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@media(max-width:760px){.foundation-grid{grid-template-columns:1fr}}
@media(max-width:760px){.base-jump{align-items:stretch;flex-direction:column}.base-jump button{width:100%}}
.challenge-button{width:100%;margin-top:12px;padding:15px;border:0;border-radius:14px;background:#263f3a;color:#fff;font-weight:900;cursor:pointer}.challenge-button:hover{background:#31564e}.challenge-score{display:flex;align-items:baseline;justify-content:center;gap:8px;margin:26px auto;padding:24px;border-radius:20px;background:#fff2cd;color:#7b5312}.challenge-score strong{font-family:serif;font-size:68px;line-height:1}.challenge-score span{font-weight:900}.result-list{display:grid;gap:9px;margin:26px 0}.result-list>div{display:grid;grid-template-columns:38px 1fr;align-items:center;gap:10px;padding:13px 15px;border-radius:13px;background:#edf5f0}.result-list>div.incorrect{background:#fff0dd}.result-list>div>b{display:grid;place-items:center;width:32px;height:32px;border-radius:50%;background:#4f8578;color:#fff}.result-list .incorrect>b{background:#ef6c4d}.result-list span{display:grid;gap:3px}.result-list small{color:#6f7d78}.review-links{display:grid;gap:9px;margin:32px 0;padding-top:24px;border-top:1px solid #ded8ca}.review-links button{display:grid;grid-template-columns:90px 1fr 18px;align-items:center;gap:10px;padding:14px;border:1px solid #d3e1d8;border-radius:13px;background:#fff;color:#21302e;text-align:left;cursor:pointer}.review-links button>span{color:#ef6c4d;font-size:11px;font-weight:900}.review-links button>b{color:#4f8578}.challenge-result{text-align:center}.challenge-result .result-list,.challenge-result .review-links{text-align:left}
@media(max-width:760px){.challenge-score strong{font-size:56px}.review-links button{grid-template-columns:78px 1fr 15px;font-size:12px}}
.session-progress{display:grid;grid-template-columns:1fr auto;align-items:end;gap:8px 14px;margin:4px 0 18px;padding:16px 18px;border-radius:15px;background:#263f3a;color:#fff}.session-progress>div:first-child{display:flex;align-items:baseline;justify-content:space-between;gap:12px}.session-progress span{font-size:13px;font-weight:800}.session-progress span strong{color:#f8d96f;font-size:25px}.session-progress small{color:#b8d7ce}.session-bar{grid-column:1/2;height:7px;border-radius:9px;background:#ffffff2b;overflow:hidden}.session-bar i{display:block;height:100%;border-radius:9px;background:#f8d96f;transition:.35s}.session-progress button{grid-column:2;grid-row:1/3;border:0;background:none;color:#c8d9d4;font-size:11px;text-decoration:underline;cursor:pointer}.lesson-grid button.completed{border-color:#79a99d;background:#edf5f0}.lesson-grid button.completed>b{display:grid;place-items:center;width:22px;height:22px;border-radius:50%;background:#4f8578;color:#fff}
@media(max-width:760px){.session-progress{grid-template-columns:1fr}.session-progress button{grid-column:1;grid-row:auto;justify-self:end}}
.support-actions{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:12px}.support-actions button{min-height:44px;border:1px solid #d3e1d8;border-radius:11px;background:#f1f6f1;color:#315f55;font-size:12px;font-weight:900;cursor:pointer}.support-actions button:hover{border-color:#4f8578;background:#e8f1e8}.map-flow{display:grid;gap:18px;margin:30px 0}.map-level{padding:21px;border:1px solid #d3e1d8;border-radius:18px;background:#edf5f0}.map-level.foundation{border-color:#e5d8b8;background:#fff8e6}.map-lessons{display:grid;grid-template-columns:repeat(2,1fr);gap:7px}.map-lessons button{display:flex;align-items:center;gap:8px;padding:10px;border:0;border-radius:9px;background:#fff;color:#315f55;text-align:left;cursor:pointer}.map-lessons i{display:grid;place-items:center;flex:0 0 24px;height:24px;border-radius:50%;background:#ef6c4d;color:#fff;font-style:normal;font-size:11px;font-weight:900}.map-arrow{text-align:center;color:#71807a;font-size:12px;font-weight:900}.prerequisite-map{display:grid;grid-template-columns:1fr 1fr;gap:9px}.prerequisite-map section{margin:0;padding:12px;border:0;border-radius:11px;background:#fff;text-align:left}.base-title{display:flex;align-items:center;gap:9px;width:100%;padding:0;border:0;background:none;color:#21302e;text-align:left;cursor:pointer}.base-title>i{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:#f8d96f;font-style:normal;font-weight:900}.base-title>span{display:grid}.base-title small{color:#80775e}.prerequisite-map section>div{display:flex;flex-wrap:wrap;gap:5px;margin-top:10px}.prerequisite-map