:root {
  --ink: #173028;
  --soft: #3e554b;
  --muted: #6d7f76;
  --paper: #f3f1ea;
  --card: #fffcf7;
  --line: #e3dfd4;
  --green: #1b8a52;
  --green-deep: #0f5c36;
  --mint: #e7f5ec;
  --shadow: 0 30px 70px rgba(18, 58, 36, 0.14);
  --radius: 28px;
  --max: 1080px;
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Zen Kaku Gothic New", "Hiragino Sans", "Hiragino Kaku Gothic ProN", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(900px 420px at 100% -10%, #dff5e6 0%, transparent 60%),
    var(--paper);
  line-height: 1.7;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
p { margin: 0; }

.skip {
  position: absolute;
  left: 12px;
  top: -40px;
  background: var(--ink);
  color: white;
  padding: 8px 12px;
  border-radius: 8px;
  z-index: 10;
}
.skip:focus { top: 12px; }

.nav {
  position: sticky;
  top: 0;
  z-index: 5;
  backdrop-filter: blur(16px);
  background: rgba(243, 241, 234, 0.82);
  border-bottom: 1px solid transparent;
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 28px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.01em;
}
.brand img {
  width: 36px;
  height: 36px;
  border-radius: 9px;
}
.nav-links {
  display: flex;
  gap: 22px;
  margin-right: auto;
  font-size: 14px;
  color: var(--soft);
}
.nav-links a { text-decoration: none; }
.nav-links a:hover { color: var(--ink); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--green);
  color: white;
  text-decoration: none;
  font-weight: 700;
  border-radius: 999px;
  padding: 12px 22px;
  box-shadow: 0 8px 20px rgba(27, 138, 82, 0.22);
}
.btn:hover { background: var(--green-deep); }
.btn-small { padding: 8px 16px; font-size: 14px; box-shadow: none; }
.btn-quiet {
  background: transparent;
  color: var(--ink);
  box-shadow: none;
  border: 1px solid var(--line);
}
.btn-quiet:hover { background: white; }

.hero {
  max-width: var(--max);
  margin: 0 auto;
  padding: 72px 24px 28px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}
.eyebrow {
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--green);
}
h1, h2, h3 { line-height: 1.25; letter-spacing: -0.02em; margin: 0; }
h1 {
  font-size: clamp(64px, 9vw, 104px);
  font-weight: 900;
  letter-spacing: -0.045em;
  line-height: 0.95;
}
.tagline {
  margin-top: 18px;
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.25;
}
h2 { font-size: clamp(28px, 3vw, 40px); font-weight: 900; }
.lede {
  margin-top: 20px;
  font-size: 18px;
  color: var(--soft);
  max-width: 38em;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.fine {
  margin-top: 16px;
  color: var(--muted);
  font-size: 13px;
}
.hero-art {
  justify-self: center;
  width: min(420px, 100%);
  padding: 36px;
  border-radius: 48px;
  background:
    radial-gradient(80% 60% at 28% 18%, #f3fff4 0%, transparent 55%),
    radial-gradient(70% 60% at 80% 8%, rgba(255, 255, 255, 0.45), transparent 50%),
    linear-gradient(165deg, #b7ebc8 0%, #46be78 46%, #1d7a4c 100%);
  box-shadow: var(--shadow);
}
.hero-art img { width: 100%; height: auto; }

.stage {
  max-width: var(--max);
  margin: 12px auto 20px;
  padding: 0 24px 40px;
}
.window {
  background: #f7f8f6;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.7);
}
.titlebar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: #eceee9;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
}
.dots { display: flex; gap: 6px; }
.dots i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  display: block;
  background: #d0d4cc;
}
.dots i:first-child { background: #ee6a5f; }
.dots i:nth-child(2) { background: #f5bd4f; }
.dots i:nth-child(3) { background: #61c554; }
.workspace {
  display: grid;
  grid-template-columns: 200px 1fr 230px;
  min-height: 340px;
  background: white;
}
.pane { padding: 16px; }
.side { background: #f4f6f3; border-right: 1px solid var(--line); }
.preview { border-left: 1px solid var(--line); background: #fcfdfb; }
.tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  background: #e7ebe6;
  border-radius: 9px;
  padding: 3px;
  font-size: 12px;
  text-align: center;
}
.tabs span { padding: 5px 0; border-radius: 7px; color: var(--soft); }
.tabs .on { background: white; color: var(--ink); font-weight: 700; }
.pane-label {
  margin: 16px 0 8px;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.tree, .tree ul { list-style: none; margin: 0; padding: 0; font-size: 14px; }
.tree li { padding: 4px 0 4px 14px; color: var(--soft); }
.tree .open { color: var(--ink); font-weight: 700; padding-left: 0; }
.tree .current {
  background: var(--mint);
  color: var(--green-deep);
  border-radius: 8px;
  padding: 4px 8px;
  margin-left: 8px;
  font-weight: 700;
}
.docbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}
.pill {
  font-size: 12px;
  background: var(--mint);
  color: var(--green-deep);
  border-radius: 999px;
  padding: 4px 10px;
  font-weight: 700;
}
.source { color: #5c6b63; font-size: 14px; }
.source p { margin: 0 0 8px; }
.source b { color: var(--ink); }
.preview h2 { color: var(--green); font-size: 26px; margin-bottom: 8px; }
.preview h3 { font-size: 16px; margin: 14px 0 6px; }
.checks { margin: 8px 0 0; padding: 0; list-style: none; font-size: 14px; }
.checks li { padding-left: 22px; position: relative; margin: 6px 0; }
.checks li::before {
  content: "";
  width: 13px;
  height: 13px;
  border: 1.5px solid #b7c4bc;
  border-radius: 4px;
  position: absolute;
  left: 0;
  top: 4px;
}
.checks .done { color: var(--muted); text-decoration: line-through; }
.checks .done::before { background: var(--green); border-color: var(--green); }

