/* =====================================
   IC4S 2026 Styles — Clean Optimized CSS
   ===================================== */

/* Root Variables */
:root {
  --bg: #f7f9fc;
  --bg-2: #eef2f9;
  --txt: #0b1020;
  --muted: #4b5565;
  --brand: #36b37e;
  --brand-2: #4c9cff;
  --danger: #b91c1c;
  --radius: 18px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  --maxw: 1200px;
}

/* Global reset */
* { box-sizing: border-box; }
html, body { height: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: #ffffff;
  color: var(--txt);
  font-family: Inter, system-ui, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.6;
  letter-spacing: .2px;
  padding-top: 70px; /* header offset */
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ===========================
   HEADER
=========================== */
header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 9999;
  background: #ffffff; backdrop-filter: blur(10px);
  border-bottom: 1px solid #e3e8f4;
}
.nav { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.brand { display: flex; gap: 12px; align-items: center; }
.brand-logo { inline-size: 34px; block-size: 34px; border-radius: 10px;
  background: linear-gradient(135deg, var(--brand), var(--brand-2));
  box-shadow: var(--shadow);
}
.brand h1 { font-size: 18px; margin: 0; font-weight: 700; }
.menu { display: flex; gap: 18px; align-items: center; }
.menu a { opacity: .9; }
.menu a:hover { opacity: 1; }
.btn {
  display: inline-grid; place-items: center; padding: 10px 16px;
  border-radius: 12px; font-weight: 600;
  border: 1px solid #d5def0; background: #ffffff; box-shadow: var(--shadow);
}
.btn.brand { background: #ffffff; border: 0; color: #04120c; }
.btn.ghost { background: transparent; border: 1px solid #d5def0; color: #0b1020; }

/* Mobile navigation */
.hamburger { display: none; cursor: pointer; }
.hamburger span {
  display: block; width: 24px; height: 2px;
  background: #d7def0; margin: 5px 0; transition: .2s;
}
@media (max-width: 900px) {
  .menu {
    display: none; position: absolute; left: 0; right: 0; top: 64px;
    background: #ffffff; padding: 16px 20px; border-bottom: 1px solid #e3e8f4;
  }
  .menu.open { display: grid; }
  .hamburger { display: block; }
}

/* ===========================
   HERO SECTION
=========================== */
.hero { position: relative; overflow: hidden; }
.hero .container {
  display: grid; grid-template-columns: 1.2fr .8fr;
  gap: 34px; padding: 20px 20px;
}
.badge {
  display: inline-block; padding: 6px 10px; border-radius: 999px;
  border: 1px solid #2c3a68; color: #92400E; font-size: 12px;
}
.title {
  font-size: clamp(30px, 4.2vw, 54px);
  line-height: 1.1; margin: 14px 0 10px; letter-spacing: .3px;
}
.subtitle { color: var(--muted); font-size: clamp(15px, 1.6vw, 18px); }
.acc { color: var(--brand); }
.cta { display: flex; gap: 12px; margin-top: 18px; flex-wrap: wrap; }
.metric-row {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 12px; margin-top: 24px;
}
.metric {
  background: #ffffff; padding: 14px; border-radius: 14px;
  border: 1px solid #e3e8f4; text-align: center;
}
.metric .num { font-size: 24px; font-weight: 800; }

.hero-card {
  background: #ffffff; border: 1px solid #e3e8f4;
  border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow);
}
.countdown {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
}
.countdown .box {
  background: #ffffff; border: 1px solid #e3e8f4;
  border-radius: 12px; padding: 12px; text-align: center;
}
.countdown .n { font-size: 20px; font-weight: 800; }
.small { font-size: 12px; color: #6b7280; }

/* Hero logo (clean final version) */
/* --- Hero header: logo + badge inline --- */
.hero-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  flex-wrap: wrap; /* so they don’t overflow on small screens */
}

.hero-header img {
  height: 90px;
  width: auto;
  max-width: 25%;
  transition: transform 0.8s ease-in-out;
  transform-origin: center;
  cursor: pointer;
}

.hero-header .badge {
  font-size: 14px;
  border-radius: 999px;
  padding: 8px 12px;
  background: #fff;
  border: 1px solid #2c3a68;
  color: #92400E;
  font-weight: 500;
}

@media (max-width: 768px) {
  .hero-header {
    justify-content: center;
    text-align: center;
  }
  .hero-header img {
    height: 70px;
    max-width: 35%;
  }
}

/* ===========================
   SECTIONS BASE
=========================== */
section { padding: 64px 0; }
.section-h { display: flex; align-items: end; justify-content: space-between; margin-bottom: 22px; }
.kicker { color: #b4c1dc; letter-spacing: .3em; text-transform: uppercase; font-weight: 700; font-size: 12px; }
h2 { margin: 6px 0 0; font-size: clamp(22px, 3.4vw, 34px); }
.lead { color: var(--muted); max-width: 800px; }

