/* ====================================
   ChinaGraph 2026 - 主样式文件
   ==================================== */

/* ---- CSS 变量 ---- */
:root {
  /* 主色调 */
  --primary: #1e3a5f;
  --primary-light: #2d5a8e;
  --primary-lighter: #e8f0fe;
  --primary-gradient: linear-gradient(135deg, #1e3a5f 0%, #2d5a8e 50%, #1a5276 100%);

  /* 强调色 */
  --accent: #c49b2c;
  --accent-light: #f5e6b8;
  --accent-gradient: linear-gradient(135deg, #c49b2c, #d4af37);

  /* 中性色 */
  --text-primary: #1a1a2e;
  --text-secondary: #4a4a6a;
  --text-light: #8888a0;
  --bg-white: #ffffff;
  --bg-light: #f8f9fc;
  --bg-section: #f0f2f8;
  --border: #e2e5ef;
  --border-light: #f0f0f5;

  /* 语义色 */
  --success: #10b981;
  --warning: #f59e0b;
  --info: #3b82f6;
  --danger: #ef4444;

  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;
  --space-3xl: 96px;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
  --shadow-xl: 0 20px 50px rgba(0,0,0,0.15);

  /* 布局 */
  --max-width: 1200px;
  --header-height: 72px;

  /* 字体 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-serif: Georgia, "Noto Serif SC", "Source Han Serif SC", serif;

  /* 字号 */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.5rem;
  --text-2xl: 2rem;
  --text-3xl: 2.5rem;
  --text-4xl: 3.5rem;

  /* 过渡 */
  --transition: 0.3s ease;
  --transition-fast: 0.15s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

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

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

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  line-height: 1.3;
  font-weight: 700;
}

/* ---- Layout ---- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

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

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

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-title {
  font-size: var(--text-2xl);
  color: var(--primary);
  margin-bottom: var(--space-sm);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--accent-gradient);
  margin: var(--space-md) auto 0;
  border-radius: var(--radius-full);
}

.section-subtitle {
  font-size: var(--text-lg);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ---- Header ---- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  transition: box-shadow var(--transition);
  border-bottom: 1px solid transparent;
}

.header--scrolled {
  box-shadow: var(--shadow-md);
  border-bottom-color: var(--border);
}

.header__inner {
  width: 100%;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  position: relative;
  display: flex;
  align-items: center;
}

.header__brand {
  position: absolute;
  left: var(--space-lg);
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  color: var(--primary);
  font-size: var(--text-lg);
  text-decoration: none;
  white-space: nowrap;
}

.header__brand img {
  height: 40px;
  width: auto;
}

.header__brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.header__brand-text .zh {
  font-size: 1rem;
  font-weight: 700;
}

.header__brand-text .en {
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--text-secondary);
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* Navigation */
.nav {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  align-items: center;
  gap: 0;
  max-width: none;
  min-width: 0;
  overflow: visible;
}

.nav__link {
  display: flex;
  align-items: center;
  padding: 10px 12px;
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav__link:hover {
  color: var(--primary);
  background: var(--primary-lighter);
}

.nav__link--active {
  color: var(--primary);
  background: var(--primary-lighter);
  font-weight: 600;
}

.nav__link i {
  margin-right: 4px;
  font-size: 0.85em;
}

/* Mobile menu toggle */
.nav-toggle {
  position: absolute;
  right: var(--space-lg);
  top: 50%;
  transform: translateY(-50%);
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--primary);
  cursor: pointer;
  padding: var(--space-sm);
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}

.nav-toggle:hover {
  background: var(--primary-lighter);
}

.header--nav-collapsed .nav {
  display: none;
}

.header--nav-collapsed .nav-toggle {
  display: flex;
}

/* Mobile nav overlay */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(12px);
  z-index: 999;
  padding: var(--space-lg);
  overflow-y: auto;
}

.nav-mobile--open {
  display: block;
  animation: fadeSlideDown 0.3s ease;
}

.nav-mobile .nav__link {
  display: flex;
  padding: var(--space-md) var(--space-lg);
  font-size: var(--text-base);
  border-bottom: 1px solid var(--border-light);
  border-radius: 0;
}

.nav-mobile .nav__link i {
  width: 24px;
  text-align: center;
  margin-right: var(--space-sm);
  color: var(--primary);
}

@keyframes fadeSlideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Spacer for fixed header */
.header-spacer {
  height: var(--header-height);
}

/* ---- Hero Banner ---- */
.hero {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--primary-gradient);
  color: #fff;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__bg-slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 1.2s ease;
}

.hero__bg-slide--active {
  opacity: 1;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(30, 58, 95, 0.85) 0%,
    rgba(45, 90, 142, 0.75) 50%,
    rgba(26, 82, 118, 0.8) 100%
  );
  z-index: 1;
}

