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

:root {
    --bg-color: #ffffff;
    --text-color: #1a1a1a;
    --border-color: #d3d6da;
    --green: #6aaa64;
    --yellow: #c9b458;
    --gray: #787c7e;
    --light-gray: #d3d6da;
    --dark-gray: #878a8c;
    --letter-size: 62px;
    --key-size: 43px;
}

body {
    font-family: 'Clear Sans', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.container {
    max-width: 500px;
    width: 100%;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: 0.2rem;
    margin-bottom: 8px;
    color: var(--text-color);
}

.subtitle {
    font-size: 0.9rem;
    color: var(--dark-gray);
    font-weight: 400;
}

.game-area {
    width: 100%;
}

.section-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--text-color);
    text-align: center;
}

.guesses-container {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 30px;
}

.guess-row {
    display: flex;
    gap: 6px;
    justify-content: center;
}

.letter-box {
    width: var(--letter-size);
    height: var(--letter-size);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 700;
    text-transform: uppercase;
    border: 2px solid var(--border-color);
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: all 0.3s ease;
    user-select: none;
}

.letter-box.empty {
    border-color: var(--light-gray);
    background-color: var(--bg-color);
}

.letter-box.filled {
    border-color: var(--text-color);
    animation: pop 0.1s ease-in-out;
}

.letter-box.green {
    background-color: var(--green);
    border-color: var(--green);
    color: white;
    animation: flip 0.6s ease-in-out;
}

.letter-box.yellow {
    background-color: var(--yellow);
    border-color: var(--yellow);
    color: white;
    animation: flip 0.6s ease-in-out;
}

.letter-box.gray {
    background-color: var(--gray);
    border-color: var(--gray);
    color: white;
    animation: flip 0.6s ease-in-out;
}

.answer-section {
    margin-top: 40px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.input-container {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}

.answer-row {
    display: flex;
    gap: 6px;
}

.message {
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 15px;
    text-align: center;
    font-weight: 500;
    min-height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    font-size: 0.95rem;
}

.message.success {
    background-color: rgba(106, 170, 100, 0.1);
    color: var(--green);
    border: 1px solid var(--green);
}

.message.error {
    background-color: rgba(220, 53, 69, 0.1);
    color: #dc3545;
    border: 1px solid #dc3545;
}

.message.info {
    background-color: rgba(201, 180, 88, 0.1);
    color: var(--yellow);
    border: 1px solid var(--yellow);
}

.button-group {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.game-btn {
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 600;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    text-transform: uppercase;
    font-family: inherit;
}

.submit-btn {
    background-color: var(--green);
    color: white;
    flex: 1;
    min-width: 100px;
}

.submit-btn:hover:not(:disabled) {
    background-color: #5a9a54;
}

.submit-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.delete-btn {
    background-color: var(--gray);
    color: white;
    min-width: 80px;
}

.delete-btn:hover:not(:disabled) {
    background-color: var(--dark-gray);
}

.new-puzzle-btn {
    background-color: var(--light-gray);
    color: var(--text-color);
    flex: 1;
    min-width: 120px;
}

.new-puzzle-btn:hover {
    background-color: var(--border-color);
}

/* Virtual Keyboard */
.keyboard-container {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}

.keyboard-row {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-bottom: 8px;
}

.key {
    height: var(--key-size);
    min-width: var(--key-size);
    padding: 0 12px;
    font-size: 0.85rem;
    font-weight: 600;
    border: none;
    border-radius: 4px;
    background-color: var(--light-gray);
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
    text-transform: uppercase;
}

.key:hover {
    background-color: var(--border-color);
}

.key:active {
    transform: scale(0.95);
}

.key.used-green {
    background-color: var(--green);
    color: white;
}

.key.used-yellow {
    background-color: var(--yellow);
    color: white;
}

.key.used-gray {
    background-color: var(--gray);
    color: white;
}

/* Animations */
@keyframes pop {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes flip {
    0% {
        transform: rotateX(0);
    }
    50% {
        transform: rotateX(-90deg);
    }
    100% {
        transform: rotateX(0);
    }
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-10px);
    }
    75% {
        transform: translateX(10px);
    }
}

.shake {
    animation: shake 0.5s ease-in-out;
}

.loading {
    text-align: center;
    padding: 40px;
    font-size: 1rem;
    color: var(--dark-gray);
}

/* Responsive */
@media (max-width: 600px) {
    :root {
        --letter-size: 50px;
        --key-size: 38px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    .letter-box {
        font-size: 1.5rem;
    }
    
    .key {
        font-size: 0.75rem;
        padding: 0 10px;
        min-width: calc(var(--key-size) - 4px);
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .game-btn {
        width: 100%;
    }
}