:root{--ink:#18322d;--muted:#61716d;--paper:#f7f4ec;--white:#fff;--lime:#d9f45d;--coral:#ff765f;--line:#dfe4db;--shadow:0 24px 60px rgba(24,50,45,.12)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font-family:"Noto Sans JP",sans-serif}button,input,select{font:inherit;color:inherit}a{color:inherit;text-decoration:none}
.site-header{height:82px;display:flex;align-items:center;justify-content:space-between;max-width:1180px;margin:auto;padding:0 28px}.brand{display:flex;align-items:center;gap:11px;font-weight:700;letter-spacing:.03em}.brand-mark{width:34px;height:34px;border-radius:50%;background:var(--coral);color:#fff;display:grid;place-items:center;font-size:22px}.site-header nav{display:flex;gap:36px;font-size:14px;font-weight:600}.site-header nav a:hover{color:var(--coral)}
.hero{min-height:575px;max-width:1240px;margin:auto;padding:68px 58px 80px;display:grid;grid-template-columns:1.05fr .95fr;align-items:center;overflow:hidden}.eyebrow{font:700 12px "DM Sans",sans-serif;letter-spacing:.16em;display:flex;align-items:center;gap:10px}.eyebrow span{width:28px;height:2px;background:var(--coral)}h1{font-size:clamp(48px,6vw,82px);line-height:1.18;letter-spacing:-.06em;margin:22px 0 26px}h1>span,h1>em{display:block;white-space:nowrap}h1 em{font-style:normal;position:relative;z-index:0;width:max-content}h1 em:after{content:"";height:17px;background:var(--lime);position:absolute;left:-2px;right:-8px;bottom:5px;z-index:-1;transform:rotate(-1deg)}.hero-text{font-size:16px;line-height:2;max-width:540px;color:var(--muted)}.primary-button{display:inline-flex;align-items:center;gap:40px;margin-top:24px;background:var(--ink);color:#fff;padding:17px 20px 17px 26px;border-radius:3px;font-weight:600;font-size:14px;box-shadow:0 10px 25px rgba(24,50,45,.18)}.primary-button span{color:var(--lime)}
.hero-visual{height:420px;position:relative}.hero-visual:before{content:"";position:absolute;width:365px;height:365px;border-radius:50%;background:var(--lime);left:70px;top:20px}.date-card,.calc-card,.unit-pill{position:absolute;background:#fff;box-shadow:var(--shadow)}.date-card{left:38px;top:48px;width:158px;height:188px;border-radius:8px;padding:18px;text-align:center;transform:rotate(-6deg);border-top:8px solid var(--coral)}.date-label{font:700 11px "DM Sans";letter-spacing:.18em;color:var(--coral)}.date-card strong{font:700 76px "DM Sans";display:block;line-height:1.05}.date-card span:last-child{font-size:13px}.calc-card{right:18px;top:118px;width:270px;border-radius:10px;padding:24px;transform:rotate(5deg)}.calc-card>span{font:500 14px "DM Sans";color:var(--muted)}.calc-card strong{font:700 34px "DM Sans";display:block;text-align:right;margin:14px 0 20px}.calc-keys{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.calc-keys i{height:25px;background:#edf0eb;border-radius:3px}.calc-keys i:nth-child(3n){background:var(--coral)}.unit-pill{left:70px;bottom:38px;padding:16px 24px;border-radius:30px;font:700 17px "DM Sans";transform:rotate(2deg)}.unit-pill b{color:var(--coral);margin:0 8px}.spark{position:absolute;color:var(--coral);font-size:30px}.spark-one{right:18px;top:25px}.spark-two{left:5px;bottom:55px;color:var(--ink)}
.tools-section{background:var(--ink);color:#fff;padding:82px max(24px,calc((100vw - 1120px)/2)) 100px}.section-heading{display:flex;justify-content:space-between;align-items:end;margin-bottom:44px}.section-heading h2,.guide h2{font-size:36px;margin:12px 0 0;letter-spacing:-.03em}.section-heading>p{color:#b8c5c1;line-height:1.8;font-size:14px}.tool-tabs{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.tool-tab{min-height:76px;border:2px solid #526a64;border-radius:7px;background:#26423c;color:#fff;padding:14px 40px 14px 14px;cursor:pointer;font-weight:700;text-align:left;display:flex;align-items:center;position:relative;box-shadow:0 8px 18px rgba(0,0,0,.12);transition:background-color .2s,border-color .2s,transform .2s,box-shadow .2s}.tool-tab:after{content:"→";position:absolute;right:16px;color:var(--lime);font:700 18px "DM Sans",sans-serif}.tool-tab span{display:inline-grid;flex:0 0 auto;place-items:center;width:34px;height:34px;border:1px solid #71837f;border-radius:50%;margin-right:10px;background:#18322d}.tool-tab:hover,.tool-tab:focus-visible{background:#31524a;border-color:var(--lime);transform:translateY(-3px);box-shadow:0 12px 24px rgba(0,0,0,.2);outline:none}.tool-tab:hover span,.tool-tab:focus-visible span{background:var(--lime);border-color:var(--lime);color:var(--ink)}.tool-tab:active{transform:translateY(0)}
