:root {
  color-scheme: light;
  --bg: #f3f6f8;
  --panel: #ffffff;
  --ink: #172026;
  --muted: #61707c;
  --line: #d6dee5;
  --accent: #0f766e;
  --accent-strong: #115e59;
  --danger: #b42318;
  --success: #146c43;
  --shadow: 0 18px 48px rgba(24, 39, 55, 0.14);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Microsoft YaHei", "Segoe UI", Arial, sans-serif;
  color: var(--ink);
  background:
    linear-gradient(115deg, rgba(15, 118, 110, 0.08), transparent 38%),
    linear-gradient(295deg, rgba(42, 98, 143, 0.08), transparent 40%),
    var(--bg);
}

.shell {
  width: min(760px, calc(100% - 32px));
  min-height: 100vh;
  margin: 0 auto;
  display: grid;
  place-items: center;
  padding: 32px 0;
}

.panel {
  width: 100%;
  background: var(--panel);
  border: 1px solid rgba(214, 222, 229, 0.9);
  border-radius: 8px;
  box-shadow: var(--shadow);
  padding: 32px;
}

.brand-row {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.mark {
  flex: 0 0 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: #e7f3f1;
  color: var(--accent-strong);
  font-size: 24px;
  font-weight: 800;
}

h1 {
  margin: 0;
  font-size: 26px;
  line-height: 1.2;
  letter-spacing: 0;
}

p {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.65;
}

.code-form {
  margin-top: 28px;
}

label {
  display: block;
  margin-bottom: 8px;
  color: #33424d;
  font-size: 14px;
  font-weight: 700;
}

.input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 132px;
  gap: 10px;
}

input,
button {
  height: 46px;
  border-radius: 6px;
  font: inherit;
}

input {
  min-width: 0;
  border: 1px solid var(--line);
  padding: 0 14px;
  color: var(--ink);
  outline: none;
  background: #fff;
}

input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.16);
}

button {
  border: 0;
  background: var(--accent);
  color: #fff;
  font-weight: 800;
  cursor: pointer;
}

button:hover {
  background: var(--accent-strong);
}

button:disabled {
  cursor: wait;
  background: #8aa8a5;
}

.result {
  margin-top: 18px;
  min-height: 72px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 16px;
  background: #f8fafb;
}

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

.result-code {
  display: block;
  margin-top: 6px;
  font-size: 36px;
  line-height: 1.1;
  font-weight: 900;
  letter-spacing: 0;
  color: var(--success);
}

.result-meta {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
  overflow-wrap: anywhere;
}

.result-error {
  border-color: rgba(180, 35, 24, 0.28);
  background: #fff7f6;
}

.result-error .result-label {
  color: var(--danger);
  font-weight: 700;
}

.result-success {
  border-color: rgba(20, 108, 67, 0.28);
  background: #f4fbf7;
}

@media (max-width: 620px) {
  .shell {
    width: min(100% - 24px, 760px);
    align-items: start;
    padding-top: 18px;
  }

  .panel {
    padding: 22px;
  }

  .brand-row {
    gap: 12px;
  }

  h1 {
    font-size: 22px;
  }

  .input-row {
    grid-template-columns: 1fr;
  }

  button {
    width: 100%;
  }
}