@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;700;900&display=swap');

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

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #0c0c0c 0%, #1a1a2e 50%, #16213e 100%);
    min-height: 100vh;
    color: #ffffff;
    overflow-x: hidden;
}

/* Background stars effect */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(2px 2px at 20px 30px, #eee, transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(255,255,255,0.8), transparent),
        radial-gradient(1px 1px at 90px 40px, #fff, transparent),
        radial-gradient(1px 1px at 130px 80px, rgba(255,255,255,0.6), transparent),
        radial-gradient(2px 2px at 160px 30px, #ddd, transparent);
    background-repeat: repeat;
    background-size: 200px 100px;
    animation: stars 20s linear infinite;
    z-index: -1;
}

@keyframes stars {
    from { transform: translateY(0px); }
    to { transform: translateY(-100px); }
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

/* Start Form Styles */
.start-form {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 40px;
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.2);
    max-width: 500px;
    width: 100%;
}

.start-form h1 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4);
    background-size: 400% 400%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: gradient 3s ease infinite;
}

@keyframes gradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.form-group {
    margin-bottom: 25px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    font-size: 1.1rem;
    color: #e0e0e0;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #4ecdc4;
    box-shadow: 0 0 15px rgba(78, 205, 196, 0.5);
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

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

.difficulty-btn {
    padding: 12px 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    min-width: 100px;
}

.difficulty-btn:hover {
    background: rgba(78, 205, 196, 0.3);
    border-color: #4ecdc4;
    transform: translateY(-2px);
}

.difficulty-btn.selected {
    background: #4ecdc4;
    border-color: #4ecdc4;
    box-shadow: 0 0 15px rgba(78, 205, 196, 0.5);
}

.start-btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
    color: #ffffff;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 20px;
    min-width: 150px;
}

.start-btn:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.start-btn:disabled {
    background: rgba(255, 255, 255, 0.2);
    cursor: not-allowed;
    transform: none;
}

/* Game Interface Styles */
.game-interface {
    width: 100%;
    max-width: 1000px;
}

.game-interface.hidden {
    display: none;
}

.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.player-info, .timer-container, .scoreboard {
    text-align: center;
}

.timer {
    font-size: 1.5rem;
    font-weight: bold;
    color: #4ecdc4;
}

.best-score {
    font-size: 1.1rem;
    color: #ffd700;
}

.game-board {
    display: grid;
    gap: 15px;
    margin-bottom: 30px;
    justify-content: center;
}

.game-board.grid-4 {
    grid-template-columns: repeat(2, 1fr);
    max-width: 400px;
}

.game-board.grid-8 {
    grid-template-columns: repeat(4, 1fr);
    max-width: 600px;
}

.game-board.grid-16 {
    grid-template-columns: repeat(4, 1fr);
    max-width: 800px;
}

.card {
    aspect-ratio: 1;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 15px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    transition: all 0.3s ease;
    border: 2px solid rgba(255, 255, 255, 0.3);
    position: relative;
    transform-style: preserve-3d;
}

.card:hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

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

.card.matched {
    background: linear-gradient(135deg, #4ecdc4 0%, #44a08d 100%);
    border-color: #4ecdc4;
    animation: pulse 1s ease-in-out;
}

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

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 13px;
}

.card-front {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    transform: rotateY(180deg);
}

.card-back {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
}

.back-btn {
    padding: 12px 25px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.back-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(15px);
    border-radius: 20px;
    padding: 40px;
    text-align: center;
    max-width: 500px;
    width: 90%;
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.modal-content h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #4ecdc4;
}

.modal-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    color: #e0e0e0;
}

.modal-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.modal-btn {
    padding: 12px 25px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
    color: #ffffff;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    min-width: 120px;
}

.modal-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .start-form {
        padding: 30px 20px;
    }
    
    .start-form h1 {
        font-size: 2rem;
    }
    
    .game-header {
        flex-direction: column;
        gap: 15px;
    }
    
    .game-board.grid-4 {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
    
    .game-board.grid-8 {
        grid-template-columns: repeat(4, 1fr);
        gap: 10px;
    }
    
    .game-board.grid-16 {
        grid-template-columns: repeat(4, 1fr);
        gap: 8px;
    }
    
    .card {
        font-size: 1.5rem;
    }
    
    .modal-content {
        padding: 30px 20px;
    }
    
    .modal-buttons {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .start-form h1 {
        font-size: 1.8rem;
    }
    
    .difficulty-buttons {
        flex-direction: column;
    }
    
    .difficulty-btn {
        min-width: auto;
    }
    
    .game-board.grid-16 {
        grid-template-columns: repeat(4, 1fr);
        gap: 5px;
    }
    
    .card {
        font-size: 1.2rem;
    }
}

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

/* Animation for card flipping */
@keyframes flipIn {
    from {
        transform: rotateY(0deg);
    }
    to {
        transform: rotateY(180deg);
    }
}

@keyframes flipOut {
    from {
        transform: rotateY(180deg);
    }
    to {
        transform: rotateY(0deg);
    }
} 
/* Card shake animation */
@keyframes cardShake { 0%,100%{transform:rotateY(180deg) translateX(0)} 25%{transform:rotateY(180deg) translateX(-5px)} 75%{transform:rotateY(180deg) translateX(5px)} }
.card.shake .card-front { animation: cardShake 0.4s ease; }