/* ============================================
   Vaibhav Balloli — Personal Website
   ============================================ */

/* ---------- Fonts ---------- */
@font-face {
  font-family: 'InterVariable';
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
  src: url('fonts/InterVariable.woff2') format('woff2');
}

@font-face {
  font-family: 'InterVariable';
  font-style: italic;
  font-weight: 100 900;
  font-display: swap;
  src: url('fonts/InterVariable-Italic.woff2') format('woff2');
}

@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=JetBrains+Mono:wght@400;500&display=swap');

/* ---------- Custom Properties (Light) ---------- */
:root {
  --bg-primary: #fbfbf9;
  --bg-secondary: #f2f1ec;
  --bg-card: #ffffff;
  --bg-elevated: #ffffff;
  --bg-hero: #0a0a0b;

  --border-subtle: #e8e6df;
  --border-medium: #d6d3c8;
  --border-accent: #18181b;

  --text-primary: #111113;
  --text-secondary: #3a3a3f;
  --text-muted: #71717a;
  --text-hero: #ffffff;
  --text-hero-sub: #a1a1aa;

  --accent: #1f8a70;
  --accent-hover: #176b57;
  --accent-light: rgba(31, 138, 112, 0.09);

  --cornell-red: #b31b1b;
  --highlight: #1f8a70;

  --content-width: min(92%, 880px);

  --font-heading: 'InterVariable', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'InterVariable', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Instrument Serif', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;

  --radius: 8px;
  --radius-sm: 6px;
  --radius-lg: 14px;

  /* Elegant, soft shadows */
  --shadow-xs: 0 1px 2px rgba(15, 15, 20, 0.04);
  --shadow-sm: 0 1px 3px rgba(15, 15, 20, 0.05), 0 1px 2px rgba(15, 15, 20, 0.03);
  --shadow-md: 0 4px 14px -2px rgba(15, 15, 20, 0.06), 0 2px 6px -1px rgba(15, 15, 20, 0.04);
  --shadow-lg: 0 12px 32px -8px rgba(15, 15, 20, 0.12), 0 4px 12px -2px rgba(15, 15, 20, 0.06);

  color-scheme: light;
}

/* ---------- Dark mode tokens ---------- */
:root[data-theme="dark"] {
  --bg-primary: #0e0e10;
  --bg-secondary: #18181b;
  --bg-card: #131316;
  --bg-elevated: #1a1a1e;
  --bg-hero: #050507;

  --border-subtle: #26262b;
  --border-medium: #34343a;
  --border-accent: #fafafa;

  --text-primary: #f4f4f5;
  --text-secondary: #d4d4d8;
  --text-muted: #8b8b93;
  --text-hero: #ffffff;
  --text-hero-sub: #a1a1aa;

  --accent: #5ec9ae;
  --accent-hover: #8fdcc8;
  --accent-light: rgba(94, 201, 174, 0.14);

  --cornell-red: #ff6b6b;
  --highlight: #5ec9ae;

  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 4px 14px -2px rgba(0, 0, 0, 0.45), 0 2px 6px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 12px 32px -8px rgba(0, 0, 0, 0.6), 0 4px 12px -2px rgba(0, 0, 0, 0.4);

  color-scheme: dark;
}

/* ---------- Earth / sepia tokens (warm beige + umber) ---------- */
:root[data-theme="sepia"] {
  --bg-primary: #f3ecdd;
  --bg-secondary: #e7dcc5;
  --bg-card: #faf4e7;
  --bg-elevated: #fbf6ec;
  --bg-hero: #2a2418;

  --border-subtle: #ddd0b6;
  --border-medium: #c8b793;
  --border-accent: #3a3326;

  --text-primary: #3a3326;
  --text-secondary: #5c5440;
  --text-muted: #8a7d62;
  --text-hero: #faf4e7;
  --text-hero-sub: #cdbf9f;

  --accent: #1c7a63;
  --accent-hover: #14594a;
  --accent-light: rgba(28, 122, 99, 0.10);

  --cornell-red: #a83232;
  --highlight: #1c7a63;

  --shadow-xs: 0 1px 2px rgba(80, 60, 30, 0.06);
  --shadow-sm: 0 1px 3px rgba(80, 60, 30, 0.08), 0 1px 2px rgba(80, 60, 30, 0.05);
  --shadow-md: 0 4px 14px -2px rgba(80, 60, 30, 0.10), 0 2px 6px -1px rgba(80, 60, 30, 0.06);
  --shadow-lg: 0 12px 32px -8px rgba(80, 60, 30, 0.16), 0 4px 12px -2px rgba(80, 60, 30, 0.10);

  color-scheme: light;
}

/* System mode: follow OS preference */
@media (prefers-color-scheme: dark) {
  :root[data-theme="system"] {
    --bg-primary: #0e0e10;
    --bg-secondary: #18181b;
    --bg-card: #131316;
    --bg-elevated: #1a1a1e;
    --bg-hero: #050507;

