#concrete12-page{--c12-ink:#234627;--c12-accent:#234627;--c12-source:#234627;--c12-border:#dedede;color:var(--c12-ink);background:#fff;font:16px/1.7 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;width:100%;margin:0;isolation:isolate}
#concrete12-page *,#concrete12-page *::before,#concrete12-page *::after{box-sizing:border-box}
#concrete12-page [hidden]{display:none!important}
#concrete12-page .c12-shell{max-width:1180px;margin:auto;padding:0 28px}
#concrete12-page h1,#concrete12-page h2,#concrete12-page h3,#concrete12-page p,#concrete12-page ul,#concrete12-page figure{margin:0}
#concrete12-page a{color:#234627;text-decoration:underline;text-underline-offset:4px;overflow-wrap:anywhere}
#concrete12-page a.external{color:var(--c12-source)}
#concrete12-page a:focus-visible,#concrete12-page button:focus-visible,#concrete12-page summary:focus-visible{outline:3px solid var(--c12-source);outline-offset:4px}
#concrete12-page .c12-hero{padding:64px 0 44px;background:radial-gradient(ellipse at 96% 5%,#edf4eb 0%,#fff 62%);border-bottom:1px solid #eee}
#concrete12-page .c12-hero-grid{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(0,.7fr);gap:68px;align-items:center}
#concrete12-page .c12-kicker{font-size:11px;letter-spacing:1.7px;font-weight:750;display:block;line-height:1.5}
#concrete12-page .c12-hero .c12-kicker::before{content:"";display:inline-block;width:22px;height:4px;background:var(--c12-accent);vertical-align:middle;margin-right:10px}
#concrete12-page h1{font-size:clamp(34px,4.5vw,58px);line-height:1.1;letter-spacing:-1.8px;margin:19px 0 24px;font-weight:780;max-width:760px}
#concrete12-page .c12-hero p{max-width:720px;color:#444;margin:0 0 14px;font-size:16px;line-height:1.7}
#concrete12-page .c12-hero-links{display:flex;flex-wrap:wrap;gap:16px 24px;align-items:center;margin-top:24px}
#concrete12-page .c12-button-link{background:#234627;color:#fff;text-decoration:none;display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:12px 21px;border-radius:8px;font-size:14px;font-weight:650}
#concrete12-page .c12-hero-art{min-width:0;border:1px solid #edf4eb;border-radius:20px;background:#fff;padding:28px;box-shadow:0 16px 40px #23462706;transform:rotate(2deg)}
#concrete12-page .c12-hero-art svg{width:100%;height:auto;display:block}
#concrete12-page .c12-art-caption{font-size:12px;text-align:center;color:#555;letter-spacing:.2px;padding-top:14px;border-top:1px solid #eee;margin-top:12px}
#concrete12-page .c12-trust-row{display:flex;flex-wrap:wrap;gap:15px 30px;font-size:12px;color:#555;margin-top:26px}
#concrete12-page .c12-trust-row span::before{content:"✓";color:#234627;margin-right:7px;font-weight:700}
#concrete12-page .c12-calculator{margin:38px 0 52px;border:1px solid var(--c12-border);border-radius:18px;overflow:hidden;background:#fff;box-shadow:0 12px 34px #23462705;scroll-margin-top:25px}
#concrete12-page .c12-tool-heading{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:26px 30px;border-bottom:1px solid var(--c12-border)}
#concrete12-page .c12-tool-heading h2{font-size:27px;line-height:1.25;letter-spacing:-.6px;margin:8px 0}
#concrete12-page .c12-tool-heading p{font-size:14px;color:#555}
#concrete12-page .c12-tag{font-size:11px;background:#edf4eb;border:1px solid #edf4eb;border-radius:30px;padding:7px 11px;white-space:nowrap}
#concrete12-page .c12-tool-grid{display:grid;grid-template-columns:minmax(0,1.25fr) minmax(0,1fr)}
#concrete12-page .c12-input-panel{padding:26px 30px;min-width:0}
#concrete12-page .c12-step{display:flex;align-items:center;gap:10px;margin:0 0 20px}
#concrete12-page .c12-step:not(:first-child){margin-top:28px}
#concrete12-page .c12-step>span{display:inline-flex;align-items:center;justify-content:center;background:#234627;color:#fff;border-radius:50%;width:28px;height:28px;font-size:11px;flex-shrink:0}
#concrete12-page .c12-step h3{font-size:18px;line-height:1.4;font-weight:700}
#concrete12-page .c12-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:14px}
#concrete12-page .c12-wide{grid-column:1/-1}
