:root{color-scheme:light;--blue:#076cbd;--navy:#0b2c50;--ink:#183c59;--muted:#4f697d;--line:#cfe0ec;--orange:#ffb84c;--bg:#edf6fc;font-family:"Yu Gothic",Meiryo,system-ui,sans-serif;font-size:16px}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);line-height:1.65}button,input{font:inherit}button,a,summary{-webkit-tap-highlight-color:transparent}button,summary{cursor:pointer}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #e88414;outline-offset:4px}a{color:var(--blue);text-underline-offset:3px}[hidden]{display:none!important}h1,h2,h3,p{margin:0}h1{font-size:clamp(1.45rem,3.4vw,2rem);line-height:1.45}h2{font-size:1.125rem;line-height:1.5}h3{font-size:1rem;line-height:1.6}fieldset{border:0;margin:0;padding:0;min-width:0}legend{padding:0;font-weight:800}input{width:100%;min-width:0;color:var(--ink);border:1px solid #90b0c8;background:#fff;border-radius:8px;padding:10px 12px;min-height:48px;font-variant-numeric:tabular-nums}input:focus{outline:3px solid #0785d32e;border-color:#0876c0}input[aria-invalid="true"]{border-color:#b33429;outline-color:#b3342922}input::placeholder{color:#627a8c;font-size:.875rem}label{font-size:.9375rem;font-weight:700}.help{font-size:.875rem;line-height:1.65;color:var(--muted);margin:5px 0 9px}.help.small{font-size:.8125rem;margin-bottom:0}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.nav{background:#fff;border-bottom:1px solid var(--line);padding:10px max(18px,calc((100vw - 1100px)/2));display:flex;align-items:center;justify-content:space-between;gap:15px}.nav a{font-size:.875rem;font-weight:700;min-height:32px;display:flex;align-items:center;text-decoration:none}.nav>span{font-size:.75rem;color:#577285;letter-spacing:.1em}main{max-width:1136px;padding:26px 18px 35px;margin:auto}.page-head{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:24px}.eyebrow{color:var(--blue);font-size:.8125rem;font-weight:800;letter-spacing:.1em;margin-bottom:3px}.page-head>div>p:last-child{color:var(--muted);margin-top:6px;font-size:1rem}.distance-mark{font-size:4.4rem;line-height:1;font-weight:900;letter-spacing:-.05em;color:#b3d8ef}.distance-mark span{font-size:2.2rem;letter-spacing:-.035em}.calculator-layout{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:24px;align-items:start}.input-panel,.reference-panel,.splits-panel,.method-details{border:1px solid var(--line);border-radius:14px;background:#fff}.input-panel{padding:23px}.section-head{display:flex;align-items:center;justify-content:space-between;gap:12px}.text-button{border:0;padding:7px 0;background:none;color:var(--blue);font-size:.875rem;text-decoration:underline;text-underline-offset:4px;min-height:36px}.sample-notice{margin:10px 0 17px;font-size:.8125rem;color:#5c572d;background:#fff6d9;border-left:3px solid #e3b33b;padding:6px 9px}.required{font-size:.75rem;font-weight:700;color:#a4440b;padding:2px 6px;background:#fff0d9;border-radius:4px;margin-left:6px}.time-input{display:flex;align-items:center;gap:10px}.time-input>label{display:flex;align-items:center;gap:7px;min-width:0}.time-input input{width:80px;text-align:center;font-size:1.8rem;font-weight:750;line-height:1.15;padding:10px 6px}.time-input>label>span:last-child{font-size:.875rem;color:var(--muted);white-space:nowrap}.separator{font-size:1.5rem;color:#87a5bb}.five-pace{margin-left:auto;white-space:nowrap;font-size:.875rem;color:var(--blue);font-variant-numeric:tabular-nums}.profile-heading{margin-top:22px;border-top:1px solid var(--line);padding-top:18px}.profile-heading h3 span,.training-block h3 span{font-size:.8125rem;color:var(--muted);margin-left:8px;font-weight:500}.field-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px 16px}.field>label{display:block;margin-bottom:5px}.unit-input{position:relative;display:flex;align-items:center}.unit-input input{padding-right:73px;font-size:1.125rem}.unit-input>span{position:absolute;right:12px;font-size:.8125rem;color:var(--muted);pointer-events:none}.field-error{margin:5px 0 0;color:#a12622;font-size:.875rem;line-height:1.5}.training-block{margin-top:20px;padding-top:18px;border-top:1px solid var(--line)}.training-block h3{margin-bottom:10px}.training-block summary{font-size:.875rem;color:var(--blue);padding:13px 0 2px;font-weight:700;line-height:1.7}.extra-fields{padding-top:12px;display:grid;gap:16px}.half-input{gap:12px;flex-wrap:wrap}.half-input input{width:58px;font-size:1.125rem}.half-input label{gap:5px}.form-actions{display:flex;flex-direction:column;align-items:center;gap:4px;margin-top:24px}.calculate-button{display:flex;justify-content:space-between;align-items:center;width:100%;min-height:52px;padding:12px 17px;border:1px solid #075fa4;border-radius:9px;background:var(--blue);color:#fff;font-weight:800;box-shadow:0 3px 0 #084c85}.calculate-button:hover{background:#075a9d}.calculate-button:active{transform:translateY(1px);box-shadow:0 2px 0 #084c85}.privacy-note{text-align:center;font-size:.75rem;color:var(--muted)}
