/* ===== CSS Variables & Reset ===== */
:root {
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-card: #16213e;
    --bg-hover: #1e2d50;
    --text-primary: #e8e8f0;
    --text-secondary: #a0a0b8;
    --text-muted: #6c6c80;
    --accent: #7c3aed;
    --accent-light: #a78bfa;
    --accent-glow: rgba(124, 58, 237, 0.3);
    --correct: #10b981;
    --correct-bg: rgba(16, 185, 129, 0.15);
    --wrong: #ef4444;
    --wrong-bg: rgba(239, 68, 68, 0.15);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.15);
    --border: #2a2a40;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 2rem 1rem;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ===== App Container ===== */
.app-container {
    width: 100%;
    max-width: 640px;
    position: relative;
}

/* ===== Screens ===== */
.screen {
    display: none;
    animation: fadeSlideIn 0.4s ease-out;
}

.screen.active {
    display: block;
}

@keyframes fadeSlideIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeSlideOut {
    from {
        opacity: 1;
        transform: translateY(0);
    }
    to {
        opacity: 0;
        transform: translateY(-20px);
    }
}

.screen.exiting {
    animation: fadeSlideOut 0.3s ease-in forwards;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    outline: none;
}

.btn:focus-visible {
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.btn-primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 2px 12px var(--accent-glow);
}

.btn-primary:hover {
    background: #6d28d9;
    transform: translateY(-1px);
    box-shadow: 0 4px 20px var(--accent-glow);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    background: #4a4a60;
    color: #8a8a9a;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

.btn-ghost {
    background: transparent;
    color: var(--accent-light);
    padding: 0.5rem 1rem;
}

.btn-ghost:hover {
    background: rgba(124, 58, 237, 0.1);
}

.btn-danger {
    background: transparent;
    color: var(--wrong);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
    background: var(--wrong-bg);
}

/* ===== Setup Screen ===== */
.logo {
    text-align: center;
    margin-bottom: 2.5rem;
}

.logo-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 0.5rem;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -1px;
}

.accent {
    color: var(--accent-light);
}

.tagline {
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-size: 1.05rem;
}

.setup-form {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group select {
    appearance: none;
    background: var(--bg-card) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23a0a0b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E") no-repeat right 1rem center;
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    font-family: inherit;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.form-group select:hover {
    border-color: var(--accent);
}

.form-group select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.setup-form .btn-primary {
    margin-top: 0.5rem;
    padding: 1rem;
    font-size: 1.1rem;
}

.high-scores-link {
    text-align: center;
    margin-top: 1.5rem;
}

/* ===== Quiz Screen ===== */
.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.quiz-info {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.question-counter {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

.quiz-category {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Timer */
.timer-container {
    position: relative;
    width: 52px;
    height: 52px;
}

.timer-svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.timer-bg {
    fill: none;
    stroke: var(--border);
    stroke-width: 3;
}

.timer-fg {
    fill: none;
    stroke: var(--accent);
    stroke-width: 3;
    stroke-linecap: round;
    stroke-dasharray: 125.66;
    stroke-dashoffset: 0;
    transition: stroke-dashoffset 1s linear, stroke 0.3s;
}

.timer-fg.warning {
    stroke: var(--warning);
}

.timer-fg.danger {
    stroke: var(--wrong);
}

.timer-text {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    font-weight: 700;
}

.timer-text.warning {
    color: var(--warning);
}

.timer-text.danger {
    color: var(--wrong);
    animation: pulse 0.5s ease-in-out infinite alternate;
}

@keyframes pulse {
    from { transform: scale(1); }
    to { transform: scale(1.15); }
}

/* Progress Bar */
.progress-bar-container {
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--accent-light));
    border-radius: 2px;
    width: 0%;
    transition: width 0.5s ease;
}

/* Question */
.question-container {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    min-height: 320px;
    animation: questionIn 0.4s ease-out;
}

@keyframes questionIn {
    from {
        opacity: 0;
        transform: scale(0.96) translateY(10px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.question-text {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.answers-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.answer-btn {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    padding: 1rem 1.25rem;
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    text-align: left;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.answer-btn:hover:not(:disabled) {
    border-color: var(--accent);
    background: var(--bg-hover);
    transform: translateX(4px);
}

.answer-btn .answer-letter {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(124, 58, 237, 0.2);
    color: var(--accent-light);
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
    transition: var(--transition);
}

.answer-btn:hover:not(:disabled) .answer-letter {
    background: var(--accent);
    color: #fff;
}

.answer-btn .answer-text {
    flex: 1;
}

.answer-btn .answer-icon {
    font-size: 1.2rem;
    opacity: 0;
    transition: var(--transition);
}

