/* ===================================================
   ICDDS 2026 – AIMLSystems-inspired Theme
   Inspired by https://www.aimlsystems.org/2025/
   =================================================== */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300;0,400;0,600;0,700;0,800;1,400;1,600&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  --primary:       #2ea3f2;   /* AIMLSystems blue accent */
  --primary-dark:  #1a7fcc;
  --primary-light: #e8f5fe;
  --dark:          #333333;
  --body-text:     #666666;
  --light-bg:      #f9f9f9;
  --border:        #e5e5e5;
  --white:         #ffffff;
  --header-h:      66px;
  --font:          'Open Sans', Arial, sans-serif;
  --shadow-sm:     0 2px 8px rgba(0,0,0,.08);
  --shadow-md:     0 4px 20px rgba(0,0,0,.10);
  --shadow-lg:     0 8px 40px rgba(0,0,0,.13);
  --radius:        4px;
  --transition:    all .3s ease-in-out;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  font-size: 14px;
  color: var(--body-text);
  background: var(--white);
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); text-decoration: none; }

h1,h2,h3,h4,h5,h6 {
  color: var(--dark);
  font-weight: 500;
  line-height: 1.2;
  padding-bottom: 10px;
}
h1 { font-size: 30px; }
h2 { font-size: 26px; }
h3 { font-size: 22px; }
h4 { font-size: 18px; }
h5 { font-size: 16px; }
h6 { font-size: 14px; }

p { padding-bottom: 1em; }
p:last-child { padding-bottom: 0; }

ul { list-style: none; }
img { max-width: 100%; height: auto; }

/* ---------- Layout Container ---------- */
.container {
  width: 80%;
  max-width: 1080px;
  margin: 0 auto;
  position: relative;
}

/* ---------- HEADER ---------- */
#header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-h);
  background: var(--white);
  box-shadow: 0 1px 0 rgba(0,0,0,.1);
  z-index: 99999;
  display: flex;
  align-items: center;
  transition: background .4s, box-shadow .4s;
}

#header .container-fluid {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0 30px;
}

/* Logo */
#logo a {
  font-size: 22px;
  font-weight: 700;
  color: var(--dark);
  letter-spacing: -0.5px;
}
#logo a:hover { color: var(--primary); }
#logo img { height: 44px; width: auto; vertical-align: middle; }

/* Nav */
#nav-menu-container { margin-left: auto; }

.nav-menu {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-menu > li { position: relative; }

.nav-menu > li > a {
  display: block;
  padding: 22px 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--dark);
  letter-spacing: .3px;
  transition: color .2s;
  white-space: nowrap;
}
.nav-menu > li > a:hover,
.nav-menu > li.menu-active > a { color: var(--primary); }

/* Dropdown */
.nav-dropdown {
  position: absolute;
  top: calc(100% + 3px);
  left: 0;
  min-width: 220px;
  background: var(--white);
  border-top: 3px solid var(--primary);
  box-shadow: 0 2px 12px rgba(0,0,0,.12);
  padding: 10px 0;
  z-index: 9999;
  display: none;
  border-radius: 0 0 var(--radius) var(--radius);
}
.nav-menu li:hover > .nav-dropdown { display: block; }

.nav-dropdown li a {
  display: block;
  padding: 8px 20px;
  font-size: 13px;
  color: var(--dark);
  transition: opacity .2s, background .2s;
}
.nav-dropdown li a:hover {
  background: rgba(0,0,0,.03);
  opacity: .75;
  color: var(--primary);
}

/* Mobile hamburger */
#nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 4px;
}
#nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--dark);
  transition: var(--transition);
}
#nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
#nav-toggle.active span:nth-child(2) { opacity: 0; }
#nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Page offset for fixed header */
#page-wrapper { padding-top: var(--header-h); }

/* ---------- HERO / BANNER ---------- */
.site-hero {
  background: linear-gradient(135deg, #0b2447 0%, #1a5a99 60%, #2ea3f2 100%);
  color: var(--white);
  padding: 80px 0 70px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.site-hero::before {
  content: '';
  position: absolute;
  top: -40%;
  left: -10%;
  width: 70%;
  height: 200%;
  background: rgba(255,255,255,.03);
  border-radius: 50%;
  transform: rotate(-15deg);
}

.hero-logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 30px;
}
.hero-logos img {
  height: 56px;
  width: auto;
  filter: brightness(0) invert(1);
  opacity: .9;
}

.site-hero h1 {
  color: var(--white);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  padding-bottom: 12px;
  text-shadow: 0 2px 8px rgba(0,0,0,.2);
}
.site-hero h2 {
  color: rgba(255,255,255,.92);
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  font-weight: 400;
  padding-bottom: 8px;
}
.site-hero h3 {
  color: rgba(255,255,255,.80);
  font-size: 1rem;
  font-weight: 400;
  padding-bottom: 0;
}