    --border-subtle: #26262b;
    --border-medium: #34343a;
    --border-accent: #fafafa;

    --text-primary: #f4f4f5;
    --text-secondary: #d4d4d8;
    --text-muted: #8b8b93;

    --accent: #5ec9ae;
    --accent-hover: #8fdcc8;
    --accent-light: rgba(94, 201, 174, 0.14);

    --cornell-red: #ff6b6b;
    --highlight: #5ec9ae;

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.25);
    --shadow-md: 0 4px 14px -2px rgba(0, 0, 0, 0.45), 0 2px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 12px 32px -8px rgba(0, 0, 0, 0.6), 0 4px 12px -2px rgba(0, 0, 0, 0.4);

    color-scheme: dark;
  }
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  font-size: 15.5px;
  font-feature-settings: "ss01", "cv11", "calt";
  overflow-x: hidden;
  transition: background 0.25s ease, color 0.25s ease;
}

.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section { padding: 3rem 0 1.5rem; }

.section-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border-subtle);
}

/* ---------- Links ---------- */
a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover, a:focus { color: var(--accent-hover); }

/* ============================================
   TOP CONTROLS
   ============================================ */
.top-controls {
  position: fixed;
  top: 1.2rem;
  right: 1.2rem;
  z-index: 100;
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.top-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: var(--shadow-xs);
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1;
  position: relative;
}

.top-btn:hover {
  border-color: var(--border-medium);
  color: var(--text-primary);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

/* Theme toggle icon — hidden by default, JS reveals the active one */
.theme-toggle .theme-icon { display: none; }
:root[data-theme="light"] .theme-toggle .theme-icon--light,
:root[data-theme="dark"]  .theme-toggle .theme-icon--dark,
:root[data-theme="sepia"] .theme-toggle .theme-icon--sepia,
:root[data-theme="system"] .theme-toggle .theme-icon--system {
  display: inline;
}

/* Nav Dropdown */
.nav-dropdown {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  min-width: 180px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 0.4rem;
  opacity: 0;
  transform: translateY(-6px) scale(0.97);
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.nav-dropdown--open {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.nav-dropdown__link {
  display: block;
  padding: 0.5rem 0.75rem;
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
  text-decoration: none;
}

.nav-dropdown__link:hover {
  background: var(--accent-light);
  color: var(--accent);
}

.nav-dropdown__link--active {
  color: var(--accent);
  background: var(--accent-light);
}

.nav-dropdown__divider {
  height: 1px;
  background: var(--border-subtle);
  margin: 0.3rem 0.5rem;
}

.nav-dropdown__hint {
  display: block;
  padding: 0.4rem 0.75rem;
  font-size: 0.72rem;
  color: var(--text-muted);
  cursor: pointer;
  border: none;
  background: none;
  font-family: var(--font-body);
  width: 100%;
  text-align: left;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.nav-dropdown__hint:hover { background: var(--accent-light); color: var(--accent); }

.nav-dropdown__hint kbd {
  font-family: var(--font-mono);
  background: var(--bg-secondary);
  padding: 0.1rem 0.35rem;
  border-radius: 3px;
  font-size: 0.65rem;
  border: 1px solid var(--border-subtle);
}

/* ============================================
   COMMAND PALETTE
   ============================================ */
.cmd-palette-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 18vh;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.cmd-palette-overlay--open { opacity: 1; pointer-events: all; }

.cmd-palette {
  width: min(92vw, 540px);
  background: var(--bg-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: translateY(-8px) scale(0.98);
  transition: transform 0.2s cubic-bezier(0.22, 1, 0.36, 1);
}

.cmd-palette-overlay--open .cmd-palette { transform: translateY(0) scale(1); }

.cmd-palette__input-wrap {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.cmd-palette__icon { font-size: 1rem; color: var(--text-muted); flex-shrink: 0; }

.cmd-palette__input {
  flex: 1;
  border: none;
  background: none;
  font-family: var(--font-body);
  font-size: 0.95rem;
  color: var(--text-primary);
  outline: none;
}

.cmd-palette__input::placeholder { color: var(--text-muted); }

.cmd-palette__kbd {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  border: 1px solid var(--border-subtle);
}

.cmd-palette__results { max-height: 320px; overflow-y: auto; padding: 0.4rem; }

.cmd-palette__item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.55rem 0.75rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.1s ease;
}

.cmd-palette__item:hover, .cmd-palette__item--active { background: var(--accent-light); }

.cmd-palette__item-icon { font-size: 0.85rem; flex-shrink: 0; width: 1.4rem; text-align: center; }
.cmd-palette__item-text { flex: 1; min-width: 0; }

.cmd-palette__item-title {
  font-family: var(--font-heading);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cmd-palette__item-sub {
  font-size: 0.74rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cmd-palette__empty {
  padding: 1.5rem 1rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ============================================
   HERO
   ============================================ */
@keyframes heroFadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes heroPhotoIn {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}

