:root {
    --primary: #4a6fa5;
    --primary-dark: #385d8a;
    --secondary: #6b9080;
    --accent: #a4c3b2;
    --light: #f6fff8;
    --dark: #2d3e50;
    --gray: #6c757d;
    --gray-light: #e9ecef;
    --success: #28a745;
    --warning: #ffc107;
    --danger: #dc3545;
    --border-radius: 10px;
    --box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #e0f7fa 0%, #bbdefb 100%);
    color: var(--dark);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 800px;
    width: 100%;
    background: white;
    border-radius: 15px;
    box-shadow: var(--box-shadow);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 25px;
    text-align: center;
}

.header h1 {
    font-size: 2.2rem;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.header p {
    opacity: 0.9;
    font-size: 1rem;
}

.main-content {
    padding: 30px;
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.input-section,
.output-section,
.algorithms-section {
    background: var(--light);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-light);
}

.section-title {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--primary-dark);
    display: flex;
    align-items: center;
    gap: 8px;
}

.input-container,
.output-container {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
    padding: 15px;
    background: white;
    border-radius: var(--border-radius);
    border: 2px solid var(--gray-light);
}

.number-input {
    width: 70px;
    height: 50px;
    text-align: center;
    font-size: 1.2rem;
    font-weight: 600;
    border: 2px solid var(--gray-light);
    border-radius: var(--border-radius);
    background: white;
    transition: var(--transition);
}

.number-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(74, 111, 165, 0.2);
}

.output-number {
    width: 70px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: 600;
    background: var(--primary);
    color: white;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.bracket {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary);
}

.comma {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--gray);
}

.sort-options {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin: 20px 0;
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-weight: 500;
}

.radio-label input {
    display: none;
}

.radio-custom {
    width: 18px;
    height: 18px;
    border: 2px solid var(--gray);
    border-radius: 50%;
    position: relative;
    transition: var(--transition);
}

.radio-label input:checked+.radio-custom {
    border-color: var(--primary);
    background: var(--primary);
}

.radio-label input:checked+.radio-custom::after {
    content: '';
    width: 8px;
    height: 8px;
    background: white;
    border-radius: 50%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.buttons-container {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex: 1;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background: var(--secondary);
    color: white;
}

.btn-secondary:hover {
    background: #5a7f70;
    transform: translateY(-2px);
}

.btn-outline {
    background: white;
    color: var(--dark);
    border: 2px solid var(--gray);
}

.btn-outline:hover {
    border-color: var(--dark);
    transform: translateY(-2px);
}

.algorithm-info {
    text-align: center;
    margin-top: 15px;
    padding: 15px;
    background: white;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--primary);
}

.stats {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 10px;
    font-size: 0.9rem;
    color: var(--gray);
}

.algorithms-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 12px;
}

.algorithm-btn {
    padding: 15px;
    background: white;
    border: 2px solid var(--gray-light);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.algorithm-btn:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
}

.algorithm-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.algorithm-btn span {
    display: block;
    font-weight: 600;
    margin-bottom: 4px;
}

.algorithm-btn small {
    opacity: 0.8;
    font-size: 0.8rem;
}

.footer {
    background: var(--dark);
    color: white;
    text-align: center;
    padding: 15px;
    font-size: 0.9rem;
    opacity: 0.8;
}

@media (max-width: 600px) {
    .container {
        border-radius: 10px;
    }

    .main-content {
        padding: 20px;
    }

    .input-container,
    .output-container {
        gap: 5px;
        padding: 10px;
    }

    .number-input,
    .output-number {
        width: 50px;
        height: 40px;
        font-size: 1rem;
    }

    .bracket {
        font-size: 1.5rem;
    }

    .comma {
        font-size: 1.2rem;
    }

    .buttons-container {
        flex-direction: column;
    }

    .algorithms-grid {
        grid-template-columns: 1fr 1fr;
    }

    .sort-options {
        flex-direction: column;
        gap: 10px;
        align-items: center;
    }
}