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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --bg-color: #f5f7fa;
    --text-color: #333;
    --border-color: #e0e0e0;
    --card-bg: white;
}

body.dark-mode {
    --bg-color: #1a1a2e;
    --text-color: #e0e0e0;
    --border-color: #404040;
    --card-bg: #2d2d44;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    min-height: 100vh;
}

/* Header */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 15px 0;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.2);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8em;
    color: white;
    margin: 0;
}

.header-controls {
    display: flex;
    gap: 10px;
}

.btn-icon {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 1.5em;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding: 30px 20px;
}


.screen {
    display: none;
    animation: fadeIn 0.5s ease-in;
}

.screen.active {
    display: block;
}

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

/* Başlangıç Sayfası */
#startScreen {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 60px 40px;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.welcome-content h1 {
    font-size: 3em;
    background: linear-gradient(135deg, #667eea, #764ba2);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.welcome-header {
    margin-bottom: 40px;
}

.features {
    display: flex;
    justify-content: space-around;
    margin-top: 30px;
    padding: 25px 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.feature-item {
    text-align: center;
}

.feature-number {
    display: block;
    font-size: 2.2em;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.feature-text {
    display: block;
    font-size: 0.9em;
    color: var(--text-color);
    opacity: 0.7;
}

.subtitle {
    font-size: 1.3em;
    color: var(--text-color);
    opacity: 0.7;
    margin-bottom: 30px;
    font-weight: 500;
}

.description {
    text-align: left;
    margin: 30px 0 40px;
    background: var(--bg-color);
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid var(--primary-color);
}

.description p {
    color: var(--text-color);
    margin-bottom: 15px;
    font-size: 1em;
    opacity: 0.9;
}

.description ul {
    list-style: none;
    color: var(--primary-color);
    font-weight: 600;
}

.description li {
    margin: 10px 0;
}

/* Test Sayfası */
#testScreen {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.test-header {
    margin-bottom: 40px;
}

.header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.progress-info {
    font-size: 0.9em;
    color: var(--primary-color);
    font-weight: 600;
}

.timer {
    font-size: 1.3em;
    font-weight: bold;
    color: var(--primary-color);
    font-variant-numeric: tabular-nums;
}

.timer.warning {
    color: #ff9800;
}

.timer.danger {
    color: #f44336;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    width: 0%;
    transition: width 0.3s ease;
}

.question-text {
    font-size: 1.4em;
    color: var(--text-color);
    margin-bottom: 30px;
    font-weight: 600;
    line-height: 1.6;
}

.options-container {
    display: grid;
    gap: 15px;
    margin-bottom: 30px;
}

.option {
    padding: 15px 20px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1em;
    text-align: left;
    background: var(--card-bg);
    color: var(--text-color);
}

.option:hover {
    border-color: var(--primary-color);
    background: var(--bg-color);
    transform: translateX(5px);
}

.option.selected {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.option.correct {
    background: #4caf50;
    color: white;
    border-color: #4caf50;
}

.option.incorrect {
    background: #f44336;
    color: white;
    border-color: #f44336;
}



.test-footer {
    display: flex;
    justify-content: space-between;
    gap: 20px;
}

/* Buttons */
.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    flex: 1;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: var(--border-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-2px);
    opacity: 0.8;
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-size: 0.95em;
    text-decoration: underline;
    padding: 5px;
    font-weight: 600;
}

.btn-link:hover {
    opacity: 0.7;
}

/* Sonuç Sayfası */
#resultScreen {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 60px 40px;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.result-content h1 {
    font-size: 2.5em;
    background: linear-gradient(135deg, #667eea, #764ba2);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 40px;
}

.score-circle {
    width: 200px;
    height: 200px;
    margin: 0 auto 40px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    box-shadow: 0 10px 40px rgba(102, 126, 234, 0.3);
}

.score-number {
    font-size: 3.5em;
    font-weight: bold;
}

.score-label {
    font-size: 1em;
    opacity: 0.9;
    margin-top: 10px;
}

.score-interpretation {
    font-size: 1.2em;
    color: var(--text-color);
    margin: 30px 0;
    padding: 20px;
    background: var(--bg-color);
    border-radius: 10px;
    min-height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-left: 4px solid var(--primary-color);
}

.detailed-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin: 40px 0;
    padding: 30px;
    background: var(--bg-color);
    border-radius: 10px;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.stat-label {
    font-size: 0.9em;
    color: var(--text-color);
    opacity: 0.6;
    font-weight: 500;
}

.stat-value {
    font-size: 1.8em;
    color: var(--primary-color);
    font-weight: bold;
}

.result-footer {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 30px;
    flex-wrap: wrap;
}

/* Stats Screen */
#statsScreen {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.stats-content h1 {
    font-size: 2.2em;
    background: linear-gradient(135deg, #667eea, #764ba2);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 30px;
    text-align: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.stat-card {
    background: var(--bg-color);
    padding: 20px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 15px;
    border: 2px solid var(--border-color);
}

.stat-icon {
    font-size: 1.5em;
    color: var(--primary-color);
    font-weight: bold;
}

.stat-info {
    flex: 1;
}

.stat-card .stat-label {
    font-size: 0.85em;
    opacity: 0.7;
    margin-bottom: 5px;
}

.stat-card .stat-value {
    font-size: 2em;
    color: var(--primary-color);
    font-weight: bold;
}

.performance-chart {
    background: var(--bg-color);
    padding: 20px;
    border-radius: 10px;
    margin: 30px 0;
    min-height: 200px;
}

/* Responsive */
@media (max-width: 600px) {
    #startScreen {
        padding: 40px 20px;
    }

    .welcome-content h1 {
        font-size: 2em;
    }

    #testScreen {
        padding: 20px;
    }

    .question-text {
        font-size: 1.2em;
    }

    .test-footer {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .detailed-stats {
        grid-template-columns: 1fr;
    }

    .score-circle {
        width: 150px;
        height: 150px;
    }

    .score-number {
        font-size: 2.5em;
    }
}

/* Reklam Alanları */
.ad-space {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    margin: 15px auto;
    max-width: 800px;
    padding: 0;
    min-height: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ad-top {
    margin-top: 20px;
    margin-bottom: 20px;
}

.ad-bottom {
    margin-top: 30px;
    margin-bottom: 20px;
}