:root {
  --bg: #e8f5ff;
  --fg: #003c4d;
  --card-bg: rgba(255, 255, 255, 0.7);
  --text: #333;
  --link: #00796b;
  --button-bg: #00796b;
  --button-text: #fff;
  --shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}
[data-theme="dark"] {
  --bg: #121212;
  --fg: #eeeeee;
  --card-bg: rgba(25, 25, 25, 0.6);
  --text: #e0e0e0;
  --link: #26a69a;
  --button-bg: #26a69a;
  --button-text: #000;
  --shadow: 0 0 20px rgba(0, 255, 255, 0.1);
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

main.card {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 16px;
  padding: 40px 30px;
  box-shadow: var(--shadow);
  max-width: 480px;
  width: 90%;
  text-align: center;
  animation: fadeIn 0.6s ease;
}

.logo {
  width: 64px;
  height: 64px;
  margin-bottom: 20px;
}

h1 {
  font-size: 24px;
  font-weight: 700;
  color: var(--link);
  margin: 0 0 10px;
}

p {
  font-size: 15px;
  line-height: 1.6;
}

.button {
  display: inline-block;
  margin-top: 24px;
  padding: 12px 24px;
  background: var(--button-bg);
  color: var(--button-text);
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  transition: all 0.3s ease;
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0,0,0,0.2);
}

footer {
  margin-top: 20px;
  font-size: 13px;
  color: #888;
}

footer a {
  color: var(--link);
  text-decoration: none;
}

.toggle-wrapper {
  position: absolute;
  top: 20px;
  right: 20px;
}

#themeToggle {
  font-size: 20px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--link);
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}