.hero__content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  max-width: 800px;
}

.hero__edition {
  display: inline-block;
  padding: var(--space-xs) var(--space-lg);
  border: 1px solid rgba(255,255,255,0.4);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  letter-spacing: 2px;
  margin-bottom: var(--space-lg);
  backdrop-filter: blur(4px);
  background: rgba(255,255,255,0.1);
}

.hero__title-zh {
  font-size: var(--text-4xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
  text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.hero__title-en {
  font-size: var(--text-xl);
  font-weight: 300;
  letter-spacing: 4px;
  text-transform: uppercase;
  opacity: 0.9;
  margin-bottom: var(--space-lg);
}

.hero__slogan {
  font-size: var(--text-lg);
  opacity: 0.85;
  margin-bottom: var(--space-xl);
  font-style: italic;
}

.hero__info {
  display: flex;
  justify-content: center;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.hero__info-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-base);
}

.hero__info-item i {
  font-size: 1.1em;
  opacity: 0.8;
}

.hero__actions {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* Carousel dots */
.hero__dots {
  position: absolute;
  bottom: var(--space-lg);
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  display: flex;
  gap: var(--space-sm);
}

.hero__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.4);
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.hero__dot--active {
  background: #fff;
  transform: scale(1.2);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  font-size: var(--text-base);
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  font-family: inherit;
}

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

.btn--primary:hover {
  background: #b38a24;
  border-color: #b38a24;
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(196,155,44,0.4);
}

.btn--outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.6);
}

.btn--outline:hover {
  background: rgba(255,255,255,0.15);
  border-color: #fff;
  color: #fff;
  transform: translateY(-2px);
}

.btn--secondary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn--secondary:hover {
  background: var(--primary-light);
  border-color: var(--primary-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(30,58,95,0.3);
}

.btn--sm {
  padding: 8px 20px;
  font-size: var(--text-sm);
}

/* ---- Announcement Cards ---- */
.announcements__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.announcement-card {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  transition: all var(--transition);
  text-decoration: none;
  color: inherit;
}

.announcement-card:hover {
  border-color: var(--primary-light);
  box-shadow: var(--shadow-sm);
  transform: translateX(4px);
  color: inherit;
}

.announcement-card__date {
  flex-shrink: 0;
  text-align: center;
  min-width: 60px;
}

.announcement-card__month {
  font-size: var(--text-xs);
  color: var(--text-light);
  text-transform: uppercase;
}

.announcement-card__day {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--primary);
  line-height: 1;
}

.announcement-card__title {
  flex: 1;
  font-size: var(--text-base);
  color: var(--text-primary);
}

.announcement-card__badge {
  display: inline-block;
  padding: 2px 10px;
  background: var(--danger);
  color: #fff;
  font-size: var(--text-xs);
  border-radius: var(--radius-full);
  font-weight: 600;
  margin-left: var(--space-sm);
  vertical-align: middle;
}

.announcements__more {
  text-align: center;
  margin-top: var(--space-lg);
}

/* ---- Introduction ---- */
.intro__text {
  max-width: 900px;
  margin: 0 auto;
  font-size: var(--text-lg);
  color: var(--text-secondary);
  line-height: 1.9;
}

.intro__text p {
  margin-bottom: var(--space-lg);
  text-indent: 2em;
}

/* ---- Timeline (Important Dates) ---- */
.timeline {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
  padding-left: 40px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 15px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--primary-lighter), var(--primary), var(--primary-lighter));
}

.timeline__item {
  position: relative;
  padding-bottom: var(--space-xl);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: -33px;
  top: 4px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--bg-white);
  border: 3px solid var(--primary);
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.timeline__item--passed .timeline__dot {
  background: var(--text-light);
  border-color: var(--text-light);
}

.timeline__item--upcoming .timeline__dot {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 4px var(--accent-light);
}

.timeline__content {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-md) var(--space-lg);
  transition: all var(--transition);
}

.timeline__item:hover .timeline__content {
  box-shadow: var(--shadow-sm);
  border-color: var(--primary-lighter);
}

.timeline__item--passed .timeline__content {
  opacity: 0.6;
}

.timeline__label {
  font-weight: 600;
  color: var(--text-primary);
  font-size: var(--text-base);
}

.timeline__date {
  color: var(--primary-light);
  font-size: var(--text-sm);
  margin-top: var(--space-xs);
}

.timeline__icon {
  color: var(--primary);
  margin-right: var(--space-sm);
}

/* ---- Person Cards ---- */
.person-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-lg);
}

.person-card {
  text-align: center;
  padding: var(--space-lg);
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.person-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.person-card__photo {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto var(--space-md);
  border: 3px solid var(--primary-lighter);
  background: var(--bg-section);
}

