:root {
    --bg: #0d1117;
    --card: #161b22;
    --text: #c9d1d9;
    --accent: #58a6ff;
    --border: #30363d;
    --success: #3fb950;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    padding: 40px 20px;
    margin: 0;
}

.container {
    background: var(--card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border);
    width: 100%;
    max-width: 450px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
}

header h1 { margin: 0; color: var(--accent); font-size: 1.4rem; letter-spacing: -0.5px; }
header p { font-size: 0.85rem; color: #8b949e; margin: 0.4rem 0 1.5rem 0; }

.settings {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 1.5rem;
}

.setting-group { display: flex; flex-direction: column; }
.setting-group.full-width { grid-column: span 2; }

.setting-group label { 
    font-size: 0.7rem; 
    font-weight: 700; 
    margin-bottom: 6px; 
    color: #8b949e; 
    text-transform: uppercase; 
    letter-spacing: 0.5px;
}

input, select {
    background: #0d1117;
    border: 1px solid var(--border);
    color: #fff;
    padding: 0 10px;
    border-radius: 6px;
    font-size: 0.9rem;
    height: 38px;
    transition: border-color 0.2s;
}

/* Constrain numerical and short inputs */
input[type="number"], 
#separator {
    max-width: 70px;
}

select { width: 100%; }

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
}

.toggle-container { 
    display: flex; 
    align-items: center; 
    height: 38px; 
}

input[type="checkbox"] { 
    width: 18px; 
    height: 18px; 
    cursor: pointer; 
    accent-color: var(--accent);
    margin: 0;
}

button {
    width: 100%;
    padding: 12px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-weight: 700;
    cursor: pointer;
    margin-bottom: 1rem;
    transition: background 0.2s;
}

button:hover { background: #79c0ff; }

.password-result {
    background: #0d1117;
    padding: 12px;
    margin-top: 10px;
    border-radius: 6px;
    border: 1px solid var(--border);
    cursor: copy;
    font-family: 'SFMono-Regular', Consolas, monospace;
    font-size: 0.95rem;
    display: flex;
    justify-content: space-between;
}

.password-result:hover { border-color: var(--accent); background: #1c2128; }

.footer-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 25px;
    padding-top: 15px;
    border-top: 1px solid var(--border);
    font-size: 0.75rem;
    color: #8b949e;
}

#entropy-bits { font-weight: bold; }
.copyright { opacity: 0.8; font-weight: 500; }