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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: #1a1a2e;
  background: #ffffff;
}

.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== HERO / HEADER ===== */
.hero {
  background: linear-gradient(135deg, #0f3460 0%, #16213e 60%, #0d7377 100%);
  color: #ffffff;
  padding: 64px 0 56px;
  text-align: center;
}

.title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 14px;
  line-height: 1.2;
}

.subtitle {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 400;
  color: #b0cfe8;
  max-width: 620px;
  margin: 0 auto 32px;
}

/* Authors */
.authors {
  margin-bottom: 36px;
}

.author-list {
  font-size: 1.05rem;
  font-weight: 500;
  color: #e0eaf5;
  margin-bottom: 6px;
}

.affiliations {
  font-size: 0.9rem;
  color: #8ab4d4;
}

/* Buttons */
.button-row {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 26px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, opacity 0.15s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.25);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background: #e63946;
  color: #ffffff;
}

.btn-primary:hover {
  background: #c1121f;
}

.btn-secondary {
  background: rgba(255,255,255,0.15);
  color: #ffffff;
  border: 1.5px solid rgba(255,255,255,0.4);
  backdrop-filter: blur(4px);
}

.btn-secondary:hover {
  background: rgba(255,255,255,0.25);
}

/* ===== SECTIONS ===== */
.section {
  padding: 56px 0;
}

.section-divider {
  border: none;
  border-top: 1px solid #e4e8ef;
  margin: 0;
}

.section-heading {
  font-size: 1.65rem;
  font-weight: 700;
  color: #0f3460;
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 3px solid #0d7377;
  display: inline-block;
}

.section-intro {
  color: #444;
  margin-bottom: 28px;
  max-width: 720px;
}

/* Abstract */
.abstract-text {
  font-size: 1.02rem;
  line-height: 1.8;
  color: #2d2d2d;
  max-width: 760px;
}

/* ===== FIGURES ===== */
.figure-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.paper-figure {
  width: 100%;
  max-width: 760px;
  border: 1px solid #dde3eb;
  border-radius: 10px;
  box-shadow: 0 4px 18px rgba(0,0,0,0.07);
}

.figure-placeholder {
  width: 100%;
  max-width: 760px;
  min-height: 220px;
  border: 2px dashed #b0bec5;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f7f9fc;
  color: #607d8b;
  font-size: 0.95rem;
  text-align: center;
  padding: 24px;
}

.figure-placeholder code {
  font-family: 'Source Code Pro', monospace;
  background: #e8edf2;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88rem;
}

.figure-caption {
  font-size: 0.9rem;
  color: #555;
  max-width: 720px;
  text-align: center;
  line-height: 1.5;
}

/* ===== BIBTEX ===== */
.bibtex-block {
  position: relative;
  background: #0f1923;
  border-radius: 10px;
  padding: 28px 32px;
  overflow: auto;
}

.bibtex-block pre {
  margin: 0;
}

.bibtex-block code {
  font-family: 'Source Code Pro', 'Courier New', monospace;
  font-size: 0.875rem;
  line-height: 1.65;
  color: #c9d1d9;
  white-space: pre;
}

.copy-btn {
  position: absolute;
  top: 14px;
  right: 16px;
  background: #0d7377;
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 14px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
}

.copy-btn:hover {
  background: #0a5c60;
}

/* ===== FOOTER ===== */
.footer {
  background: #f0f4f8;
  border-top: 1px solid #dde3eb;
  padding: 28px 0;
  text-align: center;
}

.footer p {
  font-size: 0.88rem;
  color: #607d8b;
}

.footer a {
  color: #0d7377;
  text-decoration: none;
  font-weight: 500;
}

.footer a:hover {
  text-decoration: underline;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 600px) {
  .hero {
    padding: 48px 0 40px;
  }

  .btn {
    padding: 10px 20px;
    font-size: 0.9rem;
  }

  .section {
    padding: 40px 0;
  }

  .bibtex-block {
    padding: 20px 16px 20px 20px;
  }

  .bibtex-block code {
    font-size: 0.78rem;
  }
}