/* ============================================
   Physical AI CVPR 2026 Tutorial - Styles
   ============================================ */

:root {
  --nvidia-green: #76b900;
  --nvidia-green-dark: #5a8f00;
  --nvidia-green-light: #a3d856;
  --primary: #1a1a2e;
  --primary-light: #16213e;
  --accent: #76b900;
  --accent-hover: #5a8f00;
  --text-primary: #1a1a2e;
  --text-secondary: #4a5568;
  --text-light: #718096;
  --bg-light: #f7f8fc;
  --bg-white: #ffffff;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
}

* {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---- Navbar ---- */
.tutorial-nav {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  border-bottom: 1px solid var(--border-color);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
}

.nav-logo-text {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--primary);
}

.nav-badge {
  background: var(--nvidia-green);
  color: white;
  font-size: 0.7rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  letter-spacing: 0.03em;
}

.navbar-item {
  font-weight: 500;
  font-size: 0.92rem;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.navbar-item:hover {
  color: var(--nvidia-green-dark);
  background: transparent;
}

/* ---- Hero ---- */
.hero-gradient {
  background: linear-gradient(135deg, #0d0d1a 0%, #1a1a2e 30%, #16213e 60%, #1a3a2e 100%);
  position: relative;
  overflow: hidden;
  padding-top: 80px;
}

.hero-gradient::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(118, 185, 0, 0.12) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-gradient::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(118, 185, 0, 0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-gradient .hero-body {
  position: relative;
  z-index: 1;
}

.hero-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(118, 185, 0, 0.15);
  color: var(--nvidia-green-light);
  padding: 6px 18px;
  border-radius: 30px;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
  border: 1px solid rgba(118, 185, 0, 0.2);
}

.hero-title {
  color: #ffffff !important;
  font-weight: 800 !important;
  font-size: 3rem !important;
  line-height: 1.15 !important;
  margin-bottom: 0.75rem !important;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  color: rgba(255, 255, 255, 0.7) !important;
  font-weight: 400 !important;
  line-height: 1.6 !important;
  margin-bottom: 2rem !important;
}

.author-list {
  margin-bottom: 1rem;
}

.author-block a {
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
  font-size: 1.05rem;
  transition: color 0.2s;
}

.author-block a:hover {
  color: var(--nvidia-green-light);
}

.affiliation-block {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 2rem;
}

.affiliation-logo {
  height: 22px;
  filter: brightness(0) invert(1);
  opacity: 0.7;
}

.affiliation-text {
  color: rgba(255, 255, 255, 0.6);
  font-size: 1rem;
  font-weight: 500;
}

.hero-links {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-btn-primary {
  background: var(--nvidia-green) !important;
  color: white !important;
  border: none !important;
  font-weight: 600 !important;
  transition: all 0.2s !important;
}

.hero-btn-primary:hover {
  background: var(--nvidia-green-dark) !important;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(118, 185, 0, 0.3);
}

.hero-btn-secondary {
  background: rgba(255, 255, 255, 0.1) !important;
  color: white !important;
  border: 1px solid rgba(255, 255, 255, 0.2) !important;
  font-weight: 600 !important;
  transition: all 0.2s !important;
}

.hero-btn-secondary:hover {
  background: rgba(255, 255, 255, 0.18) !important;
  transform: translateY(-1px);
}

/* ---- Section Titles ---- */
.section-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 1.8rem !important;
  color: var(--primary);
}

.section-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(118, 185, 0, 0.1);
  color: var(--nvidia-green-dark);
  font-size: 1.1rem;
}

/* ---- Light Section ---- */
.section.is-light {
  background: var(--bg-light);
}

/* ---- Info Cards ---- */
.info-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin: 2rem 0;
}

.info-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
  transition: box-shadow 0.2s, transform 0.2s;
}

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

.info-card-icon {
  font-size: 1.4rem;
  color: var(--nvidia-green);
  margin-bottom: 0.5rem;
}

.info-card-label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.25rem;
}

.info-card-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ---- Topic Tags ---- */
.topic-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-top: 1.5rem;
}

.topic-tag {
  background: rgba(118, 185, 0, 0.08) !important;
  color: var(--nvidia-green-dark) !important;
  border: 1px solid rgba(118, 185, 0, 0.2) !important;
  border-radius: 20px !important;
  font-weight: 500 !important;
  font-size: 0.85rem !important;
}

/* ---- Schedule ---- */
.schedule-timeline {
  position: relative;
  padding-left: 0;
}

.schedule-item {
  display: flex;
  gap: 24px;
  margin-bottom: 0;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border-color);
}

.schedule-item:last-child {
  border-bottom: none;
}

.schedule-time {
  flex-shrink: 0;
  width: 72px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--nvidia-green-dark);
  padding-top: 2px;
  text-align: right;
}

.schedule-content {
  flex: 1;
}

.schedule-content h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.35rem;
}

.schedule-content p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-bottom: 0.5rem;
}

.schedule-content ul {
  margin-top: 0.5rem;
  margin-left: 1.2rem;
}

.schedule-content ul li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0.3rem;
  line-height: 1.5;
}

.schedule-speaker {
  color: var(--text-light) !important;
  font-size: 0.88rem !important;
  font-weight: 500;
}

.schedule-speaker i {
  margin-right: 4px;
  color: var(--nvidia-green);
}

.schedule-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

.schedule-badge.opening {
  background: #e8f5e9;
  color: #2e7d32;
}

.schedule-badge.talk {
  background: #e3f2fd;
  color: #1565c0;
}

.schedule-badge.break {
  background: #fff3e0;
  color: #e65100;
}

.schedule-badge.panel {
  background: #f3e5f5;
  color: #7b1fa2;
}

/* ---- WIP Notice ---- */
.wip-notice {
  display: flex;
  align-items: center;
  gap: 12px;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
  color: #92400e;
  font-size: 0.92rem;
  line-height: 1.5;
}

