*{
  margin:0;
  padding:0;
  box-sizing:border-box;
}

body{
  font-family:"Helvetica Neue","Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;
  background:#f5f9ff;
  color:#1f2a44;
}

.bg{
  position:fixed;
  inset:0;
  z-index:-1;
  background-image:
    radial-gradient(circle at 28% 22%, rgba(230,43,30,.22), transparent 58%),
    radial-gradient(circle at 72% 78%, rgba(230,43,30,.16), transparent 62%),
    linear-gradient(to bottom, rgba(0,0,0,.32), rgba(0,0,0,.60)),
    url("images/background.png");
  background-size:cover;
  background-position:center;
  background-repeat:no-repeat;
  filter:saturate(.95) contrast(1.05);
}

.container{
  width:90%;
  max-width:1200px;
  margin:0 auto;
}

/* ================= HEADER ================= */

.header{
  position:sticky;
  top:0;
  z-index:50;
  height:70px;             
  background:#ffffff;
  border-bottom:1px solid rgba(0,0,0,.1);
  display:flex;            
  align-items:center;   
}

.header-inner{
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:18px;
}

/* ================= NAV ================= */

.nav{
  display:flex;
  gap:18px;
  flex-wrap:wrap;
  justify-content:flex-end;
}

.nav a{
  text-decoration:none;
  color:rgba(0,0,0,.78);
  font-size:13px;
  letter-spacing:.12em;
  padding:10px 12px;
  border-radius:999px;
  transition:all .2s ease;
}

.nav a:hover{
  background:rgba(0,0,0,.06);
  color:rgba(0,0,0,.95);
  transform:translateY(-1px);
}

/* ================= HAMBURGER ================= */

.hamburger{
  display:none;
  flex-direction:column;
  justify-content:center;
  gap:5px;
  width:28px;
  height:22px;
  background:none;
  border:none;
  cursor:pointer;
  padding:0;
}

.hamburger span{
  width:100%;
  height:3px;
  background:#000;
  border-radius:3px;
}

/* ================= PAGE ================= */

.page{
  width:min(1200px, 92vw);
  margin:0 auto;
  padding:80px 0 120px;
}

.title{
  text-align:center;
  font-size:clamp(44px, 6vw, 72px);
  font-weight:900;
  margin-bottom:60px;
  color:#243b6b;
}

.glow-title{
  background: linear-gradient(
    90deg,
    #2563eb,   
    #3b82f6,   
    #93c5fd,  
    #3b82f6,
    #2563eb
  );
  background-size:400% 100%;
  background-position:0% 50%;
  -webkit-background-clip:text;
  background-clip:text;
  color:transparent;
  animation:textShift 6s ease-in-out infinite;
}

@keyframes textShift{
  0%{background-position:0% 50%}
  50%{background-position:100% 50%}
  100%{background-position:0% 50%}
}

/* ================= SPEAKERS ================= */

.speaker-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:40px;
  align-items:start;
}

.speaker-card{
  display:grid;
  grid-template-columns:200px 1fr;
  gap:26px;
  background:#ffffff;
  border-radius:22px;
  padding:28px;
  border:4px solid #cfe0ff;
  box-shadow:0 18px 40px rgba(42,78,155,.18);
}

.speaker-image{
  display:flex;
  align-items:center;
  justify-content:center;
}

.speaker-image img{
  width:180px;
  height:180px;
  object-fit:cover;
  border-radius:14px;
}

.speaker-content{
  display:flex;
  flex-direction:column;
  gap:10px;
}

.speaker-name{
  font-size:28px;
  font-weight:900;
}

.speaker-age{
  font-size:14px;
  font-weight:600;
  margin-left:8px;
  color:#5c7cfa;
}

.speaker-time{
  font-size:14px;
  font-weight:700;
  color:#4263eb;
}

.speaker-bio{
  font-size:16px;
  line-height:1.7;
  color:#344b7a;
  margin-top:6px;
}

/* desktop layout tricks */
.lift-up{ margin-top:-37%; }
.middle{ margin-top:-5%; }

.wide-card{
  grid-column:span 2;
}

.right-card{
  grid-column:2;
  margin-top:-40%;
}

/* ================= FOOTER ================= */

.site-footer{
  width:100%;
  margin-top:-30px;
  display:flex;
  justify-content:center;
  align-items:center;
  overflow:hidden;
}

.site-footer img{
  width:120%;
  max-width:none;
  height:auto;
}

/* ================= MOBILE ================= */

@media (max-width:600px){

  .header{
    position:relative;
  }

  .nav{
    display:none;
    position:absolute;
    top:70px;
    left:0;
    width:100%;
    background:#ffffff;
    flex-direction:column;
    align-items:center;
    gap:22px;
    padding:28px 0;
    box-shadow:0 12px 30px rgba(0,0,0,0.12);
  }

  .nav.open{
    display:flex;
  }

  .hamburger{
    display:flex;
  }

  /* speakers stacked */
  .speaker-grid{
    grid-template-columns:1fr;
  }

  .speaker-card{
    grid-template-columns:1fr;
    text-align:center;
  }

  .speaker-image img{
    width:160px;
    height:160px;
    margin:0 auto;
  }

  /* remove overlapping tricks */
  .wide-card,
  .right-card{
    grid-column:auto;
  }

  .lift-up,
  .middle,
  .right-card{
    margin-top:0;
  }
}