section>div button{padding:5px 7px;border:1px solid #d3e1d8;border-radius:7px;background:#f1f6f1;color:#315f55;font-size:10px;font-weight:900;cursor:pointer}.guide-steps{display:grid;gap:12px;margin:28px 0}.guide-steps section{display:grid;grid-template-columns:48px 1fr;align-items:start;gap:14px;margin:0;padding:19px;text-align:left}.guide-steps>section>i{display:grid;place-items:center;width:44px;height:44px;border-radius:50%;background:#f8d96f;color:#5a4c20;font-style:normal;font-size:20px;font-weight:900}.guide-steps h2{margin:0 0 5px;font-family:serif}.guide-steps p{margin:0;color:#66736f}.privacy-note{padding:19px;border-left:4px solid #4f8578;border-radius:0 13px 13px 0;background:#edf5f0}.privacy-note p{margin:7px 0 0;color:#53645e;line-height:1.8}
button:focus-visible,input:focus-visible{outline:4px solid #79a99d;outline-offset:3px}@media(max-width:760px){.support-actions{grid-template-columns:1fr 1fr 1fr}.map-lessons,.prerequisite-map{grid-template-columns:1fr}.guide-steps section{grid-template-columns:40px 1fr;padding:16px}.guide-steps>section>i{width:38px;height:38px}}
.wrong-actions{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:12px 0}.wrong-actions button{min-height:44px;border:1px solid #d8c49b;border-radius:10px;background:#fff8e6;color:#6c5824;font-weight:900;cursor:pointer}.rescue{text-align:center}.rescue>b{display:inline-block;margin-bottom:15px;padding:7px 12px;border-radius:99px;background:#fff0dd;color:#a04d2d}.rescue-actions{margin-top:25px}@media(max-width:760px){.wrong-actions{grid-template-columns:1fr}}
/* 平面上の内分 */
.plane-figure{display:block;width:100%;max-width:420px;height:auto;margin:20px auto}.plane-answers .answer{display:flex;flex-wrap:wrap;gap:12px;margin:12px 0}.plane-answers label{font-size:18px;min-width:4em}.plane-answers input{min-width:0;width:88px}.plane-answers .minus-button{flex-shrink:0}
/* 小画面でも座標ごとに入力欄と符号ボタンをまとめる */
.plane-answers .answer{gap:10px;flex-wrap:nowrap}
.plane-answers label{margin:0;min-width:3.4em;flex-shrink:0}
@media(max-width:760px){article>section.plane-figure-section{padding:20px 12px}}
@media(max-width:400px){article>section.plane-answers{padding-left:12px;padding-right:12px}.plane-answers input{width:80px;flex:0 1 80px}.plane-answers .minus-button{flex:0 0 48px;min-width:48px}}
.plane-formula strong{overflow-wrap:anywhere;min-width:0;font-size:clamp(16px,3.2vw,21px);line-height:1.9}
@media(max-width:400px){.quiz-choices button{font-size:19px;padding-left:3px;padding-right:3px}}
@media(max-width:400px){.plane-formula{padding-left:12px;padding-right:12px}}
.course-group{margin:24px 0;padding:0;border:0;background:none;text-align:left}.course-group h2{font-size:22px;margin:0 0 12px}.course-note{color:#53645e;line-height:1.8}
@media(max-width:760px){aside #lesson-number{margin-right:.6em}}
/* 授業問題への橋渡し：入力ラベルを上に置き、小画面でも関連を保つ */
.bridge-page h1{font-family:inherit;font-size:clamp(24px,3.5vw,32px);line-height:1.65;overflow-wrap:anywhere}
.bridge-page h2{font-size:20px;line-height:1.7;overflow-wrap:anywhere}
.bridge-page .primary{height:auto;min-height:54px;padding:14px 12px;line-height:1.7}
.bridge-page .bridge-work{padding:18px 12px;text-align:left}
.bridge-page .steps-card p{font-size:18px;line-height:1.85;overflow-wrap:anywhere}
.bridge-help{line-height:1.9;color:#53645e}
.bridge-fields{display:grid;gap:20px;margin:24px 0}
.bridge-fields label{margin:0 0 6px;letter-spacing:0;font-size:17px}
.bridge-control{display:flex;gap:8px;align-items:center}
.bridge-control input,.bridge-control select{min-width:0;width:100%;flex:1;height:54px;padding:8px;border:2px solid #5c8e82;border-radius:12px;background:#fff;color:#21302e;font-size:23px}
.bridge-control button{flex:0 0 44px;width:44px;height:48px;border:2px solid #5c8e82;border-radius:10px;background:#fff;color:#315f55;font-size:23px;cursor:pointer}
.bridge-list{display:grid;gap:10px;margin:24px 0}.bridge-list button{padding:16px;min-height:48px;border:1px solid #c9dbd1;border-radius:12px;background:#f1f6f1;text-align:left;color:#21302e;font-size:16px;line-height:1.6;cursor:pointer}
.bridge-figure{margin:18px 0;background:#fff;border-radius:14px;padding:0}.bridge-figure svg{display:block;width:100%;height:auto;max-width:420px;margin:auto}.bridge-figure figcaption{font-size:14px;line-height:1.8;color:#53645e}
.bridge-control{flex-wrap:wrap}.bridge-control input{flex-basis:100%}.bridge-control button{min-width:44px}
.bridge-page .choices{grid-template-columns:1fr}