/* ===== VARIABLES AND RESET ===== */
:root {
    --primary-color: #00d9ff;
    --primary-dark: #00a8cc;
    --secondary-color: #ff006e;
    --tertiary-color: #8338ec;
    --success-color: #3a86ff;
    --warning-color: #fb5607;
    --danger-color: #ff006e;

    --bg-dark: #0a0e27;
    --bg-darker: #05070f;
    --bg-card: #11152e;
    --bg-hover: #1a1f3a;

    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --text-tertiary: #707070;

    --border-color: #2a2f4a;
    --border-light: #3a3f5a;

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);

    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, var(--bg-darker) 0%, var(--bg-dark) 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* ===== NAVIGATION ===== */
.navbar {
    background: rgba(5, 7, 15, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding-bottom: 0.5rem;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), transparent);
}

/* ===== LAYOUT ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    min-height: calc(100vh - 70px);
}

.page {
    display: none;
    animation: fadeIn 0.4s ease;
}

.page.active {
    display: block;
}

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

.hidden {
    display: none !important;
}

/* ===== BUTTONS ===== */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--bg-dark);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 2px solid var(--border-light);
}

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

.btn-tertiary {
    background: var(--tertiary-color);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-tertiary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ===== HOME PAGE ===== */
.home-content {
    max-width: 1000px;
    margin: 0 auto;
}

.hero {
    text-align: center;
    margin-bottom: 3rem;
    animation: slideUp 0.6s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero .tagline {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.hero .description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

.home-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
}

.stat-card:hover {
    background: var(--bg-hover);
    border-color: var(--primary-color);
    transform: translateY(-4px);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1rem;
}

.stat-value {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

/* Brain Meter */
.brain-meter {
    height: 20px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    overflow: hidden;
    margin: 1rem 0;
}

.brain-meter-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--success-color), var(--warning-color), var(--danger-color));
    width: 0%;
    transition: width 0.6s ease;
}

.brain-status {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.home-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 3rem;
}

.home-buttons .btn {
    width: 100%;
}

/* Features */
.home-features {
    margin-top: 4rem;
}

.home-features h2 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
}

.feature:hover {
    background: var(--bg-hover);
    border-color: var(--primary-color);
    transform: translateY(-4px);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature h3 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ===== PAGE HEADER ===== */
.page-header {
    text-align: center;
    margin-bottom: 2rem;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ===== READING PAGE ===== */
.filter-group {
    display: inline-block;
    margin-right: 2rem;
    margin-bottom: 1rem;
}

.filter-group label {
    color: var(--text-secondary);
    margin-right: 0.5rem;
    font-weight: 600;
}

.filter-select {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.filter-select:hover,
.filter-select:focus {
    border-color: var(--primary-color);
    outline: none;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.article-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
}

.article-card:hover {
    background: var(--bg-hover);
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.article-topic {
    display: inline-block;
    background: rgba(0, 217, 255, 0.2);
    color: var(--primary-color);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.article-title {
    font-size: 1.3rem;
    margin: 0.5rem 0;
}

.article-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0.5rem 0;
}

.reading-header {
    margin-bottom: 2rem;
}

.reading-header h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.reading-meta {
    display: flex;
    gap: 2rem;
    color: var(--text-secondary);
}

.reading-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    max-height: 500px;
    overflow-y: auto;
}

.article-container p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-primary);
}

.reading-buttons,
.test-buttons,
.result-buttons,
.game-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.reading-buttons .btn,
.test-buttons .btn,
.result-buttons .btn,
.game-buttons .btn {
    flex: 1;
}

/* Comprehension Test */
.test-header {
    margin-bottom: 2rem;
}

.summary-textarea {
    width: 100%;
    height: 200px;
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    margin-bottom: 1rem;
}

.summary-textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 217, 255, 0.1);
}

.input-stats {
    display: flex;
    gap: 2rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Results */
.reading-results {
    max-width: 600px;
    margin: 0 auto;
}

.results-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
}

.results-card h2 {
    margin-bottom: 2rem;
    font-size: 2rem;
}

.result-item {
    margin-bottom: 2rem;
}

.result-item label {
    display: block;
    color: var(--text-secondary);
    font-weight: 600;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    font-size: 0.9rem;
}

.score-display {
    background: var(--bg-hover);
    border-radius: 8px;
    padding: 1rem;
}

.score-value {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.score-bar {
    background: rgba(255, 255, 255, 0.1);
    height: 8px;
    border-radius: 4px;
    margin-top: 0.5rem;
    overflow: hidden;
}

.score-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    width: 0%;
    transition: width 0.6s ease;
}

.points-earned {
    font-size: 2rem;
    font-weight: 700;
    color: var(--success-color);
}

/* ===== GAMES PAGE ===== */
.games-menu {
    padding: 2rem 0;
}

.games-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.game-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

.game-card:hover {
    background: var(--bg-hover);
    border-color: var(--primary-color);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.game-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.game-card h3 {
    margin-bottom: 0.5rem;
}

.game-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.game-header h2 {
    font-size: 2rem;
}

.game-info {
    display: flex;
    gap: 2rem;
    color: var(--text-secondary);
}

.game-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 3rem 2rem;
    margin-bottom: 2rem;
    min-height: 300px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.game-status {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

/* Grid Memory Game */
.grid-container {
    display: grid;
    grid-template-columns: repeat(3, 80px);
    gap: 10px;
    margin: 2rem 0;
}

.grid-cell {
    width: 80px;
    height: 80px;
    background: var(--bg-darker);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.grid-cell:hover {
    border-color: var(--primary-color);
}

