:root{font-family:"Hiragino Sans","Yu Gothic",system-ui,sans-serif;color:#18354d;--blue:#176fa5;--orange:#df624b;--green:#19845e;--line:#bfd1dd;--soft:#edf7fc}
*{box-sizing:border-box}body{margin:0;background:linear-gradient(#eef7ff,#fff 45%)}button,input{font:inherit}.lab{width:min(100%,780px);margin:auto;padding:14px max(12px,env(safe-area-inset-right)) calc(22px + env(safe-area-inset-bottom)) max(12px,env(safe-area-inset-left))}header span{font-size:11px;font-weight:800;letter-spacing:.08em;color:var(--blue)}h1{font-size:24px;margin:3px 0}header p{font-size:13px;margin:0 0 10px;color:#526f82}
.tabs{display:grid;grid-template-columns:1fr 1fr;gap:7px}.tabs button{min-height:44px;border:1px solid var(--line);border-radius:12px;background:#fff;color:#34576c;font-weight:700}.tabs button[aria-pressed="true"]{background:var(--blue);border-color:var(--blue);color:#fff}
.formula{margin:10px 0 8px;text-align:center}.formula strong{font-size:13px;color:#526f82}.formula div{font-family:Georgia,"Times New Roman",serif;font-size:clamp(20px,6vw,30px);font-weight:700;margin:4px 0}.formula p{min-height:18px;margin:0;font-size:12px;color:#526f82}
.stage{width:100%;aspect-ratio:1.45;border:1px solid var(--line);border-radius:18px;background:#fff;overflow:hidden;box-shadow:0 7px 22px #17384b12}.stage svg{display:block;width:100%;height:100%}.triangle{fill:#ccebf7aa;stroke:var(--blue);stroke-width:4;stroke-linejoin:round}.guide{fill:none;stroke:#8aa5b5;stroke-width:2;stroke-dasharray:7 6}.accent{stroke:var(--orange);stroke-width:5}.radius{stroke:var(--blue);stroke-width:4}.point{fill:var(--orange);stroke:#fff;stroke-width:3}.axis{stroke:#9bb1bf;stroke-width:2}.arc{fill:none;stroke:var(--green);stroke-width:3}.right-mark{fill:none;stroke:#526f82;stroke-width:2}.label{font-size:19px;font-weight:700;fill:#18354d}.sub-label{font-size:15px;fill:#526f82}.angle-label{font-size:17px;font-weight:700;fill:var(--green)}
.values{display:grid;grid-template-columns:repeat(3,1fr);gap:6px;margin:8px 0}.value{min-width:0;text-align:center;padding:7px 3px;background:var(--soft);border-radius:10px}.value small{display:block;color:#526f82;font-size:11px}.value b{display:block;font-size:16px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.controls{display:grid;gap:10px;padding:12px;border:1px solid var(--line);border-radius:16px;background:#fff}.controls label{display:grid;gap:5px;font-size:13px;font-weight:700}.controls label span{display:flex;justify-content:space-between}.controls output{color:var(--blue);font-size:16px}.controls input{width:100%;height:28px;accent-color:var(--blue)}.discovery{margin-top:9px;padding:10px 12px;border-left:4px solid var(--green);background:#eff9f5}.discovery strong{font-size:12px;color:var(--green)}.discovery p{font-size:13px;line-height:1.55;margin:3px 0}
@media(min-width:600px){.tabs{grid-template-columns:repeat(4,1fr)}.controls{grid-template-columns:repeat(3,1fr)}.stage{aspect-ratio:1.7}.values{gap:9px}.value b{font-size:18px}}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}