#concrete12-page .c12-field{font-size:12px;font-weight:650;display:block;min-width:0;margin:0 0 16px;line-height:1.5}
#concrete12-page .c12-optional{font-size:10px;color:#666;font-weight:400}
#concrete12-page input,#concrete12-page select{font:400 16px/1.4 system-ui;color:#234627;background:#fff;border:1px solid #ccc;border-radius:7px;width:100%;min-width:0;max-width:100%;min-height:46px;padding:11px 12px;margin:7px 0 0;box-shadow:none}
#concrete12-page select{padding-right:27px}
#concrete12-page input:focus,#concrete12-page select:focus{outline:2px solid #234627;outline-offset:1px;border-color:#234627}
#concrete12-page .c12-input-unit{display:grid;grid-template-columns:minmax(0,1fr) 87px;gap:6px}
#concrete12-page .c12-input-unit select{font-size:13px;padding:10px 6px}
#concrete12-page .c12-help{display:block;font-size:11px;line-height:1.55;font-weight:400;color:#606060;margin-top:7px}
#concrete12-page .c12-unit-choice{display:flex;background:#f4f4f4;border-radius:8px;padding:4px;gap:4px;width:max-content;max-width:100%;margin-bottom:20px}
#concrete12-page button{font:600 13px/1.4 system-ui;cursor:pointer;min-height:44px;border-radius:7px;padding:11px 15px;border:1px solid transparent;box-shadow:none;transition:background .15s,color .15s;white-space:normal}
#concrete12-page .c12-unit-choice button{font-size:12px;background:transparent;color:#555;min-height:36px;padding:8px 19px}
#concrete12-page .c12-unit-choice button[aria-pressed="true"]{background:#fff;color:#234627;box-shadow:0 1px 4px #00000012}
#concrete12-page .c12-diagram{background:#fafafa;border-radius:9px;border:1px solid #eee;padding:12px;height:125px;display:flex;align-items:center;justify-content:center;margin-bottom:10px}
#concrete12-page .c12-diagram svg{max-height:105px;width:100%;height:100%}
#concrete12-page .c12-shape-help{min-height:34px;margin-bottom:15px}
#concrete12-page .c12-example-note{font-size:11px;color:#234627;margin:0 0 12px}
#concrete12-page .c12-add-row{display:flex;flex-wrap:wrap;align-items:center;gap:8px 14px}
#concrete12-page .c12-secondary{background:#fff;border-color:#ccc;color:#234627}
#concrete12-page .c12-secondary:hover{background:#f4f4f4;border-color:#234627}
#concrete12-page .c12-saved{display:grid;gap:10px;margin-top:16px}
#concrete12-page .c12-section-card{border:1px solid #ddd;border-radius:9px;padding:13px;font-size:12px;min-width:0}
#concrete12-page .c12-section-card strong{display:block;overflow-wrap:anywhere}
#concrete12-page .c12-section-card .c12-card-actions{display:flex;gap:5px;margin-top:8px}
#concrete12-page .c12-card-actions button{padding:6px 12px;background:#f7f7f7;border-color:#ddd;font-size:11px}
#concrete12-page .c12-density{border-top:1px solid #eee;border-bottom:1px solid #eee;margin:18px 0 0}
#concrete12-page .c12-yield-settings{border-top:1px solid #eee;border-bottom:1px solid #eee}
#concrete12-page summary{font-size:12px;font-weight:650;cursor:pointer;padding:15px 0;min-height:44px}
#concrete12-page .c12-product-note a{font-size:11px}
#concrete12-page .c12-actions{display:flex;gap:12px;align-items:center;margin-top:22px}
#concrete12-page .c12-primary{background:#234627;color:#fff;flex:1;min-height:50px;display:flex;justify-content:space-between;align-items:center;padding:13px 20px;font-size:14px}
#concrete12-page .c12-primary:hover{background:#333}
#concrete12-page .c12-primary span{color:#234627;font-size:20px}
#concrete12-page .c12-reset{background:transparent;color:#555;text-decoration:underline;text-underline-offset:3px;padding:10px}
#concrete12-page .c12-error{background:#edf4eb;border:1px solid #71916a;padding:12px;border-radius:8px;color:#234627;font-size:13px;margin-top:18px}
#concrete12-page .c12-result-panel{background:#f8f8f7;border-left:1px solid #ddd;padding:30px;min-width:0}
#concrete12-page .c12-result-panel h3{font-size:25px;line-height:1.3;letter-spacing:-.5px;margin:12px 0 23px}
#concrete12-page .c12-empty{padding:30px 0}
#concrete12-page .c12-empty svg{display:block;width:180px;margin:0 auto 25px}