.grid-cell.active {
    background: var(--primary-color);
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.5);
}

.grid-cell.user-active {
    background: var(--secondary-color);
    box-shadow: 0 0 20px rgba(255, 0, 110, 0.5);
}

/* Number Memory Game */
.number-display {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: 'Courier New', monospace;
}

.number-input {
    width: 100%;
    max-width: 400px;
}

.input-field {
    width: 100%;
    padding: 1rem;
    background: var(--bg-darker);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1.5rem;
    text-align: center;
    font-family: 'Courier New', monospace;
    margin-bottom: 1rem;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Sequence Memory Game */
.sequence-display {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
    margin: 2rem 0;
}

.color-box {
    width: 80px;
    height: 80px;
    border-radius: 8px;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
}

.color-buttons {
    display: grid;
    grid-template-columns: repeat(2, 100px);
    gap: 1rem;
    margin: 2rem 0;
}

.color-btn {
    width: 100px;
    height: 100px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    color: white;
}

.color-btn.red {
    background: #ff006e;
}

.color-btn.red:hover {
    background: #ff0080;
    transform: scale(1.05);
}

.color-btn.blue {
    background: #3a86ff;
}

.color-btn.blue:hover {
    background: #4a96ff;
    transform: scale(1.05);
}

.color-btn.green {
    background: #38a169;
}

.color-btn.green:hover {
    background: #48b179;
    transform: scale(1.05);
}

.color-btn.yellow {
    background: #fbbc04;
    color: #000;
}

.color-btn.yellow:hover {
    background: #fcc814;
    transform: scale(1.05);
}

.color-btn.active {
    box-shadow: 0 0 30px rgba(255, 255, 255, 0.5);
    transform: scale(1.1);
}

/* Attention Challenge */
.word-display {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.word-button {
    padding: 1rem;
    background: var(--bg-darker);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.word-button:hover {
    border-color: var(--primary-color);
}

.word-button.target {
    background: var(--success-color);
}

.target-word {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    text-transform: uppercase;
    margin-bottom: 1rem;
}

.attention-stats {
    display: flex;
    gap: 2rem;
    margin-top: 2rem;
    font-weight: 600;
}

/* Logic Puzzles */
.puzzle-content {
    width: 100%;
    max-width: 600px;
    text-align: center;
}

.puzzle-question {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.puzzle-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin: 2rem 0;
}

.puzzle-option {
    padding: 1rem;
    background: var(--bg-darker);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.puzzle-option:hover {
    border-color: var(--primary-color);
}

.puzzle-option.selected {
    background: var(--primary-color);
    color: var(--bg-dark);
    border-color: var(--primary-color);
}

.puzzle-option.correct {
    background: var(--success-color);
}

.puzzle-option.incorrect {
    background: var(--danger-color);
}

/* Game Results */
.game-results {
    max-width: 600px;
    margin: 0 auto;
}

.results-content {
    margin: 2rem 0;
}

.results-content .stat-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

/* ===== DASHBOARD ===== */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.dashboard-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    transition: var(--transition);
}

.dashboard-card:hover {
    background: var(--bg-hover);
    border-color: var(--primary-color);
}

.dashboard-card h2 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.focus-display {
    text-align: center;
    margin: 1rem 0;
}

.focus-level {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.focus-label {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.progress-bar {
    background: rgba(255, 255, 255, 0.1);
    height: 12px;
    border-radius: 6px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    width: 0%;
    transition: width 0.6s ease;
}

.stat-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
}

.stat-row span:first-child {
    color: var(--text-secondary);
}

.stat-value {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.streak-display {
    text-align: center;
    padding: 1rem 0;
}

.streak-number {
    font-size: 3rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.daily-activities {
    margin-top: 1rem;
}

.activity-item {
    padding: 0.75rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
}

/* Achievements */
.achievements-section {
    margin-top: 3rem;
}

.achievements-section h2 {
    margin-bottom: 2rem;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 1.5rem;
}

.achievement {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    transition: var(--transition);
}

.achievement:hover {
    border-color: var(--primary-color);
    transform: translateY(-4px);
}

.achievement.locked {
    opacity: 0.5;
}

.achievement-icon {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.achievement-name {
    font-weight: 600;
    margin-bottom: 0.25rem;
    font-size: 0.95rem;
}

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

.achievement.unlocked {
    background: var(--bg-hover);
    border-color: var(--success-color);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .nav-container {
        padding: 1rem;
    }

    .nav-menu {
        gap: 1rem;
    }

    .nav-link {
        font-size: 0.9rem;
    }

    .container {
        padding: 1rem;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .home-buttons {
        grid-template-columns: 1fr;
    }

    .reading-content {
        max-height: 400px;
    }

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

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

    .game-header {
        flex-direction: column;
        gap: 1rem;
    }

    .grid-container {
        grid-template-columns: repeat(3, 70px);
    }

    .grid-cell {
        width: 70px;
        height: 70px;
    }

    .color-buttons {
        grid-template-columns: repeat(2, 80px);
    }

    .color-btn {
        width: 80px;
        height: 80px;
    }

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

    .achievements-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .nav-menu {
        gap: 0.5rem;
    }

    .nav-link {
        font-size: 0.8rem;
    }

    .reading-meta {
        flex-direction: column;
        gap: 0.5rem;
    }

    .grid-container {
        grid-template-columns: repeat(3, 60px);
    }

    .grid-cell {
        width: 60px;
        height: 60px;
    }

    .color-buttons {
        grid-template-columns: repeat(2, 70px);
    }

    .color-btn {
        width: 70px;
        height: 70px;
        font-size: 0.9rem;
    }
}