/* 2次方程式。共通のg-/u-/c-/f-クラスを上書きしない。 */
*{box-sizing:border-box}body{margin:0;background:#fffdf7;color:#161616;font-family:"BIZ UDPGothic","Hiragino Sans","Yu Gothic","Meiryo",sans-serif;font-size:17px;line-height:1.85}a{color:#1f4e79;text-underline-offset:4px}button,input,textarea{font:inherit}button,.qn-button{min-height:48px;padding:10px 18px;border:3px solid #161616;border-radius:12px;background:#ffe14d;color:#161616;font-weight:700;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;line-height:1.5;box-shadow:3px 3px 0 #161616}button:hover,.qn-button:hover{background:#fff4b8}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #1f4e79;outline-offset:4px}.skip-link{position:absolute;left:8px;top:-100px;background:#fff;padding:12px;z-index:100}.skip-link:focus{top:8px}.breadcrumb{max-width:1080px;margin:10px auto;padding:0 16px;font-size:16px}.breadcrumb ol{display:flex;flex-wrap:wrap;gap:6px;list-style:none;padding:0}.breadcrumb li+li:before{content:" ＞ ";color:#555}
.qn-main{width:min(100% - 32px,920px);margin:24px auto 48px;overflow-wrap:anywhere}.qn-main h1{font-size:clamp(30px,5vw,44px);line-height:1.4;margin:12px 0 20px}.qn-main h2{font-size:clamp(22px,3vw,28px);line-height:1.5;margin:38px 0 16px;border-left:7px solid #d08000;padding-left:14px}.qn-main h3{font-size:20px;line-height:1.5}.qn-main p{margin:14px 0}.qn-kicker{font-weight:700;color:#775000;font-size:16px}.qn-hero{padding:24px 30px 20px;border:3px solid #161616;border-radius:20px;background:#fff4b8;box-shadow:5px 5px 0 #161616}.qn-hero h1{font-size:clamp(38px,6vw,56px)}.qn-lead{font-size:clamp(22px,3vw,30px);font-weight:700;line-height:1.7}.qn-mascot{display:flex;align-items:center;gap:18px;margin-top:20px}.qn-mascot img{flex:0 0 auto}.qn-mascot p{border:2px solid #161616;background:white;border-radius:16px;padding:12px 18px;margin:0;font-weight:700}.qn-start{margin:28px 0;padding:20px 26px;border:3px solid #161616;border-radius:16px;background:#fff;box-shadow:4px 4px 0 #161616}.qn-start h2{border:0;padding:0;margin:8px 0;font-size:24px}.qn-entry{padding:4px 22px 22px;border:2px dashed #9c5e00;border-radius:14px}.qn-chapters{list-style:none;padding:0;display:grid;gap:14px}.qn-chapters li a{display:flex;align-items:center;gap:18px;border:2px solid #161616;border-radius:14px;padding:18px;background:white;text-decoration:none;color:#161616}.qn-chapters li a:hover{background:#fff4b8}.qn-ch-number{font-weight:800;color:#775000;font-size:28px}.qn-chapters b{font-size:20px}.qn-chapters small{display:block;font-size:16px;color:#444;margin-top:4px}.qn-chapters li a>span:nth-child(2){flex:1}.qn-actions{display:flex;gap:16px;flex-wrap:wrap;margin:24px 0}.qn-secondary{background:white}.qn-tags{display:flex;flex-wrap:wrap;gap:10px}.qn-tags a{border:2px solid #161616;padding:6px 12px;border-radius:24px;background:white}.qn-problems{padding-left:26px}.qn-problems li{padding:14px 4px;border-bottom:1px solid #bcbcbc}.qn-problems a{display:block;text-decoration:none}.qn-problems a span{display:block;color:#333}.qn-status{font-size:16px;color:#555}.qn-page-nav{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;border-top:2px solid #161616;padding:24px 0;margin-top:32px}.qn-page-nav a{min-height:44px;display:flex;align-items:center}.qn-goal,.qn-key,.qn-experiment,.qn-course{background:#fff4b8;padding:18px 22px;border:2px solid #161616;border-radius:14px}.qn-statement{font-size:21px;font-weight:700;padding:24px;background:white;border:3px solid #161616;border-radius:14px}.qn-main details{border:2px solid #161616;border-radius:12px;background:white;margin:16px 0;padding:0 18px}.qn-main summary{font-size:18px;font-weight:700;cursor:pointer;padding:14px 0;min-height:48px}.qn-main details[open]{padding-bottom:18px}.qn-main details p:last-child{margin-bottom:0}.qn-equation{font-size:20px;line-height:2;padding:16px;background:#f4f6f7;border-radius:10px;margin:14px 0;overflow-wrap:anywhere}.qn-equation strong{color:#9c5e00}.qn-answer{font-size:22px;font-weight:700;background:#fff4b8;padding:16px;border-radius:10px}.qn-steps{padding-left:30px}.qn-steps li{padding:4px 0 18px}.qn-steps h3{margin-bottom:8px}.qn-caution{border-left:5px solid #9c5e00;padding:8px 18px;background:#fff7e8}.qn-figure{max-width:480px;margin:20px auto}.qn-figure img{width:100%;height:auto;display:block}.qn-figure figcaption{font-size:16px;margin:8px 0;color:#444}.qn-checker{border:2px solid #161616;padding:20px;border-radius:14px;background:#fff}.qn-main fieldset{border:0;padding:0;margin:0 0 20px;min-width:0}.qn-main legend{font-weight:700;font-size:20px}.qn-inputs{display:grid;grid-template-columns:1fr 1fr;gap:16px}.qn-inputs label{display:block;font-weight:700}.qn-main input[type=text],.qn-main input[type=number],.qn-main textarea{display:block;width:100%;border:2px solid #555;border-radius:8px;background:white;padding:10px;margin:8px 0;min-height:48px}.qn-main textarea{resize:vertical}.qn-experiment input{max-width:160px}.qn-option{display:flex;align-items:center;gap:10px;border-bottom:1px solid #bbb;padding:12px 0;min-height:48px}.qn-option input{width:22px;height:22px;flex:0 0 auto}.qn-feedback:not(:empty),.qn-save:not(:empty){padding:12px;border-left:5px solid #1f4e79;background:#eaf2fa}.qn-reflect{margin-top:28px}.qn-formula{font-size:clamp(18px,3vw,28px);display:flex;align-items:center;justify-content:center;gap:10px;padding:16px 0}.qn-fraction{display:inline-flex;flex-direction:column;text-align:center}.qn-fraction>span:first-child{border-bottom:2px solid #161616;padding:4px 8px}.qn-main table{border-collapse:collapse;width:100%;table-layout:fixed;font-size:16px}.qn-main th,.qn-main td{border:1px solid #999;padding:10px;text-align:left}.qn-main th{background:#fff4b8}.qn-main blockquote{margin:16px 0;border-left:4px solid #9c5e00;padding-left:16px}.qn-writing-space{height:120px}.qn-sheet article{border-bottom:1px dashed #777;padding-bottom:12px}.qn-print-solutions{break-before:page}.qn-no-print label{display:block;margin-bottom:14px}.qn-no-print input{width:22px;height:22px;vertical-align:middle}
@media(max-width:600px){.qn-main{width:calc(100% - 24px);margin-top:18px}.qn-hero,.qn-start{padding:18px}.qn-mascot{gap:10px}.qn-mascot img{width:64px;height:64px}.qn-mascot p{padding:10px;font-size:16px}.qn-inputs{grid-template-columns:1fr}.qn-chapters li a{gap:12px;padding:14px}.qn-checker{padding:14px}.qn-main table{font-size:16px}.qn-main th,.qn-main td{padding:6px}.qn-equation{font-size:18px;padding:12px}.qn-statement{font-size:19px;padding:18px}}
@media print{body{background:white;font-size:12pt}body[data-page=worksheet] header,body[data-page=worksheet] nav,body[data-page=worksheet] footer,.skip-link,.qn-no-print,.qn-page-nav{display:none!important}.qn-main{width:100%;margin:0}.qn-main h1{font-size:22pt}.qn-main h2{font-size:18pt;break-after:avoid}.qn-main h3{font-size:14pt;break-after:avoid}.qn-sheet{break-before:page}.qn-sheet article,.qn-print-solutions article{break-inside:avoid}.qn-questions-only .qn-print-solutions{display:none}.qn-writing-space{height:90px}a{color:black;text-decoration:none}}