/* 
 * Style sheet for "Rational Revision?" Workshop Website
 * Clean, elegant, premium academic design system.
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Merriweather:ital,wght@0,300;0,400;0,700;1,300&display=swap');

:root {
  --bg-primary: #fbfbf9;
  --bg-secondary: #f4f3ef;
  --bg-card: #ffffff;
  --text-primary: #1c2434;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --accent: #115e59;
  /* Deep Teal */
  --accent-hover: #0f766e;
  --accent-light: #f0fdfa;
  --accent-border: #ccfbf1;
  --border-color: #e2e8f0;
  --border-light: #edf2f7;
  --font-serif: 'Merriweather', Georgia, Cambria, "Times New Roman", Times, serif;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 1040px;
  --header-height: 70px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1,
h2,
h3,
h4 {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
}

p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Layout Containers */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 5rem 0;
  border-bottom: 1px solid var(--border-color);
}

section:last-of-type {
  border-bottom: none;
}

.section-title {
  font-size: 2.25rem;
  margin-bottom: 1.5rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -8px;
  width: 40px;
  height: 3px;
  background-color: var(--accent);
  border-radius: 2px;
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: rgba(251, 251, 249, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.logo-text {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
}

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

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 0.25rem 0;
}

.nav-links a:hover {
  color: var(--accent);
  text-decoration: none;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: var(--accent);
  transition: width var(--transition-fast);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-links a.active {
  color: var(--accent);
  font-weight: 600;
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  z-index: 1001;
}

.mobile-nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--text-primary);
  margin: 5px 0;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* Hero / Splash Section */
.hero {
  padding-top: calc(var(--header-height) + 5rem);
  padding-bottom: 6rem;
  background-color: var(--bg-secondary);
  text-align: center;
  position: relative;
  overflow: hidden;
}

/* Abstract belief-updating SVG styling */
.hero-diagram {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  opacity: 0.04;
  z-index: 0;
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
  max-width: 850px;
}

.hero-tag {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  background-color: var(--accent-light);
  border: 1px solid var(--accent-border);
  padding: 0.35rem 1rem;
  border-radius: 50px;
  margin-bottom: 1.5rem;
  animation: fadeIn 1s ease-out;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 2rem;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  animation: slideUp 0.8s ease-out;
}

.hero-meta {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 2.5rem;
  font-size: 1.05rem;
  color: var(--text-secondary);
  font-weight: 500;
  animation: fadeIn 1.2s ease-out;
}

.meta-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.meta-item svg {
  color: var(--accent);
  flex-shrink: 0;
}

.hero-cta {
  display: flex;
  justify-content: center;
  gap: 1rem;
  animation: fadeIn 1.4s ease-out;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 6px;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
}

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

.btn-primary:hover {
  background-color: var(--accent-hover);
  color: #ffffff;
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: transparent;
  border-color: var(--accent);
  color: var(--accent);
}

.btn-secondary:hover {
  background-color: var(--accent-light);
  text-decoration: none;
  transform: translateY(-1px);
}

/* About / Intro Section */
.about-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 4rem;
  align-items: start;
}

.about-text p {
  margin-bottom: 1.5rem;
  text-align: justify;
}

.about-text p:last-child {
  margin-bottom: 0;
}

.organizers-list {
  background-color: var(--bg-secondary);
  border-radius: 8px;
  padding: 2rem;
  border: 1px solid var(--border-color);
}

.organizers-list h3 {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.organizer-item {
  margin-bottom: 1.5rem;
}

.organizer-item:last-child {
  margin-bottom: 0;
}

.organizer-name {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.organizer-affiliation {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.organizer-bio {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
  line-height: 1.5;
}

/* Speakers Section */
.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.speaker-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 2rem;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
  display: flex;
  flex-direction: column;
  height: 100%;
}

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

.speaker-header {
  margin-bottom: 1rem;
}

.speaker-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.speaker-role {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  background-color: var(--accent-light);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

.speaker-affiliation {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.speaker-topic {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-style: italic;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--border-color);
  line-height: 1.5;
}

.speaker-topic::before {
  content: 'Talk Title: ';
  font-weight: 600;
  font-style: normal;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  display: block;
  margin-bottom: 0.25rem;
}

/* Schedule Section */
.schedule-table-container {
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background-color: var(--bg-card);
  margin-top: 2rem;
  box-shadow: var(--shadow-sm);
}

.schedule-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  min-width: 600px;
}

.schedule-table th {
  background-color: var(--bg-secondary);
  padding: 1.2rem 1.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  border-bottom: 2px solid var(--border-color);
}

.schedule-table td {
  padding: 1.2rem 1.5rem;
  border-bottom: 1px solid var(--border-light);
  vertical-align: top;
}

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

.schedule-table tr:hover td {
  background-color: var(--bg-secondary);
}

.time-slot {
  font-weight: 600;
  font-size: 0.95rem;
  font-family: var(--font-serif);
  color: var(--text-primary);
  white-space: nowrap;
}

.session-presenter {
  font-weight: 600;
  font-size: 0.95rem;
  font-family: var(--font-serif);
  color: var(--text-primary);
}

.session-affiliation {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 400;
  margin-top: 0.1rem;
}

.session-title-text {
  font-weight: 500;
  color: var(--text-secondary);
}

.session-special {
  background-color: var(--bg-secondary);
  font-weight: 600;
  font-size: 0.95rem;
  font-family: var(--font-serif);
  color: var(--accent);
}

.session-special td {
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

/* Call for Papers / Submissions */
.submission-card {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, rgba(240, 253, 250, 0.5) 100%);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 3rem;
  text-align: center;
  max-width: 800px;
  margin: 2rem auto 0 auto;
}

.submission-card h3 {
  font-size: 1.75rem;
  margin-bottom: 1rem;
}

.submission-card p {
  max-width: 600px;
  margin: 0 auto 2rem auto;
}

/* Footer */
footer {
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  padding: 4rem 0;
  border-top: 1px solid var(--border-color);
  font-size: 0.95rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 4rem;
  margin-bottom: 3rem;
}

.footer-about h4,
.footer-contact h4 {
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

.footer-about p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-contact p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive Styles */
@media (max-width: 900px) {
  section {
    padding: 4rem 0;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 60px;
  }

  .hero-title {
    font-size: 2rem;
  }

  .section-title {
    font-size: 1.75rem;
  }

  /* Mobile navbar */
  .mobile-nav-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--bg-primary);
    flex-direction: column;
    padding: 3rem 2rem;
    gap: 2rem;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    z-index: 999;
    border-top: 1px solid var(--border-color);
  }

  .nav-links.active {
    transform: translateX(0);
  }

  .mobile-nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .mobile-nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .mobile-nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .hero-cta .btn {
    width: 100%;
    max-width: 300px;
  }
}