:root {
    --primary: #FF006E;
    --secondary: #FB5607;
    --accent: #FFBE0B;
    --purple: #8338EC;
    --blue: #3A86FF;
    --dark: #1a1a1a;
    --darker: #0d0d0d;
    --light: #f5f5f5;
    --white: #ffffff;
    --gray: #666;
    --success: #28a745;
    --danger: #dc3545;
    --warning: #ffc107;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--dark) 0%, var(--darker) 100%);
    color: var(--light);
    min-height: 100vh;
    overflow-x: hidden;
    padding-bottom: 80px;
}

/* Header */
.header {
    background: rgba(255, 0, 110, 0.1);
    border-bottom: 2px solid var(--primary);
    padding: 1rem;
    text-align: center;
    box-shadow: 0 4px 20px rgba(255, 0, 110, 0.3);
    backdrop-filter: blur(10px);
}

.header h1 {
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
    text-shadow: 0 0 20px var(--primary);
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from { text-shadow: 0 0 20px var(--primary); }
    to { text-shadow: 0 0 30px var(--primary), 0 0 40px var(--primary); }
}

.game-info {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-top: 1rem;
}

.timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    color: var(--accent);
}

.grid-size-selector select {
    background: var(--dark);
    border: 2px solid var(--purple);
    color: var(--light);
    padding: 0.5rem;
    border-radius: 8px;
    font-size: 1rem;
    box-shadow: 0 0 10px rgba(131, 56, 236, 0.5);
}

/* Main Content */
.main-content {
    padding: 2rem 1rem;
    max-width: 800px;
    margin: 0 auto;
}

.section {
    display: none;
}

.section.active {
    display: block;
}

/* Game Section */
.game-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.game-board {
    position: relative;
    display: inline-block;
}

.grid {
    display: grid;
    gap: 2px;
    background: var(--dark);
    border: 3px solid var(--primary);
    border-radius: 12px;
    padding: 10px;
    box-shadow: 0 0 30px rgba(255, 0, 110, 0.5);
}

.grid-6 { grid-template-columns: repeat(6, 1fr); }
.grid-8 { grid-template-columns: repeat(8, 1fr); }
.grid-10 { grid-template-columns: repeat(10, 1fr); }
.grid-12 { grid-template-columns: repeat(12, 1fr); }

.cell {
    width: 40px;
    height: 40px;
    background: var(--darker);
    border: 2px solid var(--gray);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    user-select: none;
}

.cell:hover {
    border-color: var(--blue);
    box-shadow: 0 0 15px rgba(58, 134, 255, 0.5);
    transform: scale(1.05);
}

.cell.zero {
    background: var(--purple);
    color: var(--white);
    border-color: var(--purple);
    box-shadow: 0 0 15px rgba(131, 56, 236, 0.5);
}

.cell.one {
    background: var(--secondary);
    color: var(--white);
    border-color: var(--secondary);
    box-shadow: 0 0 15px rgba(251, 86, 7, 0.5);
}

.cell.error {
    background: var(--danger) !important;
    animation: shake 0.5s ease-in-out;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

.cell.hint {
    animation: pulse 1s ease-in-out 3;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* Counters */
.row-counters, .column-counters {
    position: absolute;
    display: flex;
    gap: 2px;
}

.row-counters {
    right: -60px;
    top: 10px;
    flex-direction: column;
}

.column-counters {
    bottom: -50px;
    left: 10px;
    flex-direction: row;
}

.counter {
    width: 40px;
    height: 40px;
    background: var(--dark);
    border: 2px solid var(--gray);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: bold;
}

.counter.correct {
    border-color: var(--success);
    color: var(--success);
    box-shadow: 0 0 10px rgba(40, 167, 69, 0.5);
}

.counter.error {
    border-color: var(--danger);
    color: var(--danger);
    box-shadow: 0 0 10px rgba(220, 53, 69, 0.5);
}

/* Game Controls */
.game-controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--white);
}

.btn-primary {
    background: var(--primary);
    box-shadow: 0 4px 15px rgba(255, 0, 110, 0.3);
}

.btn-primary:hover {
    background: #e6005f;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 0, 110, 0.5);
}

.btn-secondary {
    background: var(--blue);
    box-shadow: 0 4px 15px rgba(58, 134, 255, 0.3);
}

.btn-secondary:hover {
    background: #2c6ff0;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(58, 134, 255, 0.5);
}

.btn-accent {
    background: var(--accent);
    color: var(--dark);
    box-shadow: 0 4px 15px rgba(255, 190, 11, 0.3);
}

.btn-accent:hover {
    background: #e6a800;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 190, 11, 0.5);
}

.btn-danger {
    background: var(--danger);
    box-shadow: 0 4px 15px rgba(220, 53, 69, 0.3);
}

.btn-danger:hover {
    background: #c82333;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(220, 53, 69, 0.5);
}

