; font-size: 0.92rem;
  color: var(--text-2); line-height: 1.7;
  border-top: 1px solid var(--border);
  max-height: 260px;
  overflow-y: auto;
}

.paper-actions { display: flex; gap: 10px; flex-wrap: wrap; }

/* ── Nav Active State ──────────────────────────────────── */
.nav-btn--active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
  pointer-events: none;
}
[data-theme="dark"] .nav-btn--active {
  border-color: var(--cal-gold);
  color: var(--cal-gold);
  background: var(--gold-soft);
}

/* ══════════════════════════════════════════════════════════
   LANDING PAGE
   ══════════════════════════════════════════════════════════ */
.page-landing {
  background: var(--bg);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
.page-landing .landing-hero-wrap {
  flex: 1;
  display: flex;
  align-items: center;
}

/* ── Hero Background Pattern ────────────────────────────── */
.landing-hero-wrap {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--bg-subtle) 0%, var(--bg) 100%);
  border-bottom: 1px solid var(--border);
}
.landing-hero-wrap::before {
  content: '';
  position: absolute;
  top: -50%; left: -50%;
  width: 200%; height: 200%;
  background:
    radial-gradient(ellipse 600px 400px at 20% 30%, rgba(0,50,98,0.04) 0%, transparent 70%),
    radial-gradient(ellipse 500px 350px at 80% 40%, rgba(253,181,21,0.03) 0%, transparent 70%),
    radial-gradient(ellipse 300px 300px at 50% 80%, rgba(0,50,98,0.02) 0%, transparent 70%);
  pointer-events: none;
  animation: hero-drift 20s ease-in-out infinite alternate;
}
[data-theme="dark"] .landing-hero-wrap {
  background: linear-gradient(180deg, var(--bg-subtle) 0%, var(--bg) 100%);
}
[data-theme="dark"] .landing-hero-wrap::before {
  background:
    radial-gradient(ellipse 600px 400px at 20% 30%, rgba(0,74,174,0.06) 0%, transparent 70%),
    radial-gradient(ellipse 500px 350px at 80% 40%, rgba(255,195,27,0.04) 0%, transparent 70%),
    radial-gradient(ellipse 300px 300px at 50% 80%, rgba(0,74,174,0.03) 0%, transparent 70%);
}
@keyframes hero-drift {
  0% { transform: translate(0, 0); }
  100% { transform: translate(2%, 1%); }
}

/* Subtle grid pattern */
.landing-hero-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: 0.3;
  pointer-events: none;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 80%);
}
[data-theme="dark"] .landing-hero-wrap::after { opacity: 0.15; }

.landing {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
  padding: calc(var(--nav-h) + 16px) 28px 24px;
  position: relative;
  z-index: 1;
}

.landing-hero {
  text-align: center;
  margin-bottom: 0;
}

.landing-logo {
  width: 250px; height: 250px;
  margin: 0 auto 12px;
  object-fit: contain;
  animation: landing-float 6s ease-in-out infinite;
  filter: drop-shadow(0 8px 24px rgba(0,50,98,0.12));
}
[data-theme="dark"] .landing-logo {
  filter: drop-shadow(0 8px 24px rgba(255,195,27,0.15));
}
@keyframes landing-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ── Logo sparkles ────────────────────────────────────── */
.logo-constellation {
  position: relative;
  width: 340px; max-width: 100%; height: 280px;
  margin: 0 auto 4px;
  display: flex;
  align-items: center; justify-content: center;
}
.logo-constellation .landing-logo {
  margin: 0;
  position: relative;
  z-index: 1;
}

.spark {
  position: absolute;
  pointer-events: none;
  z-index: 2;
  animation: twinkle var(--dur, 4s) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
}

