:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-dim: #94a3b8;
    --accent: #38bdf8;
    --error: #ef4444;
    --success: #22c55e;
}

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

.quiz-container {
    background: var(--card-bg);
    padding: 2.5rem 2rem;
    border-radius: 32px;
    width: 90%;
    max-width: 400px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    transition: height 0.1s ease;
}

.stats {
    font-size: 0.75rem;
    color: var(--text-dim);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-weight: 700;
}

.question-header {
    font-size: 1.6rem;
    font-weight: 800;
    margin-bottom: 2rem;
    line-height: 1.25;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

button {
    padding: 18px 22px;
    cursor: pointer;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.04);
    color: var(--text-main);
    font-size: 1rem;
    text-align: left;
    outline: none;
    font-weight: 500;
}

button:hover:not(.correct):not(.wrong):not(:disabled) {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--accent);
}

.correct {
    background: var(--success) !important;
    border-color: var(--success);
    color: white;
}

.wrong {
    background: rgba(239, 68, 68, 0.15) !important;
    border-color: var(--error);
    color: var(--error);
}

.action-area {
    display: none;
    margin-top: 2rem;
}

.action-area.show {
    display: block;
}

#feedback {
    font-size: 1rem;
    text-align: center;
    margin-bottom: 1rem;
    font-weight: 600;
}

#next-btn {
    background: var(--accent);
    color: #000;
    font-weight: 800;
    width: 100%;
    text-align: center;
    border: none;
    padding: 18px;
    font-size: 1.1rem;
}