/* CSS Animations and Transitions */

/* Loading Animations */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.loading-overlay.active {
    opacity: 1;
    visibility: visible;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--bg-tertiary);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Card Hover Effects */
.topic-card {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.topic-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 10px 10px -5px rgb(0 0 0 / 0.04);
}

/* Button Hover Effects */
.btn {
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

/* Progress Bar Animation */
.progress-fill {
    transition: width 0.3s ease;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
}

/* Question Transition */
.question-card {
    animation: slideInFromRight 0.4s ease-out;
}

@keyframes slideInFromRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* Option Selection Animation */
.option-item {
    transition: all 0.2s ease;
}

.option-item:hover {
    transform: translateX(4px);
}

.option-item.selected {
    animation: pulse 0.3s ease;
}

/* Score Animation */
.score-circle {
    position: relative;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: conic-gradient(var(--success-color) 0deg, var(--bg-tertiary) 0deg);
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fillCircle 1s ease-out forwards;
}

@keyframes fillCircle {
    to {
        background: conic-gradient(var(--success-color) var(--score-angle), var(--bg-tertiary) var(--score-angle));
    }
}

/* Fade In Up Animation */
.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Stagger Animation */
.stagger-item {
    opacity: 0;
    transform: translateY(20px);
    animation: staggerIn 0.5s ease-out forwards;
}

.stagger-item:nth-child(1) { animation-delay: 0.1s; }
.stagger-item:nth-child(2) { animation-delay: 0.2s; }
.stagger-item:nth-child(3) { animation-delay: 0.3s; }
.stagger-item:nth-child(4) { animation-delay: 0.4s; }
.stagger-item:nth-child(5) { animation-delay: 0.5s; }
.stagger-item:nth-child(6) { animation-delay: 0.6s; }

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

/* Ripple Effect */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.6);
    transform: scale(0);
    animation: ripple-animation 0.6s linear;
    pointer-events: none;
}

@keyframes ripple-animation {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

/* Bounce Animation */
.bounce {
    animation: bounce 0.5s ease-in-out;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

/* Shake Animation */
.shake {
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}