/* Cross rays */
.spark::before,
.spark::after {
  content: '';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 0.5px;
}
.spark::before {
  width: var(--ray, 18px); height: var(--thick, 1.2px);
  background: linear-gradient(90deg, transparent, var(--glow) 35%, var(--core) 50%, var(--glow) 65%, transparent);
}
.spark::after {
  width: var(--thick, 1.2px); height: var(--ray, 18px);
  background: linear-gradient(180deg, transparent, var(--glow) 35%, var(--core) 50%, var(--glow) 65%, transparent);
}

/* Shared glow colors */
.spark {
  --glow: rgba(253,195,50,0.65);
  --core: rgba(255,248,220,0.95);
  --thick: 1.2px;
}

/* ─ Hero star: the main discovery star ─ */
.spark--hero {
  --ray: 44px; --thick: 2px;
  --dur: 6s; --delay: 0s;
  --glow: rgba(253,200,50,0.75);
  --core: rgba(255,252,240,1);
}
/* Diagonal rays on the hero star */
.spark--hero-diag {
  position: absolute;
  pointer-events: none;
  z-index: 2;
}

/* ─ Large ─ */
.spark--lg {
  --ray: 26px; --thick: 1.4px; --dur: 5.2s; --delay: 1.4s;
}
/* ─ Medium ─ */
.spark--md {
  --ray: 16px; --dur: 4.2s; --delay: 0.8s;
}
/* ─ Small ─ */
.spark--sm {
  --ray: 10px; --dur: 3.6s;
}
.spark--sm:nth-child(odd)  { --delay: 0.4s; }
.spark--sm:nth-child(even) { --delay: 2.2s; }

/* ─ Tiny dust ─ */
.spark--xs {
  --ray: 5px; --dur: 3s;
}
.spark--xs:nth-child(3n)   { --delay: 1.6s; }
.spark--xs:nth-child(3n+1) { --delay: 0.2s; }
.spark--xs:nth-child(3n+2) { --delay: 2.8s; }

@keyframes twinkle {
  0%, 100% { opacity: 0.08; transform: scale(0.6); }
  40% { opacity: 1; transform: scale(1.05); }
  60% { opacity: 0.9; transform: scale(1); }
}

/* Dark mode — slightly brighter, cooler tone */
[data-theme="dark"] .spark {
  --glow: rgba(255,195,27,0.55);
  --core: rgba(255,250,230,0.92);
}
[data-theme="dark"] .spark--hero {
  --glow: rgba(255,195,27,0.7);
  --core: rgba(255,252,240,1);
}

.landing-title {
  font-size: clamp(2.8rem, 6.2vw, 4rem);
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1.08;
  margin-bottom: 14px;
}
.landing-title .brand-text {
  font-size: inherit;
  font-weight: inherit;
  letter-spacing: inherit;
}

.landing-subtitle {
  font-size: 1.3rem;
  color: var(--text-3);
  max-width: 540px;
  margin: 0 auto 10px;
  line-height: 1.6;
  font-weight: 400;
}

.landing-affiliation {
  font-size: 1.0rem;
  color: var(--text-muted);
  margin-bottom: 28px;
  font-weight: 500;
}
.landing-affiliation a {
  color: var(--text-muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-hover);
}
.landing-affiliation a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

.landing-actions {
  display: flex;
  gap: 10px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Stat Highlights ──────────────────────────────────── */
.landing-highlights {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 48px;
}

.highlight-card {
  text-align: center;
  padding: 30px 20px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, border-color 0.3s, transform 0.3s;
  position: relative;
  overflow: hidden;
}
.highlight-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
[data-theme="dark"] .highlight-card::before {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}
.highlight-card:hover::before { transform: scaleX(1); }
.highlight-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.highlight-card__value {
  display: block;
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--berkeley-blue) 20%, var(--cal-gold-dark) 80%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
  line-height: 1;
}
[data-theme="dark"] .highlight-card__value {
  background: linear-gradient(135deg, var(--cal-gold) 20%, var(--cal-gold-light) 80%);
  -webkit-background-clip: text;
  background-clip: text;
}