#concrete12-page .c12-empty p{font-size:14px;color:#555}
#concrete12-page .c12-empty ul{padding-left:20px;font-size:12px;color:#555;margin-top:18px;line-height:2}
#concrete12-page .c12-result-main{background:#234627;color:#fff;border-radius:12px;padding:22px;margin-bottom:18px}
#concrete12-page .c12-result-main .c12-result-value{font-size:clamp(31px,3.5vw,45px);line-height:1.2;font-weight:750;overflow-wrap:anywhere;margin:10px 0}
#concrete12-page .c12-result-main small{font-size:12px;color:#e4e4e4;display:block}
#concrete12-page .c12-result-main .c12-unit{font-size:15px;font-weight:500;color:#234627}
#concrete12-page .c12-stat-grid{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:10px;margin:12px 0 20px}
#concrete12-page .c12-stat{padding:15px;border:1px solid #ddd;border-radius:8px;background:#fff;min-width:0}
#concrete12-page .c12-stat small{font-size:11px;color:#555;display:block}
#concrete12-page .c12-stat strong{display:block;font-size:23px;line-height:1.4;overflow-wrap:anywhere}
#concrete12-page .c12-result-lines{margin:0;border-top:1px solid #ddd}
#concrete12-page .c12-result-lines>div{display:flex;gap:15px;justify-content:space-between;border-bottom:1px solid #ddd;padding:11px 0;font-size:12px}
#concrete12-page .c12-result-lines dt{color:#555}
#concrete12-page .c12-result-lines dd{margin:0;text-align:right;font-weight:650;overflow-wrap:anywhere;min-width:0}
#concrete12-page .c12-breakdown{margin-top:20px;font-size:12px}
#concrete12-page .c12-breakdown h4{font-size:13px;margin:0 0 10px}
#concrete12-page .c12-breakdown ul{padding-left:18px}
#concrete12-page .c12-breakdown li{margin:7px 0;overflow-wrap:anywhere}
#concrete12-page .c12-assumptions{font-size:11px;color:#555;border-left:3px solid #234627;padding-left:12px;margin-top:20px}
#concrete12-page .c12-export{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
#concrete12-page .c12-export button{font-size:11px}
#concrete12-page .c12-status{font-size:12px;color:#234627;margin-top:16px}
#concrete12-page .c12-result-help{font-size:11px;line-height:1.6;color:#666;margin-top:25px}
#concrete12-page .c12-copy-fallback{width:100%;min-height:180px;margin-top:15px;font:13px/1.6 system-ui;padding:12px;border:1px solid #aaa;border-radius:7px}
#concrete12-page .c12-reading{display:grid;grid-template-columns:minmax(0,780px) minmax(0,245px);gap:62px;align-items:start;padding-bottom:60px}
#concrete12-page .c12-article{min-width:0;font-size:17px;line-height:1.8}
#concrete12-page .c12-article h2{font-size:30px;letter-spacing:-.6px;line-height:1.25;margin:44px 0 18px;scroll-margin-top:24px}
#concrete12-page .c12-article h2:first-child{margin-top:0}
#concrete12-page .c12-article h3{font-size:21px;line-height:1.4;margin:25px 0 13px}
#concrete12-page .c12-article p{margin-bottom:17px;color:#333}
#concrete12-page .c12-article ul{padding-left:22px;margin:17px 0}
#concrete12-page .c12-article li{margin-bottom:10px;color:#333}
#concrete12-page .c12-article .note,#concrete12-page .c12-article .formula{background:#edf4eb;border-left:4px solid #234627;padding:19px 22px;border-radius:0 8px 8px 0;font-size:15px;overflow-wrap:anywhere}
#concrete12-page .c12-article figure{margin:25px 0;border:1px solid #ddd;border-radius:10px;padding:15px}
#concrete12-page .c12-article svg{max-width:100%;height:auto;display:block}
#concrete12-page figcaption{font-size:12px;color:#666;margin-top:10px}
#concrete12-page .table-wrap{max-width:100%;overflow:auto;margin:25px 0}
#concrete12-page table{border-collapse:collapse;width:100%;font-size:13px;line-height:1.6}
#concrete12-page th,#concrete12-page td{text-align:left;padding:14px;border-bottom:1px solid #ddd;vertical-align:top}
#concrete12-page th{background:#234627;color:#fff;font-weight:600}
#concrete12-page tbody tr:nth-child(even){background:#fafafa}
#concrete12-page caption{text-align:left;color:#666;font-size:12px;margin-bottom:10px}
#concrete12-page .c12-reading-nav{border:1px solid #ddd;border-radius:12px;padding:23px;position:sticky;top:25px;font-size:12px}
