:root {
    /* Висококонтрастні кольори для дітей (WCAG AAA) */
    --color-primary: #004aad;
    /* Stronger Blue */
    --color-primary-light: #e0f2fe;
    --color-secondary: #d97706;
    /* High contrast Amber */
    --color-secondary-light: #fffbeb;
    --color-correct: #047857;
    /* High Contrast Emerald */
    --color-correct-light: #ecfdf5;
    --color-incorrect: #b91c1c;
    /* High Contrast Red */
    --color-incorrect-light: #fef2f2;

    --color-text-dark: #1f2937;
    /* Very Dark Gray */
    --color-background-light: #ffffff;

    --border-width: 4px;
    /* Chunky borders */
    --border-radius: 1.5rem;
    /* Large rounded corners */
}

body {
    font-family: 'Nunito', 'Inter', sans-serif;
    /* Friendly rounded font */
    background-color: #e6f7ff;
    /* Soft blue background */
    color: var(--color-text-dark);
    font-size: 18px;
    /* Base size increase */
}

.card {
    box-shadow: 0 10px 0px rgba(0, 0, 0, 0.1);
    /* Flat shadow for "sticker" look */
    border: var(--border-width) solid #e5e7eb;
    /* Default light border for cards */
    border-radius: var(--border-radius);
    background-color: var(--color-background-light);
}

.pulse-effect {
    animation: pulse-grow 2s infinite cubic-bezier(0.4, 0, 0.6, 1);
}

@keyframes pulse-grow {

    0%,
    100% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.8;
        transform: scale(1.02);
    }
}

.answer-option {
    transition: all 0.2s ease-in-out;
    cursor: pointer;
    border: var(--border-width) solid #d1d5db;
    background-color: #f9fafb;
    font-size: 1.35rem;
    /* Larger text */
    border-radius: 1rem;
    /* Slightly smaller than card */
    padding: 1rem 1.5rem;
    /* More padding */
    font-weight: 600;
}

.answer-option:hover {
    border-color: var(--color-primary);
    background-color: var(--color-primary-light);
    transform: translateY(-4px);
    /* Larger lift */
    box-shadow: 0 6px 0 var(--color-primary);
    /* 3D click effect hint */
}

/* Active/Active state adjustment to feel tactile */
.answer-option:active {
    transform: translateY(-1px);
    box-shadow: 0 2px 0 var(--color-primary);
}

.answer-option.selected {
    border-color: var(--color-primary);
    background-color: var(--color-primary-light);
    font-weight: 800;
    box-shadow: 0 0 0 2px var(--color-primary-light);
    /* Focus ring */
}

/* Custom styles for showing results */
.result-correct {
    border-color: var(--color-correct);
    background-color: var(--color-correct-light);
    color: var(--color-correct);
}

.result-incorrect {
    border-color: var(--color-incorrect);
    background-color: var(--color-incorrect-light);
    color: var(--color-incorrect);
}

#quiz-container {
    min-height: 600px;
    /* Fixed height to prevent jumping */
}

#quiz-container:not(.hidden) {
    display: flex;
    flex-direction: column;
}

#options-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    flex-grow: 1;
    /* Push buttons to bottom */
    justify-content: center;
    /* Center options vertically if few */
    margin-bottom: 2rem;
}

/* High contrast for main headings */
#question-text {
    font-size: 1.6rem;
    /* Restored size */
    line-height: 1.4;
    font-weight: 800;
    color: var(--color-text-dark);
    margin-bottom: 1.5rem;
    min-height: 4.5rem;
    /* Reserve space for ~3 lines */
    display: flex;
    align-items: center;
    /* Center text vertically in its reserved space */
}

/* Styling for the next/skip buttons for better contrast */
#next-button {
    background-color: var(--color-correct);
    border: var(--border-width) solid var(--color-correct);
    border-radius: 1rem;
    box-shadow: 0 6px 0 #065f46;
    /* Darker shade of green for shadow */
    transition: all 0.1s;
    margin-bottom: 6px;
    /* Space for shadow */
}

#next-button:hover:not(:disabled) {
    background-color: #059669;
    transform: translateY(2px);
    box-shadow: 0 4px 0 #065f46;
}

