:root {
  --bg: #f5f1e8;
  --paper: #fffdf8;
  --ink: #1f2a24;
  --muted: #5e6a63;
  --line: #d9d2c3;
  --accent: #0f6d5f;
  --accent-strong: #0a5248;
  --warn: #8a3b12;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Noto Sans SC", "Helvetica Neue", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(15, 109, 95, 0.08), transparent 32%),
    linear-gradient(180deg, #f9f5ec 0%, var(--bg) 100%);
}

.page {
  max-width: 920px;
  margin: 0 auto;
  padding: 48px 20px 72px;
}

.hero {
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 8px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
}

h1, h2 {
  margin: 0 0 12px;
}

h1 {
  font-size: 40px;
  line-height: 1.1;
}

h2 {
  font-size: 22px;
}

.lede,
.hint {
  color: var(--muted);
  line-height: 1.6;
}

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 24px;
  margin-bottom: 20px;
  box-shadow: 0 12px 28px rgba(31, 42, 36, 0.06);
}

.stack {
  display: grid;
  gap: 16px;
}

label {
  display: grid;
  gap: 8px;
  font-weight: 600;
}

input,
textarea,
select,
button {
  font: inherit;
}

input,
textarea,
select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  background: #fff;
}

textarea {
  resize: vertical;
}

button {
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  font-weight: 700;
}

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

.row {
  display: flex;
  gap: 12px;
  align-items: center;
}

.result {
  margin-top: 16px;
  padding: 14px;
  border-radius: 12px;
  background: #f3f7f6;
  border: 1px solid #cfe2dc;
  white-space: pre-wrap;
  word-break: break-word;
  line-height: 1.6;
}

.result.error {
  background: #fff3ee;
  border-color: #efc3ae;
  color: var(--warn);
}

.hidden {
  display: none;
}

code {
  background: #f1ece2;
  padding: 2px 6px;
  border-radius: 6px;
}

@media (max-width: 640px) {
  .page {
    padding: 28px 14px 48px;
  }

  h1 {
    font-size: 30px;
  }

  .card {
    padding: 18px;
  }
}