/* ============================================================
   Civil Structural Calculations — Shared Stylesheet
   ============================================================ */
@font-face {
  font-family: 'IBM Plex Sans';
  src: url('../fonts/IBMPlexSans-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Sans';
  src: url('../fonts/IBMPlexSans-Medium.woff2') format('woff2');
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Sans';
  src: url('../fonts/IBMPlexSans-SemiBold.woff2') format('woff2');
  font-weight: 600;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Sans';
  src: url('../fonts/IBMPlexSans-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Mono';
  src: url('../fonts/IBMPlexMono-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Mono';
  src: url('../fonts/IBMPlexMono-Medium.woff2') format('woff2');
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Sans Condensed';
  src: url('../fonts/IBMPlexSansCondensed-Bold.woff2') format('woff2');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}
:root {
  --white:#fff; --bg:#f4f6f8; --bg2:#edf0f3;
  --sb-bg:#1a2332; --sb-hover:#243045; --sb-active:#2e3d58; --sb-accent:#3a8fd4;
  --border:#dde2e8; --border2:#c8d0da;
  --text:#2c3a4a; --text-mid:#5a6a7a; --text-dim:#8898aa;
  --accent:#1a6db5; --accent-lt:#e8f2fc; --accent-hv:#155d9e;
  --green:#1a8a5a; --green-bg:#e8f7ef;
  --red:#c0392b;   --red-bg:#fdecea;
  --orange:#d4700a; --orange-bg:#fef3e2;
  --res-bg:#f0f5fb; --res-border:#b8d0eb;
  --mono:'Open Sans',sans-serif;
  --sans:'Open Sans',sans-serif;
  --cond:'Open Sans',sans-serif;
  --font-base:'Open Sans',sans-serif;
  --sw:268px; --hh:56px;
  --sh:0 1px 3px rgba(0,0,0,.08);
}
*{box-sizing:border-box;margin:0;padding:0;}
sub,sup{font-size:.72em;line-height:0;position:relative;vertical-align:baseline;}
sub{bottom:-0.25em;}
sup{top:-0.5em;}
html{scroll-behavior:smooth;}
body{font-family:var(--sans);font-size:14px;color:var(--text);background:var(--bg);display:flex;min-height:100vh;}

/* ── SIDEBAR ── */
.sb{width:var(--sw);min-height:100vh;background:var(--sb-bg);position:fixed;top:0;left:0;bottom:0;display:flex;flex-direction:column;z-index:200;overflow-y:auto;}
.sb-logo{padding:0 18px;height:var(--hh);display:flex;align-items:center;gap:10px;border-bottom:1px solid rgba(255,255,255,.07);flex-shrink:0;}
.sb-logo-icon{width:32px;height:32px;background:var(--sb-accent);border-radius:6px;display:flex;align-items:center;justify-content:center;font-size:15px;flex-shrink:0;}
.sb-logo-text{font-family:var(--cond);font-weight:700;font-size:.9rem;color:#fff;line-height:1.2;}
.sb-logo-text small{display:block;font-family:var(--sans);font-weight:300;font-size:.62rem;color:rgba(255,255,255,.4);letter-spacing:.06em;text-transform:uppercase;}
.sb-sec-label{font-family:var(--mono);font-size:.58rem;font-weight:500;letter-spacing:.18em;text-transform:uppercase;color:rgba(255,255,255,.25);padding:10px 18px 4px;}
.sb-item{display:flex;align-items:center;gap:10px;padding:8px 18px;cursor:pointer;transition:background .15s;border-left:3px solid transparent;color:rgba(255,255,255,.6);font-size:.81rem;text-decoration:none;}
.sb-item:hover{background:var(--sb-hover);color:rgba(255,255,255,.9);}
.sb-item.active{background:var(--sb-active);border-left-color:var(--sb-accent);color:#fff;font-weight:500;}
.sb-divider{height:1px;background:rgba(255,255,255,.06);margin:6px 14px;}
.sb-footer{margin-top:auto;padding:14px 18px;font-size:.68rem;color:rgba(255,255,255,.22);border-top:1px solid rgba(255,255,255,.05);line-height:1.6;}

