* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;
}
html {
  scroll-behavior: smooth;
}
body {
  background-color: #ffffff;
  color: #333333;
  line-height: 1.6;
}
/* Navigační menu */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #ffffff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  z-index: 1000;
}
nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}
.logo-nav {
  font-size: 1.6rem;
  font-weight: 900;
  text-decoration: none;
  color: #000000;
  letter-spacing: -1px;
}
.logo-nav span {
  color: #222E80;
  text-transform: uppercase;
}
nav ul {
  display: flex;
  list-style: none;
  gap: 30px;
}
nav ul li a {
  text-decoration: none;
  color: #333333;
  font-weight: 600;
  transition: color 0.3s;
}
nav ul li a:hover {
  color: #295da3;
}
.hero-section {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 20px;
  background: #ffffff;
}
.main-title {
  font-size: 8rem;
  font-weight: 900;
  letter-spacing: -5px;
  color: #000000;
  line-height: 0.85;
}
.main-title span {
  color: #222E80;
  text-transform: uppercase;
  font-weight: 900;
}
.main-title .year {
  font-size: 4rem;
  color: #000000;
  font-weight: 900;
  letter-spacing: -2px;
  margin-left: 15px;
  display: inline-block;
  vertical-align: top;
  margin-top: 10px;
}
.hero-logo {
  max-width: 250px;
  height: auto;
  margin-top: 40px;
  opacity: 0.95;
}
.sub-title-katedra {
  font-size: 1.8rem;
  font-weight: 700;
  color: #295da3;
  margin-top: 25px;
  max-width: 900px;
  letter-spacing: -0.5px;
}
.content-section {
  padding: 100px 20px;
  max-width: 1200px;
  margin: 0 auto;
}
.content-section h2 {
  font-size: 2.5rem;
  font-weight: 800;
  color: #000000;
  margin-bottom: 40px;
  text-align: center;
  position: relative;
  letter-spacing: -1px;
}
.content-section h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background-color: #222E80;
  margin: 12px auto 0 auto;
  border-radius: 2px;
}
.sponsors-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  justify-items: center;
  align-items: center;
  margin-top: 50px;
}
.sponsor-box {
  background-color: #f8fafc;
  border: 2px dashed #cbd5e1;
  border-radius: 8px;
  width: 100%;
  height: 120px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  color: #222E80;
  font-size: 1.2rem;
  transition: all 0.3s ease;
}
/* Témata hackathonu */
.sponsor-box:hover {
  border-color: #295da3;
  color: #295da3;
  background-color: #f1f5f9;
}
.topics-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 40px;
}
.topic-card {
  background: #ffffff;
  padding: 30px;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
  border-top: 5px solid #222E80;
}
.topic-card h3 {
  margin-bottom: 15px;
  color: #222E80;
  font-weight: 700;
}
footer {
  background-color: #1e293b;
  color: #ffffff;
  text-align: center;
  padding: 30px;
  margin-top: 60px;
}
@media (max-width: 900px) {
  .main-title {
    font-size: 5rem;
    letter-spacing: -3px;
  }
  .main-title .year {
    font-size: 2.5rem;
    margin-left: 10px;
  }
  .hero-logo {
    max-width: 180px;
    margin-top: 30px;
  }
  .sub-title-katedra {
    font-size: 1.3rem;
  }
}
@media (max-width: 600px) {
  .main-title {
    font-size: 3.5rem;
    letter-spacing: -2px;
  }
  .main-title .year {
    font-size: 1.75rem;
    margin-left: 8px;
    margin-top: 5px;
  }
  .hero-logo {
    max-width: 140px;
    margin-top: 25px;
  }
  .sub-title-katedra {
    font-size: 1.1rem;
  }
  nav {
    flex-direction: column;
    gap: 15px;
  }
}