#next-button:active:not(:disabled) {
    transform: translateY(6px);
    box-shadow: none;
}

#skip-button {
    color: #92400e;
    /* Dark amber text */
    border: var(--border-width) solid var(--color-secondary);
    background-color: white;
    font-weight: 800;
    border-radius: 1rem;
    box-shadow: 0 6px 0 #b45309;
    /* Darker amber shadow */
    transition: all 0.1s;
    margin-bottom: 6px;
}

#skip-button:hover {
    background-color: var(--color-secondary-light);
    transform: translateY(2px);
    box-shadow: 0 4px 0 #b45309;
}

#skip-button:active {
    transform: translateY(6px);
    box-shadow: none;
}

#review-button {
    font-size: 1.2rem;
}

/* Ensure all text uses high contrast dark color */
.text-gray-800 {
    color: var(--color-text-dark);
}

/* --- Grade Button Styles (Extracted from JS) --- */
.grade-button {
    /* Base styles from JS: p-6 font-extrabold text-2xl rounded-2xl transition-all duration-100 border-4 focus:outline-none mb-4 */
    padding: 1.5rem;
    font-weight: 800;
    font-size: 1.5rem;
    line-height: 2rem;
    border-radius: 1rem;
    transition: all 0.1s;
    border-width: 4px;
    outline: 2px solid transparent;
    outline-offset: 2px;
    margin-bottom: 1rem;
    width: 100%;
    /* Ensure full width in grid if needed, or controlled by grid */
    text-align: center;
}

.btn-grade-2 {
    /* border-amber-500 text-amber-900 bg-amber-50 */
    border-color: #f59e0b;
    color: #78350f;
    background-color: #fffbeb;
    /* shadow-[0_6px_0_#d97706] */
    box-shadow: 0 6px 0 #d97706;
}

.btn-grade-2:hover {
    /* hover:bg-amber-100 hover:translate-y-[2px] hover:shadow-[0_4px_0_#d97706] */
    background-color: #fef3c7;
    transform: translateY(2px);
    box-shadow: 0 4px 0 #d97706;
}

.btn-grade-2:active {
    /* active:translate-y-[6px] active:shadow-none */
    transform: translateY(6px);
    box-shadow: none;
}

.btn-grade-3 {
    /* border-green-500 text-green-900 bg-green-50 */
    border-color: #22c55e;
    color: #14532d;
    background-color: #f0fdf4;
    /* shadow-[0_6px_0_#059669] */
    box-shadow: 0 6px 0 #059669;
}

.btn-grade-3:hover {
    /* hover:bg-green-100 hover:translate-y-[2px] hover:shadow-[0_4px_0_#059669] */
    background-color: #dcfce7;
    transform: translateY(2px);
    box-shadow: 0 4px 0 #059669;
}

.btn-grade-3:active {
    transform: translateY(6px);
    box-shadow: none;
}

.btn-grade-4 {
    /* border-blue-500 text-blue-900 bg-blue-50 */
    border-color: #3b82f6;
    color: #1e3a8a;
    background-color: #eff6ff;
    /* shadow-[0_6px_0_#004aad] */
    box-shadow: 0 6px 0 #004aad;
}

.btn-grade-4:hover {
    /* hover:bg-blue-100 hover:translate-y-[2px] hover:shadow-[0_4px_0_#004aad] */
    background-color: #dbeafe;
    transform: translateY(2px);
    box-shadow: 0 4px 0 #004aad;
}

.btn-grade-4:active {
    transform: translateY(6px);
    box-shadow: none;
}

/* --- Accessibility: Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .pulse-effect {
        animation: none;
    }

    .answer-option:hover,
    #next-button:hover,
    #skip-button:hover,
    .grade-button:hover {
        transform: none !important;
        /* Keep the shadow changes or remove them if distracting, keeping it simple for now */
    }

    .answer-option:active,
    #next-button:active,
    #skip-button:active,
    .grade-button:active {
        transform: none !important;
        box-shadow: inherit !important;
        /* Prevent the shadow disappearance "click" effect */
    }
}