.grid { display: grid; gap: 18px; }
.cards-3 { grid-template-columns: repeat(3, 1fr); }
.cards-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 900px) {
  .cards-3, .cards-2 { grid-template-columns: 1fr; }
}
.card {
  background: #ffffff; border: 1px solid #e3e8f4;
  border-radius: var(--radius); padding: 18px;
}
.chip {
  display: inline-block; padding: 6px 10px;
  border-radius: 999px; border: 1px solid #32457e;
  color: #92400E; font-size: 12px;
}

/* ===========================
   SPEAKERS
=========================== */
.speakers-grid-vertical {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 28px;
}
.speaker-card-vertical {
  display: flex; flex-direction: column;
  background: #ffffff; border: 1px solid #e3e8f4;
  border-radius: 16px; box-shadow: 0 6px 18px rgba(0,0,0,0.05);
  overflow: hidden; transition: transform .25s ease, box-shadow .25s ease;
}
.speaker-card-vertical:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0,0,0,0.08);
}
.speaker-media {
  position: relative; width: 100%; background: #f5f7fb;
  border-bottom: 1px solid #e3e8f4; overflow: hidden;
}
.ratio-4x5 { aspect-ratio: 4 / 5; }
.fit-cover img { object-fit: cover; }
.focus-center img { object-position: 50% 50%; }
.speaker-media img {
  position: absolute; inset: 0; width: 100%; height: 100%;
  transition: transform .45s ease, filter .3s ease;
}
@media (hover:hover) and (pointer:fine) {
  .speaker-card-vertical:hover .speaker-media img { transform: scale(1.05); }
}
.speaker-body { padding: 16px; text-align: center; }
.speaker-name { margin: 10px 0 4px; font-size: 20px; color: #0b1020; }
.speaker-affil { color: #4b5565; font-size: 14px; margin-bottom: 8px; }
.speaker-talk { color: #111827; font-weight: 500; margin-bottom: 14px; }
.speaker-social { display: flex; justify-content: center; gap: 10px; }
.speaker-social .ico {
  display: inline-grid; place-items: center;
  width: 36px; height: 36px; border-radius: 8px;
  background: #f3f6fb; border: 1px solid #e3e8f4;
  transition: background .15s ease, transform .15s ease;
}
.speaker-social .ico:hover { transform: translateY(-2px); background: #ffffff; }
.speaker-social .ico.scopus:hover { color: #E9711C; }

/* ===========================
   TICKETS / BANK TRANSFER
=========================== */
.pricing { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.price-card { padding: 20px; }
.price { font-size: 36px; font-weight: 800; }
.muted-list { list-style: none; padding: 0; margin: 0; }
.muted-list li { padding: 6px 0; color: #374151; }

@media (max-width: 900px) {
  .pricing { grid-template-columns: 1fr; }
}

.bank-transfer {
  margin-top: 2rem; padding: 1.5rem;
  background: #f9fafb; border: 1px solid #e5e7eb;
  border-radius: 12px; box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}
.bank-transfer h3 {
  margin-bottom: 1rem; font-size: 1.3rem;
  color: #e94e3f; text-align: center;
}
.bank-transfer p {
  margin: .3rem 0; font-size: .95rem; color: #333;
}
.bank-transfer .note {
  margin-top: 1rem; font-size: .9rem; color: #555;
  background: #fff; border-left: 3px solid #e94e3f;
  padding: .5rem .8rem; border-radius: 4px;
}

/* ===========================
   SPONSORS
=========================== */
.sponsors {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 14px;
}
@media (max-width: 900px) { .sponsors { grid-template-columns: repeat(3, 1fr); } }
.sponsor {
  height: 68px; border-radius: 12px; border: 1px dashed #e3e8f4;
  display: grid; place-items: center;
}
.sponsor img {
  max-width: 100%; max-height: 60px; object-fit: contain;
  filter: grayscale(20%); transition: filter .2s, transform .2s;
}
.sponsor img:hover { filter: none; transform: scale(1.05); }

/* ===========================
   COMMITTEES
=========================== */
.comm-controls { display: flex; gap: 8px; align-items: center; }
.comm-acc {
  background: #ffffff; border: 1px solid #e3e8f4; border-radius: 12px;
  margin-bottom: 14px; box-shadow: 0 2px 6px rgba(0,0,0,0.04);
}
.comm-acc summary {
  list-style: none; cursor: pointer; display: flex;
  justify-content: space-between; align-items: center;
  padding: 14px 16px; font-weight: 600; color: #0b1020;
}
.comm-acc summary::-webkit-details-marker { display: none; }
.comm-acc[open] .chev { transform: rotate(180deg); }
.comm-acc .chev { transition: transform .2s ease; }
.comm-list {
  list-style: none; margin: 0; padding: 0 16px 14px;
}
.comm-list li {
  padding: 8px 0; color: #374151; border-bottom: 1px dashed #e5e7eb;
}
.comm-list li:last-child { border-bottom: none; }

