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/* 階段形は最初から見せ、各ステップでは考え方だけを強調する */
.base-area{opacity:.62!important}.extra-area{opacity:.42!important;transform:none!important}
.step-outline{fill:none;stroke:#365f58;stroke-width:2.4;stroke-linejoin:round}
.helper-line{stroke:#df8356;stroke-width:2;stroke-dasharray:6 5;opacity:0;transition:.4s}
.area-box.step1 .helper-line,.area-box.step2 .helper-line,.area-box.step3 .helper-line{opacity:1}
.area-box.step2 .extra-area{opacity:.82!important}.area-box.step3 .extra-area{opacity:1!important}
.known-text{font-size:12px;font-weight:600;fill:#365f58}.total-tag{fill:#e5f1ed;stroke:#8ebcb0;stroke-width:1}.total-pointer{fill:none;stroke:#4b8176;stroke-width:1.5}.reveal1{opacity:0;transition:.4s}.area-box.step1 .reveal1,.area-box.step2 .reveal1,.area-box.step3 .reveal1{opacity:1}
.unknown-width{opacity:1;transition:.25s}.area-box.step3 .unknown-width{opacity:0}.scale-note{font-size:9px;fill:#7b8986}
/* 右側は手順名を常に見せ、算式だけをクリック後に表示する */
.calc-title{text-align:center;color:#4b8176;font-size:11px;font-weight:600;letter-spacing:.08em;margin-bottom:1px}.calc-card{position:relative;opacity:1!important;transform:none!important}.calc-card small{opacity:1}.calc-card strong{display:none}.wait{display:block;margin-top:4px;color:#91a09d;font-size:10px}
.calc-box.step1 .base strong,.calc-box.step2 .base strong,.calc-box.step2 .diff strong,.calc-box.step3 .calc-card strong{display:block}.calc-box.step1 .base .wait,.calc-box.step2 .base .wait,.calc-box.step2 .diff .wait,.calc-box.step3 .wait{display:none}
.calc-box.step1 .base,.calc-box.step2 .diff,.calc-box.step3 .target{border-color:#8ebcb0;box-shadow:0 0 0 2px rgba(75,129,118,.1);background:#fbfffd}
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.lesson-nav{display:flex;justify-content:center;gap:7px;margin-bottom:5px}.lesson-nav a{padding:6px 11px;border:1px solid var(--line);border-radius:999px;background:#fff;color:var(--green);font-size:9px;font-weight:600;text-decoration:none}@media(max-width:720px){.lesson-nav{margin-bottom:2px}.lesson-nav a{padding:4px 8px;font-size:8px}}