/* ===== RESET & BASE ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-solid: #667eea;
    --secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #1a1a2e;
    --darker: #0f0f1e;
    --light: #eee;
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-border: rgba(255, 255, 255, 0.1);
    --text: #ffffff;
    --text-dim: #a0a0b0;
}

body {
    font-family: 'Quicksand', sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
}

.app-container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* ===== HEADER ===== */
.header {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 20px 30px;
    margin-bottom: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.logo {
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    font-weight: 900;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 20px;
    text-align: center;
}

.nav-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-btn {
    padding: 12px 24px;
    border: 2px solid var(--card-border);
    background: transparent;
    color: var(--text-dim);
    border-radius: 12px;
    cursor: pointer;
    font-family: 'Quicksand', sans-serif;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: var(--card-bg);
    color: var(--text);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: var(--primary);
    border-color: var(--primary-solid);
    color: white;
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

/* ===== SCREENS ===== */
.screen {
    display: none;
    animation: fadeIn 0.4s ease;
}

.screen.active {
    display: block;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== MENU ===== */
.menu-container {
    text-align: center;
}

.menu-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 40px;
    background: var(--accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.game-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 20px;
}

.game-card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 2px solid var(--card-border);
    border-radius: 20px;
    padding: 35px 25px;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.game-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary);
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: -1;
}

.game-card:hover::before {
    opacity: 0.1;
}

.game-card:hover {
    transform: translateY(-10px) scale(1.02);
    border-color: var(--primary-solid);
    box-shadow: 0 15px 40px rgba(102, 126, 234, 0.3);
}

.card-icon {
    font-size: 4rem;
    margin-bottom: 15px;
}

.game-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.game-card p {
    color: var(--text-dim);
    font-size: 0.95rem;
    line-height: 1.5;
}

/* ===== GAME CONTAINER ===== */
.game-container {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 20px;
}

.game-header h2 {
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    background: var(--secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stats {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.stat {
    background: rgba(255, 255, 255, 0.08);
    padding: 8px 16px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 1rem;
}

.progress-info {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-dim);
}

/* ===== BUTTONS ===== */
.game-controls {
    display: flex;
    gap: 15px;
    margin-top: 30px;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    padding: 14px 32px;
    border: none;
    border-radius: 12px;
    font-family: 'Quicksand', sans-serif;
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(102, 126, 234, 0.6);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text);
    border: 2px solid var(--card-border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-3px);
}

.btn-accent {
    background: var(--accent);
    color: white;
    box-shadow: 0 5px 20px rgba(79, 172, 254, 0.4);
}

.btn-accent:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(79, 172, 254, 0.6);
}

/* ===== FLASH CARD ===== */
.flashcard-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 400px;
    perspective: 1000px;
}

.flashcard {
    width: 100%;
    max-width: 500px;
    height: 350px;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    cursor: pointer;
}

.flashcard.flipped {
    transform: rotateY(180deg);
}

.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 30px;
    background: var(--card-bg);
    border: 2px solid var(--card-border);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.4);
}

.card-front {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.2) 0%, rgba(118, 75, 162, 0.2) 100%);
}

.card-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, rgba(240, 147, 251, 0.2) 0%, rgba(245, 87, 108, 0.2) 100%);
}

.card-number {
    font-family: 'Orbitron', sans-serif;
    font-size: 8rem;
    font-weight: 900;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.pao-info {
    width: 100%;
}

.pao-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    margin-bottom: 15px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    border-left: 4px solid var(--primary-solid);
}

.pao-label {
    font-weight: 700;
    color: var(--primary-solid);
    font-size: 1.1rem;
}

.pao-value {
    font-size: 1.2rem;
    font-weight: 600;
    text-align: right;
}

/* ===== QUIZ ===== */
.quiz-container {
    min-height: 400px;
}

.question-box {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
    border: 2px solid var(--primary-solid);
    border-radius: 20px;
    padding: 40px;
    text-align: center;
    margin-bottom: 30px;
}

.question-box.reverse {
    background: linear-gradient(135deg, rgba(240, 147, 251, 0.15) 0%, rgba(245, 87, 108, 0.15) 100%);
    border-color: #f093fb;
}

.question-number {
    font-family: 'Orbitron', sans-serif;
    font-size: 6rem;
    font-weight: 900;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 10px;
}

.question-text {
    font-size: 1.3rem;
    color: var(--text-dim);
    font-weight: 600;
}