/* ---------- PAGE HERO (inner pages) ---------- */
.page-hero {
  background: linear-gradient(135deg, #0b2447 0%, #1a5a99 100%);
  padding: 50px 0 40px;
  text-align: center;
}
.page-hero h1 {
  color: var(--white);
  font-size: clamp(1.4rem, 2.5vw, 2rem);
  font-weight: 700;
  padding-bottom: 0;
}
.page-hero .breadcrumb-nav {
  margin-top: 10px;
  font-size: 13px;
  color: rgba(255,255,255,.7);
}
.page-hero .breadcrumb-nav a { color: rgba(255,255,255,.85); }
.page-hero .breadcrumb-nav a:hover { color: var(--white); }

/* ---------- SECTION STYLES ---------- */
section { padding: 60px 0; }
section.alt-bg { background: var(--light-bg); }

.section-title {
  font-size: 26px;
  font-weight: 600;
  color: var(--dark);
  margin-bottom: 8px;
  position: relative;
  padding-bottom: 0;
}
.section-title::after {
  content: '';
  display: block;
  width: 50px;
  height: 3px;
  background: var(--primary);
  margin-top: 10px;
}
.section-title.center { text-align: center; }
.section-title.center::after { margin: 10px auto 0; }

.section-subtitle {
  font-size: 15px;
  color: var(--body-text);
  margin-bottom: 30px;
}

/* ---------- CARDS ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 24px;
  margin-top: 30px;
}

.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .3s, transform .3s;
}
.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

/* ---------- PERSON / COMMITTEE CARD ---------- */
.person-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
  margin-top: 24px;
}

.person-card {
  width: 180px;
  text-align: center;
}

.person-photo-wrap {
  display: block;
  width: 160px;
  height: 160px;
  margin: 0 auto 12px;
  border: 2px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .3s;
  position: relative;
}
.person-photo-wrap:hover { box-shadow: var(--shadow-md); }
.person-photo-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,.85);
  opacity: 0;
  transition: opacity .3s;
}
.person-photo-wrap:hover::after { opacity: 1; }

.person-photo {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.person-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--dark);
  padding-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.person-name a { color: var(--dark); }
.person-name a:hover { color: var(--primary); }

.person-affil {
  font-size: 12px;
  color: var(--body-text);
  padding-bottom: 0;
}

/* Role group heading */
.role-heading {
  font-size: 20px;
  font-weight: 600;
  color: var(--dark);
  padding: 30px 0 12px;
  border-bottom: 2px solid var(--primary-light);
  margin-bottom: 4px;
}

/* ---------- IMPORTANT DATES ---------- */
.dates-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 30px;
}
.date-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  box-shadow: var(--shadow-sm);
}
.date-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  border-bottom: 1px solid var(--border);
  padding-bottom: 12px;
  margin-bottom: 16px;
}
.date-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  padding: 6px 0;
  border-bottom: 1px dashed var(--border);
  font-size: 13px;
}
.date-item:last-child { border-bottom: none; }
.date-label { color: var(--body-text); flex: 1; }
.date-value { font-weight: 600; color: var(--dark); text-align: right; }

/* ---------- KEYNOTE / SPEAKERS ---------- */
.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 28px;
  margin-top: 30px;
}

.speaker-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .3s, transform .3s;
}
.speaker-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.speaker-photo-wrap {
  position: relative;
  overflow: hidden;
  padding-top: 100%; /* square */
}
.speaker-photo-wrap img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .4s;
}
.speaker-card:hover .speaker-photo-wrap img { transform: scale(1.05); }

.speaker-info {
  padding: 16px;
  text-align: center;
}
.speaker-info h3 { font-size: 16px; font-weight: 700; padding-bottom: 4px; color: var(--dark); }
.speaker-info p { font-size: 12px; margin: 0; }

/* ---------- CALL FOR PAPERS ---------- */
.cfp-grid {
  display: grid;
  grid-template-columns: 1.7fr 1fr;
  gap: 28px;
  align-items: start;
  margin-top: 30px;
}
@media (max-width: 768px) { .cfp-grid { grid-template-columns: 1fr; } }

.cfp-card, .sidebar-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 28px;
  box-shadow: var(--shadow-sm);
}

.topic-list {
  columns: 2;
  gap: 16px;
  padding: 0;
}
.topic-list li {
  break-inside: avoid;
  padding: 5px 0 5px 18px;
  position: relative;
  font-size: 13px;
  color: var(--body-text);
}
.topic-list li::before {
  content: '›';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: 700;
}
@media (max-width: 600px) { .topic-list { columns: 1; } }

/* ---------- BUTTONS ---------- */
.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
  letter-spacing: .3px;
}
.btn-primary {
  background: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}
.btn-primary:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: var(--white);
}
.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}
.btn-outline:hover {
  background: var(--primary);
  color: var(--white);
}