.section, .split {
  max-width: var(--max);
  margin: 0 auto;
  padding: 72px 24px;
  scroll-margin-top: 76px;
}
.cmd {
  font-family: "Hiragino Sans", "SF Pro Text", system-ui, sans-serif;
  font-weight: 500;
}
.section-head { max-width: 640px; margin-bottom: 32px; }
.section-head p:last-child, .split p { color: var(--soft); margin-top: 14px; }
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 24px;
}
.card h3 { font-size: 22px; margin-bottom: 10px; }
.card p { color: var(--soft); }

.split {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}
.points { margin: 20px 0 0; padding: 0; list-style: none; }
.points li {
  padding: 10px 0 10px 18px;
  border-top: 1px solid var(--line);
  position: relative;
}
.points li::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--green);
  position: absolute;
  left: 0;
  top: 18px;
}
.folder {
  background: var(--card);
  border-radius: var(--radius);
  border: 1px solid var(--line);
  padding: 28px;
  box-shadow: 0 16px 40px rgba(23, 48, 40, 0.05);
}
.folder > p { font-weight: 700; margin-bottom: 12px; }
.folder ul { list-style: none; margin: 0; padding: 0; }
.folder li {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}
.folder span {
  color: var(--ink);
  font-weight: 700;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.keys { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.keys span {
  border: 1px solid var(--line);
  background: white;
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 700;
}
.day { list-style: none; margin: 0; padding: 0; }
.day li {
  background: var(--card);
  border-radius: 20px;
  padding: 18px 20px;
  margin-bottom: 12px;
  border: 1px solid var(--line);
}
.day span {
  display: block;
  font-weight: 900;
  color: var(--green);
  margin-bottom: 4px;
}
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  counter-reset: step;
}
.steps li {
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--line);
  counter-increment: step;
}
.steps li::before {
  content: counter(step);
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--mint);
  color: var(--green-deep);
  font-weight: 900;
  margin-bottom: 14px;
}
.steps p { color: var(--soft); margin-top: 8px; }
.watch {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 28px;
  align-items: end;
}
.watch figure { margin: 0; }
.watch iframe {
  width: 100%;
  border: 0;
  border-radius: 22px;
  background: #173028;
  display: block;
  box-shadow: var(--shadow);
}
.watch .short iframe { aspect-ratio: 9 / 16; }
.watch .guide iframe { aspect-ratio: 16 / 9; }
.watch figcaption {
  margin-top: 10px;
  font-weight: 700;
}
.watch figcaption a { text-decoration: none; }
.watch figcaption a:hover { text-decoration: underline; }
.faqs { display: grid; gap: 12px; }
.faqs article {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 22px 24px;
}
.faqs h3 { font-size: 18px; margin-bottom: 8px; }
.faqs p { color: var(--soft); }
.cta {
  max-width: 760px;
  margin: 20px auto 80px;
  text-align: center;
  padding: 48px 24px;
  background:
    radial-gradient(80% 80% at 50% 0%, #e8f8ee, transparent 70%),
    var(--card);
  border: 1px solid var(--line);
  border-radius: 36px;
}
.cta img {
  width: 88px;
  height: 88px;
  margin: 0 auto 16px;
  border-radius: 22px;
}
.cta p { color: var(--soft); margin: 12px auto 22px; max-width: 36em; }
.foot {
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px 24px 48px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-size: 14px;
  border-top: 1px solid var(--line);
}
.foot a { color: var(--green-deep); font-weight: 700; text-decoration: none; }
.foot-links { display: flex; gap: 20px; }
.foot strong { color: var(--ink); }

@media (max-width: 860px) {
  .nav-links { display: none; }
  .hero, .split, .cards, .steps, .workspace, .watch { grid-template-columns: 1fr; }
  .hero { padding-top: 40px; }
  .preview { display: none; }
  .side { border-right: 0; border-bottom: 1px solid var(--line); }
  .reverse { display: flex; flex-direction: column-reverse; }
  .foot { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}