:root {
  color-scheme: light;
  --ink: #1c1917;
  --muted: #57534e;
  --line: #e7e5e4;
  --bg: #fafaf9;
  --card: #ffffff;
  --accent: #9a3412;
  --good: #166534;
  --good-bg: #f0fdf4;
  --bad: #991b1b;
  --bad-bg: #fef2f2;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.8;
}

main {
  max-width: 62rem;
  margin: 0 auto;
  padding: 3.5rem 1.25rem 6rem;
}

.label {
  margin: 0 0 0.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--accent);
}

h1 {
  margin: 0 0 0.75rem;
  font-size: 2rem;
  font-weight: 650;
  letter-spacing: -0.03em;
  line-height: 1.3;
}

h2 {
  margin: 3.5rem 0 0.75rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line);
  font-size: 1.4rem;
  letter-spacing: -0.02em;
  line-height: 1.4;
}

h2 .num {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--accent);
}

h3 {
  margin: 2rem 0 0.4rem;
  font-size: 1.05rem;
}

h4 {
  margin: 1.25rem 0 0.25rem;
  font-size: 0.95rem;
}

.lead, .note { color: var(--muted); }
.lead { margin: 0 0 1.5rem; }
.note { font-size: 0.9rem; }

nav ol { margin: 0; padding-left: 1.25rem; }
nav a { color: inherit; }

ul, ol { padding-left: 1.25rem; }
li { margin: 0.3rem 0; }

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.86em;
  padding: 0.05em 0.3em;
  background: #f5f5f4;
  border-radius: 4px;
}

pre {
  overflow-x: auto;
  margin: 0.75rem 0 1rem;
  padding: 0.9rem 1rem;
  background: #1c1917;
  color: #f5f5f4;
  border-radius: 8px;
  font-size: 0.82rem;
  line-height: 1.6;
}

pre code { padding: 0; background: none; font-size: inherit; }

.table-wrap { overflow-x: auto; margin: 0.75rem 0 1rem; }

table {
  width: 100%;
  min-width: 36rem;
  border-collapse: collapse;
  font-size: 0.9rem;
  background: var(--card);
}

th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.6rem 0.7rem;
  border-bottom: 1px solid var(--line);
}

th { font-weight: 600; color: var(--muted); font-size: 0.8rem; white-space: nowrap; }

.card {
  margin: 1rem 0;
  padding: 1rem 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.card > :first-child { margin-top: 0; }
.card > :last-child { margin-bottom: 0; }

.summary {
  border-left: 3px solid var(--accent);
}

.pair {
  display: grid;
  gap: 0.75rem;
  margin: 0.75rem 0 1rem;
}

@media (min-width: 720px) {
  .pair { grid-template-columns: 1fr 1fr; }
}

.bad, .good {
  padding: 0.8rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
}

.bad { background: var(--bad-bg); }
.good { background: var(--good-bg); }

.bad strong { color: var(--bad); }
.good strong { color: var(--good); }

.bad p, .good p { margin: 0.25rem 0 0; }

dl { margin: 0.75rem 0; }
dt { font-weight: 600; margin-top: 0.9rem; }
dd { margin: 0.15rem 0 0; color: var(--muted); }

.check li { list-style: "□ "; }

.label a { color: inherit; }

/* 入門編 */
.goal {
  margin: 1.5rem 0;
  padding: 1.1rem 1.2rem;
  background: #fff7ed;
  border-radius: 10px;
}

.goal > :first-child { margin-top: 0; }
.goal > :last-child { margin-bottom: 0; }

.flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
  margin: 1rem 0;
  font-size: 0.9rem;
}

.flow span {
  padding: 0.45rem 0.75rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 999px;
  white-space: nowrap;
}

.flow span.me { background: #fff7ed; border-color: #fed7aa; }
.flow span.ai { background: #eff6ff; border-color: #bfdbfe; }
.flow i { font-style: normal; color: var(--muted); }

.step {
  margin: 1.25rem 0;
  padding: 1rem 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.step > :first-child { margin-top: 0; }
.step > :last-child { margin-bottom: 0; }

.step-title {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  margin: 0 0 0.5rem;
  font-size: 1rem;
  font-weight: 650;
}

.step-title b {
  flex: none;
  display: inline-grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 0.8rem;
}

.ok {
  margin: 0.75rem 0 0;
  padding: 0.6rem 0.85rem;
  background: var(--good-bg);
  border-radius: 8px;
  font-size: 0.9rem;
}

.ok::before { content: "こうなれば OK： "; font-weight: 650; color: var(--good); }

.warn {
  margin: 0.75rem 0 0;
  padding: 0.6rem 0.85rem;
  background: var(--bad-bg);
  border-radius: 8px;
  font-size: 0.9rem;
}

.warn::before { content: "注意： "; font-weight: 650; color: var(--bad); }

.say {
  margin: 0.6rem 0;
  padding: 0.75rem 1rem;
  background: #eff6ff;
  border-left: 3px solid #3b82f6;
  border-radius: 0 8px 8px 0;
  white-space: pre-wrap;
  font-size: 0.92rem;
}

.say::before {
  display: block;
  content: "AI にこう打ち込む";
  margin-bottom: 0.25rem;
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: #1d4ed8;
}

.words { display: grid; gap: 0.6rem; margin: 1rem 0; }

@media (min-width: 720px) {
  .words { grid-template-columns: 1fr 1fr; }
}

@media (min-width: 960px) {
  .words { grid-template-columns: 1fr 1fr 1fr; }
}

.word {
  padding: 0.8rem 1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.word strong { display: block; }
.word .like { display: block; margin: 0.1rem 0 0.3rem; font-size: 0.85rem; color: var(--accent); }
.word p { margin: 0; font-size: 0.9rem; color: var(--muted); }

.faq { margin: 0.75rem 0; padding: 0.9rem 1.1rem; background: var(--card); border: 1px solid var(--line); border-radius: 8px; }
.faq summary { cursor: pointer; font-weight: 600; }
.faq[open] summary { margin-bottom: 0.5rem; }
.faq > :last-child { margin-bottom: 0; }

.tools { display: grid; gap: 0.6rem; margin: 0.75rem 0 1rem; }

@media (min-width: 720px) {
  .tools { grid-template-columns: 1fr 1fr; }
}

.tool {
  padding: 0.85rem 1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.tool strong { font-size: 0.95rem; }
.tool p { margin: 0.35rem 0 0; font-size: 0.88rem; line-height: 1.7; }
.tool .for { color: var(--muted); font-size: 0.82rem; }
.tool .price { margin-top: 0.45rem; font-size: 0.82rem; }
.tool .price strong { font-size: inherit; }

.next-link {
  display: block;
  margin-top: 1rem;
  padding: 1rem 1.2rem;
  background: var(--ink);
  color: #fff;
  border-radius: 10px;
  text-decoration: none;
}

.next-link small { display: block; color: #d6d3d1; }