/* RECOMB 2007 Modern Responsive Design System */
/* Color Palette: UC Berkeley Blue and Gold */

:root {
  --primary-color: #003262;       /* Berkeley Blue */
  --primary-light: #004f99;
  --secondary-color: #FDB515;     /* California Gold */
  --secondary-light: #ffc845;
  --text-dark: #222222;
  --text-light: #555555;
  --bg-light: #f8f9fa;
  --bg-card: #ffffff;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
  font-family: var(--font-family);
  color: var(--text-dark);
  background-color: var(--bg-light);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

a:hover {
  color: var(--primary-light);
}

/* Header */
.site-header {
  background: linear-gradient(135deg, #001f3f 0%, #003262 50%, #004f99 100%);
  color: #ffffff;
  padding: 3rem 1.5rem;
  text-align: center;
  border-bottom: 5px solid var(--secondary-color);
  position: relative;
  overflow: hidden;
}

.site-header::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: radial-gradient(circle at 80% 20%, rgba(253, 181, 21, 0.1) 0%, transparent 50%);
  pointer-events: none;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
}

.site-title {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.05em;
  color: var(--secondary-color);
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.site-subtitle {
  font-size: 1.25rem;
  font-weight: 400;
  max-width: 800px;
  margin: 0 auto 1.5rem auto;
  opacity: 0.9;
  line-height: 1.4;
}

.site-meta {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #ffffff;
  background-color: rgba(255, 255, 255, 0.1);
  display: inline-block;
  padding: 0.5rem 1.25rem;
  border-radius: 50px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

/* Main Layout */
.main-container {
  display: flex;
  max-width: 1200px;
  margin: 2rem auto;
  padding: 0 1.5rem;
  gap: 2rem;
}

/* Sidebar Navigation */
.sidebar {
  width: 260px;
  flex-shrink: 0;
}

.nav-menu {
  background-color: var(--bg-card);
  border-radius: 12px;
  padding: 1rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 2rem;
}

.nav-item {
  display: block;
  padding: 0.75rem 1rem;
  color: var(--text-light);
  font-weight: 600;
  border-radius: 8px;
  margin-bottom: 0.25rem;
  transition: all 0.2s ease;
}

.nav-item:hover {
  background-color: #f1f5f9;
  color: var(--primary-color);
  padding-left: 1.25rem;
}

.nav-item.active {
  background-color: var(--primary-color);
  color: #ffffff;
}

.nav-item.active:hover {
  background-color: var(--primary-light);
  color: #ffffff;
}

/* Content Area */
.content-area {
  flex-grow: 1;
  background-color: var(--bg-card);
  border-radius: 12px;
  padding: 2.5rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  min-height: 500px;
}

.content-area h2 {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.content-area h3 {
  font-size: 1.4rem;
  color: var(--primary-light);
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.content-area p {
  color: var(--text-light);
  margin-bottom: 1.25rem;
}

.content-area ul, .content-area ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
  color: var(--text-light);
}

.content-area li {
  margin-bottom: 0.5rem;
}

/* Tables styling (Critical for accepted papers, program info, committees) */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  border-radius: 8px;
  overflow: hidden;
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background-color: #f1f5f9;
  color: var(--primary-color);
  font-weight: 700;
}

tr:hover td {
  background-color: #f8fafc;
}

/* Grid & Card Layouts for Committees or Keynote Speakers */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}

.card {
  background-color: var(--bg-light);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.card-title {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--primary-color);
  margin-bottom: 0.25rem;
}

.card-subtitle {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.75rem;
  font-style: italic;
}

.card-content {
  font-size: 0.95rem;
}

/* Buttons and Callouts */
.btn {
  display: inline-block;
  background-color: var(--primary-color);
  color: #ffffff !important;
  font-weight: 600;
  padding: 0.6rem 1.25rem;
  border-radius: 6px;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  cursor: pointer;
}

.btn:hover {
  background-color: var(--primary-light);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary-color) !important;
  border: 1px solid var(--primary-color);
}

.btn-secondary:hover {
  background-color: #f1f5f9;
}

.callout {
  background-color: #eff6ff;
  border-left: 4px solid var(--primary-light);
  padding: 1.25rem;
  border-radius: 0 8px 8px 0;
  margin: 1.5rem 0;
}

.callout-title {
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 0.25rem;
}

/* Footer */
.site-footer {
  background-color: #0f172a;
  color: #94a3b8;
  padding: 2.5rem 1.5rem;
  text-align: center;
  font-size: 0.9rem;
  border-top: 4px solid var(--primary-color);
  margin-top: 4rem;
}

.site-footer p {
  margin-bottom: 0.5rem;
}

.site-footer a {
  color: #ffffff;
}

/* Photo Gallery styling */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.gallery-item {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-light);
}

.gallery-item img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  display: block;
}

.gallery-item-caption {
  padding: 0.5rem;
  font-size: 0.8rem;
  text-align: center;
  color: var(--text-light);
}

/* Responsive Rules */
@media (max-width: 900px) {
  .main-container {
    flex-direction: column;
  }
  
  .sidebar {
    width: 100%;
  }
  
  .nav-menu {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    position: static;
  }
  
  .nav-item {
    margin-bottom: 0;
  }
}