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

:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #e74c3c;
  --text-color: #333;
  --light-bg: #f8f9fa;
  --white: #ffffff;
  --gray: #6c757d;
  --light-gray: #e9ecef;
  --spacing-unit: 1rem;
  --max-width: 1200px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  font-size: 16px;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--white);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  transition: all 0.3s ease;
}

.navbar.scrolled {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
}

.nav-brand {
  font-size: 1.25rem;
  font-weight: bold;
  color: var(--primary-color);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-menu a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.nav-menu a:hover {
  color: var(--secondary-color);
}

.nav-menu a.nav-highlight {
  color: var(--secondary-color);
}

/* Hamburger Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.hamburger,
.hamburger::before,
.hamburger::after {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--primary-color);
  border-radius: 2px;
  transition: all 0.3s ease;
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  left: 0;
  width: 24px;
}

.hamburger::before {
  top: -7px;
}

.hamburger::after {
  top: 7px;
}

/* Animate to X when open */
.nav-toggle[aria-expanded="true"] .hamburger {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
  top: 0;
  transform: rotate(-45deg);
}

/* CFP Banner */
.cfp-banner {
  background: var(--secondary-color);
  color: var(--white);
  text-align: center;
  padding: 0.75rem 0;
  font-size: 1.1rem;
}

.cfp-banner a {
  color: var(--white);
  text-decoration: underline;
  font-weight: 600;
}

.cfp-banner a:hover {
  opacity: 0.85;
}

/* Hero Section */
.hero {
  margin-top: 60px;
  background:
    linear-gradient(135deg, rgba(44, 62, 80, 0.75) 0%, rgba(52, 152, 219, 0.65) 100%),
    url('../img/banner.png') center / cover no-repeat;
  color: var(--white);
  padding: 6rem 0;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.hero h2 {
  font-size: 1.75rem;
  margin-bottom: 1rem;
  font-weight: 400;
}

.hero .location {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
}

.hero .date {
  font-size: 1.1rem;
  opacity: 0.9;
}

/* Sections */
.section {
  padding: 4rem 0;
}

.section.bg-light {
  background: var(--light-bg);
}

.section h2 {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 2rem;
  border-bottom: 3px solid var(--secondary-color);
  padding-bottom: 0.5rem;
}

.section h3 {
  font-size: 1.5rem;
  color: var(--primary-color);
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.section p {
  margin-bottom: 1rem;
  text-align: justify;
}

/* Objectives List */
.objectives-list {
  list-style: none;
  padding-left: 0;
}

.objectives-list li {
  margin-bottom: 1.5rem;
  padding-left: 2rem;
  position: relative;
  text-align: justify;
}

.objectives-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--secondary-color);
  font-weight: bold;
  font-size: 1.25rem;
}

/* Organizers */
.organizer {
  margin-bottom: 2.5rem;
  padding: 1.5rem;
  background: var(--white);
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.organizer .headshot {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  margin-top: 0.15rem;
}

.organizer .organizer-info {
  flex: 1;
  min-width: 0;
}

.bg-light .organizer {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.organizer h3 {
  margin-top: 0;
  color: var(--primary-color);
  font-size: 1.3rem;
}

.organizer .affiliation {
  color: var(--secondary-color);
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.organizer .contact {
  margin-top: 1rem;
  font-weight: 500;
}

.organizer .experience {
  font-size: 0.95rem;
  color: var(--gray);
  margin-top: 0.5rem;
}

.organizer p {
  text-align: left;
}

/* Links */
a {
  color: var(--secondary-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* TBD styling */
.tbd {
  font-style: italic;
  color: var(--gray);
  text-align: center;
  padding: 2rem;
}

.submission-details {
  margin-top: 2rem;
  padding: 1rem;
  background: var(--light-gray);
  border-left: 4px solid var(--secondary-color);
  font-size: 1.1rem;
}

/* Schedule Table */
.schedule-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 2rem;
}

.schedule-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--light-gray);
}

.schedule-table td:first-child {
  white-space: nowrap;
  font-weight: 500;
  color: var(--secondary-color);
  width: 160px;
}

.schedule-table tr:last-child td {
  border-bottom: none;
}

/* Footer */
.footer {
  background: var(--primary-color);
  color: var(--white);
  text-align: center;
  padding: 2rem 0;
  margin-top: 4rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .navbar .container {
    flex-wrap: wrap;
  }

  .nav-menu {
    display: none;
    flex-direction: column;
    width: 100%;
    gap: 0;
    padding: 0.5rem 0 1rem;
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-menu li a {
    display: block;
    padding: 0.6rem 0;
  }

  .hero {
    padding: 4rem 0;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero h2 {
    font-size: 1.25rem;
  }

  .section {
    padding: 3rem 0;
  }

  .section h2 {
    font-size: 1.5rem;
  }

  .container {
    padding: 0 1rem;
  }

  .section p {
    text-align: left;
  }

  .objectives-list li {
    text-align: left;
  }
}