/* ── MAIN WRAPPER ── */
.main-wrapper{margin-left:var(--sw);flex:1;display:flex;flex-direction:column;min-height:100vh;}
.topbar{height:var(--hh);background:var(--white);border-bottom:1px solid var(--border);display:flex;align-items:center;padding:0 28px;position:sticky;top:0;z-index:100;gap:10px;}
.breadcrumb{font-size:.8rem;color:var(--text-dim);display:flex;align-items:center;gap:6px;}
.breadcrumb a{color:var(--accent);text-decoration:none;}.breadcrumb a:hover{text-decoration:underline;}
.breadcrumb .sep{color:var(--border2);}
.breadcrumb span{color:var(--text);font-weight:500;}
.topbar-r{margin-left:auto;display:flex;gap:8px;align-items:center;}
.cbadge{font-family:var(--mono);font-size:.62rem;background:var(--accent-lt);color:var(--accent);border:1px solid #b8d0eb;border-radius:4px;padding:3px 8px;letter-spacing:.02em;}
.content{padding:28px;flex:1;}

/* ── PAGE TITLE ── */
.page-title{margin-bottom:22px;}
.page-title h1{font-family:var(--cond);font-weight:700;font-size:1.45rem;color:var(--text);margin-bottom:4px;}
.page-title p{font-size:.8rem;color:var(--text-mid);line-height:1.5;}

/* ── CARDS ── */
.card{background:var(--white);border:1px solid var(--border);border-radius:8px;box-shadow:var(--sh);}
.card-hdr{padding:13px 18px;border-bottom:1px solid var(--border);display:flex;align-items:center;gap:8px;background:var(--bg2);}
.card-hdr h3{font-family:var(--cond);font-weight:700;font-size:.82rem;letter-spacing:.05em;text-transform:uppercase;color:var(--text);}
.card-hdr .ctag{font-family:var(--mono);font-size:.6rem;background:var(--white);color:var(--text-dim);border:1px solid var(--border);border-radius:3px;padding:2px 7px;margin-left:auto;}
.card-body{padding:20px;}

/* ── CALC LAYOUT ── */
.calc-layout{display:grid;grid-template-columns:380px 1fr;gap:20px;align-items:start;}
@media(max-width:960px){.calc-layout{grid-template-columns:minmax(300px,1fr) 1fr;gap:16px;}}
@media(max-width:768px){.calc-layout{grid-template-columns:1fr;gap:16px;}}

/* ── FORMS ── */
.form-group{margin-bottom:14px;}
.form-row-2{display:grid;grid-template-columns:1fr 1fr;gap:12px;}
.form-row-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:10px;}
@media(max-width:960px){.form-row-3{grid-template-columns:1fr 1fr;}}
@media(max-width:768px){.form-row-2,.form-row-3{grid-template-columns:1fr;}}
label{display:block;font-size:.75rem;font-weight:500;color:var(--text-mid);margin-bottom:5px;}
label .lu{font-family:var(--mono);font-size:.65rem;color:var(--text-dim);font-weight:400;}
.iw{position:relative;}
.iw .us{position:absolute;right:9px;top:50%;transform:translateY(-50%);font-family:var(--mono);font-size:.67rem;color:var(--text-dim);pointer-events:none;}
input[type=number],input[type=text],select{width:100%;height:40px;padding:0 10px;border:1.5px solid var(--border2);border-radius:5px;font-family:var(--sans);font-size:.85rem;color:var(--text);background:var(--white);outline:none;transition:border-color .18s,box-shadow .18s;}
input[type=number]{padding-right:34px;}
@media(max-width:768px){input[type=number],input[type=text],select{height:44px;font-size:16px;}}
input:focus,select:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(26,109,181,.1);}
.form-div{height:1px;background:var(--border);margin:15px 0;}
.form-div-lbl{font-size:.67rem;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--text-dim);background:var(--white);padding:0 8px;margin:-8px auto 0;width:fit-content;position:relative;top:-1px;white-space:nowrap;}
.btn-calc{width:100%;height:42px;background:var(--accent);color:#fff;border:none;border-radius:6px;font-family:var(--sans);font-size:.85rem;font-weight:600;cursor:pointer;transition:background .18s;display:flex;align-items:center;justify-content:center;gap:8px;margin-top:18px;}
.btn-calc:hover{background:var(--accent-hv);}
@media(max-width:768px){.btn-calc{height:46px;font-size:.9rem;}}
.btn-sec{height:38px;padding:0 16px;background:var(--bg2);color:var(--text);border:1.5px solid var(--border2);border-radius:5px;font-family:var(--sans);font-size:.8rem;font-weight:500;cursor:pointer;transition:all .15s;}
.btn-sec:hover{border-color:var(--accent);color:var(--accent);}
@media(max-width:768px){.btn-sec{height:44px;}}

