:root {
  --ink: #1c1914;
  --muted: #5c564c;
  --paper: #f3efe6;
  --sheet: #fffcf6;
  --line: #d8d0c2;
  --accent: #9a3412;
  --accent-ink: #fffaf5;
  --ok: #14532d;
  --warn-bg: #f4e6d4;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.5;
}

.sheet {
  max-width: 28rem;
  margin: 0 auto;
  padding: 2.25rem 1.25rem 3rem;
}

.brand-kicker {
  margin: 0 0 0.35rem;
  font-size: 0.8rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

h1 {
  margin: 0;
  font-family: "Noto Serif TC", "PMingLiU", serif;
  font-size: 2rem;
  font-weight: 700;
}

.brand-lead {
  margin: 0.75rem 0 0;
  color: var(--muted);
}

.form {
  display: grid;
  gap: 1rem;
  margin-top: 1.75rem;
}

label {
  display: grid;
  gap: 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
}

input {
  width: 100%;
  padding: 0.85rem 0.9rem;
  font-size: 1.1rem;
  border: 1px solid var(--line);
  background: var(--sheet);
  color: var(--ink);
  border-radius: 2px;
}

input:focus {
  outline: 2px solid var(--ink);
  outline-offset: 1px;
}

button {
  margin-top: 0.35rem;
  padding: 0.95rem 1rem;
  font-size: 1.05rem;
  font-weight: 700;
  border: 0;
  background: var(--accent);
  color: var(--accent-ink);
  cursor: pointer;
}

button:disabled {
  opacity: 0.6;
  cursor: wait;
}

.result {
  margin-top: 1.5rem;
  padding: 1.1rem 1rem;
  border: 1px solid var(--line);
  background: var(--sheet);
}

.result h2 {
  margin: 0 0 0.6rem;
  font-size: 1.15rem;
}

.result dl {
  margin: 0;
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 0.35rem 0.75rem;
}

.result dt {
  color: var(--muted);
}

.result dd {
  margin: 0;
  font-weight: 600;
}

.result .amount {
  font-size: 1.45rem;
  font-variant-numeric: tabular-nums;
}

.result .actions {
  display: grid;
  gap: 0.6rem;
  margin-top: 1rem;
}

.result a.pay {
  display: block;
  text-align: center;
  padding: 0.9rem 1rem;
  background: var(--accent);
  color: var(--accent-ink);
  text-decoration: none;
  font-weight: 700;
}

.result button.reset {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

.result.paid {
  border-color: #86efac;
}

.result.paid h2 {
  color: var(--ok);
}

.result.missing,
.result.error {
  background: var(--warn-bg);
}

.note {
  margin: 0.75rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}