/* ===== CSS Variables for Theming ===== */
:root {
    --accent-color: #FF9900;
    --secondary-color: #232F3E;
    --background: #FFFFFF;
    --text-color: #232F3E;
    --card-bg: #FFFFFF;
    --success-color: #4CAF50;
    --error-color: #F44336;
    --border-color: #E0E0E0;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --hover-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] {
    --accent-color: #FF9900;
    --secondary-color: #FFFFFF;
    --background: #1A1A1A;
    --text-color: #FFFFFF;
    --card-bg: #2A2A2A;
    --success-color: #66BB6A;
    --error-color: #EF5350;
    --border-color: #404040;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --hover-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

/* ===== Reset and Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background: var(--background);
    color: var(--text-color);
    transition: background 0.3s ease, color 0.3s ease;
    line-height: 1.6;
}

/* ===== Container ===== */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
}

/* ===== Header ===== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
    margin-bottom: 30px;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 15px;
}

.aws-logo {
    width: 50px;
    height: 50px;
    background: var(--accent-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
    font-size: 20px;
}

.app-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
}

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

.settings-btn,
.analytics-btn,
.external-quiz-btn {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 8px 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    color: var(--text-color);
}

.settings-btn:hover,
.analytics-btn:hover,
.external-quiz-btn:hover {
    transform: scale(1.05);
    border-color: var(--accent-color);
}

.theme-toggle {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 25px;
    padding: 8px 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
    font-size: 1.2rem;
}

.theme-toggle:hover {
    transform: scale(1.05);
    border-color: var(--accent-color);
}

/* ===== Modal Styles ===== */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.show {
    display: flex;
}

.modal {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 30px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

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

.modal-header {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--text-color);
}

.modal-body {
    margin-bottom: 25px;
    color: var(--text-color);
    opacity: 0.9;
}

.modal-body h3 {
    margin: 20px 0 10px 0;
    font-size: 1.1rem;
}

.modal-body section:first-child h3 {
    margin-top: 0;
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.modal-btn {
    padding: 10px 20px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.modal-btn-primary {
    background: var(--accent-color);
    color: white;
}

.modal-btn-primary:hover {
    filter: brightness(0.9);
}

.modal-btn-secondary {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-color);
}

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

.full-width {
    width: 100%;
    margin-bottom: 10px;
}

/* ===== Color Picker ===== */
.color-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: 10px;
    margin: 15px 0;
}

.color-option {
    width: 100%;
    height: 50px;
    border-radius: 8px;
    border: 3px solid transparent;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.color-option:hover {
    transform: scale(1.05);
}

.color-option.selected {
    border-color: var(--text-color);
}

.color-option.selected::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
    text-shadow: 0 0 3px rgba(0, 0, 0, 0.5);
}

/* ===== Filter Options ===== */
.filter-option {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    margin: 8px 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-option:hover {
    border-color: var(--accent-color);
}

.filter-option input[type="checkbox"],
.filter-option input[type="radio"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

.mode-description {
    font-size: 0.85rem;
    opacity: 0.8;
    margin-top: 4px;
}

.offline-status {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 10px;
}

/* ===== Badges ===== */
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-left: 10px;
}

.badge-review {
    background: #8B5CF6;
    color: white;
}

.badge-spaced {
    background: #F59E0B;
    color: white;
}

.badge-offline {
    background: #10B981;
    color: white;
}

/* ===== Certification Selector ===== */
.cert-selector {
    display: block;
}

.cert-selector h2 {
    margin-bottom: 10px;
    font-size: 1.8rem;
}

.subtitle {
    opacity: 0.8;
    margin-bottom: 20px;
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.cert-card {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.cert-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
    border-color: var(--accent-color);
}

.cert-badge {
    width: 60px;
    height: 60px;
    background: var(--accent-color);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: white;
    font-size: 18px;
    margin-bottom: 15px;
}

.cert-name {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text-color);
}

.cert-description {
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
    margin-bottom: 15px;
}

.start-btn {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s ease;
}

.start-btn:hover {
    filter: brightness(0.9);
    transform: scale(1.02);
}

/* ===== Quiz Interface ===== */
.quiz-interface {
    display: block;
}

.quiz-header {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 25px;
    box-shadow: var(--shadow);
}

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

.exit-btn {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.exit-btn:hover {
    border-color: var(--error-color);
    color: var(--error-color);
}

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

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent-color);
    transition: width 0.3s ease;
    width: 0%;
}

.question-card {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
    margin-bottom: 25px;
    box-shadow: var(--shadow);
}

.category-badge {
    display: inline-block;
    background: var(--accent-color);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.question-text {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 25px;
    line-height: 1.6;
}

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

.answer-option {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 15px 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 12px;
}

.answer-option:hover {
    border-color: var(--accent-color);
    background: var(--accent-color);
    color: white;
    transform: translateX(5px);
}

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

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

.answer-option.incorrect {
    border-color: var(--error-color);
    background: var(--error-color);
    color: white;
}

.answer-option.disabled {
    cursor: not-allowed;
    opacity: 0.6;
}

.answer-letter {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.answer-option:hover .answer-letter,
.answer-option.selected .answer-letter,
.answer-option.correct .answer-letter,
.answer-option.incorrect .answer-letter {
    background: rgba(255, 255, 255, 0.3);
    color: white;
}

/* ===== Feedback Section ===== */
.feedback-section {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    display: none;
    box-shadow: var(--shadow);
}

.feedback-section.show {
    display: block;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feedback-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    font-size: 1.1rem;
    font-weight: 600;
}

.feedback-header.correct {
    color: var(--success-color);
}

.feedback-header.incorrect {
    color: var(--error-color);
}

.feedback-icon {
    font-size: 1.5rem;
}

.explanation {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-color);
    opacity: 0.9;
}

/* ===== Buttons ===== */
.submit-btn,
.next-btn {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.submit-btn:hover,
.next-btn:hover {
    filter: brightness(0.9);
    transform: scale(1.02);
}

.submit-btn:disabled {
    background: var(--border-color);
    cursor: not-allowed;
    transform: none;
}

/* ===== Analytics Dashboard ===== */
.analytics-page {
    display: block;
}

.analytics-page h2 {
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.analytics-page h3 {
    margin: 30px 0 15px 0;
    font-size: 1.2rem;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin: 20px 0;
}

.stat-card {
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
    margin: 10px 0;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
}

.back-btn {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-color);
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
    margin-bottom: 20px;
}

.back-btn:hover {
    border-color: var(--accent-color);
    color: var(--accent-color);
}

/* ===== Utility Classes ===== */
.hidden {
    display: none !important;
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    .header {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .cert-grid {
        grid-template-columns: 1fr;
    }

    .app-title {
        font-size: 1.2rem;
    }

    .question-text {
        font-size: 1.1rem;
    }

    .quiz-controls {
        flex-direction: column;
        gap: 10px;
        align-items: stretch;
    }

    .modal {
        max-width: 95%;
        padding: 20px;
    }
}