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

:root {
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-border: #e2e8f0;
  --color-text: #1a202c;
  --color-muted: #64748b;
  --color-primary: #0e3c5c;   /* Vector dark blue */
  --color-accent: #1a9fc4;    /* Vector teal */
  --color-accent-light: #e8f6fb;
  --color-highlight: #fff8e1;
  --font-sans: system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", monospace;
  --radius: 8px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,.10);
  --max-w: 1100px;
  --nav-h: 56px;
}

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 16px); }
body { font-family: var(--font-sans); color: var(--color-text); background: var(--color-bg); line-height: 1.65; font-size: 16px; }
a { color: var(--color-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
code { font-family: var(--font-mono); font-size: .88em; background: var(--color-surface); padding: .1em .35em; border-radius: 4px; }
pre code { background: none; padding: 0; font-size: .85rem; }

/* ========== Layout ========== */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }
.section { padding: 4rem 0; border-bottom: 1px solid var(--color-border); }
.section:last-child { border-bottom: none; }
.section-intro { font-size: 1.05rem; color: var(--color-muted); margin-bottom: 1.75rem; max-width: 70ch; }

/* ========== Topbar ========== */
.topbar {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.95); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  height: var(--nav-h);
}
.topbar-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem;
  height: 100%; display: flex; align-items: center; gap: 1rem;
}
.topbar-logos { display: flex; align-items: center; gap: .75rem; }
.logo-img { height: 28px; width: auto; }
.brand { display: flex; align-items: center; gap: .4rem; font-weight: 700; font-size: 1rem; color: var(--color-primary); margin-left: .5rem; }
.brand:hover { text-decoration: none; }
.brand-mark { font-size: .9em; opacity: .7; }
.nav { display: flex; gap: 1.5rem; margin-left: auto; align-items: center; }
.nav a { font-size: .9rem; color: var(--color-muted); font-weight: 500; transition: color .15s; }
.nav a:hover { color: var(--color-accent); text-decoration: none; }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: .4rem; flex-direction: column; gap: 5px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--color-text); border-radius: 2px; transition: .2s; }

/* ========== Hero ========== */
.hero { background: var(--color-bg); color: var(--color-text); padding: 3rem 0 2.5rem; border-bottom: 1px solid var(--color-border); }
.hero-content { display: flex; flex-direction: column; gap: 2.5rem; align-items: stretch; }
.hero-header { text-align: center; max-width: 820px; margin: 0 auto; width: 100%; }
.hero-intro { text-align: center; max-width: 820px; margin: 0 auto; width: 100%; }
.title { font-size: clamp(1.5rem, 3vw, 2.25rem); font-weight: 800; line-height: 1.25; margin-bottom: 1rem; color: var(--color-primary); }
.authors { font-size: .95rem; margin-bottom: .4rem; color: var(--color-text); }
.authors a { color: var(--color-accent); }
.authors a:hover { color: var(--color-primary); }
.affiliations { font-size: .85rem; color: var(--color-muted); margin-bottom: 1.25rem; }
.lead { font-size: 1rem; color: var(--color-muted); margin-bottom: 1.25rem; line-height: 1.7; }
.hero-attribution { font-size: .78rem; color: var(--color-muted); margin-bottom: 0; }
.hero-attribution a { color: var(--color-accent); text-decoration: underline; }
.lead strong { color: var(--color-text); }
.hero-header .button-row { justify-content: center; margin-bottom: 1rem; }
.hero-intro .badge-row { justify-content: center; }
.hero-figure { width: 100%; max-width: var(--max-w); margin: 0 auto; }
.hero-figure figure { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
.hero-figure .teaser-img { display: block; width: 100%; height: auto; vertical-align: middle; }
.hero-figure figcaption { padding: .85rem 1.1rem; font-size: .82rem; color: var(--color-muted); line-height: 1.55; text-align: left; background: var(--color-bg); }
.hero-figure figcaption code { font-size: .78rem; background: var(--color-surface); padding: .1rem .35rem; border-radius: 4px; }

