:root {
  --bg: #f9f9f9;
  --card: #ffffff;
  --text: #1c1c1e;
  --accent: #007aff;
  --border: #e5e5ea;
  --radius: 16px;
  --shadow: 0 4px 12px rgba(0,0,0,0.06);
  --transition: 0.3s ease;
}

* {
  box-sizing: border-box;
  transition: all var(--transition);
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

header {
  background-color: var(--card);
  padding: 20px;
  text-align: center;
  font-size: 20px;
  font-weight: 600;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

#auth-nav {
  margin-top: 10px;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
}

#auth-nav button {
  padding: 8px 16px;
  font-size: 15px;
  background-color: var(--accent);
  color: #fff;
  border: none;
  border-radius: 12px;
  cursor: pointer;
}

main {
  max-width: 600px;
  margin: 32px auto;
  padding: 0 16px;
}

.card {
  background-color: var(--card);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.4s forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

input, button {
  width: 100%;
  padding: 12px;
  font-size: 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

button {
  background-color: var(--accent);
  color: white;
  cursor: pointer;
}

button:hover {
  background-color: #005fcc;
}

.concert img, .ticket img {
  width: 100%;
  border-radius: 12px;
  margin-bottom: 12px;
  border: 1px solid #dcdcdc;
}