.hero__name, .hero__bio > p, .hero__mentoring, .hero__links, .hero__photo {
  opacity: 0;
  animation: heroFadeUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

.hero__name { animation-delay: 0s; }
.hero__bio > p:nth-child(1) { animation-delay: 0.08s; }
.hero__bio > p:nth-child(2) { animation-delay: 0.16s; }
.hero__bio > p:nth-child(3) { animation-delay: 0.24s; }
.hero__bio > p:nth-child(4) { animation-delay: 0.32s; }
.hero__mentoring { animation-delay: 0.38s; }
.hero__links { animation-delay: 0.44s; }
.hero__photo { animation-name: heroPhotoIn; animation-delay: 0.15s; animation-duration: 0.7s; }

.hero { padding: 3.5rem 0 1rem; }

.hero__inner {
  display: flex;
  align-items: flex-start;
  gap: 2.5rem;
}

.hero__text { flex: 1; min-width: 0; }

.hero__name {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.hero__bio p {
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
  line-height: 1.7;
}

.hero__bio a { font-weight: 500; }
.hero__bio strong { color: var(--text-primary); font-weight: 600; }

.hero__mentoring {
  margin-top: 1rem;
  padding: 0.9rem 1.1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-xs);
  font-size: 0.93rem;
  color: var(--text-secondary);
}

.hero__mentoring strong { color: var(--text-primary); font-weight: 600; }

.hero__links {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1.3rem;
}

.hero__links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  transition: all 0.15s ease;
}

.hero__links a:hover {
  border-color: var(--border-medium);
  color: var(--text-primary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

/* External-link arrow on hero buttons */
.hero__links a[href^="http"]::after,
.hero__links a[href^="mailto"]::after {
  content: '';
  display: inline-block;
  width: 0.7em;
  height: 0.7em;
  margin-left: 0.15em;
  background-color: currentColor;
  -webkit-mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><path d='M7 17L17 7M9 7h8v8'/></svg>") no-repeat center / contain;
  mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'><path d='M7 17L17 7M9 7h8v8'/></svg>") no-repeat center / contain;
  opacity: 0.6;
  transition: transform 0.2s ease, opacity 0.2s ease;
  vertical-align: -0.05em;
}

.hero__links a[href^="http"]:hover::after,
.hero__links a[href^="mailto"]:hover::after {
  opacity: 1;
  transform: translate(2px, -2px);
}


.hero__link--primary {
  background: var(--text-primary) !important;
  color: var(--bg-primary) !important;
  border-color: var(--text-primary) !important;
}

.hero__link--primary:hover {
  background: var(--text-secondary) !important;
  border-color: var(--text-secondary) !important;
  color: var(--bg-primary) !important;
}

.hero__photo {
  flex-shrink: 0;
  width: 220px;
}

.hero__photo img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);
  filter: saturate(0.85);
  transition: box-shadow 0.3s ease, filter 0.3s ease, transform 0.3s ease;
}

.hero__photo img:hover {
  filter: saturate(1);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* ============================================
   RESEARCH
   ============================================ */
.research__intro {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.filter-tag {
  padding: 0.4rem 0.9rem;
  font-size: 0.8rem;
  font-weight: 500;
  font-family: var(--font-body);
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.18s ease;
}

.filter-tag:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-light);
}

.filter-tag--active {
  color: var(--bg-primary);
  background: var(--text-primary);
  border-color: var(--text-primary);
}

.filter-tag--active:hover {
  background: var(--text-primary);
  border-color: var(--text-primary);
  color: var(--bg-primary);
}

/* ============================================
   FILTER PILL
   ============================================ */
.pill-anchor { height: 0; overflow: visible; }

.filter-pill {
  display: flex;
  align-items: center;
  gap: 0;
  max-width: min(860px, 92vw);
  width: max-content;
  background: var(--bg-card);
  backdrop-filter: blur(16px) saturate(1.6);
  -webkit-backdrop-filter: blur(16px) saturate(1.6);
  border: 1px solid var(--border-subtle);
  border-radius: 9999px;
  box-shadow: var(--shadow-sm);
  padding: 0.45rem 0.75rem;
  z-index: 200;
  will-change: transform;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.filter-pill:hover {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-md);
}

.filter-pill--inline {
  position: relative;
  left: auto;
  bottom: auto;
  margin: 1rem auto 1.5rem;
  max-width: min(720px, 90%);
  transform: none;
  opacity: 1;
  pointer-events: all;
}

.filter-pill--fixed {
  position: fixed;
  top: 1rem;
  left: 50%;
  margin: 0;
  max-width: min(720px, 90%);
  transform: translateX(-50%);
  box-shadow: var(--shadow-md);
  opacity: 1;
  pointer-events: all;
}

.filter-pill--hidden {
  position: fixed;
  top: 1rem;
  left: 50%;
  margin: 0;
  transform: translateX(-50%) translateY(calc(-100% - 2rem));
  opacity: 0;
  pointer-events: none;
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1), opacity 0.3s ease;
}

