*{box-sizing:border-box}
:root{--blue:#002060;--blue2:#0b66b2;--yellow:#fff2cc;--green:#d9ead3;--text:#07142f}
html,body{margin:0;padding:0;background:linear-gradient(180deg,#dfefff,#fff);font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;color:var(--text)}
body{max-width:980px;margin:0 auto;padding:10px}
.app-splash{position:fixed;inset:0;z-index:9999;background:#000;display:flex;align-items:center;justify-content:center;transition:opacity .35s ease}
.app-splash.hide{opacity:0;pointer-events:none}
.app-splash img{width:100%;height:100%;object-fit:cover}
.lite-header,.lite-footer{background:linear-gradient(180deg,var(--blue),var(--blue2));color:#fff;text-align:center;border:4px solid #000;border-radius:24px;padding:16px 10px;margin:10px 0;box-shadow:0 10px 26px rgba(0,0,0,.22)}
.lite-header h1{margin:0;font-size:clamp(28px,7vw,54px);line-height:1.05}
.lite-version{color:var(--yellow);font-weight:1000;font-size:clamp(18px,4.7vw,30px);margin-top:8px}
.install-column{width:100%;display:block;background:#fff;border:4px solid #000;border-radius:24px;overflow:hidden;margin:12px 0;box-shadow:0 10px 26px rgba(0,0,0,.20);padding:0;color:var(--text);text-align:left}
.install-column img{width:100%;display:block;aspect-ratio:1/1;object-fit:cover}
.install-text{padding:14px;text-align:center;background:linear-gradient(180deg,#fff,#eef7ff)}
.install-text h2{margin:0 0 8px;color:var(--blue);font-size:clamp(28px,7vw,46px)}
.install-text p{margin:0;font-weight:1000;font-size:clamp(17px,4.6vw,25px)}
.install-text small{display:block;margin-top:8px;font-weight:900;color:#38506f;font-size:clamp(13px,3.6vw,18px)}
.tank-card{background:#fff;border:4px solid #000;border-radius:24px;overflow:hidden;margin:12px 0;box-shadow:0 10px 26px rgba(0,0,0,.20)}
.tank-title{background:var(--blue);color:#fff;text-align:center;font-weight:1000;font-size:clamp(30px,8vw,56px);line-height:1.12;padding:18px 12px 6px}
.tank-subtitle{background:var(--blue);color:#fff;text-align:center;font-weight:900;font-size:clamp(20px,5.4vw,34px);line-height:1.18;padding:0 12px 18px}
.tank-grid{display:grid;grid-template-columns:1fr 1fr;border-top:2px solid #000;border-bottom:2px solid #000}
.tank-cell{min-height:116px;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;border-right:2px solid #000;border-bottom:2px solid #000;padding:10px}
.tank-cell:nth-child(2),.tank-cell:nth-child(4){border-right:0}
.tank-cell:nth-child(3),.tank-cell:nth-child(4){border-bottom:0}
.input-cell{background:var(--yellow)}
.result-cell{background:var(--green)}
.tank-cell span{font-weight:1000;font-size:clamp(20px,5vw,32px);line-height:1.1;margin-bottom:8px}
.tank-cell input{width:100%;border:0;background:transparent;text-align:center;font-weight:1000;color:#000;font-size:clamp(22px,5.4vw,34px);outline:0}
.tank-cell small{font-weight:1000;font-size:clamp(18px,4.5vw,28px);margin-top:-2px}
.tank-cell b{font-size:clamp(23px,5.6vw,36px)}
.practice-btn{display:block;width:88%;margin:18px auto;border:4px solid #000;border-radius:18px;background:#00a6df;color:#fff;font-weight:1000;font-size:clamp(15px,4.4vw,25px);padding:14px 10px;box-shadow:0 6px 14px rgba(0,0,0,.22)}
.practice-notice{display:none;width:88%;margin:0 auto 16px;background:var(--yellow);border:3px solid #000;border-radius:14px;padding:10px;text-align:center;font-weight:900}
.practice-notice.show{display:block}
.placeholder-card{background:#fff;border:4px solid #000;border-radius:24px;padding:14px;margin:12px 0;text-align:center}
.placeholder-card h2{margin:0 0 10px;color:var(--blue);font-size:clamp(26px,6vw,42px)}
.signature{font-family:'Brush Script MT','Segoe Script','Lucida Handwriting',cursive;font-size:clamp(28px,7vw,46px);margin-top:8px}
@media(max-width:520px){body{padding:8px}.tank-cell{min-height:106px}.practice-btn{width:90%}}