* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    background: #0d1117;
    color: #e6edf3;
    min-height: 100vh;
    padding: 20px;
}
.container { max-width: 900px; margin: 0 auto; }
header { text-align: center; margin-bottom: 24px; }
header h1 { color: #58a6ff; font-size: 26px; }
.sub { color: #8b949e; font-size: 13px; margin-top: 6px; }
.sub a { color: #58a6ff; text-decoration: none; }
.tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.tab {
    background: #161b22;
    border: 1px solid #30363d;
    color: #e6edf3;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    transition: 0.2s;
}
.tab:hover { border-color: #58a6ff; }
.tab.active { background: #1f6feb; border-color: #1f6feb; }
.panel { display: none; }
.panel.active { display: block; }
.card {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 10px;
    padding: 16px;
    margin-bottom: 12px;
}
.card h3 { color: #58a6ff; font-size: 14px; margin-bottom: 10px; }
.card input {
    width: 100%;
    background: #0d1117;
    border: 1px solid #30363d;
    color: #e6edf3;
    padding: 10px;
    border-radius: 6px;
    margin-bottom: 8px;
    font-size: 13px;
}
.card input:focus { outline: none; border-color: #58a6ff; }
.card button {
    background: #238636;
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    font-weight: 600;
}
.card button:hover { background: #2ea043; }
.output-wrap {
    background: #161b22;
    border: 1px solid #30363d;
    border-radius: 10px;
    margin-top: 20px;
    overflow: hidden;
}
.output-header {
    display: flex;
    justify-content: space-between;
    padding: 10px 16px;
    background: #1c2128;
    border-bottom: 1px solid #30363d;
    font-size: 13px;
    color: #8b949e;
}
.output-header button {
    background: #21262d;
    border: 1px solid #30363d;
    color: #e6edf3;
    padding: 4px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 12px;
}
pre#output {
    padding: 16px;
    font-family: 'Consolas', monospace;
    font-size: 12px;
    color: #7ee787;
    overflow-x: auto;
    min-height: 150px;
    max-height: 400px;
    overflow-y: auto;
    white-space: pre-wrap;
    word-break: break-all;
}