/* ============================================================
   Collaboration Layer — project page
   Design language matches the Coco desktop app:
   Primary blue #204A79 · Light surface #E9EFFF · PT Sans · pill buttons
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=PT+Sans:wght@400;700&display=swap');

:root {
  --accent: #204A79;
  --accent-dark: #1a3d66;
  --accent-bg: #E9EFFF;
  --accent-border: #BCD0FC;
  --indigo: #6366f1;
  --text: #374151;
  --text-strong: #111827;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --surface: #f8f9fb;
  --card-shadow: 0 2px 4px rgba(0, 0, 0, 0.06), 0 8px 24px rgba(32, 74, 121, 0.10);
  --font: 'PT Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 24px; }

body {
  font-family: var(--font);
  color: var(--text);
  background: #ffffff;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Full-screen hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  /* Fallback backdrop until the hero video is added */
  background:
    radial-gradient(ellipse 80% 60% at 70% 20%, rgba(99, 102, 241, 0.35) 0%, transparent 60%),
    radial-gradient(ellipse 70% 55% at 25% 85%, rgba(188, 208, 252, 0.22) 0%, transparent 60%),
    linear-gradient(160deg, #16334f 0%, var(--accent) 55%, #2c5d94 100%);
}

.hero-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(16, 34, 54, 0.35) 0%, rgba(16, 34, 54, 0.55) 100%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 48px 24px 96px;
  max-width: 920px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  padding: 6px 16px;
  margin-bottom: 28px;
  backdrop-filter: blur(4px);
}

.hero h1 {
  font-size: clamp(32px, 5.5vw, 54px);
  font-weight: 700;
  line-height: 1.15;
  color: #ffffff;
  margin: 0 auto 22px;
  text-shadow: 0 2px 16px rgba(16, 34, 54, 0.35);
}

.hero-subtitle {
  font-size: clamp(16px, 2vw, 19px);
  color: rgba(255, 255, 255, 0.88);
  max-width: 700px;
  margin: 0 auto 26px;
}

.hero-authors {
  font-size: 15px;
  color: rgba(255, 255, 255, 0.72);
  margin-bottom: 34px;
}

.hero-authors a { color: #ffffff; text-decoration: none; }
.hero-authors a:hover { text-decoration: underline; }

.scroll-indicator {
  position: absolute;
  z-index: 1;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  animation: scroll-bounce 2.2s ease-in-out infinite;
  transition: color 0.15s ease;
}

.scroll-indicator:hover { color: #ffffff; }

.scroll-indicator svg { width: 18px; height: 18px; }

@keyframes scroll-bounce {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}

.hero-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: 999px;
  font-family: var(--font);
  font-size: 14.5px;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.1s ease;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
  background: var(--accent);
  color: #ffffff;
}
.btn-primary:hover { background: var(--accent-dark); }

.btn-secondary {
  background: #ffffff;
  color: var(--accent);
  border-color: var(--accent-border);
}
.btn-secondary:hover { background: var(--accent-bg); }

/* Buttons on the dark hero */
.hero .btn-primary {
  background: #ffffff;
  color: var(--accent);
}
.hero .btn-primary:hover { background: var(--accent-bg); }

.hero .btn-secondary {
  background: rgba(255, 255, 255, 0.10);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.45);
  backdrop-filter: blur(4px);
}
.hero .btn-secondary:hover { background: rgba(255, 255, 255, 0.22); }

.btn svg { width: 17px; height: 17px; fill: currentColor; }

/* ---------- Layout ---------- */
.container {
  max-width: 780px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-wide {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 56px 0 8px; }

.post-title {
  font-size: 34px;
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-strong);
  margin-bottom: 12px;
}

.post-author {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 28px;
}

section h2 {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-strong);
  line-height: 1.3;
  margin-bottom: 20px;
  scroll-margin-top: 24px;
}

section h2::before {
  content: '';
  display: block;
  width: 44px;
  height: 4px;
  border-radius: 999px;
  background: var(--accent);
  margin-bottom: 14px;
}

p { margin-bottom: 18px; }

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

strong { color: var(--text-strong); }

em { font-style: italic; }

/* ---------- Pain point list ---------- */
.pain-list {
  margin: 0 0 18px;
  padding-left: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.pain-list li::marker { color: var(--accent); }

/* ---------- Figures ---------- */
figure { margin: 32px 0; text-align: center; }

figure img {
  max-width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: #ffffff;
}

figure.borderless img { border: none; }

figcaption {
  margin-top: 12px;
  font-size: 14px;
  color: var(--text-muted);
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- Citation ---------- */
.bibtex {
  position: relative;
  background: #1f2937;
  color: #f9fafb;
  border-radius: 14px;
  padding: 24px 28px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
  overflow-x: auto;
  white-space: pre;
  margin: 20px 0;
}

.copy-btn {
  position: absolute;
  top: 14px;
  right: 14px;
  background: rgba(255, 255, 255, 0.1);
  color: #f9fafb;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  padding: 5px 14px;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.15s ease;
}

.copy-btn:hover { background: rgba(255, 255, 255, 0.2); }

/* ---------- Footer ---------- */
footer {
  margin-top: 72px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 40px 24px 48px;
  text-align: center;
  font-size: 14px;
  color: var(--text-muted);
}

footer .ack {
  max-width: 720px;
  margin: 0 auto 20px;
  line-height: 1.7;
}

footer .ack-title {
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 12px;
  color: var(--accent);
  margin-bottom: 8px;
}

/* ---------- Responsive ---------- */
@media (max-width: 760px) {
  body { font-size: 16px; }
  section h2 { font-size: 24px; }
}