.calculator-shell{margin-top:30px}.tool-panel{display:none;background:#fff;color:var(--ink);min-height:370px;border-radius:7px;overflow:hidden;grid-template-columns:340px 1fr}.tool-panel.active{display:grid}.panel-info{background:#f1eee5;padding:42px}.panel-icon{display:grid;place-items:center;width:50px;height:50px;border-radius:50%;background:var(--coral);color:#fff;font:700 24px "DM Sans"}.panel-kicker{font:700 11px "DM Sans";letter-spacing:.16em;color:var(--coral);margin:26px 0 7px}.panel-info h3{font-size:26px;margin:0 0 15px}.panel-info>p:not(.panel-kicker){font-size:14px;line-height:1.8;color:var(--muted)}.mini-note{margin-top:28px;padding-top:17px;border-top:1px solid #d9d7cf;font-size:11px;line-height:1.7;color:#7d8986}.calculator-form{padding:44px}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}.form-grid.single{grid-template-columns:1fr}.calculator-form label{display:flex;flex-direction:column;gap:9px;font-size:12px;font-weight:600}.calculator-form input,.calculator-form select{width:100%;height:50px;border:1px solid var(--line);background:#fff;padding:0 14px;border-radius:3px;font:600 16px "DM Sans","Noto Sans JP";outline:none}.calculator-form input:focus,.calculator-form select:focus{border-color:#90a629;box-shadow:0 0 0 3px rgba(217,244,93,.35)}.input-unit{display:flex;align-items:center;border:1px solid var(--line);padding-right:14px;border-radius:3px;font-weight:500}.input-unit input{border:0}.result-box{margin-top:28px;background:var(--ink);color:#fff;padding:23px 27px;display:flex;align-items:center;justify-content:space-between;border-radius:4px}.result-box div{display:flex;flex-direction:column;gap:5px}.result-box span{font-size:11px;color:#b6c6c1}.result-box strong{font:700 30px "DM Sans";color:var(--lime)}.result-box b{font:600 16px "DM Sans";color:#fff}.calendar-result{gap:25px;justify-content:flex-start;flex-wrap:wrap}.calendar-result div{min-width:120px}.converter-row{display:grid;grid-template-columns:1fr 44px 1fr;gap:12px;align-items:end}.swap-button{height:44px;width:44px;border:0;border-radius:50%;background:var(--lime);font-size:20px;cursor:pointer;margin-bottom:3px}
.ad-unit{display:block;width:100%;max-width:1120px;min-height:90px;margin:42px auto;padding:0 24px;overflow:hidden}.hero+.ad-unit{margin-top:0;margin-bottom:56px}.guide{max-width:1120px;margin:0 auto;padding:100px 24px}.guide>div:first-child{text-align:center}.guide>div:first-child .eyebrow{justify-content:center}.guide-items{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);margin-top:58px}.guide article{background:var(--paper);padding:38px}.guide article b{font:700 12px "DM Sans";color:var(--coral)}.guide article h3{font-size:18px;margin:15px 0 10px}.guide article p{font-size:13px;line-height:1.8;color:var(--muted)}
footer{background:#eae6dc;padding:45px max(28px,calc((100vw - 1120px)/2));display:grid;grid-template-columns:1fr auto;align-items:center;gap:8px}footer p{font-size:13px;color:var(--muted);margin:0}footer small{grid-column:2;grid-row:1/3;color:#88928f}
.sub-header{border-bottom:1px solid var(--line)}.tool-page{max-width:1120px;margin:auto;padding:58px 24px 100px}.breadcrumbs{font-size:12px;color:var(--muted);margin-bottom:38px}.breadcrumbs a{text-decoration:underline;text-underline-offset:3px}.tool-page-intro{max-width:780px}.tool-page-intro .eyebrow{color:var(--coral)}.tool-page h1{font-size:clamp(38px,5vw,62px);margin:14px 0 18px}.tool-page-intro>p:last-child{color:var(--muted);line-height:1.9}.standalone-calculator{margin-top:42px}.standalone-calculator .tool-panel{display:grid;box-shadow:var(--shadow)}.seo-content{display:grid;grid-template-columns:1fr 1fr;gap:55px;margin-top:75px}.seo-content h2{font-size:27px;margin:0 0 20px}.seo-content h3{font-size:17px;margin:28px 0 8px}.seo-content p,.seo-content li{color:var(--muted);font-size:14px;line-height:1.9}.formula{background:#eae6dc;border-left:4px solid var(--coral);padding:18px 22px;font:600 15px "DM Sans","Noto Sans JP"}.related-tools{margin-top:70px;padding-top:35px;border-top:1px solid var(--line)}.related-links{display:flex;flex-wrap:wrap;gap:10px}.related-links a{background:var(--white);border:1px solid var(--line);padding:12px 18px;border-radius:30px;font-size:13px;font-weight:600}.related-links a:hover{border-color:var(--coral)}
@media(max-width:800px){.site-header{height:68px}.site-header nav{display:none}.hero{grid-template-columns:1fr;padding:55px 25px}.hero-visual{height:390px;margin-top:35px}.hero-visual:before{left:50%;transform:translateX(-50%);width:330px;height:330px}.calc-card{right:3%}.date-card{left:3%}.section-heading{display:block}.section-heading>p{margin-top:18px}.tool-tabs{grid-template-columns:1fr 1fr}.tool-tab{white-space:nowrap}.tool-panel.active,.standalone-calculator .tool-panel{grid-template-columns:1fr}.panel-info{padding:30px}.calculator-form{padding:28px}.ad-unit{min-height:60px;margin:30px auto}.hero+.ad-unit{margin-bottom:38px}.guide-items,.seo-content{grid-template-columns:1fr}footer{grid-template-columns:1fr}footer small{grid-column:1;grid-row:auto}}@media(max-width:520px){.hero h1{font-size:clamp(32px,10.7vw,45px)}.tool-page h1{font-size:38px}.hero{padding-top:38px}.hero-visual{transform:scale(.88);margin-left:-20px;margin-right:-20px}.tool-tabs{grid-template-columns:1fr}.form-grid{grid-template-columns:1fr}.result-box{align-items:flex-start;gap:17px;flex-direction:column}.section-heading h2,.guide h2{font-size:30px}.tool-page{padding-top:35px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}