/* Basic reset */
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: #f6f8fb;
}

:root{
  --brand: #2C65C5;
  --brand-dark: #1f56b6;
  --text: #25313a;
  --muted: rgba(37,49,58,0.75);
  --card: rgba(255,255,255,0.92);
  --shadow: 0 12px 40px rgba(0,0,0,0.12);
  --radius: 20px;
}

.container{
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}
.container--narrow{
  width: min(780px, calc(100% - 40px));
}

/* HERO */
.hero{
  position: relative;
  min-height: 86vh;
  padding: 110px 0 80px;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(18,34,55,0.08), rgba(18,34,55,0.18)),
    url("assets/bg-hero.jpg");
  background-size: cover;
  background-position: center;
}

.hero__nav{
  position: absolute;
  top: 0; left: 0; right: 0;
  z-index: 10;
  padding: 18px 0;
}

.nav{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand__img{
  width: 70px;
  height: 70px;
  object-fit: cover;
  border-radius: 14px;
  box-shadow: 0 6px 18px rgba(0,0,0,0.15);
}

.nav__cta{
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Buttons */
.btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 24px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 14px;
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn--primary{
  background: var(--brand);
  color: #fff;
  box-shadow: 0 10px 20px rgba(44,101,197,0.25);
}
.btn--primary:hover{ background: var(--brand-dark); }
.btn--secondary{
  background: rgba(255,255,255,0.18);
  color: #fff;
  border: 2px solid rgba(255,255,255,0.55);
  backdrop-filter: blur(6px);
}
.btn--secondary:hover{
  background: rgba(255,255,255,0.26);
  border-color: rgba(255,255,255,0.7);
}

/* Hero content */
.hero__content{
  position: relative;
  z-index: 2;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 22px;
}

.hero__logo{
  width: min(720px, 92vw);
  height: auto;
  filter: drop-shadow(0 16px 30px rgba(0,0,0,0.18));
  border-radius: 12px;
}

.hero__sponsors{
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  padding: 14px 18px;
  border-radius: 18px;
  background: rgba(255,255,255,0.72);
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.10);
}

.sponsor__logo{
  width: 160px;
  height: auto;
  border-radius: 10px;
}

.sponsor__copy{
  text-align: left;
  line-height: 1.2;
  color: var(--text);
  font-size: 14px;
}

.sponsor__title{
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
  font-weight: 600;
  color: rgba(37,49,58,0.9);
}

.sponsor__mark{
  width: 42px;
  height: 42px;
  border-radius: 10px;
}

/* Waves */
.wave{
  position: absolute;
  left: 0; right: 0;
  height: 120px;
  background-image: url("assets/wave-divider.jpg");
  background-repeat: repeat-x;
  background-size: auto 100%;
  opacity: 0.95;
}
.wave--bottom{ bottom: -2px; }
.wave--top{ top: -2px; transform: scaleY(-1); }

/* AGENDA */
.agenda{
  position: relative;
  padding: 70px 0 85px;
  background:
    radial-gradient(1200px 500px at 50% 20%, rgba(255,255,255,0.9), rgba(233,238,242,0.85));
}

.agenda__title{
  margin: 0;
  text-align: center;
  font-size: clamp(22px, 2.6vw, 34px);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #2f3f3a;
}

.agenda__date{
  margin: 10px 0 4px;
  text-align: center;
  font-weight: 800;
  font-size: 18px;
}

.agenda__location{
  margin: 0 0 28px;
  text-align: center;
  color: var(--muted);
}

.agenda__list{
  display: grid;
  gap: 12px;
  padding: 22px 18px;
  border-radius: var(--radius);
  background: rgba(255,255,255,0.7);
  box-shadow: 0 10px 26px rgba(0,0,0,0.08);
}

.agenda__item{
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 14px;
  align-items: start;
}

.agenda__time{
  font-weight: 800;
  color: #2f3f3a;
  white-space: nowrap;
}

.agenda__desc{
  color: rgba(37,49,58,0.92);
}

/* GALLERY */
.gallery{
  position: relative;
  padding: 74px 0 90px;
  overflow: hidden;
}

.gallery__bg{
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(20,30,40,0.05), rgba(20,30,40,0.25)),
    url("assets/bg-crowd.jpg");
  background-size: cover;
  background-position: center;
  transform: scale(1.02);
  z-index: 0;
}

.grid{
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 20px;
  align-items: start;
}

.card{
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px;
}

.collage__grid{
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 10px;
  align-items: stretch;
}

.collage__img{
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 14px;
}

.collage__img--tall{
  grid-row: 1 / span 2;
}

.sponsor__row{
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.sponsor__img{
  height: 60px;
  width: auto;
  border-radius: 14px;
}

.sponsor__img--wide{
  height: 60px;
}

.sponsor__footnote{
  margin: 14px 0 0;
  color: var(--muted);
  font-weight: 600;
}

/* Footer */
.footer{
  padding: 22px 0;
  background: #0f1c2e;
  color: rgba(255,255,255,0.85);
}
.footer a{
  color: rgba(255,255,255,0.9);
  text-decoration: none;
}
.footer__inner{
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

/* Responsive */
@media (max-width: 860px){
  .grid{ grid-template-columns: 1fr; }
}

@media (max-width: 640px){
  .nav__cta{ gap: 10px; }
  .btn{ padding: 12px 18px; font-size: 13px; }
  .brand__img{ width: 56px; height: 56px; }

  .agenda__item{ grid-template-columns: 1fr; gap: 6px; }
  .agenda__time{ opacity: 0.95; }

  .hero{ padding: 96px 0 78px; }
}