:root {
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  color: #18243a;
  background: #f4f7fc;
  font-synthesis: none;
  line-height: 1.6;
  --blue: #2056d8;
  --muted: #58677e;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; border-top: 4px solid var(--blue); min-width: 280px; }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: wait; }
.page { width: min(100% - 40px, 560px); margin: 54px auto 30px; }
.page-heading { text-align: center; margin-bottom: 28px; }
.app-icon { display: grid; place-items: center; width: 54px; height: 54px; margin: 0 auto 16px; border-radius: 17px; background: #e5edff; color: var(--blue); }
.app-icon svg { width: 29px; height: 29px; }
h1 { margin: 0; font-size: 1.875rem; letter-spacing: -.035em; line-height: 1.45; font-weight: 750; }
.form-card { background: white; padding: 30px; border: 1px solid #dee5f0; border-radius: 20px; box-shadow: 0 10px 35px #18397008; }
.field + .field { margin-top: 26px; }
label { display: block; font-weight: 650; font-size: 1rem; }
input, textarea { display: block; width: 100%; padding: 13px 15px; border-radius: 10px; border: 1px solid #aebcd1; color: #18243a; background: #fff; font-size: 1rem; line-height: 1.65; transition: border-color .15s, box-shadow .15s; }
input { margin-top: 9px; letter-spacing: .02em; }
textarea { resize: vertical; min-height: 180px; }
input::placeholder, textarea::placeholder { color: #728099; opacity: 1; }
input:focus, textarea:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px #2056d81c; }
input[aria-invalid="true"], textarea[aria-invalid="true"] { border-color: #b53335; }
input:read-only, textarea:read-only { background: #f8faff; }
button:focus-visible { outline: 3px solid #779df5; outline-offset: 4px; }
.field-error { color: #aa282a; font-size: .875rem; margin: 8px 0 0; }
.label-row { display: flex; min-height: 36px; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 7px; }
.paste-button { display: inline-flex; align-items: center; gap: 6px; color: #184dbc; background: #eef3ff; border: 0; border-radius: 8px; padding: 8px 10px; font-size: .875rem; font-weight: 600; }
.paste-button:hover { background: #e0eaff; }
.paste-button svg { width: 17px; height: 17px; }
.message-meta { display: flex; align-items: baseline; justify-content: flex-end; margin-top: 8px; }
.count { color: var(--muted); font-size: .8125rem; white-space: nowrap; font-variant-numeric: tabular-nums; }
.send-button { display: flex; align-items: center; justify-content: center; gap: 12px; width: 100%; min-height: 54px; margin-top: 26px; padding: 13px 18px; border: 0; border-radius: 10px; background: var(--blue); color: white; font-weight: 650; transition: background .15s; }
.send-button:hover:not(:disabled) { background: #1747bb; }
.send-button:disabled { background: #426bcc; }
.send-icon { height: 19px; width: 19px; }
.status { padding: 12px 14px; margin-top: 20px; border: 1px solid #c3d5ff; border-radius: 10px; font-size: .9375rem; background: #eff5ff; color: #204677; overflow-wrap: anywhere; }
.status[data-kind="error"] { background: #fff4f3; border-color: #f0cbca; color: #93292a; }
.status[data-kind="success"] { background: #edf8f5; border-color: #b9ddd2; color: #185d4b; }
.spinner { width: 18px; height: 18px; border: 2px solid #ffffff70; border-top-color: white; border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { animation: none !important; transition: none !important; } }
@media (max-width: 480px) {
  .page { width: calc(100% - 28px); margin-top: 27px; }
  .page-heading { margin-bottom: 22px; }
  h1 { font-size: 1.65rem; }
  .form-card { padding: 22px 20px; border-radius: 16px; }
  .message-meta { flex-wrap: wrap; gap: 4px 12px; }
  .count { margin-left: auto; }
}