.highlight-card__label {
  display: block;
  font-size: 0.84rem;
  color: var(--text-3);
  line-height: 1.4;
  font-weight: 500;
}

/* ── About Section ────────────────────────────────────── */
.landing-about {
  margin-bottom: 56px;
  text-align: center;
}
.landing-about p {
  font-size: 1.04rem;
  color: var(--text-2);
  line-height: 1.75;
  max-width: 680px;
  margin: 0 auto;
}

/* ── Feature Cards ────────────────────────────────────── */
.landing-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 56px;
}

.feature-card {
  padding: 24px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  background: var(--bg-card);
  box-shadow: var(--shadow-xs);
  transition: box-shadow 0.3s, border-color 0.3s, transform 0.3s;
  position: relative;
}
.feature-card::after {
  content: '';
  position: absolute;
  bottom: 0; left: 16px; right: 16px;
  height: 2px;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  border-radius: 2px;
  opacity: 0;
  transition: opacity 0.3s;
}
[data-theme="dark"] .feature-card::after {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}
.feature-card:hover::after { opacity: 1; }
.feature-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-hover);
  transform: translateY(-3px);
}

.feature-card__icon {
  width: 40px; height: 40px;
  border-radius: var(--r-md);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
  font-size: 1.3rem;
}
.feature-card__icon--blue {
  background: rgba(29,78,216,0.08);
  color: var(--blue);
}
[data-theme="dark"] .feature-card__icon--blue {
  background: rgba(96,165,250,0.1);
}
.feature-card__icon--gold {
  background: rgba(253,181,21,0.1);
  color: var(--cal-gold-dark);
}
[data-theme="dark"] .feature-card__icon--gold {
  color: var(--cal-gold);
}
.feature-card__icon--green {
  background: rgba(4,120,87,0.08);
  color: var(--green);
}
[data-theme="dark"] .feature-card__icon--green {
  background: rgba(52,211,153,0.1);
}
.feature-card__icon--purple {
  background: rgba(109,40,217,0.08);
  color: var(--purple);
}
[data-theme="dark"] .feature-card__icon--purple {
  background: rgba(167,139,250,0.1);
}

.feature-card__title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.feature-card__desc {
  font-size: 0.88rem;
  color: var(--text-3);
  line-height: 1.55;
}

/* ── Team ─────────────────────────────────────────────── */
.landing-team {
  text-align: center;
  padding: 36px 0 0;
  border-top: 1px solid var(--border);
}

.landing-team__heading {
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 20px;
  position: relative;
}
.landing-team__heading::after {
  content: '';
  display: block;
  width: 72px; height: 2px;
  margin: 10px auto 0;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  border-radius: 2px;
}
[data-theme="dark"] .landing-team__heading::after {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}

.landing-team__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
  justify-content: center;
  margin-bottom: 12px;
}

.landing-author {
  font-size: 0.9rem;
  color: var(--text-3);
  white-space: nowrap;
}
.landing-author a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s;
}
.landing-author a:hover {
  color: var(--accent);
}

.landing-author--lead {
  color: var(--text);
  font-weight: 600;
}

.landing-team__note {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Blog Page ────────────────────────────────────────── */
.page-blog .article h2 {
  padding-left: 0;
  border-bottom: none;
  position: static;
}
.page-blog .article h2::before {
  display: none;
}
.page-blog .article {
  padding-top: 40px;
}

