:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #ec4899;
    --bg-gradient: radial-gradient(circle at top left, #1e1b4b, #0f172a);
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --correct: #10b981;
    --wrong: #ef4444;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, "apple-system", sans-serif;
}

body {
    min-height: 100vh;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--bg-gradient);
    color: var(--text-main);
    padding: 20px;
    overflow-y: auto;
}

body::before {
    content: '';
    position: fixed;
    width: 300px;
    height: 300px;
    background: var(--primary);
    filter: blur(120px);
    border-radius: 50%;
    top: 10%;
    left: 10%;
    opacity: 0.15;
    z-index: -1;
}

.startScreen,
.resultScreen,
.quiz-app-container {
    background: var(--card-bg);
    padding: 40px;
    border-radius: 24px;
    border: 1px solid var(--card-border);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    width: 100%;
    max-width: 550px;
    text-align: center;
    margin: 20px auto;
    animation: slideUp 0.5s;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

h1 {
    font-size: clamp(24px, 5vw, 32px);
    font-weight: 800;
    margin-bottom: 16px;
}

.subtitle {
    color: var(--text-muted);
    margin-bottom: 32px;
    font-size: 16px;
    line-height: 1.6;
}

.progress-container {
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    margin: 15px 0 25px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(to right, var(--primary), var(--secondary));
    width: 0%;
    transition: 0.4s ease;
}

h3 {
    color: var(--primary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 700;
}

#question {
    font-size: clamp(18px, 4vw, 22px);
    font-weight: 600;
    margin: 20px 0 25px;
    line-height: 1.5;
    color: #fff;
    text-align: left;
    background: none;
}

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

.btn {
    width: 100%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    padding: 16px 20px;
    border-radius: 16px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-main);
    cursor: pointer;
    transition: 0.2s;
    text-align: left;
    display: flex;
    align-items: center;
}

.btn::before {
    content: '';
    flex-shrink: 0;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--text-muted);
    margin-right: 15px;
    transition: 0.2s ease;
}

.btn:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateX(8px);
}

#btn-action {
    background: var(--primary);
    color: white;
    justify-content: center;
    font-weight: 700;
    margin-top: 24px;
    border: none;
    box-shadow: 0 10px 15px -3px rgba(99, 102, 241, 0.3);
}

#btn-action::before {
    display: none;
}

#btn-action:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.score {
    color: #fff;
    font-size: 20px;
    margin-bottom: 8px;
}

.score-circle {
    width: 100px;
    height: 100px;
    border: 4px solid var(--primary);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    background: rgba(99, 102, 241, 0.1);
}

.score-num {
    font-size: 32px;
    font-weight: 800;
    color: #fff;
}

.hidden {
    display: none !important;
}

.correct-ans {
    background: rgba(16, 185, 129, 0.2) !important;
    border-color: var(--correct) !important;
}

.correct-ans::before {
    background: var(--correct) !important;
    box-shadow: 0 0 8px var(--correct);
}

.wrong-ans {
    background: rgba(239, 68, 68, 0.2) !important;
    border-color: var(--wrong) !important;
}

.wrong-ans::before {
    background: var(--wrong) !important;
    box-shadow: 0 0 8px var(--wrong);
}

#point {
    font-size: 10px;
    color: var(--text-muted);
}

@media (max-width: 480px) {

    .startScreen,
    .resultScreen,
    .quiz-app-container {
        padding: 24px 20px;
        border-radius: 16px;
    }

    .btn {
        padding: 14px 16px;
        font-size: 15px;
    }
}