:root{
        --primary:#07879A;
        --primary-dark:#056B7A;
        --primary-soft:#EAF7F8;
        --accent:#F28C45;
        --text:#26343A;
        --muted:#6B777C;
        --border:#E4EAEC;
        /* --bg:#F6F9FA; */
        --white:#FFFFFF;
        --shadow:0 8px 30px rgba(28,55,65,.07);
    }

    .calculator-info *{box-sizing:border-box}

    .calculator-info{
        width:70%;
        margin:32px 0 48px 5%;
        color:var(--text);
        font-family:Arial, Helvetica, sans-serif;
        line-height:1.65;
    }

    .description-layout{
        display:grid;
        grid-template-columns:minmax(0, 1fr);
        gap:14px;
    }

    /* ---------------------------
       TABLE OF CONTENTS
    ---------------------------- */
    .toc-card{
        /* background:var(--white); */
        border:1px solid var(--border);
        border-radius:14px;
        padding:20px 22px;
        margin:0;
        box-shadow:0 5px 20px rgba(28,55,65,.055);
        position:static;
        border-top:3px solid var(--primary);
    }

    .toc-header{
        display:block;
        margin-bottom:12px;
    }

    .toc-title{
        display:flex;
        align-items:center;
        gap:10px;
        margin:20;
        font-size:20px;
        font-weight:800;
        letter-spacing:.7px;
        text-transform:uppercase;
    }

    .toc-icon{
        width:3px;
        height:14px;
        display:inline-block;
        border-radius:3px;
        background:var(--accent);
    }

    .toc-subtitle{
        display:block;
        margin:4px 0 0 11px;
        color:var(--muted);
        font-size:12px;
        line-height:1.4;
    }

    .toc-list{
        display:grid;
        grid-template-columns:repeat(3, minmax(0, 1fr));
        gap:6px 8px;
        margin:0;
        padding:0;
        list-style:none;
    }

    .toc-list a{
        display:flex;
        align-items:center;
        gap:10px;
        min-height:44px;
        padding:8px 10px;
        border:1px solid #edf1f2;
        border-radius:9px;
        color:var(--text);
        text-decoration:none;
        background:#fcfefe;
        font-size:12px;
        font-weight:600;
        line-height:1.35;
        transition:background .2s ease, border-color .2s ease, color .2s ease, transform .2s ease;
    }

    .toc-list a:hover{
        border-color:#B9DDE2;
        background:var(--primary-soft);
        color:var(--primary-dark);
        border-left-color:var(--accent);
        transform:translateY(-1px);
    }

    .toc-list a:focus-visible,
    .related-link:focus-visible{
        outline:3px solid rgba(7,135,154,.25);
        outline-offset:2px;
    }

    .toc-list li:first-child a{
        border-left:3px solid var(--accent);
        background:var(--primary-soft);
        color:var(--primary-dark);
    }

    .toc-number{
        flex:0 0 25px;
        width:25px;
        height:25px;
        display:grid;
        place-items:center;
        border-radius:50%;
        background:var(--primary-soft);
        color:var(--primary-dark);
        font-size:10px;
        font-weight:800;
    }

    /* ---------------------------
       MAIN CONTENT CARD
    ---------------------------- */
    .content-card{
        background:var(--white);
        border:1px solid var(--border);
        border-radius:15px;
        padding:28px 30px;
        box-shadow:0 6px 24px rgba(28,55,65,.055);
    }

    .calculator-info .section{
        padding:0 0 23px;
        margin:0 0 23px;
        border-bottom:1px solid #EEF1F2;
        scroll-margin-top:25px;
    }

    .calculator-info .section:last-child{
        border-bottom:0;
        margin-bottom:0;
        padding-bottom:0;
    }

    .calculator-info .section h2{
        margin:0 0 10px;
        font-size:21px;
        line-height:1.25;
        color:#25343A;
        letter-spacing:-.3px;
    }

    .calculator-info .section h2::before{display:none}
    .calculator-info .section-number{display:none}

