:root {
  color-scheme: light;
  --paper: #f5f6f0;
  --ink: #172d26;
  --subtle: #486057;
  --green: #285c46;
  --line: #d5ded4;
  --white: #fffefb;
  font-family: "Hiragino Sans", "Yu Gothic", Meiryo, system-ui, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 22px; }
body { margin: 0; background: var(--paper); color: var(--ink); }
.wrap { width: min(100% - 40px, 920px); margin-inline: auto; }
.masthead { background: var(--white); border-bottom: 1px solid var(--line); }
.brand { display: flex; justify-content: space-between; align-items: center; min-height: 62px; gap: 12px; }
.brand span:first-child { font: 800 1.2rem/1.1 Inter, system-ui, sans-serif; letter-spacing: -.035em; }
.brand span:last-child { color: var(--green); font-size: .83rem; font-weight: 800; }
.hero { padding: 55px 46px 52px; margin-top: 28px; border-radius: 22px; background: #193e31; color: #fffefb; }
.eyebrow { margin: 0 0 8px; color: var(--green); font-size: .77rem; letter-spacing: .09em; font-weight: 850; }
.hero .eyebrow { color: #c9e3cd; }
h1, h2, h3, p { margin: 0; }
h1 { font-size: clamp(1.75rem, 5vw, 3.25rem); line-height: 1.3; letter-spacing: -.055em; }
h1 em { color: #c8e9b6; font-style: normal; }
.hero > p:last-child { margin-top: 17px; color: #f1f7ed; line-height: 1.85; }
a { color: #1d5840; text-underline-offset: .18em; }
a:focus-visible, video:focus-visible { outline: 3px solid #99700d; outline-offset: 4px; }
.jump { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin: 16px 0 30px; }
.jump a { display: grid; grid-template-columns: minmax(0, 96px) 1fr auto; align-items: center; gap: 13px; padding: 10px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); color: var(--ink); text-decoration: none; }
.jump a:hover { background: #e9f1e6; }
.jump img { width: 100%; height: auto; border-radius: 7px; }
.jump small { display: block; margin-bottom: 2px; color: var(--green); font-size: .72rem; font-weight: 850; }
.jump strong { font-size: clamp(.94rem, 2.2vw, 1.16rem); line-height: 1.4; }
.arrow { color: var(--green); font-weight: 850; padding-inline: 5px; }
.lesson { margin-bottom: 20px; padding: 32px 38px; background: var(--white); border: 1px solid var(--line); border-radius: 18px; }
h2 { font-size: clamp(1.4rem, 3.8vw, 2.05rem); letter-spacing: -.045em; line-height: 1.4; }
h3 { font-size: 1rem; line-height: 1.5; }
.subheading { margin-top: 22px; }
.lesson > .detail { margin-top: 5px; }
.lesson > p:not(.eyebrow) { margin-top: 12px; }
.lesson p:not(.eyebrow) { font-size: .96rem; line-height: 1.8; color: var(--subtle); }
.roles { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin: 18px 0; }
.roles > div, .exercise { padding: 14px 16px; border-radius: 10px; background: #edf4ea; }
.roles > div:last-child { background: #f6f0df; }
.roles p, .exercise p { margin-top: 4px; }
.work-examples { margin: 8px 0 18px; }
.work-examples > div { padding: 9px 0; border-bottom: 1px solid var(--line); }
.work-examples dt, h4 { margin: 0; font-size: .92rem; font-weight: 800; }
.work-examples dd { margin: 2px 0 0; color: var(--subtle); font-size: .92rem; line-height: 1.65; }
details { margin-top: 9px; }
summary { padding: 9px 0; color: var(--green); font-weight: 750; cursor: pointer; }
summary:focus-visible { outline: 3px solid #99700d; outline-offset: 2px; }
.help { padding: 0 13px 5px; border: 1px solid var(--line); border-radius: 10px; }
.help p + p, .instructions p + p { margin-top: 8px; }
.os { margin: 9px 0 0; }
.folder-list { padding-left: 1.3rem; color: var(--subtle); }
.folder-list li { margin-bottom: 4px; }
.primary { display: inline-flex; gap: 10px; align-items: center; min-height: 44px; margin-top: 16px; padding: 6px 13px; border-radius: 8px; background: #285c46; color: white; font-weight: 750; text-decoration: none; }
.primary:hover { background: #193e31; }
.demo { margin: 18px 0 20px; max-width: 660px; }
.demo video { display: block; width: 100%; aspect-ratio: 16 / 9; background: #122d23; border-radius: 12px; }
.prompt { margin: 0 0 20px; padding: 14px 16px; border: 1px solid var(--line); border-radius: 10px; background: #edf4ea; }
.prompt p { margin-top: 4px; }
.prompt pre { margin: 12px 0 0; padding: 12px; border-radius: 8px; background: var(--white); white-space: pre-wrap; overflow-wrap: anywhere; font-size: .9rem; line-height: 1.65; }
.prompt button { margin-top: 10px; border: 0; font: inherit; font-weight: 750; cursor: pointer; }
.prompt button[hidden] { display: none; }
.prompt button:focus-visible { outline: 3px solid #99700d; outline-offset: 3px; }
.copy-status { margin-inline-start: 8px; font-size: .85rem; color: var(--green); }
.folder-guide { margin: 13px 0; }
.instructions .folder-guide a { display: block; }
.folder-guide img { display: block; width: 100%; height: auto; border-radius: 10px; border: 1px solid var(--line); }
figcaption { margin-top: 5px; color: var(--subtle); font-size: .8rem; }
.instructions { margin: 0 0 18px; padding-left: 1.45rem; }
.instructions li { padding-left: .25rem; margin-bottom: 13px; }
.instructions li::marker { color: var(--green); font-weight: 850; }
.instructions a { display: inline-flex; align-items: center; min-height: 44px; font-size: .88rem; font-weight: 750; }
code { overflow-wrap: anywhere; }
.footer { display: flex; gap: 10px; justify-content: space-between; padding: 0 0 25px; color: var(--subtle); font-size: .78rem; align-items: center; }
.footer a { display: inline-flex; align-items: center; min-height: 44px; }
@media (max-width: 580px) {
  .wrap { width: calc(100% - 28px); }
  .brand { min-height: 50px; }
  .hero { margin-top: 14px; padding: 25px 17px; border-radius: 14px; }
  .hero > p:last-child { margin-top: 10px; font-size: .89rem; }
  .desktop { display: none; }
  .jump { grid-template-columns: 1fr; gap: 7px; margin: 9px 0 19px; }
  .jump a { grid-template-columns: 72px 1fr auto; gap: 9px; padding: 8px; }
  .lesson { padding: 18px 15px; border-radius: 13px; }
  .roles { grid-template-columns: 1fr; gap: 7px; }
}