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

/* PROMĚNNÉ (moderní CSS) */
:root {
  --primary: #4f46e5;
  --secondary: #06b6d4;
  --bg: #0f172a;
  --card-bg: rgba(255, 255, 255, 0.05);
  --text: #e5e7eb;
  --radius: 12px;
}

/* BODY */
body {
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  color: var(--text);
  min-height: 100vh;
}

/* NAVBAR */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 5%;
  background: rgba(15, 23, 42, 0.7);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.navbar a {
  color: var(--text);
  text-decoration: none;
  margin-left: 20px;
  position: relative;
}

/* underline animace */
.navbar a::after {
  content: "";
  position: absolute;
  width: 0%;
  height: 2px;
  background: var(--secondary);
  bottom: -5px;
  left: 0;
  transition: 0.3s;
}

.navbar a:hover::after {
  width: 100%;
}

/* HERO */
.hero {
  height: 300px;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  background: radial-gradient(circle at top, #4f46e5, transparent);
}

.hero h1 {
  font-size: 2.5rem;
  animation: fadeIn 1s ease-in-out;
}

/* CONTAINER */
.container {
  width: 85%;
  margin: 40px auto;
}

/* CARD */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 25px;
  margin-bottom: 20px;
  border: 1px solid rgba(255,255,255,0.1);
  transition: 0.3s;
}

/* hover efekt */
.card:hover {
  transform: translateY(-5px) scale(1.01);
  box-shadow: 0 10px 25px rgba(0,0,0,0.3);
}

/* BUTTON */
.button {
  display: inline-block;
  padding: 10px 18px;
  border-radius: var(--radius);
  text-decoration: none;
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  transition: 0.3s;
  margin-top: 10px;
}

/* glow efekt */
.button:hover {
  transform: scale(1.05);
  box-shadow: 0 0 15px rgba(79,70,229,0.7);
}

/* FOOTER */
.footer {
  text-align: center;
  padding: 15px;
  margin-top: 40px;
  font-size: 0.9rem;
  opacity: 0.7;
}

/* ANIMACE */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* RESPONSIVE */
@media (max-width: 768px) {
  .container {
    width: 95%;
  }

  .hero h1 {
    font-size: 2rem;
  }
}