.filter-pill__search-wrap {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-shrink: 0;
  padding: 0 0.4rem;
}

.filter-pill__search-icon { font-size: 0.8rem; opacity: 0.5; flex-shrink: 0; }

.filter-pill__input {
  border: none;
  outline: none;
  background: transparent;
  font-family: var(--font-body);
  font-size: 0.82rem;
  color: var(--text-primary);
  width: 130px;
  min-width: 0;
}

.filter-pill__input::placeholder { color: var(--text-muted); opacity: 0.7; }

.filter-pill__divider {
  width: 1px;
  height: 1.4rem;
  background: var(--border-subtle);
  flex-shrink: 0;
  margin: 0 0.4rem;
}

.filter-pill__tags {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding: 0.15rem 0.1rem;
  flex: 1;
  min-width: 0;
  -webkit-mask-image: linear-gradient(to right, transparent, black 1.5rem, black calc(100% - 1.5rem), transparent);
  mask-image: linear-gradient(to right, transparent, black 1.5rem, black calc(100% - 1.5rem), transparent);
}

.filter-pill__tags::-webkit-scrollbar { display: none; }

.filter-pill__tags .filter-tag {
  padding: 0.3rem 0.75rem;
  font-size: 0.78rem;
  white-space: nowrap;
  flex-shrink: 0;
  border-radius: 9999px;
}

@media (max-width: 640px) {
  .filter-pill, .filter-pill--fixed, .filter-pill--hidden {
    position: relative !important;
    top: auto !important;
    left: auto !important;
    transform: none !important;
    opacity: 1 !important;
    pointer-events: all !important;
    margin: 1rem auto 1.5rem;
    max-width: calc(100vw - 2rem);
    padding: 0.4rem 0.6rem;
  }
  .filter-pill__input { width: clamp(110px, 40vw, 200px); }
}

.filter-pill__badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  white-space: nowrap;
  margin-left: 0.25rem;
  flex-shrink: 0;
  animation: badgePop 0.2s ease;
}

@keyframes badgePop {
  from { transform: scale(0.7); opacity: 0; }
  to   { transform: scale(1); opacity: 1; }
}

.filter-pill--searching {
  border-color: var(--accent);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--accent-light);
}

.filter-pill__tags .filter-tag:hover {
  color: var(--filter-hover-color, var(--accent));
  border-color: var(--filter-hover-border, var(--accent));
  background: var(--filter-hover-bg, var(--accent-light));
}

/* ---------- Paper Card ---------- */
.paper-card {
  display: flex;
  gap: 1.5rem;
  padding: 1.5rem;
  margin-bottom: 0.9rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  box-shadow: var(--shadow-xs);
  transition: box-shadow 0.2s ease, border-color 0.2s ease, transform 0.2s ease,
    opacity 0.3s ease, max-height 0.4s ease, padding 0.3s ease, margin 0.3s ease;
  max-height: 800px;
  overflow: hidden;
}

.paper-card--hidden {
  opacity: 0;
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  margin-bottom: 0;
  border-color: transparent;
  box-shadow: none;
  pointer-events: none;
}

.paper-card:hover {
  border-color: var(--border-medium);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.paper-card__thumb {
  flex-shrink: 0;
  width: 140px;
  display: flex;
  align-items: flex-start;
  justify-content: center;
}

.paper-card__thumb img, .paper-card__thumb video {
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  object-fit: cover;
}

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

.paper-card__title {
  font-family: var(--font-heading);
  font-size: 1.08rem;
  font-weight: 600;
  line-height: 1.35;
  margin-bottom: 0.35rem;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.paper-card__title .highlight { color: var(--cornell-red); }

.paper-card__authors {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 0.25rem;
}

.paper-card__authors strong { color: var(--text-primary); }

.paper-card__venue {
  font-size: 0.84rem;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 0.4rem;
}

.paper-card__venue strong { font-style: normal; }

.paper-card__links {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.paper-card__links a {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.22rem 0.6rem;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--accent);
  transition: all 0.15s ease;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.paper-card__links a:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.paper-card__desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.paper-card__sub-heading {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  margin-top: 0.8rem;
  margin-bottom: 0.3rem;
  color: var(--text-primary);
}

.paper-card__sub-pub {
  font-size: 0.86rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.6rem;
}

.paper-card__sub-pub strong { color: var(--text-primary); }
.paper-card__sub-pub em { color: var(--text-muted); }
.paper-card__sub-pub a { font-size: 0.82rem; }

.paper-card__impact {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  background: var(--bg-secondary);
  padding: 0.5rem 0.8rem;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--accent);
}

.paper-card__impact a { color: var(--accent); text-decoration: none; font-weight: 600; }
.paper-card__impact a:hover { text-decoration: underline; }

.paper-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.6rem;
}

.paper-card__tag {
  display: inline-flex;
  align-items: center;
  padding: 0.18rem 0.6rem;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 4px;
  background: var(--tag-bg, var(--bg-secondary));
  color: var(--tag-color, var(--text-muted));
  border: none;
  line-height: 1.5;
  user-select: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, opacity 0.15s ease;
}

