:root {
    --primary-color: #4a69bd;
    --secondary-color: #6c5ce7;
    --background-color: #f4f7f6;
    --text-color: #2c3e50;
    --border-color: #dcdde1;
    --button-bg: #ffffff;
    --button-hover-bg: #f1f2f6;
    --font-family: 'Inter', sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: #fff;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

header {
    text-align: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

header h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

header p {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.input-output-area {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 2rem;
}

.text-area-container {
    display: flex;
    flex-direction: column;
}

.text-area-container label {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-color);
}

textarea {
    width: 100%;
    min-height: 300px;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: 'Courier New', Courier, monospace;
    resize: vertical;
    transition: border-color 0.3s;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.controls {
    text-align: center;
}

.button-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
    margin-bottom: 20px;
}

.btn {
    padding: 12px 18px;
    border: 1px solid var(--border-color);
    background-color: var(--button-bg);
    color: var(--text-color);
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn:hover {
    background-color: var(--button-hover-bg);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
}

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

.btn-action {
    padding: 12px 25px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

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

footer {
    text-align: center;
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    color: #95a5a6;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .input-output-area {
        grid-template-columns: 1fr;
    }
    .button-group {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }
    .action-buttons {
        flex-direction: column;
    }
    .btn-action {
        width: 100%;
    }
}