/* Answer states */
.answer-btn.correct {
    border-color: var(--correct);
    background: var(--correct-bg);
}

.answer-btn.correct .answer-letter {
    background: var(--correct);
    color: #fff;
}

.answer-btn.correct .answer-icon {
    opacity: 1;
}

.answer-btn.wrong {
    border-color: var(--wrong);
    background: var(--wrong-bg);
}

.answer-btn.wrong .answer-letter {
    background: var(--wrong);
    color: #fff;
}

.answer-btn.wrong .answer-icon {
    opacity: 1;
}

.answer-btn.dimmed {
    opacity: 0.45;
}

.answer-btn:disabled {
    cursor: default;
}

/* Quiz Footer */
.quiz-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 1.25rem;
}

.score-display {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.btn-next {
    min-width: 120px;
}

/* ===== Results Screen ===== */
.results-header {
    text-align: center;
    margin-bottom: 2rem;
}

.results-emoji {
    font-size: 3.5rem;
    display: block;
    margin-bottom: 0.5rem;
}

.results-header h2 {
    font-size: 2rem;
    font-weight: 800;
}

.results-subtitle {
    color: var(--text-secondary);
    margin-top: 0.5rem;
    font-size: 1.1rem;
}

.results-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.stat-card.correct {
    border-color: rgba(16, 185, 129, 0.3);
}

.stat-card.wrong {
    border-color: rgba(239, 68, 68, 0.3);
}

.stat-card.score {
    border-color: rgba(124, 58, 237, 0.3);
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
}

.stat-card.correct .stat-number { color: var(--correct); }
.stat-card.wrong .stat-number { color: var(--wrong); }
.stat-card.score .stat-number { color: var(--accent-light); }

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.5px;
}

/* Results Breakdown */
.results-breakdown {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    margin-bottom: 2rem;
    max-height: 400px;
    overflow-y: auto;
}

.results-breakdown::-webkit-scrollbar {
    width: 6px;
}

.results-breakdown::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.results-breakdown::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.breakdown-item {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.breakdown-item:last-child {
    border-bottom: none;
}

.breakdown-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
    margin-top: 0.1rem;
}

.breakdown-content {
    flex: 1;
    min-width: 0;
}

.breakdown-question {
    font-size: 0.95rem;
    font-weight: 500;
    margin-bottom: 0.35rem;
    color: var(--text-primary);
}

.breakdown-answer {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.breakdown-answer .correct-answer {
    color: var(--correct);
    font-weight: 600;
}

.breakdown-answer .your-answer {
    color: var(--wrong);
    font-weight: 600;
}

/* Results Actions */
.results-actions {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.results-actions .btn {
    width: 100%;
}

/* ===== Scores Screen ===== */
.scores-title {
    text-align: center;
    font-size: 1.75rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
}

.scores-list {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    margin-bottom: 1.5rem;
    max-height: 450px;
    overflow-y: auto;
}

.scores-list::-webkit-scrollbar {
    width: 6px;
}

.scores-list::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.scores-list::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.no-scores {
    padding: 2rem;
    text-align: center;
    color: var(--text-muted);
}

.score-entry {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
}

.score-entry:last-child {
    border-bottom: none;
}

.score-rank {
    font-size: 1.1rem;
    font-weight: 800;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--bg-card);
    flex-shrink: 0;
}

.score-rank.gold { background: rgba(245, 158, 11, 0.2); color: #f59e0b; }
.score-rank.silver { background: rgba(156, 163, 175, 0.2); color: #9ca3af; }
.score-rank.bronze { background: rgba(180, 83, 9, 0.2); color: #d97706; }

.score-details {
    flex: 1;
    min-width: 0;
}

.score-meta {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

.score-info {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.score-pct {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--accent-light);
}

.scores-actions {
    display: flex;
    gap: 0.75rem;
}

.scores-actions .btn {
    flex: 1;
}

/* ===== Loading Spinner ===== */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding: 3rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-text {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ===== Error State ===== */
.error-container {
    text-align: center;
    padding: 2rem;
}

.error-container p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* ===== Responsive ===== */
@media (max-width: 480px) {
    body {
        padding: 1rem 0.75rem;
    }

    .logo h1 {
        font-size: 2rem;
    }

    .setup-form {
        padding: 1.5rem;
    }

    .question-container {
        padding: 1.5rem;
        min-height: 280px;
    }

    .question-text {
        font-size: 1.05rem;
    }

    .results-stats {
        gap: 0.5rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .scores-actions {
        flex-direction: column;
    }
}