/* 教科書 (app/kyokasho/*.html) のスタイル。乙4テーマ (Phase 1 の色に合わせる)。 */
@font-face { font-family: "Dela Gothic One"; src: url(../fonts/dela-gothic-one.woff2) format("woff2"); font-display: swap; }
@font-face { font-family: "Zen Maru Gothic"; src: url(../fonts/zen-maru-gothic-bold.woff2) format("woff2"); font-weight: 700; font-display: swap; }
@font-face { font-family: "Zen Maru Gothic"; src: url(../fonts/zen-maru-gothic-black.woff2) format("woff2"); font-weight: 900; font-display: swap; }
:root { --ink: #1b1d4d; --paper: #fff8ec; --card: #fff; --sign: #c2410c; --sign-bright: #e85d1f; --pink: #e8558f; --muted: #5b5f8f; --line: #d9daf0; --soft: #fdf0e6;
  --text: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", "Noto Sans JP", sans-serif;
  --round: "Zen Maru Gothic", "Hiragino Maru Gothic ProN", "Hiragino Sans", "Yu Gothic", sans-serif;
  --chunky: "Dela Gothic One", "Zen Maru Gothic", "Hiragino Sans", sans-serif; color-scheme: light; }
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--text); font-size: 16px; line-height: 1.85;
  background-image: linear-gradient(rgba(194,65,12,.07) 1px, transparent 1px), linear-gradient(90deg, rgba(194,65,12,.07) 1px, transparent 1px); background-size: 28px 28px; }
.wrap { max-width: 760px; margin: 0 auto; padding-block: calc(24px + env(safe-area-inset-top, 0px)) calc(48px + env(safe-area-inset-bottom, 0px));
  padding-left: max(16px, env(safe-area-inset-left, 0px)); padding-right: max(16px, env(safe-area-inset-right, 0px)); display: grid; gap: 18px; }
.topnav { display: flex; justify-content: space-between; font-family: var(--round); font-weight: 900; }
.topnav a { color: var(--ink); text-decoration: none; padding: 6px 14px; border: 3px solid var(--ink); border-radius: 14px; background: var(--card); box-shadow: 0 4px 0 var(--ink); }
.plate { justify-self: start; background: var(--sign); color: #fff; border: 4px solid var(--ink); border-radius: 12px; box-shadow: 0 6px 0 var(--ink); padding: 4px; max-width: 100%; }
.plate p { margin: 0; padding: 6px 18px 0; font-family: var(--round); font-weight: 900; font-size: 13px; letter-spacing: .08em; }
.plate h1 { margin: 0; padding: 2px 18px 10px; border: 3px solid #fff; border-radius: 8px; font-family: var(--chunky); font-weight: 400; font-size: clamp(24px, 7vw, 34px); line-height: 1.3; }
.card { background: var(--card); border: 3px solid var(--ink); border-radius: 18px; padding: 18px 20px; box-shadow: 0 5px 0 var(--ink); }
.card h2 { margin: 0 0 8px; font-family: var(--chunky); font-weight: 400; font-size: 21px; line-height: 1.4; display: flex; gap: 10px; align-items: baseline; }
.card h2 .no { flex: none; display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--sign); color: #fff; font-size: 15px; font-family: var(--round); font-weight: 900; }
.card p { margin: 8px 0 0; }
.card ul, .card ol { margin: 8px 0 0; padding-left: 1.3em; }
.card li + li { margin-top: 5px; }
.goal { margin: 8px 0 0; padding-left: 1.3em; }
b.k, .k { color: var(--sign); }
.fig { margin: 14px 0 4px; padding: 14px; border: 2px solid var(--line); border-radius: 14px; background: #fffdf8; }
.fig .cap { margin: 10px 0 0; font-size: 14px; color: var(--muted); }
.vs { display: grid; gap: 8px; }
@media (min-width: 560px) { .vs { grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); } }
.vs > div { padding: 10px 12px; border-radius: 12px; border: 2px solid var(--ink); font-size: 14px; line-height: 1.6; }
.vs .h { display: block; font-family: var(--round); font-weight: 900; margin-bottom: 4px; }
.vs .blue { background: #e8f0fe; }
.vs .pinkb { background: #ffe3ee; }
.vs .yel { background: #fff3c4; }
.vs .grn { background: #dcf5e6; }
.box { margin: 12px 0 0; padding: 10px 14px; border-radius: 12px; font-size: 15px; }
.box.tip { background: var(--soft); border: 2px dashed var(--sign); }
.tree { text-align: center; }
.tree .root { display: inline-block; padding: 6px 18px; border: 3px solid var(--ink); border-radius: 12px; background: var(--sign); color: #fff; font-family: var(--round); font-weight: 900; }
.tree .kids { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-top: 12px; }
.tree .kids > div { flex: 1 1 140px; max-width: 220px; padding: 10px; border: 2px solid var(--ink); border-radius: 12px; background: #fff; font-size: 14px; }
.stamp { display: inline-block; margin-top: 6px; padding: 0 10px; border: 2px solid var(--sign); border-radius: 6px; color: var(--sign); font-family: var(--round); font-weight: 900; font-size: 13px; }
table.spec { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 14px; }
table.spec th, table.spec td { border: 2px solid var(--line); padding: 6px 10px; text-align: left; }
table.spec th { background: var(--soft); font-family: var(--round); }
.okng { display: grid; gap: 8px; margin-top: 10px; }
.okng > div { padding: 8px 12px; border-radius: 10px; font-size: 15px; }
.okng .good { background: #dcf5e6; }
.okng .bad { background: #ffe0e0; }
.q { margin-top: 12px; padding: 12px 14px; border: 3px solid var(--ink); border-radius: 14px; background: #fffdf8; }
.q .qq { font-family: var(--round); font-weight: 900; }
.q ol { margin: 8px 0 0; padding-left: 1.4em; }
.q .ans { margin-top: 10px; padding: 8px 12px; border-radius: 10px; background: var(--soft); font-size: 15px; }
.cta { justify-self: center; display: inline-flex; padding: 10px 22px; border-radius: 16px; background: var(--pink); color: #fff; text-decoration: none; font-family: var(--round); font-weight: 900; border: 3px solid var(--ink); box-shadow: 0 5px 0 var(--ink); }
.src { color: var(--muted); font-size: 13px; }
.pager { display: flex; justify-content: space-between; gap: 10px; }
.pager a { flex: 1; padding: 8px 14px; border: 3px solid var(--ink); border-radius: 14px; background: var(--card); color: var(--ink); text-decoration: none; font-family: var(--round); font-weight: 900; box-shadow: 0 4px 0 var(--ink); }
.pager a.next { text-align: right; }
.pager a small { display: block; color: var(--muted); font-size: 12px; }
.toc-group ul.toc-list { list-style: none; margin: 8px 0 0; padding: 0; display: grid; gap: 8px; }
.toc-list li a { display: flex; gap: 10px; align-items: center; padding: 8px 12px; border: 2px solid var(--ink); border-radius: 12px; background: #fff; color: var(--ink); text-decoration: none; }
.toc-list .st { flex: none; display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; background: var(--sign); color: #fff; font-size: 12px; font-weight: 700; }
.toc-list small { display: block; color: var(--muted); font-size: 12px; }
footer { text-align: center; color: var(--muted); font-size: 13px; }
a { color: var(--sign); }
a:focus-visible { outline: 3px solid var(--pink); outline-offset: 2px; }