/* ── RESULTS ── */
.res-card{background:var(--white);border:1px solid var(--border);border-radius:8px;box-shadow:var(--sh);overflow:hidden;}
.res-hdr{background:var(--res-bg);border-bottom:1px solid var(--res-border);padding:11px 18px;display:flex;align-items:center;gap:8px;}
.res-hdr h4{font-family:var(--cond);font-weight:700;font-size:.8rem;letter-spacing:.06em;text-transform:uppercase;color:var(--accent);}
.res-body{padding:18px;}
.res-empty{text-align:center;padding:38px 20px;color:var(--text-dim);font-size:.82rem;}
.res-empty .ri{font-size:2rem;margin-bottom:8px;}
.res-table{width:100%;border-collapse:collapse;}
.res-table tr{border-bottom:1px solid var(--border);}
.res-table tr:last-child{border-bottom:none;}
.res-table td{padding:8px 3px;font-size:.82rem;vertical-align:middle;}
.res-table td:first-child{color:var(--text-mid);width:56%;}
.res-table td:last-child{text-align:right;font-family:var(--mono);font-size:.83rem;font-weight:500;color:var(--text);}
.res-sec{font-family:var(--mono);font-size:.6rem;font-weight:500;letter-spacing:.14em;text-transform:uppercase;color:var(--text-dim);background:var(--bg);padding:5px 8px;margin:10px 0 4px;border-left:3px solid var(--border2);}
.val-ok{color:var(--green)!important;}
.val-warn{color:var(--orange)!important;}
.val-err{color:var(--red)!important;}
.val-hl{color:var(--accent)!important;font-size:1rem!important;}
.status-banner{display:flex;align-items:center;gap:10px;padding:11px 14px;border-radius:6px;font-size:.81rem;font-weight:500;margin-top:14px;}
.status-banner.ok{background:var(--green-bg);color:var(--green);border:1px solid #a8e0c0;}
.status-banner.warn{background:var(--orange-bg);color:var(--orange);border:1px solid #f4c97a;}
.status-banner.err{background:var(--red-bg);color:var(--red);border:1px solid #f4b0a8;}

/* ── FORMULA BOX ── */
.fml-box{background:var(--bg);border:1px solid var(--border);border-radius:6px;padding:13px 15px;margin-top:14px;}
.fml-title{font-size:.64rem;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--text-dim);margin-bottom:7px;}
.fml-box code{font-family:var(--mono);font-size:.74rem;color:var(--text-mid);line-height:1.9;display:block;}
.fml-box code b{color:var(--accent);}

/* ── NOTE ── */
.note-box{background:#fffbeb;border:1px solid #f8d888;border-radius:6px;padding:9px 13px;font-size:.77rem;color:#7a5a00;margin-top:13px;line-height:1.6;}
.disclaimer{background:var(--orange-bg);border:1px solid #f4c97a;border-radius:6px;padding:11px 15px;font-size:.76rem;color:var(--text-mid);line-height:1.6;margin-bottom:18px;display:flex;gap:10px;}

/* ── SUB TABS ── */
.sub-tabs{display:flex;border-bottom:2px solid var(--border);margin-bottom:12px;}
.sub-tab{background:none;border:none;border-bottom:2px solid transparent;padding:10px 20px;min-height:44px;font-family:var(--sans);font-size:.8rem;font-weight:500;color:var(--text-dim);cursor:pointer;margin-bottom:-2px;transition:color .15s,border-color .15s;}
.sub-tab:hover{color:var(--text);}
.sub-tab.active{color:var(--accent);border-bottom-color:var(--accent);}
.sub-pane{display:none;}.sub-pane.active{display:block;}