#concrete12-page .c12-reading-nav strong{font-size:14px}
#concrete12-page .c12-reading-nav ul{padding:0;list-style:none;display:grid;gap:14px;margin:17px 0 0}
#concrete12-page .c12-reading-nav a{text-decoration:none;color:#555}
#concrete12-page .c12-reading-nav a:hover{text-decoration:underline;color:#234627}
#concrete12-page .c12-related-note{border-top:1px solid #ddd;margin-top:22px;padding-top:20px;color:#555;font-size:12px}
#concrete12-page .c12-related-note a{display:block;margin-top:12px;text-decoration:underline;color:#234627}
#concrete12-page .muted{font-size:12px!important;color:#666!important;border-top:1px solid #ddd;padding-top:18px}
#concrete12-page .c12-notice{padding:20px}
@media(max-width:950px){#concrete12-page .c12-hero-grid{gap:30px}#concrete12-page .c12-reading{grid-template-columns:minmax(0,1fr);gap:20px}#concrete12-page .c12-reading-nav{grid-row:1;position:static}#concrete12-page .c12-reading-nav ul{display:grid;grid-template-columns:repeat(3,minmax(0,1fr))}#concrete12-page .c12-related-note{display:none}#concrete12-page .c12-tool-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}#concrete12-page .c12-input-panel,#concrete12-page .c12-result-panel{padding:23px}}
@media(max-width:720px){#concrete12-page .c12-shell{padding:0 18px}#concrete12-page .c12-hero{padding:34px 0 28px}#concrete12-page .c12-hero-grid{grid-template-columns:minmax(0,1fr)}#concrete12-page .c12-hero-art{display:none}#concrete12-page h1{letter-spacing:-1px;font-size:39px}#concrete12-page .c12-hero p{font-size:15px}#concrete12-page .c12-trust-row{gap:7px 16px;font-size:11px}#concrete12-page .c12-calculator{margin:25px 0 32px;border-radius:12px}#concrete12-page .c12-tool-heading{padding:20px;display:block}#concrete12-page .c12-tool-heading h2{font-size:23px}#concrete12-page .c12-tag{display:none}#concrete12-page .c12-tool-grid{grid-template-columns:minmax(0,1fr)}#concrete12-page .c12-input-panel,#concrete12-page .c12-result-panel{padding:20px}#concrete12-page .c12-result-panel{border-left:0;border-top:1px solid #ddd}#concrete12-page .c12-result-panel h3{font-size:24px}#concrete12-page .c12-empty{padding:0}#concrete12-page .c12-empty svg,#concrete12-page .c12-empty ul{display:none}#concrete12-page .c12-empty p{font-size:13px}#concrete12-page .c12-reading-nav{padding:19px}#concrete12-page .c12-reading-nav ul{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}#concrete12-page .c12-article{font-size:16px;line-height:1.8}#concrete12-page .c12-article h2{font-size:26px;margin-top:35px}#concrete12-page .c12-article h3{font-size:20px}#concrete12-page .c12-article .formula,#concrete12-page .c12-article .note{padding:16px;font-size:14px}#concrete12-page th,#concrete12-page td{padding:10px}#concrete12-page .c12-input-unit{grid-template-columns:minmax(0,1fr) 77px}}
@media(max-width:420px){#concrete12-page .c12-shell{padding:0 12px}#concrete12-page h1{font-size:34px}#concrete12-page .c12-input-panel,#concrete12-page .c12-result-panel,#concrete12-page .c12-tool-heading{padding:16px}#concrete12-page .c12-grid{grid-template-columns:minmax(0,1fr);gap:0}#concrete12-page .c12-field{margin-bottom:15px}#concrete12-page .c12-input-unit{grid-template-columns:minmax(0,1fr) 96px}#concrete12-page .c12-add-row button{width:100%}#concrete12-page .c12-result-main{padding:18px}}
@media(prefers-reduced-motion:reduce){#concrete12-page button{transition:none}}
@media print{#concrete12-page .c12-hero,#concrete12-page .c12-tool-heading,#concrete12-page .c12-input-panel,#concrete12-page .c12-reading,#concrete12-page .c12-export,#concrete12-page .c12-copy-fallback{display:none!important}#concrete12-page .c12-shell{padding:0;max-width:none}#concrete12-page .c12-calculator{margin:0;box-shadow:none;border:0}#concrete12-page .c12-tool-grid{display:block}#concrete12-page .c12-result-panel{border:0;background:#fff;padding:10px}#concrete12-page .c12-result-main{background:#fff;color:#234627;border:1px solid #234627}#concrete12-page .c12-result-main small,#concrete12-page .c12-result-main .c12-unit{color:#234627}}