/* ── Collapsible Category Sections ─────────────────────── */
details.category-toggle {
  margin: 12px 0 28px;
  border-radius: var(--r-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
details.category-toggle summary {
  padding: 16px 22px;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  background: var(--bg-subtle);
  user-select: none;
  display: flex;
  align-items: center;
  gap: 10px;
  list-style: none;
  transition: background 0.2s;
}
details.category-toggle summary::-webkit-details-marker { display: none; }
details.category-toggle summary::before {
  content: '';
  display: inline-block;
  width: 0; height: 0;
  border-left: 6px solid var(--cal-gold);
  border-top: 5px solid transparent;
  border-bottom: 5px solid transparent;
  transition: transform 0.2s;
  flex-shrink: 0;
}
details.category-toggle[open] summary::before { transform: rotate(90deg); }
details.category-toggle summary:hover { background: var(--bg-muted); }
details.category-toggle summary .category-toggle__count {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg-muted);
  padding: 2px 9px;
  border-radius: 50px;
  margin-left: auto;
}
details.category-toggle .category-toggle__body {
  padding: 8px 22px 22px;
  border-top: 1px solid var(--border);
}

/* ── Papers Page Enhancements ──────────────────────────── */
.page-papers .papers-grid {
  max-width: 1100px;
  gap: 20px;
}

.page-papers .paper-card {
  border-radius: 16px;
  overflow: hidden;
  position: relative;
  border-left: none;
  padding-top: 0;
}

.paper-card__accent {
  height: 3px;
  background: linear-gradient(90deg, var(--berkeley-blue), var(--cal-gold));
  border-radius: 16px 16px 0 0;
}
[data-theme="dark"] .paper-card__accent {
  background: linear-gradient(90deg, var(--cal-gold), var(--cal-gold-light));
}

.paper-card__inner {
  padding: 20px;
  display: flex;
  gap: 22px;
}

.page-papers .paper-card:hover {
  border-left: none;
  transform: translateY(-3px);
}

.paper-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 5px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--gold-soft);
  color: var(--cal-gold-dark);
  border: 1px solid var(--gold-border);
  margin-bottom: 8px;
}
[data-theme="dark"] .paper-tag {
  color: var(--cal-gold);
}

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 768px) {
  .hero { padding: calc(var(--nav-h) + 32px) 20px 36px; }
  .hero h1 { font-size: 1.8rem; }
  .article { padding: 36px 20px 56px; }
  .article h2 { margin-top: 40px; font-size: 1.8rem; }
  .case-study { padding: 20px; }
  .figure { max-width: 90%; }
  .figure--table { max-width: 100%; }
  .cs-figure { max-width: 90%; }
  .gif-container { max-width: 90%; }
  .cta { padding: 28px 20px; }
  .nav-inner { padding: 0 16px; }
  .brand-text { font-size: 1.2rem; }
  .nav-brand img { height: 32px; width: 32px; }
  .paper-card { flex-direction: column; }
  .paper-card__inner { flex-direction: column; }
  .paper-thumb { width: 100%; height: 260px; }
  .papers-grid { padding: 16px 20px 40px; }
  .landing { padding: calc(var(--nav-h) + 16px) 20px 24px; }
  .landing-logo { width: 170px; height: 170px; }
  .landing-highlights { grid-template-columns: 1fr; gap: 14px; }
  .landing-features { grid-template-columns: 1fr; }
  .landing-team__list { gap: 3px 12px; }
}

@media (max-width: 480px) {
  .hero { padding: calc(var(--nav-h) + 24px) 16px 28px; }
  .hero h1 { font-size: 1.6rem; }
  .article { padding: 28px 16px 44px; }
  .article h2 { font-size: 1.65rem; }
  .authors { gap: 2px 8px; }
  .author { font-size: 0.84rem; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .footer__inner { flex-direction: column; text-align: center; }
  .figure__img { padding: 10px; }
  .landing { padding: calc(var(--nav-h) + 12px) 16px 20px; }
  .landing-logo { width: 150px; height: 150px; }
  .landing-actions { flex-direction: column; align-items: stretch; }
  .landing-author { font-size: 0.88rem; }
}

@media print {
  .nav, .progress-bar, .theme-toggle, .footer__bar { display: none; }
  .hero { padding-top: 20px; }
  .article { max-width: 100%; padding: 20px 0; }
  .reveal { opacity: 1 !important; transform: none !important; }
}