:root {
  color: #15213b;
  background: #f7f3eb;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Noto Sans JP", sans-serif;
  line-height: 1.65;
}
* { box-sizing: border-box; }
body { margin: 0; min-width: 320px; background: radial-gradient(circle at 8% 0%, #ffdf9e 0, transparent 27rem), radial-gradient(circle at 95% 18%, #b8e9ea 0, transparent 28rem), #f7f3eb; }
button { font: inherit; }
button:focus-visible, summary:focus-visible { outline: 3px solid #ee6d5f; outline-offset: 3px; }
.app { width: min(1120px, calc(100% - 32px)); margin: 0 auto; padding: 28px 0 72px; }
.hero { display: grid; grid-template-columns: 1.25fr .75fr; gap: 26px; align-items: end; padding: clamp(24px, 6vw, 66px) 0 34px; }
.eyebrow { margin: 0 0 10px; color: #b54841; font-size: .76rem; font-weight: 800; letter-spacing: .13em; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 10ch; margin-bottom: 18px; font-family: Georgia, "Noto Serif JP", serif; font-size: clamp(2.8rem, 8vw, 6.3rem); line-height: .98; letter-spacing: -.075em; }
.lead { max-width: 38rem; color: #4b5974; font-size: clamp(1rem, 2vw, 1.18rem); }
.cat-card { min-height: 190px; padding: 23px; border: 2px solid #15213b; border-radius: 28px 28px 28px 4px; background: #15213b; color: #fffdf7; box-shadow: 9px 9px 0 #ee6d5f; }
.cat-card .cat { display: block; margin-bottom: 9px; font-size: 4.3rem; line-height: 1; }.cat-card p { margin: 0; color: #d8e8ff; }.cat-card strong { color: #ffcf70; }
.progress-panel { display: grid; grid-template-columns: 1fr auto; gap: 12px; align-items: center; padding: 15px 18px; border: 1px solid #ccd0d8; border-radius: 18px; background: #fffdf8c9; }.progress-panel p { margin: 0; font-weight: 800; }.progress-panel small { color: #59667e; }.progress-panel progress { grid-column: 1 / -1; width: 100%; height: 11px; accent-color: #ee6d5f; }
.layout { display: grid; grid-template-columns: 280px minmax(0, 1fr); gap: 24px; margin-top: 22px; }.lesson-menu { align-self: start; position: sticky; top: 16px; padding: 13px; border: 1px solid #ccd0d8; border-radius: 22px; background: #fffdf8d9; }.lesson-menu h2 { margin: 7px 8px 13px; font-size: 1rem; }.lesson-menu button { display: flex; width: 100%; gap: 10px; align-items: center; padding: 12px; border: 0; border-radius: 13px; background: transparent; color: #34415c; text-align: left; cursor: pointer; }.lesson-menu button:hover { background: #f2eee5; }.lesson-menu button[aria-current="true"] { background: #15213b; color: #fff; }.check { color: #2a9c76; font-weight: 900; }.lesson-menu button[aria-current="true"] .check { color: #ffcf70; }
.lesson { overflow: hidden; border: 1px solid #ccd0d8; border-radius: 26px; background: #fffdf8d9; box-shadow: 0 16px 50px #20345612; }.lesson-header { padding: clamp(22px, 4vw, 40px) clamp(20px, 4vw, 44px) 25px; background: linear-gradient(135deg, #fbe5d0, #d8f0ef); }.lesson-header h2 { max-width: 18ch; margin-bottom: 10px; font-family: Georgia, "Noto Serif JP", serif; font-size: clamp(1.8rem, 4vw, 3rem); line-height: 1.13; letter-spacing: -.04em; }.lesson-header p { max-width: 43rem; margin: 0; color: #47546b; }.content { padding: clamp(20px, 4vw, 44px); }.idea { display: grid; grid-template-columns: auto 1fr; gap: 15px; margin-bottom: 27px; padding: 17px; border-left: 5px solid #ee6d5f; background: #fff2e5; }.idea .number { display: grid; width: 32px; height: 32px; place-items: center; border-radius: 50%; background: #ee6d5f; color: #fff; font-weight: 900; }.idea p { margin: 0; }
.code-lab { margin: 28px 0; border-radius: 18px; overflow: hidden; background: #15213b; box-shadow: 6px 6px 0 #8bcfd0; }.code-top { display: flex; justify-content: space-between; padding: 10px 14px; background: #26395e; color: #d9e6ff; font-size: .78rem; }.dots { letter-spacing: .2em; color: #ffcf70; }.code-lab pre { overflow: auto; margin: 0; padding: 22px; color: #eef4ff; font-family: "SFMono-Regular", Consolas, monospace; font-size: .9rem; line-height: 1.8; }.code-lab code b { color: #ffcf70; }.code-lab code em { color: #8ee6dd; font-style: normal; }.playground { display: grid; grid-template-columns: 1fr auto; gap: 18px; align-items: center; padding: 20px; border: 2px dashed #8bcfd0; border-radius: 18px; background: #edfafa; }.playground p { margin: 0; }.big-count { color: #b54841; font-family: Georgia, serif; font-size: 2rem; font-weight: 800; }.primary, .secondary { border: 0; border-radius: 12px; padding: 12px 17px; font-weight: 800; cursor: pointer; }.primary { background: #ee6d5f; color: #fff; box-shadow: 3px 3px 0 #9b3a36; }.primary:hover { background: #d85c50; }.secondary { background: #fffdf8; color: #26395e; border: 1px solid #aeb6c5; }.secondary:hover { background: #f2eee5; }
.quiz { margin-top: 30px; padding: 20px; border: 1px solid #ccd0d8; border-radius: 18px; background: #f3f5fa; }.quiz h3 { margin-bottom: 7px; }.options { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin-top: 15px; }.option { min-height: 65px; border: 1px solid #bcc4d2; border-radius: 12px; background: #fff; color: #26395e; cursor: pointer; }.option:hover { border-color: #ee6d5f; }.result { margin: 14px 0 0; font-weight: 800; }.success { color: #167152; }.wrong { color: #a6403a; }.lesson-footer { display: flex; justify-content: space-between; gap: 16px; align-items: center; margin-top: 35px; padding-top: 22px; border-top: 1px solid #d7d9df; }.lesson-footer p { margin: 0; color: #59667e; }
details { margin-top: 20px; padding: 15px 17px; border-radius: 13px; background: #f6f0e7; } summary { cursor: pointer; font-weight: 800; } details p { margin: 10px 0 0; color: #4b5974; }
.reset { display: block; margin: 28px auto 0; background: transparent; color: #59667e; text-decoration: underline; cursor: pointer; border: 0; }
@media (max-width: 760px) { .hero, .layout { grid-template-columns: 1fr; }.cat-card { min-height: auto; }.lesson-menu { position: static; display: grid; grid-template-columns: repeat(2, 1fr); }.lesson-menu h2 { grid-column: 1 / -1; }.playground { grid-template-columns: 1fr; }.options { grid-template-columns: 1fr; }.lesson-footer { align-items: flex-start; flex-direction: column; } }
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; animation: none !important; } }