/* Modern CSS Design System for MIMO Iterative Separation Website */

:root {
  --bg-dark: #0b0f19;
  --bg-card: rgba(23, 30, 48, 0.7);
  --bg-card-border: rgba(255, 255, 255, 0.1);
  --bg-card-hover: rgba(30, 41, 67, 0.85);
  
  --primary: #6366f1;
  --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
  --accent-cyan: #06b6d4;
  --accent-pink: #ec4899;
  --accent-green: #10b981;
  
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --code-bg: #0d1117;
  --code-border: #21262d;
  
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  
  --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.25);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
}

/* Background Ambient Glows */
body::before, body::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  filter: blur(140px);
  z-index: -1;
  pointer-events: none;
}

body::before {
  width: 500px;
  height: 500px;
  top: -100px;
  left: -100px;
  background: rgba(99, 102, 241, 0.15);
}

body::after {
  width: 600px;
  height: 600px;
  top: 800px;
  right: -150px;
  background: rgba(217, 70, 239, 0.12);
}

/* Container */
.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Navigation Header */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(11, 15, 25, 0.85);
  border-bottom: 1px solid var(--bg-card-border);
  padding: 16px 0;
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 700;
  font-size: 1.1rem;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--text-main);
}

/* Hero Section */
.hero {
  padding: 80px 0 50px;
  text-align: center;
  position: relative;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 100px;
  background: rgba(99, 102, 241, 0.1);
  border: 1px solid rgba(99, 102, 241, 0.3);
  color: #a5b4fc;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #6366f1;
  box-shadow: 0 0 10px #6366f1;
}

.hero-title {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Authors & Individual Social Links */
.hero-authors-container {
  margin-top: 24px;
  margin-bottom: 28px;
}

.author-cards {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 36px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.author-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.author-name {
  font-size: 1.15rem;
  font-weight: 600;
  color: #f1f5f9;
  letter-spacing: -0.01em;
}

.author-socials {
  display: flex;
  align-items: center;
  gap: 8px;
}

.author-icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: #cbd5e1;
  font-size: 0.88rem;
  text-decoration: none;
  transition: all 0.2s ease;
}

.author-icon-btn:hover {
  background: rgba(99, 102, 241, 0.25);
  border-color: rgba(129, 140, 248, 0.6);
  color: #a5b4fc;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.author-affiliation {
  font-size: 0.92rem;
  color: var(--text-muted);
  font-weight: 500;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 820px;
  margin: 0 auto 36px;
  font-weight: 400;
}

/* Action Links / Buttons */
.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 26px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #fff;
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 40px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--bg-card-border);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

/* Section Styling */
.section {
  padding: 50px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.section-header {
  margin-bottom: 28px;
}

.section-tag {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.01em;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-top: 6px;
}

/* Text Content & Clean Lists */
.text-content p {
  color: var(--text-muted);
  font-size: 1.02rem;
  margin-bottom: 16px;
}

.text-content p strong {
  color: var(--text-main);
}

.subsection-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: #c7d2fe;
  margin-bottom: 12px;
}

ul.clean-list, ol.clean-list {
  margin: 16px 0 24px 24px;
  color: var(--text-muted);
  font-size: 1rem;
}

ul.clean-list li, ol.clean-list li {
  margin-bottom: 12px;
  padding-left: 6px;
  line-height: 1.65;
}

ul.clean-list li strong, ol.clean-list li strong {
  color: var(--text-main);
}

/* Figure Placeholder Container */
.figure-container {
  background: rgba(15, 23, 42, 0.6);
  border: 1px dashed rgba(99, 102, 241, 0.35);
  border-radius: var(--radius-md);
  padding: 36px 24px;
  margin: 32px 0;
  text-align: center;
}

.figure-badge {
  display: inline-block;
  background: rgba(99, 102, 241, 0.2);
  color: #a5b4fc;
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 20px;
  text-transform: uppercase;
}

.figure-placeholder-box {
  background: rgba(30, 41, 59, 0.8);
  border: 1px dashed rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-sm);
  padding: 48px 24px;
  color: #a5b4fc;
  font-weight: 500;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.figure-placeholder-box i {
  font-size: 2.2rem;
  color: #818cf8;
}

.figure-image {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: var(--radius-sm);
  background: #ffffff;
}

.figure-caption {
  margin-top: 16px;
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
}

/* Table Styling */
.table-wrapper {
  overflow-x: auto;
  margin: 20px 0 36px;
  border-radius: var(--radius-md);
  border: 1px solid var(--bg-card-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: center;
  font-size: 0.9rem;
  background: var(--bg-card);
}

caption {
  padding: 12px;
  caption-side: bottom;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-style: italic;
}

th, td {
  padding: 12px 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  border-right: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
  vertical-align: middle;
}

th:first-child, td:first-child {
  text-align: left;
}

th:last-child, td:last-child {
  border-right: none;
}

th {
  background: rgba(30, 41, 59, 0.85);
  color: #a5b4fc;
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* Stem divider vertical lines */
td:nth-child(3n):not(:last-child) {
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

thead tr:first-child th:nth-child(n+3):not(:last-child) {
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

thead tr:nth-child(2) th:nth-child(3n):not(:last-child) {
  border-right: 1px solid rgba(255, 255, 255, 0.2);
}

tr.highlight-row {
  background: rgba(99, 102, 241, 0.1);
}

tr.highlight-row td {
  color: var(--text-main);
}

/* Code Snippet Box */
.code-wrapper {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-top: 24px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

.code-header {
  background: #161b22;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--code-border);
}

.code-tabs {
  display: flex;
  gap: 8px;
}

.code-tab {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 6px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border-radius: 6px;
  transition: var(--transition);
}

.code-tab.active {
  background: rgba(99, 102, 241, 0.25);
  color: #a5b4fc;
}

.copy-btn {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-muted);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.8rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
}

.copy-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-main);
}

pre {
  padding: 24px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.6;
  color: #e6edf3;
}

.code-block {
  display: none;
}

.code-block.active {
  display: block;
}

.code-keyword { color: #ff7b72; }
.code-class { color: #ffa657; }
.code-func { color: #d2a8ff; }
.code-comment { color: #8b949e; font-style: italic; }
.code-string { color: #a5d6ff; }
.code-num { color: #79c0ff; }

/* Footer */
footer {
  padding: 40px 0 30px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.9rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

footer a {
  color: var(--text-muted);
  text-decoration: underline;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }
  .nav-links {
    display: none;
  }
  .code-tabs {
    flex-wrap: wrap;
  }
}