/* ── DATA TABLES ── */
.tbl-wrap{overflow-x:auto;}
table.dt{width:100%;border-collapse:collapse;font-size:.78rem;}
table.dt thead tr{background:var(--bg2);}
table.dt thead th{position:relative;padding:14px 12px;font-family:var(--sans);font-weight:700;font-size:.92rem;letter-spacing:.01em;color:var(--text);text-align:center;white-space:nowrap;border-bottom:1px solid var(--border);box-shadow:0 1px 0 var(--border2);cursor:pointer;user-select:none;}
table.dt thead th[title]{border-bottom:2px solid var(--accent);}
table.dt thead th[title]::after{content:attr(title);position:absolute;left:50%;transform:translateX(-50%);top:calc(100% + 6px);background:#1a2332;color:#fff;font-size:.72rem;font-weight:400;padding:5px 9px;border-radius:5px;white-space:nowrap;pointer-events:none;opacity:0;transition:opacity .08s;z-index:99;}
table.dt thead th[title]:hover::after{opacity:1;}
table.dt thead th:first-child{text-align:left;border-bottom:1px solid var(--border)!important;cursor:pointer;}
table.dt thead th:hover{color:var(--accent);}
table.dt thead th.sa::after{content:' ↑';}
table.dt thead th.sd::after{content:' ↓';}
table.dt thead th sub{font-size:.58rem;line-height:0;}
table.dt tbody tr{border-bottom:1px solid var(--border);transition:background .12s;cursor:pointer;}
table.dt tbody tr:hover{background:var(--accent-lt);}
table.dt tbody tr.sel{background:#dbeeff!important;}
table.dt tbody tr:last-child{border-bottom:none;}
table.dt td{padding:10px 12px;font-family:var(--mono);font-size:.76rem;color:var(--text-mid);text-align:center;white-space:nowrap;}
table.dt td:first-child{font-family:var(--sans);font-weight:600;font-size:.81rem;color:var(--text);text-align:left;letter-spacing:.01em;}
.no-results{text-align:center;padding:30px;color:var(--text-dim);font-size:.82rem;}

/* ── REBAR TILES ── */
.rebar-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(100px,1fr));gap:10px;margin-top:13px;}
.rebar-tile{background:var(--white);border:1.5px solid var(--border);border-radius:6px;padding:11px 9px 9px;text-align:center;transition:border-color .15s,box-shadow .15s;}
.rebar-tile:hover{border-color:var(--accent);box-shadow:0 0 0 3px rgba(26,109,181,.08);}
.rt-no{font-family:var(--cond);font-weight:700;font-size:1.1rem;color:var(--accent);}
.rt-d{font-family:var(--mono);font-size:.61rem;color:var(--text-dim);margin-top:2px;}
.rt-a{font-family:var(--mono);font-size:.76rem;color:var(--text);font-weight:500;margin-top:4px;}
.rt-w{font-family:var(--mono);font-size:.61rem;color:var(--text-dim);margin-top:1px;}

/* ── HOME CARDS ── */
.home-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px;}
@media(max-width:960px){.home-grid{grid-template-columns:repeat(2,1fr);gap:14px;}}
@media(max-width:580px){.home-grid{grid-template-columns:1fr;gap:12px;}}
.home-card{background:var(--white);border:1px solid var(--border);border-radius:8px;padding:20px;cursor:pointer;transition:border-color .18s,box-shadow .18s,transform .15s;box-shadow:var(--sh);}
.home-card:hover{border-color:var(--accent);box-shadow:0 4px 16px rgba(26,109,181,.12);transform:translateY(-2px);}
.hc-icon{width:40px;height:40px;background:var(--accent-lt);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:18px;margin-bottom:12px;}
.home-card h3{font-family:var(--cond);font-weight:700;font-size:.95rem;color:var(--text);margin-bottom:6px;}
.home-card p{font-size:.77rem;color:var(--text-mid);line-height:1.6;}
.hc-codes{display:flex;gap:5px;margin-top:10px;}
.hc-code{font-family:var(--mono);font-size:.6rem;padding:2px 7px;border-radius:3px;background:var(--bg2);color:var(--text-dim);}
.info-strip{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:11px;margin-bottom:22px;}
@media(max-width:768px){.info-strip{grid-template-columns:repeat(2,1fr);gap:10px;}}
@media(max-width:480px){.info-strip{grid-template-columns:1fr;gap:9px;}}
.info-item{background:var(--white);border:1px solid var(--border);border-radius:6px;padding:13px 15px;display:flex;align-items:center;gap:11px;}
.ii-icon{width:34px;height:34px;background:var(--accent-lt);border-radius:6px;display:flex;align-items:center;justify-content:center;font-size:15px;flex-shrink:0;}
.ii-text{font-size:.74rem;}.ii-text strong{display:block;color:var(--text);font-weight:600;font-size:.79rem;}.ii-text span{color:var(--text-dim);}

/* ── SCROLLBAR ── */
::-webkit-scrollbar{width:5px;height:5px;}
::-webkit-scrollbar-track{background:transparent;}
::-webkit-scrollbar-thumb{background:var(--border2);border-radius:3px;}