/* Game Message */
.game-message {
    text-align: center;
    padding: 1rem;
    border-radius: 8px;
    font-weight: bold;
    margin-top: 1rem;
    animation: fadeIn 0.5s ease-in-out;
}

.game-message.success {
    background: rgba(40, 167, 69, 0.2);
    border: 2px solid var(--success);
    color: var(--success);
    box-shadow: 0 0 20px rgba(40, 167, 69, 0.3);
}

.game-message.error {
    background: rgba(220, 53, 69, 0.2);
    border: 2px solid var(--danger);
    color: var(--danger);
    box-shadow: 0 0 20px rgba(220, 53, 69, 0.3);
}

.hidden {
    display: none !important;
}

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

/* Rules Summary */
.rules-summary {
    background: rgba(131, 56, 236, 0.1);
    border: 2px solid var(--purple);
    border-radius: 12px;
    padding: 1.5rem;
    margin-top: 2rem;
    box-shadow: 0 0 20px rgba(131, 56, 236, 0.3);
}

.rules-summary h3 {
    color: var(--accent);
    margin-bottom: 1rem;
}

.rules-summary ul {
    list-style: none;
    padding-left: 0;
}

.rules-summary li {
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.rules-summary li:last-child {
    border-bottom: none;
}

/* Stats Section */
.stats-container {
    text-align: center;
}

.stats-container h2 {
    color: var(--accent);
    margin-bottom: 2rem;
    text-shadow: 0 0 15px var(--accent);
}

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

.stat-card {
    background: rgba(58, 134, 255, 0.1);
    border: 2px solid var(--blue);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 0 20px rgba(58, 134, 255, 0.3);
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: var(--blue);
    margin-bottom: 0.5rem;
}

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

.stats-by-size {
    background: rgba(255, 0, 110, 0.1);
    border: 2px solid var(--primary);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 0 20px rgba(255, 0, 110, 0.3);
}

.stats-by-size h3 {
    color: var(--primary);
    margin-bottom: 1rem;
}

.size-stat {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.size-stat:last-child {
    border-bottom: none;
}

/* FAQ Section */
.faq-container h2 {
    color: var(--accent);
    margin-bottom: 2rem;
    text-align: center;
    text-shadow: 0 0 15px var(--accent);
}

.faq-item {
    background: rgba(131, 56, 236, 0.1);
    border: 2px solid var(--purple);
    border-radius: 12px;
    margin-bottom: 1rem;
    overflow: hidden;
    box-shadow: 0 0 15px rgba(131, 56, 236, 0.2);
}

.faq-question {
    width: 100%;
    background: none;
    border: none;
    color: var(--light);
    padding: 1.5rem;
    text-align: left;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
}

.faq-question:hover {
    background: rgba(131, 56, 236, 0.2);
    color: var(--purple);
}

.faq-question[aria-expanded="true"] {
    background: rgba(131, 56, 236, 0.2);
    color: var(--purple);
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-icon {
    font-size: 1.5rem;
    transition: transform 0.3s ease;
    color: var(--purple);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--light);
    line-height: 1.6;
    animation: fadeIn 0.3s ease-in-out;
}

.faq-answer ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.faq-answer li {
    margin: 0.5rem 0;
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(26, 26, 26, 0.95);
    backdrop-filter: blur(10px);
    border-top: 2px solid var(--primary);
    display: flex;
    justify-content: space-around;
    padding: 1rem 0;
    z-index: 1000;
    box-shadow: 0 -4px 20px rgba(255, 0, 110, 0.3);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--gray);
    transition: all 0.3s ease;
    padding: 0.5rem;
    border-radius: 8px;
    min-width: 60px;
}

.nav-item:hover, .nav-item.active {
    color: var(--primary);
    transform: translateY(-2px);
}

.nav-item.active {
    background: rgba(255, 0, 110, 0.1);
    box-shadow: 0 0 15px rgba(255, 0, 110, 0.3);
}

.nav-item i {
    font-size: 1.5rem;
    margin-bottom: 0.25rem;
}

.nav-item span {
    font-size: 0.8rem;
    font-weight: 500;
}

/* Footer */
footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--gray);
    font-size: 0.9rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header h1 {
        font-size: 1.5rem;
    }
    
    .game-info {
        flex-direction: column;
        gap: 1rem;
    }
    
    .cell {
        width: 35px;
        height: 35px;
        font-size: 1.3rem;
    }
    
    .counter {
        width: 35px;
        height: 35px;
        font-size: 0.7rem;
    }
    
    .row-counters {
        right: -50px;
    }
    
    .column-counters {
        bottom: -45px;
    }
    
    .game-controls {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 200px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 1rem 0.5rem;
    }
    
    .cell {
        width: 30px;
        height: 30px;
        font-size: 1.1rem;
    }
    
    .counter {
        width: 30px;
        height: 30px;
        font-size: 0.6rem;
    }
    
    .row-counters {
        right: -40px;
    }
    
    .column-counters {
        bottom: -35px;
    }
    
    .grid {
        padding: 5px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}