/* ─── Research sub-pages shared stylesheet ─── */

/* Theme tokens */
[data-theme="dark"] {
  --bg: #0a0a0f;
  --bg-elevated: #111118;
  --bg-card: #16161f;
  --bg-card-hover: #1c1c28;
  --text: #ececf2;
  --text-muted: #b8b8cc;
  --text-dim: #8e8ea3;
  --accent: #7B61FF;
  --accent-glow: rgba(123, 97, 255, 0.15);
  --border: rgba(255,255,255,0.06);
  --border-accent: rgba(123,97,255,0.25);
  --toggle-bg: rgba(255,255,255,0.06);
  --toggle-hover: rgba(255,255,255,0.12);
}
[data-theme="light"] {
  --bg: #f5f5f7;
  --bg-elevated: #eeeef2;
  --bg-card: #ffffff;
  --bg-card-hover: #f8f8fc;
  --text: #1a1a2e;
  --text-muted: #5a5a78;
  --text-dim: #8888a0;
  --accent: #5a3de8;
  --accent-glow: rgba(90, 61, 232, 0.12);
  --border: rgba(0,0,0,0.08);
  --border-accent: rgba(90,61,232,0.25);
  --toggle-bg: rgba(0,0,0,0.06);
  --toggle-hover: rgba(0,0,0,0.12);
}

/* Alt Maria Clara */
@font-face {
  font-family: 'Alt Maria Clara';
  src: url('/fonts/alt-mariaclara/altmariaclara-light.otf') format('opentype');
  font-weight: 300; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Alt Maria Clara';
  src: url('/fonts/alt-mariaclara/altmariaclara-regular.otf') format('opentype');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Alt Maria Clara';
  src: url('/fonts/alt-mariaclara/altmariaclara-medium.otf') format('opentype');
  font-weight: 500; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Alt Maria Clara';
  src: url('/fonts/alt-mariaclara/altmariaclara-semibold.otf') format('opentype');
  font-weight: 600; font-style: normal; font-display: swap;
}

/* Base */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background 0.3s ease, color 0.3s ease;
  font-size: 15px;
}
a { color: var(--accent); text-decoration: none; transition: opacity 0.2s; }
a:hover { opacity: 0.8; }
::selection { background: var(--accent); color: #fff; }

/* Nav */
.rp-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.rp-nav-inner {
  max-width: 860px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 24px; height: 52px;
}
.rp-nav-brand {
  display: flex; align-items: center; gap: 10px;
  font-family: 'Alt Maria Clara', Georgia, serif;
  font-size: 14px; font-weight: 500; letter-spacing: 0.03em;
  color: var(--text); text-decoration: none; white-space: nowrap;
}
.rp-nav-brand img { width: 26px; height: 26px; border-radius: 6px; display: block; }
.rp-nav-links { display: flex; gap: 20px; align-items: center; }
.rp-nav-links a { font-size: 12px; font-weight: 500; color: var(--text-muted); letter-spacing: 0.01em; }
.rp-nav-links a:hover { color: var(--text); opacity: 1; }

/* Theme toggle */
.theme-toggle {
  width: 32px; height: 32px; border-radius: 7px;
  background: var(--toggle-bg); border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; font-size: 14px; color: var(--text-muted);
  transition: background 0.2s, border-color 0.2s;
}
.theme-toggle:hover { background: var(--toggle-hover); border-color: var(--border-accent); }
[data-theme="dark"] .icon-light { display: inline; }
[data-theme="dark"] .icon-dark  { display: none; }
[data-theme="light"] .icon-light { display: none; }
[data-theme="light"] .icon-dark  { display: inline; }

/* Page layout */
.rp-page {
  max-width: 860px; margin: 0 auto;
  padding: 96px 24px 80px;
}

/* Breadcrumb */
.rp-breadcrumb {
  font-size: 11px; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--text-dim); margin-bottom: 36px;
  display: flex; align-items: center; gap: 8px;
}
.rp-breadcrumb a { color: var(--text-dim); }
.rp-breadcrumb a:hover { color: var(--text-muted); opacity: 1; }
.rp-breadcrumb span { opacity: 0.4; }

