body {
    font-family: Arial, sans-serif;
    margin: 20px;
    color: #111;
    background: #fff;
}
.notebook-box {
    max-width: 900px;
}
h3 { margin-bottom: 8px; }
.field {
    margin: 8px 0;
}
.field label {
    display: inline-block;
    width: 120px;
}
input, select {
    min-width: 310px;
    padding: 4px 6px;
    font-size: 14px;
}
.rowline {
    display: flex;
    gap: 12px;
    align-items: center;
}
.rowline .small input { min-width: 110px; width: 110px; }
.rowline .minute select { min-width: 90px; width: 90px; }
button {
    width: 180px;
    height: 38px;
    background: #28a745;
    color: white;
    border: 0;
    border-radius: 3px;
    font-weight: bold;
    cursor: pointer;
}
.output {
    font-family: Consolas, "Courier New", monospace;
    font-size: 14px;
    white-space: pre;
    margin-top: 20px;
    background: #fff;
    border: 0;
    padding: 0;
}
.error { color: #b00020; }
table.df {
    border-collapse: collapse;
    margin-top: 10px;
    font-family: Arial, sans-serif;
    font-size: 13px;
}
table.df th, table.df td {
    border: 1px solid #ddd;
    padding: 5px 8px;
    text-align: left;
}
table.df th { font-weight: bold; background: #f6f6f6; }