.results-column{display:grid;gap:17px;min-width:0}.result-panel{position:relative;overflow:hidden;background:var(--navy);color:#fff;border:1px solid #14395d;border-top:5px solid var(--orange);border-radius:14px;padding:23px 26px 24px;box-shadow:0 10px 25px #073d6812;scroll-margin-top:15px}.result-panel:focus{outline:3px solid #218cc1;outline-offset:4px}.result-head{display:flex;gap:10px;justify-content:space-between;align-items:center;flex-wrap:wrap}.method-badge{font-size:.75rem;color:#c5eafa;border:1px solid #698fad;border-radius:5px;padding:3px 7px}.result-source{margin-top:25px;font-size:.875rem;color:#bed5e8}.finish-time{display:flex;align-items:baseline;gap:9px;flex-wrap:wrap;margin:4px 0 16px;font-variant-numeric:tabular-nums}.finish-time output{font-size:clamp(3rem,6.8vw,5.1rem);font-weight:800;line-height:1.16;letter-spacing:-.035em;color:#fff}.about{font-size:1rem;color:#cadcea}.time-unit{font-size:.8125rem;color:#cadcea;white-space:nowrap}.pace-row{display:flex;align-items:center;justify-content:space-between;gap:16px;border-top:1px solid #ffffff2c;padding-top:15px}.pace-row>span{font-size:.875rem;color:#d9e4ec}.pace-row strong{color:#ffd089;font-size:1.7rem;font-variant-numeric:tabular-nums;white-space:nowrap}.pace-row small{font-size:.9375rem;font-weight:500}.range-block{margin-top:19px;padding:14px 16px;background:#ffffff09;border:1px solid #ffffff26;border-radius:8px}.range-block>div{display:flex;justify-content:space-between;gap:10px;align-items:center;flex-wrap:wrap}.range-block span{font-size:.875rem;color:#d1e0eb}.range-block strong{font-size:1.125rem;font-variant-numeric:tabular-nums}.range-block p{font-size:.8125rem;line-height:1.65;margin-top:7px;color:#bdcedd}.result-caution{font-size:.875rem;line-height:1.65;color:#d0e0ed;margin-top:17px}.empty-result{padding:35px 0}.empty-result strong{font-size:1.25rem}.empty-result p{color:#c6d9e7;margin-top:10px}.reference-panel{padding:20px 23px}.reference-values{margin:13px 0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px 18px}.reference-values>div{border-bottom:1px solid #e3edf4;padding-bottom:10px}.reference-values dt{font-size:.8125rem;color:var(--muted)}.reference-values dt small{font-size:.75rem}.reference-values dd{margin:3px 0 0;font-size:1.45rem;font-weight:750;font-variant-numeric:tabular-nums}.reference-panel>.help{margin-bottom:0}.context-notes p{font-size:.875rem;line-height:1.7;margin-top:12px;padding-top:12px;border-top:1px solid var(--line);color:#4c6577}.splits-panel{padding:15px 23px}.splits-panel summary,.method-details>summary{font-size:1rem;font-weight:750;line-height:1.7}.splits-panel .help{margin-top:10px}table{width:100%;border-collapse:collapse;font-variant-numeric:tabular-nums}th{font-size:.875rem;color:var(--muted);font-weight:500}th,td{padding:8px 0;text-align:left;border-bottom:1px solid #e3edf4}td:last-child,th:last-child{text-align:right}tr:last-child td{border-bottom:0;font-weight:800;color:var(--blue)}.method-details{padding:17px 23px;margin-top:24px}.method-body{padding-top:15px;max-width:920px}.method-body h2{margin-bottom:10px}.method-body h3{margin:19px 0 7px}.method-body p{font-size:.9375rem;line-height:1.85;color:var(--muted);margin-bottom:10px}.source-list{padding-left:20px;font-size:.875rem;color:var(--muted)}.source-list li{margin-bottom:10px;overflow-wrap:anywhere}footer{text-align:center;color:var(--muted);padding:0 18px 25px;font-size:.8125rem}footer span{margin:0 5px}.noscript{background:#fff4df;border:1px solid #dbb574;padding:16px;margin-top:15px}
@media(max-width:900px){.calculator-layout{gap:16px}.input-panel{padding:18px}.result-panel{padding:20px}.five-pace{width:100%;margin-left:0}.time-input:not(.half-input){flex-wrap:wrap}.reference-panel{padding:18px}.distance-mark{display:none}}
@media(max-width:700px){main{padding:19px 12px 25px}.page-head{margin-bottom:18px}.page-head>div>p:last-child{font-size:.9375rem}.calculator-layout{grid-template-columns:1fr;gap:20px}.input-panel{padding:18px}.results-column{gap:15px}.five-pace{width:auto;margin-left:auto}.finish-time output{font-size:4.5rem}.result-panel{padding:21px}.method-details{margin-top:20px;padding:16px 18px}.nav{padding:8px 13px}.nav>span{display:none}}
@media(max-width:370px){.five-pace{width:100%;margin-left:0}.time-input input{width:72px}.field-grid{gap:12px}.unit-input input{padding-left:8px;padding-right:62px}.unit-input>span{right:8px;font-size:.75rem}.half-input{gap:8px}.half-input input{width:49px}.finish-time output{font-size:3.6rem}.reference-values{gap:12px}}
.field-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,8.5rem),1fr))}.unit-input{gap:.4rem}.unit-input input{flex:1;padding-right:12px}.unit-input>span{position:static;flex-shrink:0;font-size:.8125rem}.time-input:not(.half-input) input{width:5rem}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}