    .calculator-info .section p{
        margin:8px 0;
        font-size:13px;
        color:#56646A;
        line-height:1.7;
    }

    .calculator-info .section-content{
        color:#56646A;
        font-size:14px;
        line-height:1.75;
    }

    .calculator-info .section-content h3{
        margin:16px 0 6px;
        color:#285C64;
        font-size:15px;
        line-height:1.4;
    }

    .calculator-info .section-content ul,
    .calculator-info .section-content ol{
        padding-left:21px;
    }

    .calculator-info .section-content li + li{margin-top:5px}

    .calculator-info .lead{
        font-size:16px !important;
        color:#435158 !important;
    }

    /* ---------------------------
       HOW IT WORKS
    ---------------------------- */
    .calculator-info .steps{
        display:grid;
        grid-template-columns:repeat(3, 1fr);
        gap:14px;
        margin-top:18px;
    }

    .calculator-info .step{
        padding:18px;
        border:1px solid var(--border);
        border-radius:14px;
        background:#FBFDFD;
    }

    .calculator-info .step-number{
        width:30px;
        height:30px;
        display:grid;
        place-items:center;
        margin-bottom:11px;
        border-radius:8px;
        background:var(--primary);
        color:#fff;
        font-size:12px;
        font-weight:800;
    }

    .calculator-info .step h3{
        margin:0 0 5px;
        font-size:15px;
    }

    .calculator-info .step p{
        margin:0;
        font-size:13px;
    }

    /* ---------------------------
       FORMULA
    ---------------------------- */
    .calculator-info .formula-box{
        margin:17px 0 12px;
        padding:12px 14px;
        background:var(--primary-soft);
        border-left:4px solid var(--accent);
        border-radius:8px;
        overflow-x:auto;
        font-family:"Courier New", monospace;
        font-size:13px;
        font-weight:600;
        color:#24545C;
    }

    /* ---------------------------
       VARIABLES
    ---------------------------- */
    .calculator-info .variable-table{
        width:100%;
        border-collapse:collapse;
        margin-top:17px;
        overflow:hidden;
        border:1px solid var(--border);
        border-radius:12px;
    }

    .calculator-info .variable-table table{
        width:100%;
        border-collapse:collapse;
    }

    .calculator-info .variable-table th{
        text-align:left;
        background:var(--primary-soft);
        color:#24545C;
        font-size:13px;
        padding:12px 14px;
    }

    .calculator-info .variable-table th:first-child,
    .calculator-info .variable-table td:first-child{
        width:84px;
        min-width:84px;
        white-space:nowrap;
        word-break:normal;
        overflow-wrap:normal;
    }

    .calculator-info .variable-table td{
        padding:12px 14px;
        border-top:1px solid var(--border);
        font-size:14px;
        color:#56646A;
    }

    .calculator-info .variable-table td:first-child{
        color:#26343A;
        font-weight:700;
        white-space:nowrap;
    }

    /* ---------------------------
       EXAMPLE
    ---------------------------- */
    .calculator-info .example-box{
        margin-top:17px;
        padding:20px;
        background:#FBFDFD;
        border:1px solid var(--border);
        border-radius:14px;
    }

    .calculator-info .example-row{
        display:flex;
        justify-content:space-between;
        gap:20px;
        padding:10px 0;
        border-bottom:1px solid #EDF1F2;
        font-size:14px;
    }

    .calculator-info .example-row:last-child{
        border-bottom:0;
        padding-bottom:0;
    }

    .calculator-info .example-row strong{
        color:#26343A;
    }

    .calculator-info .result-box{
        margin-top:15px;
        padding:14px 16px;
        border-radius:10px;
        background:var(--primary-soft);
        color:#24545C;
        font-weight:800;
    }

    /* ---------------------------
       INTERPRETATION / MISTAKES
    ---------------------------- */
    .calculator-info .info-grid{
        display:grid;
        /* grid-template-columns:repeat(2, 1fr); */
        gap:14px;
        margin-top:17px;
    }