.paper-card__tag:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-xs);
  opacity: 0.9;
}

/* ============================================
   NEWS
   ============================================ */
.news {
  /* container styling */
}

.news__list {
  list-style: none;
  padding: 0;
  margin: 0 0 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  overflow: hidden;
}

.news__item {
  padding: 0.95rem 1.1rem;
  border-bottom: 1px solid var(--border-subtle);
  transition: background 0.15s ease;
}

.news__item:last-child { border-bottom: none; }

.news__item:hover { background: var(--bg-secondary); }

.news__date {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  margin-bottom: 0.3rem;
  display: block;
  text-transform: uppercase;
}

.news__content {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.news__content p { margin: 0; }
.news__content p + p { margin-top: 0.4rem; }

.news__content a { color: var(--accent); font-weight: 500; }
.news__content strong { color: var(--text-primary); font-weight: 600; }

.news__view-all {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.84rem;
  font-weight: 500;
  color: var(--accent);
  cursor: pointer;
  background: none;
  border: none;
  padding: 0.4rem 0;
  font-family: var(--font-body);
  transition: gap 0.2s ease;
}

.news__view-all:hover { gap: 0.6rem; color: var(--accent-hover); }

.news__view-all::after { content: '→'; }

/* News drawer (desktop: right side panel; mobile: bottom sheet) */
.news-drawer-overlay {
  position: fixed;
  inset: 0;
  z-index: 250;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.news-drawer-overlay--open { opacity: 1; pointer-events: all; }

.news-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  z-index: 260;
  width: min(480px, 92vw);
  background: var(--bg-elevated);
  border-left: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.22, 1, 0.36, 1);
  display: flex;
  flex-direction: column;
}

.news-drawer--open { transform: translateX(0); }

.news-drawer__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.2rem 1.5rem 0.9rem;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.news-drawer__title {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.news-drawer__close {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 1px solid var(--border-subtle);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
}

.news-drawer__close:hover {
  color: var(--text-primary);
  border-color: var(--border-medium);
}

.news-drawer__body {
  flex: 1;
  overflow-y: auto;
  padding: 0.5rem 1.5rem 1.5rem;
}

.news-drawer__body .news__item {
  border-bottom: 1px solid var(--border-subtle);
  background: transparent;
  padding: 1.1rem 0;
}

.news-drawer__body .news__item:hover { background: transparent; }
.news-drawer__body .news__item:last-child { border-bottom: none; }

/* Mobile: drawer slides up from bottom */
@media (max-width: 768px) {
  .news-drawer {
    top: auto;
    right: 0;
    left: 0;
    bottom: 0;
    width: 100%;
    max-height: 85vh;
    border-left: none;
    border-top: 1px solid var(--border-subtle);
    border-top-left-radius: var(--radius-lg);
    border-top-right-radius: var(--radius-lg);
    transform: translateY(100%);
  }
  .news-drawer--open { transform: translateY(0); }

  .news-drawer__header {
    padding: 1rem 1.25rem 0.8rem;
    position: relative;
  }

  /* Mobile grabber */
  .news-drawer__header::before {
    content: '';
    position: absolute;
    top: 0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 36px;
    height: 4px;
    border-radius: 2px;
    background: var(--border-medium);
  }
}

/* ============================================
   PRESS
   ============================================ */
.press__category { margin-bottom: 2rem; }
.press__category:last-child { margin-bottom: 0; }

.press__category-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.8rem;
  letter-spacing: -0.01em;
}

.press__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.8rem;
}

.press__logo {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  min-height: 60px;
}

.press__logo:hover {
  border-color: var(--border-medium);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.press__logo img {
  max-width: 100%;
  max-height: 36px;
  height: auto;
  object-fit: contain;
}

/* In dark mode, give press logos a light backdrop (they're dark on white) */
:root[data-theme="dark"] .press__logo { background: #f3f3f3; }

@media (prefers-color-scheme: dark) {
  :root[data-theme="system"] .press__logo { background: #f3f3f3; }
}

/* ============================================
   LINKS
   ============================================ */
.links__list { list-style: none; padding: 0; }

.links__list li {
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border-subtle);
  transition: background 0.15s ease;
}

.links__list li:last-child { border-bottom: none; }

.links__list li:hover {
  background: var(--accent-light);
  margin: 0 -0.75rem;
  padding-left: 0.75rem;
  padding-right: 0.75rem;
  border-radius: var(--radius-sm);
}

.links__list a {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--accent);
}

.links__list a:visited { color: var(--accent); }

.links__list .links__author {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  padding: 2.5rem 0;
  border-top: 1px solid var(--border-subtle);
  margin-top: 2rem;
}

.footer__ack {
  text-align: center;
  font-size: 0.78rem;
  color: var(--text-muted);
  opacity: 0.75;
}

