:root { font-family: system-ui, -apple-system, "Segoe UI", Arial, "Noto Sans TC", sans-serif; }
body { margin: 0; background: #f6f7fb; color: #111; }
.container { max-width: 900px; margin: 0 auto; padding: 20px; }
.card { background: white; border: 1px solid #e7e7ee; border-radius: 12px; padding: 16px; margin: 12px 0; }
label { display: block; margin: 10px 0; }
input, select, button { font-size: 16px; padding: 10px; margin-top: 6px; }
input, select { width: min(420px, 100%); box-sizing: border-box; }
button { cursor: pointer; }
.hint { color: #555; }
.row { display: flex; gap: 18px; flex-wrap: wrap; }
.msg { margin-top: 10px; min-height: 22px; }
.msg.ok { color: #0a7a2f; }
.msg.err { color: #b00020; }
.output { background: #0b1020; color: #d6e1ff; padding: 12px; border-radius: 10px; overflow: auto; }
.invalid { border: 2px solid #b00020; }