.comm-acc summary .title {
  font-size: 16px;   /* 👈 adjust as you wish (e.g., 15px or 14px) */
  font-weight: 600;
  color: #0b1020;
}

/* ===========================
   MISC
=========================== */
footer {
  border-top: 1px solid #e3e8f4;
  background: #ffffff;
  padding: 28px 0;
  color: #4b5565;
}
input, select, textarea {
  width: 100%; padding: 12px;
  border-radius: 12px; border: 1px solid #d5def0;
  background: #ffffff; color: #0b1020;
}
input:focus, select:focus, textarea:focus {
  outline: none; box-shadow: 0 0 0 3px rgba(54, 179, 126, .25);
}
label { font-size: 14px; color: #c6d0ea; }
form small { color: #9fb0d4; }
.map-wrap {
  width: 100%; border: 1px solid #e3e8f4;
  border-radius: 12px; overflow: hidden; box-shadow: var(--shadow);
}
.tba {
  background: #f9fafb; border: 1px dashed #d1d5db;
  border-radius: 12px; padding: 20px; text-align: center; color: #374151;
}
.tba .note { color: #6b7280; font-size: .9rem; margin-top: 6px; }

/* Schedule */
.tabs{display:flex; gap:10px; flex-wrap:wrap; margin:12px 0 18px}
.tab{padding:8px 12px; border:1px solid #e3e8f4; border-radius:10px; cursor:pointer; background:#ffffff; border-color:#b3ccff}
.slot{display:grid; grid-template-columns:120px 1fr; gap:14px; padding:12px; border:1px solid #e3e8f4; border-radius:12px; margin-bottom:10px; background:#ffffff; grid-template-columns:repeat(3,1fr); gap:16px}
.price-card{padding:20px}
.price{font-size:36px; font-weight:800}
.muted-list{list-style:none; padding:0; margin:0}
.muted-list li{padding:6px 0; color:#374151}
@media (max-width:900px){ .pricing{grid-template-columns:1fr}}

/* ------------------------------
   MOBILE-FRIENDLY LAYOUT (≤ 768 px)
---------------------------------*/
/* ===== MOBILE (≤768px) — VERSION CORRIGÉE ===== */
@media (max-width: 768px) {

  /* GLOBAL */
  html, body { overflow-x: hidden; }
  body {
    font-size: 15px;
    padding-top: 60px; /* header un peu plus bas */
  }
  .container { padding: 0 16px; }

  header .brand h1 { font-size: 16px; }

  /* NAVIGATION */
  .menu {
    display: none;
    position: absolute;
    left: 0; right: 0; top: 60px;
    background: #ffffff;
    padding: 12px 16px;
    border-bottom: 1px solid #e3e8f4;
  }
  .menu.open { display: grid; gap: 10px; }
  .hamburger { display: block; }

  /* HERO */
  .hero, .hero .container, .hero .hero-card { overflow-x: hidden; }

  .hero .container{
    display: grid;
    grid-template-columns: 1fr;
    grid-template-areas:
      "main"
      "card";                /* la carte passe en dessous */
    gap: 16px;
    padding: 32px 16px;
    text-align: center;
  }
  .hero .container > :first-child { grid-area: main; }
  .hero .hero-card{
    grid-area: card;
    width: 100%;
    max-width: 560px;
    justify-self: center;
    margin-top: 8px;
  }

  /* Logo + badge (inline -> wrap centré en mobile) */
  .hero-header{ justify-content: center; flex-wrap: wrap; text-align: center; }
  .hero-header img{ height: 70px; max-width: 140px; margin: 12px auto; }
  .badge{ display: inline-block; margin: 0 auto; }

  .title { font-size: 26px; }
  .subtitle { font-size: 15px; }
  .metric-row { grid-template-columns: repeat(3, 1fr); }

  /* Countdown lisible sur mobile */
  .countdown{ grid-template-columns: repeat(2, 1fr); gap: 8px; }
  .countdown .box{ padding: 10px; }
  .countdown .n{ font-size: 18px; }

  /* CARTES / GRILLES */
  .cards-3,
  .cards-2,
  .pricing {
    grid-template-columns: 1fr;
    display: grid;
    gap: 16px;
  }
  .card { padding: 16px; }

  /* COMMITTEES */
  .comm-acc summary .title { font-size: 15px; }
  .comm-list li { font-size: 14px; }

  /* TABS (Schedule) */
  .tabs { flex-wrap: wrap; justify-content: center; gap: 8px; }
  .tab { flex: 1 1 100px; text-align: center; font-size: 14px; }