/* ============================================
   EASTER EGG
   ============================================ */
.easter-egg-overlay {
  position: fixed;
  inset: 0;
  z-index: 300;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.easter-egg-overlay--open { opacity: 1; pointer-events: all; }

.easter-egg-popup {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  transform: scale(0.92);
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}

.easter-egg-overlay--open .easter-egg-popup { transform: scale(1); }

.easter-egg-close {
  position: absolute;
  top: 8px;
  right: 8px;
  z-index: 10;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: none;
  background: rgba(0, 0, 0, 0.6);
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s ease;
}

.easter-egg-close:hover { background: rgba(0, 0, 0, 0.9); }

/* ============================================
   SECTION INDICATOR
   ============================================ */
.section-indicator {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 50;
  display: flex;
  gap: 2px;
  padding: 4px;
  border-radius: 999px;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease, transform 0.4s ease;
  pointer-events: none;
}

.section-indicator--visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}

.section-indicator__item {
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 0.75rem;
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.25s ease, background 0.25s ease;
}

.section-indicator__item:hover { color: var(--text-primary); }

.section-indicator__item--active {
  background: var(--accent-light);
  color: var(--accent);
}

@media (max-width: 768px) {
  .section-indicator { display: none; }
}

/* ============================================
   SIDEBAR FILTERS (wide screens)
   ============================================ */
@media (min-width: 1280px) {
  .research__filters {
    position: fixed;
    left: max(1.5rem, calc(50vw - 620px));
    top: 2.5rem;
    width: 160px;
    flex-direction: column;
    z-index: 50;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1), transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(-10px);
    border-bottom: none;
    padding: 0.75rem;
    margin-bottom: 0;
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
  }

  .research__filters.sidebar-visible {
    opacity: 1;
    pointer-events: all;
    transform: translateX(0);
  }

  .research__filters .filter-tag {
    width: 100%;
    text-align: left;
    font-size: 0.78rem;
    padding: 0.35rem 0.65rem;
    border-radius: var(--radius-sm);
  }
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
  .hero__inner {
    flex-direction: column-reverse;
    align-items: center;
    text-align: center;
    gap: 1.5rem;
  }
  .hero__photo { width: 160px; }
  .hero__links { justify-content: center; }
  .hero__mentoring { text-align: left; }
  .hero__name { font-size: 2.2rem; }

  .paper-card {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .paper-card__thumb { width: 180px; }
  .paper-card__links { justify-content: center; }

  .press__grid { grid-template-columns: repeat(2, 1fr); }
  .section-title { font-size: 1.6rem; }
  .top-controls { top: 0.8rem; right: 0.8rem; }
  .top-btn { width: 36px; height: 36px; font-size: 1rem; }
}

@media (max-width: 480px) {
  body { font-size: 14.5px; }
  .hero__name { font-size: 1.9rem; }
  .paper-card__thumb { width: 140px; }
  .press__grid { grid-template-columns: repeat(2, 1fr); gap: 0.5rem; }
  .hero__links a { font-size: 0.78rem; padding: 0.4rem 0.8rem; }
}

/* Hero links: single row on desktop */
@media (min-width: 769px) {
  .hero__links {
    flex-wrap: nowrap;
    white-space: nowrap;
  }
  .hero__links a {
    flex-shrink: 0;
  }
}

/* ============================================
   Ledger-style paper list
   ============================================ */
.paper-list { margin-top: 0.5rem; }

.paper {
  display: grid;
  grid-template-columns: 130px 1fr;
  grid-template-rows: auto auto;
  column-gap: 1.75rem;
  row-gap: 1rem;
  padding: 1.75rem 0;
  border-top: 1px solid var(--border-subtle);
  transition: opacity 0.3s ease, max-height 0.4s ease, padding 0.3s ease;
  max-height: 1000px;
  overflow: hidden;
}

.paper__meta { grid-column: 1; grid-row: 1; }
.paper__body { display: contents; }
.paper__thumb {
  grid-column: 1;
  grid-row: 2;
  width: 100%;
  height: auto;
  align-self: start;
}
.paper__text { grid-column: 2; grid-row: 1 / span 2; min-width: 0; }

.paper:last-child { border-bottom: 1px solid var(--border-subtle); }

.paper--hidden {
  opacity: 0;
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  border-color: transparent;
  pointer-events: none;
}

.paper__meta {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  padding-top: 0.25rem;
  font-family: var(--font-mono);
}

.paper__venue {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
  line-height: 1.25;
}

.paper__venue + .paper__venue {
  padding-top: 0.7rem;
  border-top: 1px dashed var(--border-subtle);
}

.paper__venue-acronym {
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.02em;
}

.paper__year {
  color: var(--text-muted);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
}

.paper__venue-kind {
  color: var(--text-muted);
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-style: italic;
  margin-top: 0.15rem;
}

.paper__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.35rem;
}

.paper__badge {
  font-family: var(--font-body);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1;
  padding: 0.25rem 0.45rem;
  border-radius: 4px;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
  white-space: nowrap;
}

