:root {
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #555555;
    --accent-color: #0088cc;
    --border-color: #0088cc;
    --input-bg: #e8f4f8;
    --button-bg: #e94560;
    --error-color: #cc0000;
    --warning-color: #ff8800;
    --success-color: #0088cc;
}

body.dark-mode {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --text-primary: white;
    --text-secondary: #cccccc;
    --accent-color: #4cc9f0;
    --border-color: #4cc9f0;
    --input-bg: #0f3460;
    --button-bg: #e94560;
    --error-color: #ff4d4d;
    --warning-color: #ffaa00;
    --success-color: #4cc9f0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    margin: 0;
    padding-top: 60px;
    transition: background-color 0.3s, color 0.3s;
}

.header-controls {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 20px;
    align-items: center;
    background: var(--bg-secondary);
    padding: 10px 15px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.variant-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
}

.variant-label {
    font-size: 1.2rem;
    opacity: 0.6;
    transition: opacity 0.3s;
    user-select: none;
}

.variant-label.uk {
    opacity: 1;
}

.variant-label.us {
    opacity: 0.6;
}

.variant-toggle.us-mode .variant-label.uk {
    opacity: 0.6;
}

.variant-toggle.us-mode .variant-label.us {
    opacity: 1;
}

.toggle-switch {
    display: inline-flex;
    align-items: center;
    cursor: pointer;
    position: relative;
}

.toggle-switch input {
    display: none;
}

.toggle-slider {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
    background-color: var(--input-bg);
    border-radius: 14px;
    border: 2px solid var(--border-color);
    transition: background-color 0.3s;
    cursor: pointer;
}

.toggle-slider::before {
    content: '';
    position: absolute;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background-color: var(--border-color);
    top: 3px;
    left: 2px;
    transition: transform 0.3s;
}

.variant-toggle.us-mode .toggle-slider::before {
    transform: translateX(22px);
}

.theme-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
}

.theme-toggle input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--accent-color);
}

.theme-toggle label {
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
}

.game-container {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    text-align: center;
    width: 90%;
    max-width: 500px;
    margin-top: 20px;
    transition: background-color 0.3s;
}

.game-container h1 {
    color: var(--accent-color);
    margin-top: 0;
}

.game-container p {
    color: var(--text-secondary);
}

#puzzle-day {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 5px 0 15px 0;
    display: none;
}

#day-number {
    font-weight: bold;
    color: var(--accent-color);
}

.source-word {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: 8px;
    color: var(--accent-color);
    margin: 20px 0;
    text-transform: uppercase;
}

input {
    background: var(--input-bg);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    color: var(--text-primary);
    padding: 12px;
    font-size: 1.2rem;
    width: 80%;
    outline: none;
    text-align: center;
    transition: background-color 0.3s, color 0.3s;
}

input::placeholder {
    color: var(--text-secondary);
}

.feedback {
    height: 24px;
    margin: 10px 0;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.stats {
    color: var(--text-secondary);
    font-weight: 600;
    margin: 15px 0;
}

.word-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-top: 20px;
    padding: 10px;

}

.found-word {
    background: var(--accent-color);
    color: var(--bg-primary);
    padding: 5px;
    border-radius: 5px;
    font-weight: bold;
    text-transform: uppercase;
    animation: bounce 0.3s ease;
}

button {
    margin-top: 20px;
    padding: 10px 20px;
    background: var(--button-bg);
    border: none;
    color: white;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
    transition: opacity 0.3s;
}

button:hover:not(:disabled) {
    opacity: 0.9;
}

button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

@keyframes bounce {
    0% {
        transform: scale(0.8);
    }

    50% {
        transform: scale(1.1);
    }

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