  /* FOOTER */
  footer .container {
    flex-direction: column;
    text-align: center;
    gap: 8px;
  }

  /* SPONSORS GRID */
  .sponsors { grid-template-columns: repeat(2, 1fr); }

  /* TRACKS */
  #tracks .grid.cards-2 { grid-template-columns: 1fr; }
  .track-card {
    background: #ffffff;
    border: 1px solid #e3e8f4;
    border-radius: 12px;
    padding: 16px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.04);
  }
  .track-card h3 {
    color: #0b1020;
    margin: 0 0 10px;
    font-size: 18px;
  }
  .track-list { list-style: none; margin: 0; padding-left: 0; }
  .track-list li {
    position: relative;
    padding-left: 24px;
    margin-bottom: 6px;
    color: #374151;
  }
  .track-list li::before {
    content: "•";
    position: absolute;
    left: 8px;
    color: #36b37e;
    font-size: 20px;
    line-height: 1;
  }

  /* CONTACT FORM */
  form.card { padding: 16px; }
}


/* Acknowledgment Section */
.acknowledgment {
  background: #ffffff;
  border: 1px solid #e3e8f4;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.acknowledgment h3 {
  margin-top: 0;
  color: #0b1020;
  font-size: 20px;
  margin-bottom: 10px;
}

.acknowledgment p {
  color: #374151;
  font-size: 15px;
  line-height: 1.6;
}

/* Mobile */
@media (max-width: 768px) {
  .acknowledgment {
    padding: 18px;
  }
  .acknowledgment h3 {
    font-size: 18px;
  }
  .acknowledgment p {
    font-size: 14px;
  }
}

.submission-guidelines { background:#fff; border:1px solid #e3e8f4; border-radius:12px; padding:24px; box-shadow:0 4px 10px rgba(0,0,0,0.04); }
.submission-guidelines h3 { margin:0 0 12px; color:#0b1020; font-size:20px; }
.submission-guidelines ul { list-style:none; margin:0; padding:0; }
.submission-guidelines li { position:relative; padding-left:28px; margin-bottom:8px; color:#374151; }
.submission-guidelines li::before { content:"✓"; position:absolute; left:0; color:#36b37e; font-weight:700; }
@media (max-width:768px){ .submission-guidelines{ padding:18px; } .submission-guidelines h3{ font-size:18px; } .submission-guidelines li{ font-size:14px; } }


/* Publication Info Section */
.publication-info {
  background: #ffffff;
  border: 1px solid #e3e8f4;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.publication-info h3 {
  margin-top: 0;
  color: #0b1020;
  font-size: 20px;
  margin-bottom: 16px;
}

.pub-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  align-items: center;
  gap: 20px;
}

.pub-text p {
  color: #374151;
  font-size: 15px;
  line-height: 1.6;
}

.pub-cover img {
  width: 100%;
  max-width: 180px;
  border-radius: 8px;
  border: 1px solid #e3e8f4;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease;
}

.pub-cover img:hover {
  transform: scale(1.05);
}

/* Mobile layout */
@media (max-width: 768px) {
  .pub-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .pub-cover img {
    margin: 12px auto 0;
  }
  .publication-info {
    padding: 18px;
  }
  .publication-info h3 {
    font-size: 18px;
  }
  .publication-info p {
    font-size: 14px;
  }
}

/* Submission link styling */
.submission-link {
  font-size: 15px;
  color: #374151;
  margin-top: 10px;
  line-height: 1.6;
}

.submission-link a {
  color: #0056b3;                 /* blue color matching academic tone */
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;     /* adds subtle spacing under text */
  transition: color 0.2s ease, background 0.2s ease;
}

.submission-link a:hover,
.submission-link a:focus {
  color: #1d4ed8;                 /* slightly brighter blue */
  background: rgba(59, 130, 246, 0.1); /* subtle blue highlight */
  border-radius: 4px;
  padding: 2px 4px;
}

/* Mobile adaptation */
@media (max-width: 768px) {
  .submission-link {
    font-size: 14px;
    text-align: center;
  }
}



/* Grid des keynote speakers : 3 colonnes desktop, puis 2, puis 1 */
.speakers-grid-vertical {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}

@media (max-width: 900px) {
  .speakers-grid-vertical {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .speakers-grid-vertical {
    grid-template-columns: 1fr;
  }
}



/* --- Social Section (inside card) --- */

.social-links {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.social-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: 10px;
  background: #ffffff;
  border: 1px solid #e3e8f4;
  color: #374151;
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  transition: all .2s ease;
  box-shadow: 0 2px 6px rgba(0,0,0,.04);
}

.social-btn:hover {
  background: #f9fafb;
  border-color: #d0d7ea;
  transform: translateY(-2px);
}

.social-btn.linkedin:hover { color:#0a66c2; }
.social-btn.facebook:hover { color:#1877f2; }