.paper__badge--accent {
  background: var(--accent-light);
  color: var(--accent);
  border-color: transparent;
}

.paper__badge--highlight {
  background: transparent;
  color: var(--cornell-red);
  border-color: var(--cornell-red);
}

.paper__thumb {
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.paper__thumb img,
.paper__thumb video {
  width: 100%;
  height: auto;
  display: block;
}

.paper__title {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.paper--featured .paper__title { font-size: 1.18rem; }

.paper__authors {
  font-size: 0.86rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 0.55rem;
}

.paper__authors strong { color: var(--text-primary); font-weight: 600; }

.paper__desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 0.7rem;
}

.paper__desc p { margin: 0; }

.paper__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 0.55rem;
  font-size: 0.83rem;
}

.paper__actions a,
.paper__actions button {
  color: var(--accent);
  font-weight: 500;
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  transition: color 0.15s ease;
}

.paper__actions a:hover,
.paper__actions button:hover { color: var(--accent-hover); }

.paper__actions > * + *::before {
  content: '·';
  color: var(--text-muted);
  margin-right: 0.55rem;
  pointer-events: none;
}

.paper__actions button[data-copied]::after {
  content: ' ✓';
  color: var(--text-muted);
}

.paper__bibtex {
  margin-top: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 1.55;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  padding: 0.8rem 0.95rem;
  white-space: pre-wrap;
  word-break: break-word;
  overflow-wrap: anywhere;
  overflow-x: auto;
  border: 1px solid var(--border-subtle);
}

.paper__bibtex[hidden] { display: none; }

/* BibTeX copy toast */
.bibtex-toast {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: 200;
  width: min(440px, calc(100vw - 2.5rem));
  max-height: min(60vh, 480px);
  display: flex;
  flex-direction: column;
  background: var(--bg-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease;
  pointer-events: none;
  overflow: hidden;
}

.bibtex-toast--visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.bibtex-toast__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.65rem 0.85rem;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
}

.bibtex-toast__title {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--text-primary);
}

.bibtex-toast__check {
  color: var(--accent);
  font-weight: 700;
}

.bibtex-toast__close {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 1.05rem;
  line-height: 1;
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
  transition: color 0.15s ease, background 0.15s ease;
}

.bibtex-toast__close:hover {
  color: var(--text-primary);
  background: var(--bg-primary);
}

.bibtex-toast__body {
  margin: 0;
  padding: 0.8rem 0.95rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  line-height: 1.55;
  color: var(--text-secondary);
  white-space: pre;
  overflow: auto;
  flex: 1 1 auto;
  tab-size: 2;
}

.bibtex-toast__progress {
  height: 2px;
  background: var(--accent);
  width: 100%;
  transform-origin: left center;
  transform: scaleX(1);
}

.bibtex-toast--counting .bibtex-toast__progress {
  transform: scaleX(0);
  transition: transform linear;
}

@media (max-width: 640px) {
  .bibtex-toast {
    right: 0.75rem;
    left: 0.75rem;
    bottom: 0.75rem;
    width: auto;
  }
  /* Wrap long BibTeX lines instead of horizontal-scrolling on narrow screens */
  .bibtex-toast__body {
    white-space: pre-wrap;
    word-break: break-word;
    overflow-wrap: anywhere;
  }
}

/* Paper list — mobile */
@media (max-width: 640px) {
  .paper {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    row-gap: 0.6rem;
    padding: 1.4rem 0;
  }
  .paper__meta {
    grid-column: 1; grid-row: auto;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 0.5rem 0.8rem;
    padding-top: 0;
    align-items: center;
  }
  .paper__thumb {
    grid-column: 1; grid-row: auto;
    max-width: 120px;
    width: 100%;
    justify-self: start;
  }
  .paper__text { grid-column: 1; grid-row: auto; }
  .paper__venue {
    flex-direction: row;
    align-items: baseline;
    gap: 0.35rem;
  }
  .paper__venue + .paper__venue {
    padding-top: 0;
    border-top: none;
    padding-left: 0.7rem;
    border-left: 1px dashed var(--border-subtle);
  }
  .paper__venue-acronym { font-size: 0.9rem; }
  .paper__venue-kind { margin-top: 0; }
  .paper__badges { margin-top: 0; width: 100%; }

  /* Let the long inline action row (Project · Code · Copy BibTeX) breathe */
  .paper__actions { row-gap: 0.3rem; }

  /* Prevent iOS Safari auto-zoom on focus (triggers when font-size < 16px) */
  .filter-pill__input,
  .cmd-palette__input { font-size: 16px; }
}

/* ============================================
   READING / LIBRARY
   ============================================ */
.library__intro {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.library__groups {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.5rem;
}

.library__group-title {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.library__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.library__item {
  padding: 0.9rem 0;
  border-top: 1px solid var(--border-subtle);
}

.library__item:first-child { border-top: none; }

.library__item-title {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-primary);
}

.library__item-title a { color: var(--text-primary); }
.library__item-title a:hover { color: var(--accent); }