.person-card__name {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--primary);
  margin-bottom: var(--space-xs);
}

.person-card__affiliation {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.person-card__role {
  display: inline-block;
  margin-top: var(--space-sm);
  padding: 2px 12px;
  background: var(--primary-lighter);
  color: var(--primary);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
}

/* ---- Sponsor Section ---- */
.sponsors-tier {
  margin-bottom: var(--space-2xl);
}

.sponsors-tier__title {
  text-align: center;
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

.sponsors-tier__badge {
  display: inline-block;
  padding: 2px 14px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.sponsors-tier--special .sponsors-tier__badge { background: linear-gradient(135deg, #ffd700, #ffaa00); color: #5c3a00; }
.sponsors-tier--diamond .sponsors-tier__badge { background: linear-gradient(135deg, #b9f2ff, #e0f7fa); color: #006064; }
.sponsors-tier--platinum .sponsors-tier__badge { background: linear-gradient(135deg, #e8e8e8, #f5f5f5); color: #424242; }
.sponsors-tier--gold .sponsors-tier__badge { background: linear-gradient(135deg, #fff3cd, #ffeeba); color: #856404; }
.sponsors-tier--silver .sponsors-tier__badge { background: linear-gradient(135deg, #e9ecef, #dee2e6); color: #495057; }

.sponsors-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-lg);
}

.sponsor-card {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-lg);
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
  min-width: 180px;
}

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

.sponsor-card img {
  max-height: 60px;
  width: auto;
}

.sponsor-card--large img {
  max-height: 80px;
}

/* ---- History List ---- */
.history-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--space-md);
  max-width: 900px;
  margin: 0 auto;
}

.history-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  background: var(--bg-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  transition: all var(--transition);
}

.history-item:hover {
  border-color: var(--primary-lighter);
  box-shadow: var(--shadow-sm);
}

.history-item__year {
  font-size: var(--text-xl);
  font-weight: 800;
  color: var(--primary);
  min-width: 55px;
}

.history-item__info {
  flex: 1;
}

.history-item__edition {
  font-weight: 600;
  font-size: var(--text-sm);
}

.history-item__location {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

/* ---- Contact Section ---- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-xl);
  max-width: 800px;
  margin: 0 auto;
}

.contact-item {
  text-align: center;
  padding: var(--space-lg);
}

.contact-item__icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--primary-lighter);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin: 0 auto var(--space-md);
}

.contact-item__label {
  font-size: var(--text-sm);
  color: var(--text-light);
  margin-bottom: var(--space-xs);
}

.contact-item__value {
  font-weight: 600;
  color: var(--text-primary);
  word-break: break-all;
}

.contact-item__qr {
  width: 150px;
  height: 150px;
  margin: 0 auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

/* ---- Footer ---- */
.footer {
  background: var(--primary);
  color: rgba(255,255,255,0.8);
  padding: var(--space-2xl) 0 var(--space-lg);
}

.footer__inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer__brand {
  font-size: var(--text-lg);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-md);
}

.footer__desc {
  font-size: var(--text-sm);
  line-height: 1.8;
  opacity: 0.8;
}

.footer__heading {
  font-size: var(--text-base);
  font-weight: 600;
  color: #fff;
  margin-bottom: var(--space-md);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer__link {
  color: rgba(255,255,255,0.7);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--accent-light);
}

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
  opacity: 0.7;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* ---- Page Content (Sub-pages) ---- */
.page-banner {
  background: var(--primary-gradient);
  color: #fff;
  padding: var(--space-2xl) 0;
  text-align: center;
}

.page-banner__title {
  font-size: var(--text-3xl);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.page-banner__subtitle {
  font-size: var(--text-lg);
  opacity: 0.8;
}

.page-content {
  padding: var(--space-2xl) 0;
}

.content-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  margin-bottom: var(--space-xl);
}

.content-card__title {
  font-size: var(--text-xl);
  color: var(--primary);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--primary-lighter);
}

/* ---- Tables ---- */
.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

.table th {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  padding: 14px var(--space-md);
  text-align: left;
  white-space: nowrap;
}

.table td {
  padding: 12px var(--space-md);
  border-bottom: 1px solid var(--border);
}

.table tr:nth-child(even) td {
  background: var(--bg-light);
}

.table tr:hover td {
  background: var(--primary-lighter);
}

/* ---- Program Tabs ---- */
.program-tabs {
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.program-tab {
  padding: 10px 24px;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-white);
  border: 2px solid var(--border);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.program-tab:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.program-tab--active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.program-day {
  display: none;
}

.program-day--active {
  display: block;
  animation: fadeIn 0.3s ease;
}

/* ---- Event Cards (Program) ---- */
.event-card {
  display: flex;
  gap: var(--space-lg);
  padding: var(--space-lg);
  background: var(--bg-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  margin-bottom: var(--space-md);
  transition: all var(--transition);
}