/* ---------- ANNOUNCEMENTS / MARQUEE ---------- */
.announcement-bar {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  padding: 12px 20px;
  border-radius: var(--radius);
  font-size: 13px;
  margin-bottom: 24px;
  overflow: hidden;
}
.marquee-text {
  display: inline-block;
  animation: marquee 30s linear infinite;
  white-space: nowrap;
}
@keyframes marquee {
  from { transform: translateX(100%); }
  to   { transform: translateX(-100%); }
}

/* ---------- UPDATES LIST ---------- */
.updates-list { padding: 0; }
.updates-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.updates-list li::before {
  content: '▸';
  color: var(--primary);
  flex-shrink: 0;
  margin-top: 1px;
}
.updates-list li:last-child { border-bottom: none; }

/* ---------- TABLE ---------- */
.table-wrapper { overflow-x: auto; margin-top: 20px; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
thead th {
  background: var(--primary);
  color: var(--white);
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
}
tbody tr:nth-child(even) { background: var(--light-bg); }
tbody td { padding: 10px 16px; border-bottom: 1px solid var(--border); }

/* ---------- ACCORDION ---------- */
.accordion-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 8px;
  overflow: hidden;
}
.accordion-header {
  background: var(--light-bg);
  padding: 14px 20px;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  transition: background .2s;
}
.accordion-header:hover { background: var(--primary-light); }
.accordion-header .icon { font-size: 18px; color: var(--primary); transition: transform .3s; }
.accordion-item.open .accordion-header .icon { transform: rotate(180deg); }
.accordion-body {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s ease, padding .3s ease;
}
.accordion-item.open .accordion-body {
  padding: 16px 20px;
  max-height: 1000px;
}

/* ---------- FADE-IN ANIMATIONS ---------- */
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity .6s ease, transform .6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }
.fade-left { opacity: 0; transform: translateX(-30px); transition: opacity .6s ease, transform .6s ease; }
.fade-left.visible { opacity: 1; transform: translateX(0); }
.fade-right { opacity: 0; transform: translateX(30px); transition: opacity .6s ease, transform .6s ease; }
.fade-right.visible { opacity: 1; transform: translateX(0); }

/* ---------- FOOTER ---------- */
#footer {
  background: #0b2447;
  color: rgba(255,255,255,.75);
  padding: 50px 0 30px;
  font-size: 13px;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 40px;
}
.footer-col h4 {
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255,255,255,.15);
}
.footer-col ul { padding: 0; }
.footer-col ul li { margin-bottom: 6px; }
.footer-col ul li a { color: rgba(255,255,255,.65); transition: color .2s; }
.footer-col ul li a:hover { color: var(--primary); }
.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,.10);
  color: rgba(255,255,255,.45);
  font-size: 12px;
}
.footer-bottom a { color: rgba(255,255,255,.55); }
.footer-bottom a:hover { color: var(--primary); }

/* Social icons */
.social-links { display: flex; gap: 14px; margin-top: 14px; }
.social-links a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: rgba(255,255,255,.1);
  color: rgba(255,255,255,.7);
  font-size: 15px;
  transition: background .3s, color .3s;
}
.social-links a:hover { background: var(--primary); color: var(--white); }

/* ---------- MISC UTILITIES ---------- */
.text-center { text-align: center; }
.text-right  { text-align: right; }
.mt-sm { margin-top: 16px; }
.mt-md { margin-top: 30px; }
.mt-lg { margin-top: 50px; }
.mb-sm { margin-bottom: 16px; }
.mb-md { margin-bottom: 30px; }
.tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary-dark);
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 50px;
  letter-spacing: .4px;
}
.divider { border: none; border-top: 1px solid var(--border); margin: 30px 0; }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 980px) {
  .container { width: 90%; }
  #header .container-fluid { padding: 0 16px; }

  #nav-toggle { display: flex; }

  #nav-menu-container {
    position: absolute;
    top: var(--header-h);
    left: 0;
    width: 100%;
    background: var(--white);
    border-top: 3px solid var(--primary);
    box-shadow: var(--shadow-md);
    display: none;
  }
  #nav-menu-container.open { display: block; }

  .nav-menu {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 0;
  }
  .nav-menu > li > a { padding: 12px 20px; }

  .nav-dropdown {
    position: static;
    box-shadow: none;
    border-top: none;
    padding: 0;
    background: var(--light-bg);
  }
  .nav-menu li:hover > .nav-dropdown { display: none; }
  .nav-menu li.open > .nav-dropdown { display: block; }

  .person-grid { gap: 16px; }
  .person-card { width: 140px; }
  .person-photo-wrap { width: 120px; height: 120px; }
}

@media (max-width: 600px) {
  section { padding: 40px 0; }
  .site-hero { padding: 50px 0 40px; }
  .card-grid { grid-template-columns: 1fr 1fr; }
  .person-grid { gap: 12px; }
  .person-card { width: 120px; }
  .person-photo-wrap { width: 100px; height: 100px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}