.wip-notice i {
  font-size: 1.2rem;
  color: #d97706;
  flex-shrink: 0;
}

.wip-notice p {
  margin: 0;
}

.tba-text {
  color: var(--text-light) !important;
  font-style: italic;
}

/* ---- Program Cards ---- */
.program-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  margin-bottom: 1.5rem;
  overflow: hidden;
  transition: box-shadow 0.2s;
}

.program-card:hover {
  box-shadow: var(--shadow-md);
}

.program-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  background: #fafbfd;
}

.program-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--nvidia-green);
  color: white;
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
}

.program-card-header .title {
  margin-bottom: 0.15rem !important;
  color: var(--primary);
}

.program-speakers {
  font-size: 0.88rem;
  color: var(--text-light);
  font-weight: 500;
}

.program-card-body {
  padding: 1.5rem;
}

.program-card-body p {
  color: var(--text-secondary);
  font-size: 0.94rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.program-card-body p:last-child {
  margin-bottom: 0;
}

.program-card-body a {
  color: var(--nvidia-green-dark);
  font-weight: 500;
  transition: color 0.2s;
}

.program-card-body a:hover {
  color: var(--nvidia-green);
}

/* ---- Takeaway Box ---- */
.takeaway-box {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-top: 2rem;
}

.takeaway-box .title {
  color: var(--primary);
  margin-bottom: 1.25rem !important;
}

.takeaway-box .title i {
  color: var(--nvidia-green);
  margin-right: 8px;
}

.takeaway-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
}

.takeaway-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--bg-light);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.takeaway-item i {
  color: var(--nvidia-green);
  font-size: 1.1rem;
  flex-shrink: 0;
}

a.takeaway-link {
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
}

a.takeaway-link:hover {
  background: rgba(118, 185, 0, 0.1);
  border-color: var(--nvidia-green);
  transform: translateY(-1px);
}

/* ---- Organizers ---- */
.organizer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.organizer-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  text-align: center;
  transition: box-shadow 0.2s, transform 0.2s;
}

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

.organizer-avatar {
  margin-bottom: 1rem;
}

.avatar-placeholder {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--nvidia-green), var(--nvidia-green-dark));
  color: white;
  font-size: 1.8rem;
}

.organizer-card img.organizer-photo {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
}

.organizer-name {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.organizer-name a {
  color: var(--primary);
  transition: color 0.2s;
}

.organizer-name a:hover {
  color: var(--nvidia-green-dark);
}

.organizer-role {
  font-size: 0.85rem;
  color: var(--nvidia-green-dark);
  font-weight: 600;
  margin-bottom: 0.15rem;
}

.organizer-affiliation {
  font-size: 0.82rem;
  color: var(--text-light);
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.organizer-links {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 0.75rem;
}

.organizer-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--bg-light);
  color: var(--text-light);
  font-size: 1.05rem;
  transition: all 0.2s;
}

.organizer-links a:hover {
  background: #0a66c2;
  color: white;
}

.organizer-bio {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
  text-align: left;
}

/* ---- Resources ---- */
.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.resource-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: all 0.2s;
  display: block;
}

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

.resource-icon {
  font-size: 1.4rem;
  color: var(--nvidia-green);
  margin-bottom: 0.5rem;
}

.resource-card h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.25rem;
}

.resource-card p {
  font-size: 0.82rem;
  color: var(--text-light);
  line-height: 1.5;
}

/* ---- Prior Work ---- */
.prior-works-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.prior-work-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  flex-wrap: wrap;
}

.prior-work-badge {
  flex-shrink: 0;
  font-size: 0.7rem;
  font-weight: 700;
  background: var(--primary);
  color: white;
  padding: 3px 10px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.prior-work-author {
  margin-left: auto;
  font-size: 0.82rem;
  color: var(--text-light);
  font-weight: 500;
  flex-shrink: 0;
}

/* ---- Footer ---- */
.footer {
  background: var(--primary) !important;
  color: rgba(255, 255, 255, 0.6);
  padding: 2rem 1.5rem !important;
}

.footer .content p {
  color: rgba(255, 255, 255, 0.5);
  font-size: 0.85rem;
}

.footer a {
  color: var(--nvidia-green-light);
  transition: color 0.2s;
}

.footer a:hover {
  color: var(--nvidia-green);
}

/* ---- Responsive ---- */
@media screen and (max-width: 768px) {
  .hero-title {
    font-size: 2rem !important;
  }

  .hero-subtitle {
    font-size: 1rem !important;
  }

  .schedule-item {
    flex-direction: column;
    gap: 8px;
  }

  .schedule-time {
    text-align: left;
    width: auto;
  }

  .info-cards {
    grid-template-columns: repeat(2, 1fr);
  }

  .organizer-grid {
    grid-template-columns: 1fr;
  }

  .resources-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .prior-work-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .prior-work-author {
    margin-left: 0;
  }
}

@media screen and (max-width: 480px) {
  .info-cards {
    grid-template-columns: 1fr;
  }

  .resources-grid {
    grid-template-columns: 1fr;
  }

  .takeaway-grid {
    grid-template-columns: 1fr;
  }
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-light);
}

::-webkit-scrollbar-thumb {
  background: #c1c9d4;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #a0aab5;
}

/* ---- Selection ---- */
::selection {
  background: rgba(118, 185, 0, 0.2);
  color: var(--primary);
}

/* ---- Smooth scroll ---- */
html {
  scroll-behavior: smooth;
}