body {
    font-family: 'Roboto', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
    color: #333;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    background-color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    max-width: 600px;
    width: 100%;
    transition: background-color 0.3s;
}

h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 20px;
    transition: color 0.3s;
}

.input-section, .output-section {
    margin-bottom: 20px;
}

textarea {
    width: 100%;
    height: 120px;
    margin-bottom: 15px;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    resize: vertical;
    font-size: 16px;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

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

button {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    transition: background-color 0.3s, transform 0.1s;
}

button:hover {
    background-color: #2980b9;
}

button:active {
    transform: scale(0.98);
}

#clearBtn {
    background-color: #e74c3c;
}

#clearBtn:hover {
    background-color: #c0392b;
}

#output {
    font-size: 24px;
    white-space: pre-wrap;
    word-break: break-all;
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 5px;
    min-height: 100px;
    margin-bottom: 15px;
    transition: background-color 0.3s, color 0.3s;
}

.copy-btn {
    background-color: #2ecc71;
    width: 100%;
}

.copy-btn:hover {
    background-color: #27ae60;
}

#fontSize {
    width: 60px;
    margin-left: 10px;
}

.settings {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.font-size-control {
    display: flex;
    align-items: center;
}

body.dark-mode {
    background-color: #2c3e50;
    color: #ecf0f1;
}

.dark-mode .container {
    background-color: #34495e;
}

.dark-mode #output {
    background-color: #2c3e50;
    color: #ecf0f1;
}

.dark-mode textarea {
    background-color: #2c3e50;
    color: #ecf0f1;
    border-color: #4a6278;
}

.dark-mode h1 {
    color: #ecf0f1;
}

@media (max-width: 480px) {
    .button-group {
        flex-direction: column;
    }

    .button-group button {
        width: 100%;
    }

    .settings {
        flex-direction: column;
        align-items: flex-start;
    }

    .font-size-control {
        margin-bottom: 10px;
    }
}