    .calculator-info .info-card{
        border:1px solid var(--border);
        border-radius:14px;
        padding:18px;
        background:#fff;
    }

    .calculator-info .info-card h3{
        margin:0 0 6px;
        font-size:15px;
        color:#285C64;
    }

    .calculator-info .info-card p{
        margin:0;
        font-size:13px;
    }

    .calculator-info .mistakes{
        margin:16px 0 0;
        color:#56646A;
    }

    .calculator-info .mistakes ul,
    .calculator-info .mistakes ol{
        margin:0;
        padding-left:20px;
    }

    .calculator-info .mistakes li{
        margin:8px 0;
        font-size:14px;
    }

    /* ---------------------------
       FAQ
    ---------------------------- */
    .calculator-info .faq-list{
        margin-top:16px;
        display:grid;
        gap:9px;
    }

    .calculator-info .faq{
        border:1px solid var(--border);
        border-radius:11px;
        overflow:hidden;
        background:#fff;
    }

    .calculator-info .faq + .faq{
        margin-top:10px;
    }

    .calculator-info .faq summary{
        cursor:pointer;
        padding:11px 13px;
        font-size:13px;
        font-weight:600;
        color:#34464C;
        list-style:none;
        transition:background .2s ease;
    }

    .calculator-info .faq summary:hover{background:#fbfefe}

    .calculator-info .faq summary::-webkit-details-marker{display:none}

    .calculator-info .faq summary::before{
        content:"+";
        display:inline-grid;
        place-items:center;
        width:22px;
        height:22px;
        margin-right:9px;
        border-radius:50%;
        background:var(--primary-soft);
        color:var(--primary-dark);
    }

    .calculator-info .faq[open] summary::before{content:"−"}

    .calculator-info .faq p{
        padding:0 16px 15px 47px;
        margin:0;
        font-size:13px;
    }

    .calculator-info .faq-answer{
        padding:0 16px 15px 47px;
        color:#56646A;
        font-size:13px;
    }

    /* ---------------------------
       SOURCES
    ---------------------------- */
    .sources{
        margin-top:16px;
        padding:18px 20px;
        border-radius:14px;
        background:#F9FBFB;
        border:1px solid var(--border);
    }

    .sources ul{
        margin:8px 0 0;
        padding-left:20px;
    }

    .sources li{
        margin:7px 0;
        font-size:13px;
        color:#56646A;
    }

    .sources a{
        color:var(--primary-dark);
        font-weight:650;
    }

    .related-section{
        padding-top:0;
        margin-bottom:0;
        border-bottom:0;
    }

    .related-links{
        display:flex;
        flex-wrap:wrap;
        gap:8px;
        margin-top:14px;
    }

    .related-link{
        display:inline-flex;
        align-items:center;
        padding:7px 13px;
        border:1px solid #e2edef;
        border-radius:999px;
        background:#fbfdfd;
        color:var(--primary-dark);
        font-size:13px;
        text-decoration:none;
        transition:background .2s ease, border-color .2s ease;
    }

    .related-link:hover{
        background:var(--primary-soft);
        border-color:#b9dde2;
        color:var(--primary-dark);
    }

    /* ---------------------------
       RESPONSIVE
    ---------------------------- */
    @media(max-width:900px){
        .toc-list{
            grid-template-columns:repeat(2, minmax(0, 1fr));
        }

        .calculator-info .steps{
            grid-template-columns:1fr;
        }

        .content-card{
            padding:25px 24px;
        }
    }

    @media(max-width:600px){
        .calculator-info{
            width:calc(100% - 24px);
            margin:25px 12px;
        }

        .toc-card{
            padding:18px;
        }

        .toc-list{
            grid-template-columns:1fr;
        }

        .content-card{
            padding:24px 18px;
            border-radius:15px;
        }

        .calculator-info .section h2{
            font-size:21px;
        }

        .calculator-info .info-grid{
            grid-template-columns:1fr;
        }

        .calculator-info .variable-table{
            display:block;
            overflow-x:auto;
        }

        .calculator-info .variable-table table{
            min-width:420px;
        }
    }