:root {
    --primary-color: #0056b3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --card-bg: #ffffff;
    --border-radius: 8px;
    --spacing: 16px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    -webkit-tap-highlight-color: transparent;
}

#app {
    max-width: 600px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-size: 0.75rem;
}

.header-links {
    display: flex;
    gap: 12px;
}

.nav-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
}

.nav-link:hover {
    color: white;
    border-bottom-color: white;
}

.header-main {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-titles {
    width: 100%;
}

.title-row {
    display: flex;
    align-items: baseline;
    gap: 12px;
}

.repo-link {
    font-size: 0.75rem;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    border: 1px solid rgba(255,255,255,0.3);
    padding: 2px 6px;
    border-radius: 4px;
}

.repo-link:hover {
    color: white;
    border-color: white;
}

.subtitle {
    font-size: 1.1rem;
    font-weight: bold;
    margin-top: 2px;
    opacity: 0.95;
}

.subtitle-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 6px;
    flex-wrap: wrap;
}

.header-btn {
    background-color: rgba(255,255,255,0.25);
    color: white;
    padding: 4px 10px !important;
    font-size: 0.85rem !important;
    font-weight: bold;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 4px;
    white-space: nowrap;
}

.header-actions-right {
    margin-left: auto;
    display: flex;
    gap: 8px;
}

#stop-btn.header-btn {
    background-color: var(--danger-color);
    border-color: rgba(0,0,0,0.1);
}

.header-btn:hover {
    background-color: rgba(255,255,255,0.4);
}

.timer {
    font-family: monospace;
    font-size: 1.2rem;
    background: rgba(0,0,0,0.2);
    padding: 2px 8px;
    border-radius: 4px;
    color: #fff;
}

.timer.warning {
    color: #ff4d4d;
    background: rgba(255,255,255,0.9);
    animation: blink 1s infinite;
}

@keyframes blink {
    50% { opacity: 0.5; }
}

.time-up-msg {
    color: var(--danger-color);
    font-weight: bold;
    font-size: 1.5rem;
    margin-bottom: 16px;
    padding: 10px;
    border: 2px solid var(--danger-color);
    border-radius: var(--border-radius);
}

.time-taken {
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

h1 { font-size: 1.25rem; }
.author { font-size: 0.8rem; opacity: 0.9; }

h2 { font-size: 1.1rem; margin-bottom: var(--spacing); }
h3 { font-size: 1rem; margin-bottom: var(--spacing); }

.features {
    background: white;
    padding: var(--spacing);
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    font-size: 0.9rem;
    border: 1px solid #eee;
}

.features p { margin-bottom: 8px; }
.features p:last-child { margin-bottom: 0; }

.center-action {
    display: flex;
    justify-content: center;
    margin-bottom: 24px;
}

.download-link {
    font-size: 0.85rem;
    color: var(--primary-color);
    text-decoration: none;
    padding: 10px 20px;
    border: 1px solid var(--primary-color);
    border-radius: 4px;
    text-align: center;
}

.download-link.wide {
    width: 80%;
}

.special-modes {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 24px;
    width: 100%;
}

.special-modes button {
    width: 100%;
    padding: 16px 8px;
    font-weight: bold;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    line-height: 1.2;
}

.primary-action {
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
    border: 2px solid var(--primary-color);
}

.primary-action:hover {
    background-color: white;
    color: var(--primary-color);
}

.download-link:hover {
    background-color: var(--primary-color);
    color: white;
}

.home-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 40px;
    margin-bottom: var(--spacing);
    flex-wrap: wrap;
    gap: 10px;
}

#home-view .home-actions:first-of-type {
    margin-top: 0;
}

.home-actions h2 {
    margin-bottom: 0;
}

main {
    flex: 1;
    padding: var(--spacing);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: 12px;
}

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

button {
    font-size: 1rem;
    padding: 12px;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: opacity 0.2s, background-color 0.2s;
    user-select: none;
}

button:active {
    opacity: 0.7;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#exam-list {
    grid-template-columns: repeat(5, 1fr);
}

#exam-list button {
    background-color: white;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    font-weight: bold;
    font-size: 0.8rem;
    padding: 10px 2px;
    white-space: nowrap;
}

@media (max-width: 480px) {
    #exam-list {
        grid-template-columns: repeat(4, 1fr);
    }
}

.answer-option {
    display: flex;
    align-items: center;
    background: white;
    padding: 14px;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.95rem;
}

.answer-option.selected {
    border-color: var(--primary-color);
    background-color: #e7f1ff;
}

.answer-option input {
    margin-right: 12px;
    width: 20px;
    height: 20px;
}

.answer-option.correct {
    background-color: #d4edda;
    border-color: var(--success-color);
    color: #155724;
}

.answer-option.incorrect {
    background-color: #f8d7da;
    border-color: var(--danger-color);
    color: #721c24;
}

.controls {
    margin-top: 24px;
    display: flex;
    gap: 12px;
}

#check-btn, #next-btn, #restart-btn {
    flex: 1;
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
}

#next-btn {
    background-color: var(--success-color);
}

#result-home-btn {
    flex: 1;
    background-color: var(--secondary-color);
    color: white;
}

#feedback-container {
    margin-top: 20px;
    padding: 16px;
    border-radius: var(--border-radius);
    background-color: #fff;
    border: 1px solid #ddd;
}

#result-status {
    font-weight: bold;
    margin-bottom: 8px;
    font-size: 1.1rem;
}

#explanation-text {
    font-size: 0.9rem;
    color: #555;
}

/* Result Card Styles */
.result-card {
    background: white;
    padding: 24px;
    border-radius: var(--border-radius);
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

#score-container {
    margin: 24px 0;
}

#score-text {
    font-size: 1.2rem;
    font-weight: bold;
    display: block;
    margin-bottom: 8px;
}

#score-percentage {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
}

#wrong-answers-container {
    text-align: left;
    margin-top: 32px;
}

#wrong-answers-container h3 {
    border-bottom: 2px solid #eee;
    padding-bottom: 8px;
    margin-bottom: 16px;
}

.wrong-item {
    padding: 16px;
    border: 1px solid #eee;
    border-radius: var(--border-radius);
    background: #fffcfc;
}

.wrong-question {
    font-weight: bold;
    margin-bottom: 8px;
}

.correct-answer-was {
    font-size: 0.9rem;
    color: var(--success-color);
    margin-bottom: 8px;
}

.wrong-explanation {
    font-size: 0.85rem;
    color: #666;
    font-style: italic;
}

.hidden { display: none !important; }

footer {
    padding: var(--spacing);
    text-align: center;
    font-size: 0.8rem;
    color: var(--secondary-color);
    border-top: 1px solid #eee;
    margin-top: auto;
}

.update-info { 
    color: var(--secondary-color); 
    font-size: 0.75rem; 
    margin-top: 4px; 
}

@media (max-width: 480px) {
    header { padding: 12px; }
    main { padding: 12px; }
    .answer-option { padding: 12px; }
    #score-percentage { font-size: 2.5rem; }
    .special-modes {
        grid-template-columns: 1fr;
    }
}