/* ── ADBLOCK NOTICE ── */
.adblock-notice{position:fixed;bottom:0;left:0;right:0;background:#fff8ed;border-top:2px solid #f4c97a;padding:10px 20px;display:none;align-items:center;justify-content:space-between;gap:12px;box-shadow:0 -2px 12px rgba(0,0,0,.08);z-index:9999;font-family:var(--sans);font-size:.8rem;}
.adblock-notice.show{display:flex;}
.adblock-notice-content{display:flex;align-items:center;gap:10px;}
.adblock-notice-icon{font-size:1.1rem;flex-shrink:0;}
.adblock-notice-text{color:#6b5000;line-height:1.5;}
.adblock-notice-close{background:transparent;border:1px solid #f4c97a;border-radius:4px;font-size:.75rem;font-weight:600;cursor:pointer;color:#6b5000;padding:4px 10px;font-family:var(--sans);transition:background .13s;}
.adblock-notice-close:hover{background:#fef3d0;}

/* ── PAGE FOOTER LEGAL LINKS ── */
.footer-legal{font-size:.68rem;color:var(--text-dim);text-align:center;padding-top:8px;margin-top:4px;border-top:1px solid var(--border);}
.footer-legal a{color:var(--text-dim);text-decoration:none;transition:color .13s;}
.footer-legal a:hover{color:var(--accent);}

/* ── TABLE WRAPPER (horizontal scroll) ── */
.tbl-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch;}

/* ── VALIDATION ── */
input.val-err{border-color:#dc3545!important;background:#fff5f5!important;box-shadow:0 0 0 2px rgba(220,53,69,.15)!important;}
.val-banner{display:flex;gap:10px;align-items:flex-start;background:#fff3cd;border:1px solid #f4c97a;border-radius:6px;padding:11px 14px;font-size:.77rem;color:#6b5000;line-height:1.65;margin-bottom:12px;}
.val-banner ul{margin:4px 0 0 18px;padding:0;}
.val-banner li{margin-bottom:2px;}

/* ── SVG TOUCH & SELECT ── */
svg text{user-select:none;-webkit-user-select:none;}

/* ── MOBILE FONT & SPACING ── */
@media(max-width:768px){
  body{font-size:15px;}
  .form-group{margin-bottom:18px;}
  label{font-size:13px;margin-bottom:6px;}
  .footer-legal{font-size:12px;}
  /* Ensure unit toggle buttons are tappable */
  .unit-btn{min-height:36px;padding:6px 12px;}
  .unit-toggle .unit-btn{min-height:34px;}
  /* Sidebar items larger touch targets */
  .sb-item,.sb-group-hdr,.sb-sub{min-height:44px;}
  /* Page title */
  .page-title h1{font-size:1.25rem;}
  .page-title p{font-size:.8rem;}
  /* Card body padding */
  .card-body{padding:16px;}
  /* Report body padding */
  .report-body{padding:14px 16px!important;}
  /* Footer wrapping */
  footer{flex-wrap:wrap;}
}
@media(max-width:480px){
  .adblock-notice{font-size:.78rem;padding:10px 14px;}
  .adblock-notice-close{min-height:36px;padding:6px 12px;}
  .page-title h1{font-size:1.1rem;}
  .card-body{padding:13px;}
  /* Sub-tabs scroll on tiny screens */
  .sub-tabs{overflow-x:auto;flex-wrap:nowrap;}
  .sub-tab{white-space:nowrap;flex-shrink:0;}
}

/* ── ACCESSIBILITY (WCAG 2.1 Level AA) ── */

/* Visually hidden but accessible to screen readers */
.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;}

/* Skip to content link */
.skip-link{position:absolute;top:-48px;left:8px;background:var(--white);color:var(--accent);padding:8px 16px;text-decoration:none;z-index:10000;border:2px solid var(--accent);border-radius:4px;font-size:.85rem;font-weight:600;transition:top .12s;}
.skip-link:focus{top:8px;}

/* Focus indicators — keyboard only */
*:focus{outline:none;}
*:focus-visible{outline:2px solid #0066cc;outline-offset:2px;}
button:focus-visible,.btn-calc:focus-visible,.sub-tab:focus-visible,.mod-tab:focus-visible,.unit-btn:focus-visible{outline:2px solid #0066cc;outline-offset:2px;box-shadow:0 0 0 4px rgba(0,102,204,.12);}
input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid #0066cc;outline-offset:0;border-color:#0066cc!important;}
a:focus-visible{outline:2px solid #0066cc;outline-offset:2px;text-decoration:underline;}

/* Fieldset / legend */
fieldset{border:none;padding:0;margin:0 0 16px 0;}
legend{font-size:.87rem;font-weight:600;margin-bottom:10px;color:var(--text);padding:0;}

/* Table caption */
table caption{font-size:.78rem;font-weight:600;text-align:left;padding:0 0 8px;color:var(--text-mid);caption-side:top;}