.event-card:hover {
  box-shadow: var(--shadow-sm);
}

.event-card__time {
  flex-shrink: 0;
  min-width: 100px;
  font-weight: 700;
  color: var(--primary);
  font-size: var(--text-sm);
}

.event-card__body {
  flex: 1;
}

.event-card__title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-xs);
}

.event-card__meta {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.event-card__type {
  display: inline-block;
  padding: 1px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  margin-left: var(--space-sm);
}

.event-card__type--keynote { background: var(--accent-light); color: #856404; }
.event-card__type--paper { background: #dcfce7; color: #166534; }
.event-card__type--panel { background: #f3e8ff; color: #6b21a8; }
.event-card__type--course { background: #dbeafe; color: #1e40af; }
.event-card__type--ceremony { background: #fee2e2; color: #991b1b; }
.event-card__type--social { background: #fef3c7; color: #92400e; }

/* ---- Keynote Cards ---- */
.keynote-card {
  display: flex;
  gap: var(--space-xl);
  padding: var(--space-xl);
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  margin-bottom: var(--space-xl);
  transition: all var(--transition);
}

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

.keynote-card__photo-wrap {
  flex-shrink: 0;
  width: 200px;
}

.keynote-card__photo {
  width: 200px;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius-md);
  background: var(--bg-section);
}

.keynote-card__body {
  flex: 1;
}

.keynote-card__title {
  font-size: var(--text-xl);
  color: var(--primary);
  margin-bottom: var(--space-sm);
}

.keynote-card__speaker {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.keynote-card__affiliation {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.keynote-card__info {
  display: flex;
  gap: var(--space-lg);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
  flex-wrap: wrap;
}

.keynote-card__info i {
  color: var(--primary);
  margin-right: var(--space-xs);
}

.keynote-card__abstract {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.8;
}

.keynote-card__toggle {
  background: none;
  border: none;
  color: var(--primary-light);
  font-size: var(--text-sm);
  cursor: pointer;
  padding: 0;
  margin-top: var(--space-sm);
  font-weight: 500;
  font-family: inherit;
}

.keynote-card__toggle:hover {
  text-decoration: underline;
}

/* ---- Organizer Logos ---- */
.org-logos {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: var(--space-xl);
  padding: var(--space-lg) 0;
}

.org-logo {
  height: 60px;
  width: auto;
  opacity: 0.85;
  transition: opacity var(--transition);
  filter: grayscale(20%);
}

.org-logo:hover {
  opacity: 1;
  filter: grayscale(0%);
}

/* ---- Topic Tags ---- */
.topic-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.topic-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  background: var(--primary-lighter);
  color: var(--primary);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: all var(--transition);
}

.topic-tag:hover {
  background: var(--primary);
  color: #fff;
}

.topic-tag i {
  font-size: 0.8em;
}

/* ---- Registration Fees ---- */
.fee-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
}

.fee-table th {
  background: var(--primary);
  color: #fff;
  padding: 14px var(--space-lg);
  font-weight: 600;
}

.fee-table td {
  padding: 14px var(--space-lg);
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.fee-table tr:nth-child(even) td {
  background: var(--bg-light);
}

.fee-table .fee-highlight {
  color: var(--accent);
  font-weight: 700;
}

/* ---- Hotel Cards ---- */
.hotel-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: var(--space-lg);
}

.hotel-card {
  background: var(--bg-white);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: all var(--transition);
}

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

.hotel-card__img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  background: var(--bg-section);
}

.hotel-card__body {
  padding: var(--space-lg);
}

.hotel-card__name {
  font-weight: 700;
  font-size: var(--text-base);
  margin-bottom: var(--space-sm);
}

.hotel-card__meta {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.8;
}

/* ---- PC Member List ---- */
.pc-list {
  column-count: 3;
  column-gap: var(--space-xl);
  font-size: var(--text-sm);
  line-height: 2.2;
  color: var(--text-secondary);
}

/* ---- Utility ---- */
.text-center { text-align: center; }
.text-muted { color: var(--text-light); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

/* ---- Scroll Reveal Animation ---- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ---- Back to Top ---- */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
  z-index: 100;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background: var(--primary-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* ---- Empty State ---- */
.empty-state {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-light);
}

.empty-state__icon {
  font-size: 3rem;
  margin-bottom: var(--space-md);
  opacity: 0.5;
}

.empty-state__text {
  font-size: var(--text-lg);
}

/* ---- Includes list ---- */
.includes-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.includes-list__item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--text-sm);
  color: var(--text-secondary);
}

.includes-list__item i {
  color: var(--success);
}