/* ========== Buttons ========== */
.button-row { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: 1.5rem; }
.btn {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .45rem 1rem; border-radius: 6px; font-size: .88rem; font-weight: 600;
  border: 1.5px solid var(--color-border); color: var(--color-text); background: var(--color-bg);
  transition: background .15s, border-color .15s; cursor: pointer; text-decoration: none;
}
.btn:hover { background: var(--color-surface); border-color: var(--color-accent); text-decoration: none; color: var(--color-primary); }
.btn-primary { background: var(--color-accent); border-color: var(--color-accent); color: #fff; }
.btn-primary:hover { background: #1589ab; border-color: #1589ab; color: #fff; }
.btn-small { padding: .3rem .7rem; font-size: .8rem; }
.btn-copy { border: 1.5px solid var(--color-border); color: var(--color-muted); background: var(--color-surface); }
.btn-copy:hover { background: var(--color-accent-light); color: var(--color-accent); border-color: var(--color-accent); }
.btn-icon { width: 16px; height: 16px; flex-shrink: 0; }
.btn-icon-fa { font-size: 1rem; line-height: 1; }

/* ========== Badges / pills ========== */
.badge-row { display: flex; flex-wrap: wrap; gap: .5rem; }
.pill { background: var(--color-accent-light); border: 1px solid #b3e0f0; color: var(--color-primary); border-radius: 20px; padding: .3rem .85rem; font-size: .8rem; font-weight: 500; }
.pill-small { background: var(--color-accent-light); color: var(--color-accent); border-radius: 20px; padding: .2rem .65rem; font-size: .78rem; font-weight: 600; }

/* ========== Headings ========== */
h2 { font-size: 1.65rem; font-weight: 800; color: var(--color-primary); margin-bottom: 1.25rem; }
.h3 { font-size: 1.1rem; font-weight: 700; color: var(--color-text); margin-bottom: .75rem; }

/* ========== Abstract box ========== */
.abstract-box { background: var(--color-surface); border-left: 4px solid var(--color-accent); border-radius: 0 var(--radius) var(--radius) 0; padding: 1.5rem 1.75rem; }
.abstract-box p + p { margin-top: .9rem; }

/* ========== Pipeline ========== */
.pipeline { display: flex; flex-direction: column; align-items: center; gap: 0; max-width: 640px; margin: 0 auto; }
.pipeline-step {
  display: flex; align-items: flex-start; gap: 1rem;
  background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); padding: 1rem 1.25rem; width: 100%;
}
.pipeline-step--output { background: var(--color-accent-light); border-color: var(--color-accent); }
.step-number {
  flex-shrink: 0; width: 32px; height: 32px; border-radius: 50%;
  background: var(--color-accent); color: #fff; font-weight: 800; font-size: .9rem;
  display: flex; align-items: center; justify-content: center;
}
.pipeline-step--output .step-number { background: var(--color-primary); }
.step-body h3 { font-size: 1rem; font-weight: 700; margin-bottom: .3rem; }
.step-body p { font-size: .9rem; color: var(--color-muted); }
.pipeline-arrow { color: var(--color-accent); font-size: 1.4rem; padding: .2rem 0 .2rem 15px; }

/* ========== Two-col grid ========== */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; align-items: start; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; margin-bottom: 2rem; }

/* ========== Stat ========== */
.stat { text-align: center; padding: 1rem; background: var(--color-surface); border-radius: var(--radius); border: 1px solid var(--color-border); }
.stat-value { font-size: 2rem; font-weight: 800; color: var(--color-primary); line-height: 1; }
.stat-label { font-size: .8rem; color: var(--color-muted); margin-top: .3rem; }

/* ========== Card ========== */
.card { background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1.5rem; }
.info-box { background: var(--color-accent-light); border: 1px solid #b3e0f0; border-radius: var(--radius); padding: 1.25rem 1.5rem; }
.info-box .h3 { color: var(--color-primary); }

