:root {
  color-scheme: dark light;
  --bg: #f6f8fb;
  --bg-alt: #ffffff;
  --text: #14213d;
  --muted: #475569;
  --accent: #1a73e8;
  --accent-soft: #e8f0fe;
  --card: #ffffff;
  --border: #d8e0ea;
  --footer: #0f172a;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select,
textarea {
  font: inherit;
}

.container {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(14px);
}

.header-inner,
.footer-inner,
.hero-grid,
.deadlines-grid,
.faq-grid,
.contact-grid {
  display: grid;
  gap: 1.75rem;
}

.header-inner {
  grid-template-columns: 1fr auto;
  align-items: center;
  padding: 1rem 0;
}

.brand h1 {
  margin: 0.25rem 0 0;
  font-size: clamp(1.75rem, 2.2vw, 2.5rem);
}

.eyebrow {
  display: inline-block;
  margin-bottom: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.78rem;
  color: var(--accent);
}

.main-nav {
  position: relative;
}

.nav-toggle {
  display: none;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  padding: 0.75rem 1rem;
  border-radius: 999px;
  cursor: pointer;
}

.nav-list {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  color: var(--muted);
  font-size: 0.95rem;
}

.section {
  padding: 4rem 0;
}

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

.section-dark {
  background: #0f172a;
  color: #eef2ff;
}

.section-accent {
  background: var(--accent);
  color: white;
}

.section-header {
  max-width: 760px;
  margin-bottom: 2rem;
}

.section-header h3 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.8rem, 2.4vw, 2.3rem);
}

.section-header p {
  margin: 0;
  color: inherit;
  opacity: 0.9;
}

.hero {
  position: relative;
  overflow: hidden;
  padding-top: 3rem;
  padding-bottom: 3rem;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('../images/hero-bg.jpg') center/cover no-repeat;
  opacity: 0.22;
  transform: scale(1.05);
  filter: saturate(1.05);
  z-index: 0;
}

.hero-decor {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
}

.hero-motif {
  position: absolute;
  opacity: 0.96;
  max-width: 34%;
  filter: drop-shadow(0 18px 40px rgba(20, 33, 61, 0.16));
}

.hero-motif-1 {
  top: 5%;
  left: -4%;
  animation: float-slow 10s ease-in-out infinite alternate;
}

.hero-motif-2 {
  bottom: -4%;
  right: -6%;
  max-width: 45%;
  animation: float-slow 14s ease-in-out infinite alternate-reverse;
}

.hero-grid {
  position: relative;
  z-index: 2;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
}

.hero-copy h2 {
  margin: 0;
  font-size: clamp(2.5rem, 4vw, 3.6rem);
  line-height: 1.04;
}

.hero-copy p {
  margin: 1.5rem 0;
  max-width: 620px;
  color: var(--muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.hero-image {
  display: grid;
  place-items: center;
}

.hero-copy {
  animation: fade-in-up 0.9s ease-out both;
}

.hero-image img {
  animation: float-image 8s ease-in-out infinite alternate;
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.85s ease, transform 0.85s ease;
  will-change: opacity, transform;
}

.animate-on-scroll.reveal {
  opacity: 1;
  transform: translateY(0);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.95rem 1.8rem;
  border-radius: 999px;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 18px 32px rgba(26, 115, 232, 0.18);
}

.btn-secondary {
  background: var(--card);
  color: var(--text);
  border: 1px solid var(--border);
}

@keyframes fade-in-up {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float-image {
  from {
    transform: translateY(0) scale(1);
  }
  to {
    transform: translateY(-10px) scale(1.02);
  }
}

@keyframes float-slow {
  from {
    transform: translateY(0) translateX(0) rotate(0deg);
  }
  to {
    transform: translateY(-18px) translateX(10px) rotate(1deg);
  }
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.5rem;
}

.feature-card,
.deadline-card,
.faq-item,
.contact-card,
.sponsor-highlight {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 1.25rem;
  padding: 1.75rem;
  min-height: 190px;
}

.feature-card img {
  width: 72px;
  margin-bottom: 1rem;
}

.feature-card h4,
.deadline-card h4,
.faq-item h4,
.contact-card h4 {
  margin-top: 0;
}

.programme-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.programme-list li {
  padding: 1.25rem 1.5rem;
  background: var(--card);
  border-radius: 1rem;
  border: 1px solid var(--border);
}

.deadlines-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.deadline-card {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.18);
  color: white;
}

.deadline-card h4 {
  margin-bottom: 0.75rem;
}

.sponsor-highlight {
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.16);
}

.faq-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.faq-item {
  background: rgba(255,255,255,0.08);
  border-color: rgba(255,255,255,0.14);
}

.contact-grid {
  grid-template-columns: 1.4fr 0.8fr;
}

.contact-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.site-footer {
  background: var(--footer);
  color: #cbd5e1;
  padding: 2rem 0;
}

.footer-inner {
  grid-template-columns: 1fr;
  gap: 1rem;
}

.footer-inner p {
  margin: 0;
}

@media (max-width: 900px) {
  .header-inner,
  .hero-grid,
  .grid-3,
  .deadlines-grid,
  .faq-grid,
  .contact-grid {
    grid-template-columns: 1fr;
  }

  .hero-copy h2 {
    font-size: 2.4rem;
  }
}

@media (max-width: 720px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    width: 100%;
    margin-top: 1rem;
    gap: 0.75rem;
  }

  .nav-list.show {
    display: flex;
  }

  .nav-list a {
    padding: 0.75rem 0.9rem;
    border-radius: 999px;
    background: var(--bg-alt);
  }
}