.question-text.large {
    font-size: 2.5rem;
    color: var(--text);
    font-weight: 700;
    margin: 20px 0;
}

.type-label {
    display: inline-block;
    padding: 8px 20px;
    background: var(--secondary);
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 15px;
}

.question-hint {
    font-size: 1.1rem;
    color: var(--text-dim);
    margin-top: 10px;
}

.quiz-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
}

.option-btn {
    padding: 20px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--card-border);
    border-radius: 15px;
    color: var(--text);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: left;
}

.option-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateX(5px);
    border-color: var(--primary-solid);
}

.option-btn.correct {
    background: var(--success);
    border-color: var(--success);
    animation: pulse 0.5s ease;
}

.option-btn.wrong {
    background: var(--danger);
    border-color: var(--danger);
    animation: shake 0.5s ease;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-10px);
    }

    75% {
        transform: translateX(10px);
    }
}

/* ===== NUMBER INPUT ===== */
.number-input-container {
    display: flex;
    gap: 15px;
    justify-content: center;
    align-items: center;
    margin-top: 30px;
}

.number-input {
    padding: 18px 30px;
    font-size: 2rem;
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--card-border);
    border-radius: 15px;
    color: var(--text);
    text-align: center;
    width: 150px;
    transition: all 0.3s ease;
}

.number-input:focus {
    outline: none;
    border-color: var(--primary-solid);
    box-shadow: 0 0 20px rgba(102, 126, 234, 0.3);
}

/* ===== MEMORY MATCH ===== */
.match-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin: 30px 0;
}

.match-card {
    aspect-ratio: 1;
    background: var(--card-bg);
    border: 2px solid var(--card-border);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.match-card::before {
    content: '?';
    position: absolute;
    font-size: 3rem;
    color: var(--text-dim);
}

.match-card.flipped {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.3) 0%, rgba(118, 75, 162, 0.3) 100%);
    border-color: var(--primary-solid);
}

.match-card.flipped::before {
    content: '';
}

.match-card.matched {
    background: var(--success);
    border-color: var(--success);
    transform: scale(0.95);
    opacity: 0.7;
    pointer-events: none;
}

.match-card:hover:not(.flipped):not(.matched) {
    transform: scale(1.05);
    border-color: var(--primary-solid);
}

.difficulty-select {
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--card-border);
    border-radius: 12px;
    color: var(--text);
    font-family: 'Quicksand', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
}

.difficulty-select:focus {
    outline: none;
    border-color: var(--primary-solid);
}

/* ===== CHAIN CHALLENGE ===== */
.chain-container {
    min-height: 400px;
}

.phase-container {
    text-align: center;
}

.phase-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 30px;
    color: var(--text-dim);
}

.number-chain {
    font-family: 'Orbitron', sans-serif;
    font-size: 4rem;
    font-weight: 900;
    background: var(--accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 30px 0;
    letter-spacing: 10px;
}

.countdown {
    font-family: 'Orbitron', sans-serif;
    font-size: 5rem;
    font-weight: 900;
    background: var(--secondary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 30px 0;
}

.recall-grid {
    display: grid;
    gap: 20px;
    max-width: 600px;
    margin: 0 auto 30px;
}

.recall-item {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--card-border);
    border-radius: 15px;
    padding: 20px;
}

.recall-number {
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    font-weight: 900;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 15px;
}

.recall-inputs {
    display: grid;
    gap: 10px;
}

.recall-input {
    padding: 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid var(--card-border);
    border-radius: 10px;
    color: var(--text);
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
}

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

.recall-input.correct {
    border-color: var(--success);
    background: rgba(16, 185, 129, 0.2);
}

.recall-input.wrong {
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.2);
}

.result-message {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 20px;
}

.result-message.success {
    color: var(--success);
}

.result-message.failure {
    color: var(--danger);
}

.result-detail {
    font-size: 1.2rem;
    color: var(--text-dim);
    margin-bottom: 30px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .logo {
        font-size: 1.5rem;
    }

    .nav-buttons {
        gap: 8px;
    }

    .nav-btn {
        padding: 10px 16px;
        font-size: 0.85rem;
    }

    .menu-title {
        font-size: 2rem;
    }

    .game-cards {
        grid-template-columns: 1fr;
    }

    .card-number {
        font-size: 5rem;
    }

    .question-number {
        font-size: 4rem;
    }

    .number-chain {
        font-size: 2.5rem;
        letter-spacing: 5px;
    }

    .match-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}