/* Article header */
.rp-label {
  font-size: 10px; font-weight: 600; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 14px;
}
.rp-title {
  font-family: 'Alt Maria Clara', Georgia, serif;
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 500; line-height: 1.18; letter-spacing: -0.01em;
  margin-bottom: 16px; color: var(--text);
}
.rp-venue {
  font-size: 12px; color: var(--text-dim); letter-spacing: 0.06em;
  text-transform: uppercase; font-weight: 500; margin-bottom: 40px;
}

/* CTA */
.rp-cta {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: 8px;
  background: var(--accent); color: #fff;
  font-size: 13px; font-weight: 600; letter-spacing: 0.02em;
  transition: opacity 0.2s; margin-bottom: 48px;
}
.rp-cta:hover { opacity: 0.85; }
.rp-cta .ext { font-size: 11px; opacity: 0.75; }

/* Divider */
.rp-divider {
  border: none; border-top: 1px solid var(--border);
  margin: 0 0 40px;
}

/* Abstract */
.rp-abstract {
  font-size: 15px; line-height: 1.78; color: var(--text-muted);
  max-width: 680px; margin-bottom: 40px; font-weight: 300;
}
.rp-abstract strong { color: var(--text); font-weight: 500; }

/* Topics row */
.rp-topics-label {
  font-size: 10px; font-weight: 600; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-dim); margin-bottom: 12px;
}
.rp-topics {
  display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 48px;
}
.rp-topic-tag {
  padding: 4px 12px; border-radius: 20px;
  border: 1px solid var(--border); font-size: 11px;
  color: var(--text-muted); letter-spacing: 0.04em;
  font-weight: 500;
}

/* Related papers list */
.rp-related-label {
  font-size: 10px; font-weight: 600; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--text-dim); margin-bottom: 20px;
}
.rp-related-list {
  display: flex; flex-direction: column; gap: 10px;
}
.rp-related-item {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 14px 18px;
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 8px;
  transition: border-color 0.2s, background 0.2s;
}
.rp-related-item:hover { border-color: var(--border-accent); background: var(--bg-card-hover); }
.rp-related-item a { color: var(--text); font-size: 13px; font-weight: 400; line-height: 1.5; border-bottom: 1px solid var(--border-accent); padding-bottom: 1px; }
.rp-related-item a:hover { color: var(--accent); opacity: 1; }
.rp-related-venue { font-size: 11px; color: var(--text-dim); margin-top: 3px; }
.rp-related-bullet { width: 5px; height: 5px; border-radius: 50%; background: var(--accent); margin-top: 7px; flex-shrink: 0; opacity: 0.55; }

/* Hub page: paper grid */
.rp-hub-intro {
  font-size: 16px; line-height: 1.7; color: var(--text-muted);
  max-width: 640px; font-weight: 300; margin-bottom: 48px;
}
.rp-paper-list {
  display: flex; flex-direction: column; gap: 12px;
}
.rp-paper-card {
  padding: 20px 24px;
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 10px;
  transition: border-color 0.25s, background 0.25s;
  text-decoration: none; display: block; color: var(--text);
}
.rp-paper-card:hover { border-color: var(--border-accent); background: var(--bg-card-hover); opacity: 1; }
.rp-paper-card-title { font-size: 14px; font-weight: 500; line-height: 1.4; margin-bottom: 6px; }
.rp-paper-card-meta { font-size: 11px; color: var(--text-dim); letter-spacing: 0.04em; text-transform: uppercase; }

/* Footer */
.rp-footer {
  border-top: 1px solid var(--border); padding: 28px 24px;
  max-width: 860px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12px; color: var(--text-dim);
}
.rp-footer a { color: var(--text-dim); }
.rp-footer a:hover { color: var(--text); opacity: 1; }

/* Responsive */
@media (max-width: 600px) {
  .rp-nav-inner { padding: 0 16px; }
  .rp-page { padding: 80px 16px 64px; }
  .rp-footer { flex-direction: column; gap: 10px; text-align: center; }
}