.library__item-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.1rem;
}

.library__item-note {
  font-size: 0.86rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-top: 0.35rem;
}

@media (max-width: 768px) {
  .library__groups {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }
}

/* ============================================
   SEO / A11Y ENHANCEMENTS
   ============================================ */

/* Visually hidden but available to screen readers */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Hero subtitle / descriptor under the name */
.hero__tagline {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.01em;
  margin-top: -0.6rem;
  margin-bottom: 1.1rem;
}

/* Research areas list */
.research__areas {
  list-style: none;
  margin: 0 0 1.75rem;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.research__areas li {
  position: relative;
  padding-left: 1.25rem;
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: 0.95rem;
}

.research__areas li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent);
}

.research__areas strong { color: var(--text-primary); font-weight: 600; }

/* News loading state with spinner */
.news__loading {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.news__spinner {
  width: 0.9rem;
  height: 0.9rem;
  border: 2px solid var(--border-subtle);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: newsSpin 0.7s linear infinite;
  flex-shrink: 0;
}

@keyframes newsSpin {
  to { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .news__spinner { animation-duration: 1.8s; }
}

/* Clear-search button inside the filter pill */
.filter-pill__clear {
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.8rem;
  line-height: 1;
  padding: 0.15rem 0.3rem;
  border-radius: var(--radius-sm, 6px);
  flex-shrink: 0;
  transition: color 0.18s ease, background 0.18s ease;
}

.filter-pill__clear:hover { color: var(--accent); background: var(--bg-card); }

/* Footer social + back-to-top */
.footer__social {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.4rem 1.1rem;
  margin-bottom: 1rem;
}

.footer__social a {
  font-size: 0.82rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.18s ease;
}

.footer__social a:hover { color: var(--accent); text-decoration: underline; }

.footer__top-link {
  display: block;
  text-align: center;
  margin-top: 1rem;
  font-size: 0.78rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.18s ease;
}

.footer__top-link:hover { color: var(--accent); }

/* ============================================
   COOL DEMOS (Lottie)
   ============================================ */
.research__demos-link {
  margin: 0 0 0.5rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.research__demos-link a {
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  transition: opacity 0.18s ease;
}

.research__demos-link a:hover { opacity: 0.75; text-decoration: underline; }

.demos__intro {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}

.demos__carousel {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.demos__track {
  display: flex;
  gap: 1.5rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scroll-behavior: smooth;
  flex: 1;
  min-width: 0;
  padding: 0.25rem;
  margin: -0.25rem;
  scrollbar-width: none;
}

.demos__track::-webkit-scrollbar { display: none; }

.demos__nav {
  flex-shrink: 0;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  line-height: 1;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 50%;
  box-shadow: var(--shadow-xs);
  cursor: pointer;
  transition: color 0.18s ease, background 0.18s ease, opacity 0.18s ease;
}

.demos__nav:hover { color: var(--accent); background: var(--bg-muted, rgba(127, 127, 127, 0.06)); }

.demos__nav:disabled { opacity: 0.35; cursor: default; }

.demo-card {
  margin: 0;
  flex: 0 0 100%;
  scroll-snap-align: center;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  box-shadow: var(--shadow-xs);
  overflow: hidden;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.demo-card:hover {
  box-shadow: var(--shadow-sm, var(--shadow-xs));
  transform: translateY(-2px);
}

.demo-card__lottie {
  width: 100%;
  aspect-ratio: var(--demo-aspect, 1280 / 600);
  background: var(--bg-muted, rgba(127, 127, 127, 0.06));
  display: block;
}

.demo-card__lottie svg { display: block; }

.demo-card__caption {
  padding: 1rem 1.15rem 1.25rem;
}

.demo-card__title {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text-primary);
  margin: 0 0 0.35rem;
}

.demo-card__caption p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.6;
  margin: 0 0 0.6rem;
}

.demo-card__caption a {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}

.demo-card__caption a:hover { text-decoration: underline; }

/* Hand-drawn "explore more" hint, shown once, themed via --accent */
.demos__hint {
  display: flex;
  justify-content: flex-end;
  align-items: flex-start;
  gap: 0.3rem;
  margin-top: 0.5rem;
  padding-right: 0.4rem;
  color: var(--accent);
  cursor: pointer;
  transition: opacity 0.45s ease, transform 0.45s ease;
}

.demos__hint--hidden {
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
}

.demos__hint-text {
  font-family: 'Caveat', 'Segoe Script', 'Bradley Hand', cursive;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.05;
  white-space: nowrap;
  transform: rotate(-4deg);
  margin-top: 0.55rem;
}

.demos__hint-arrow {
  width: 2rem;
  height: auto;
  flex-shrink: 0;
  margin-right: 0.35rem;
  animation: hintBob 1.7s ease-in-out infinite;
}

@keyframes hintBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-5px); }
}

@media (prefers-reduced-motion: reduce) {
  .demos__hint-arrow { animation: none; }
}