:root {
  --primary: #0066cc;
  --secondary: #00d4ff;
  --bg: #0a0a1a;
  --card-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --text: #ffffff;
  --text-muted: #a0a0b0;
  --correct: #00ff88;
  --wrong: #ff4d4d;
  --font-main: 'Outfit', sans-serif;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg);
  color: var(--text);
  overflow-x: hidden;
  min-height: 100vh;
}

.glass-container {
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 30px;
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

h1, h2, h3 {
  font-weight: 700;
  letter-spacing: -0.5px;
}

input, button {
  font-family: inherit;
  border-radius: 12px;
  border: none;
  padding: 12px 20px;
  font-size: 1rem;
}

input {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  width: 100%;
  margin-bottom: 20px;
  outline: none;
  transition: all 0.3s ease;
}

input:focus {
  background: rgba(255, 255, 255, 0.15);
  box-shadow: 0 0 0 2px var(--primary);
}

button {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

button:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}

button:active {
  transform: translateY(0);
}

/* Specific page layouts */
.centered-page {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}

.card-form {
  max-width: 400px;
  width: 100%;
}

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

.animate-fade {
  animation: fadeIn 0.5s ease forwards;
}

/* Quiz Options */
.option-btn {
  width: 100%;
  text-align: left;
  margin-bottom: 15px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 15px;
}

.option-btn .letter {
  background: var(--primary);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  flex-shrink: 0;
}

.option-btn.selected {
  border-color: var(--secondary);
  background: rgba(0, 212, 255, 0.1);
}

.option-btn.correct {
  border-color: var(--correct);
  background: rgba(0, 255, 136, 0.1);
}

.option-btn.wrong {
  border-color: var(--wrong);
  background: rgba(255, 77, 77, 0.1);
}