/* ========== Lists ========== */
.bullets { list-style: none; padding: 0; }
.bullets li { padding: .35rem 0 .35rem 1.4rem; position: relative; font-size: .95rem; }
.bullets li::before { content: "→"; position: absolute; left: 0; color: var(--color-accent); font-weight: 700; }
.compact { list-style: disc; padding-left: 1.2rem; font-size: .9rem; }
.compact li { padding: .15rem 0; }
ol.compact { list-style: decimal; padding-left: 1.4rem; }
ol.compact li { padding: .2rem 0; font-size: .9rem; }

/* ========== Table ========== */
.table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--color-border); }
.table { width: 100%; border-collapse: collapse; font-size: .9rem; }
.table th { background: var(--color-primary); color: #fff; padding: .65rem 1rem; text-align: left; font-weight: 600; white-space: nowrap; }
.table td { padding: .6rem 1rem; border-bottom: 1px solid var(--color-border); }
.table tbody tr:last-child td { border-bottom: none; }
.table tbody tr:hover td { background: var(--color-surface); }
.table .highlight td { background: #f0f9ff; font-weight: 600; }
.table .delta-row td { background: #f0fdf4; font-size: .85rem; color: #166534; border-bottom: 2px solid var(--color-border); }
.table .center { text-align: center; }
.metric-desc { font-weight: 400; font-size: .78rem; color: rgba(255,255,255,.75); }
.table-note { font-size: .82rem; color: var(--color-muted); margin-top: .75rem; }

/* ========== Figure placeholder ========== */
.figure-placeholder {
  background: rgba(255,255,255,.08); border: 2px dashed rgba(255,255,255,.2);
  border-radius: var(--radius); padding: 3rem 1rem;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .5rem; color: rgba(255,255,255,.5); text-align: center; min-height: 220px;
}
.figure-placeholder span { font-size: 1rem; font-weight: 600; }
.figure-placeholder p { font-size: .85rem; }

/* ========== Code cards ========== */
.code-section { margin-bottom: 2rem; }
.code-card { position: relative; background: #1e293b; border-radius: var(--radius); overflow: hidden; }
.code-card pre { padding: 1.25rem 1.5rem; overflow-x: auto; }
.code-card code { color: #e2e8f0; font-size: .85rem; }
.code-copy {
  position: absolute; top: .6rem; right: .6rem;
  background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.15);
  color: rgba(255,255,255,.7); border-radius: 5px; padding: .3rem .5rem;
  cursor: pointer; display: flex; align-items: center; transition: background .15s;
}
.code-copy:hover { background: rgba(255,255,255,.2); color: #fff; }

/* ========== BibTeX ========== */
.bibtex-section { position: relative; margin-top: 1rem; }
.bibtex { background: #1e293b; color: #e2e8f0; border-radius: var(--radius); padding: 1.25rem 1.5rem; overflow-x: auto; font-size: .85rem; margin-top: .75rem; }
.copy-status { font-size: .82rem; color: var(--color-accent); height: 1.2em; margin-top: .4rem; }

/* ========== Footer ========== */
.footer { background: var(--color-primary); color: rgba(255,255,255,.7); padding: 2rem 0; margin-top: 2rem; }
.footer-inner { display: flex; align-items: center; gap: 1.5rem; }
.footer-logo { height: 28px; filter: brightness(0) invert(1); opacity: .85; }
.footer-logo--color { filter: none; opacity: .9; }
.footer-text { font-size: .88rem; }
.footer-text a { color: rgba(255,255,255,.7); }
.footer-text a:hover { color: #fff; }

/* ========== Misc ========== */
.muted { color: var(--color-muted); }
.small { font-size: .85rem; }
sup { font-size: .7em; vertical-align: super; }

/* ========== Responsive ========== */
@media (max-width: 768px) {
  .two-col { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr 1fr; }
  .nav { display: none; flex-direction: column; position: absolute; top: var(--nav-h); left: 0; right: 0; background: #fff; border-bottom: 1px solid var(--color-border); padding: 1rem 1.5rem; gap: .75rem; z-index: 99; }
  .nav.open { display: flex; }
  .nav-toggle { display: flex; margin-left: auto; }
  .footer-inner { flex-direction: column; text-align: center; gap: .75rem; }
}

@media (max-width: 480px) {
  .grid-4 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
}