:root {
    --bg: #f2f2f2;
    --text: #000;
    --card-bg: #fff;
    --button-bg: #007bff;
    --button-hover: #0056b3;
    --copy-bg: #28a745;
    --copy-hover: #218838;
}
body.dark {
    --bg: #121212;
    --text: #f0f0f0;
    --card-bg: #1e1e1e;
    --button-bg: #0d6efd;
    --button-hover: #0b5ed7;
    --copy-bg: #198754;
    --copy-hover: #157347;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 1rem;
    font-family: sans-serif;
    background: var(--bg);
    color: var(--text);
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 100%;
    width: 100%;
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin: 0 auto;
}

h2 {
    text-align: center;
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-top: 1rem;
    font-weight: bold;
    font-size: 1rem;
}

input[type="number"] {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    margin-top: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 6px;
    background: var(--bg);
    color: var(--text);
}

.options {
    margin-top: 1rem;
}

.options label {
    font-weight: normal;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

button {
    margin-top: 1.5rem;
    padding: 0.75rem;
    width: 100%;
    background-color: var(--button-bg);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: var(--button-hover);
}

.copy-button {
    background-color: var(--copy-bg);
    margin-top: 0.75rem;
}

.copy-button:hover {
    background-color: var(--copy-hover);
}

.theme-toggle {
    margin-top: 1rem;
    text-align: center;
}

.output {
    margin-top: 1.5rem;
    font-size: 1.1rem;
    word-wrap: break-word;
    line-height: 1.5;
}