:root{--bg:#0d0f14;--surface:#161921;--surface2:#1e2230;--border:#2a2f42;
--accent:#00e5b0;--accent2:#5b6af0;--text:#e8eaf0;--muted:#6b7190;
--danger:#ff5f6d;--radius:14px;}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{font-family:'DM Sans',sans-serif;background:var(--bg);color:var(--text);min-height:100vh;overflow-x:hidden;}
body::before{content:'';position:fixed;inset:0;
background-image:linear-gradient(rgba(91,106,240,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(91,106,240,.04) 1px,transparent 1px);
background-size:40px 40px;pointer-events:none;z-index:0;}
body::after{content:'';position:fixed;top:-200px;left:50%;transform:translateX(-50%);
width:600px;height:600px;background:radial-gradient(circle,rgba(0,229,176,.08) 0%,transparent 70%);pointer-events:none;z-index:0;}

/* ── HEADER ── */
header{position:sticky;top:0;z-index:100;background:rgba(13,15,20,.9);backdrop-filter:blur(20px);
border-bottom:1px solid var(--border);padding:0 20px;}
.header-inner{max-width:1100px;margin:0 auto;display:flex;align-items:center;
justify-content:space-between;height:58px;gap:12px;}
.logo{font-family:'Syne',sans-serif;font-size:1.4rem;font-weight:800;color:var(--accent);
letter-spacing:-.5px;white-space:nowrap;text-decoration:none;}
.logo span{color:var(--text);}
.header-search{flex:1;max-width:340px;position:relative;}
.header-search input{width:100%;background:var(--surface2);border:1px solid var(--border);
border-radius:8px;padding:8px 12px 8px 36px;color:var(--text);font-family:'DM Sans',sans-serif;
font-size:.85rem;outline:none;transition:border-color .2s;}
.header-search input:focus{border-color:var(--accent);}
.header-search input::placeholder{color:var(--muted);}
.search-icon{position:absolute;left:10px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:.85rem;pointer-events:none;}
.home-btn{display:flex;align-items:center;gap:6px;padding:6px 14px;border-radius:7px;
background:rgba(0,229,176,.1);border:1px solid rgba(0,229,176,.25);color:var(--accent);
font-family:'DM Sans',sans-serif;font-size:.78rem;font-weight:600;text-decoration:none;
white-space:nowrap;transition:all .15s;}
.home-btn:hover{background:rgba(0,229,176,.2);}

/* ── LAYOUT ── */
.main{position:relative;z-index:1;max-width:1100px;margin:0 auto;padding:28px 16px 60px;
display:grid;grid-template-columns:240px 1fr;gap:20px;align-items:start;}

/* ── SIDEBAR ── */
.sidebar{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
overflow:hidden;position:sticky;top:78px;max-height:calc(100vh - 100px);overflow-y:auto;}
.sidebar::-webkit-scrollbar{width:4px;}
.sidebar::-webkit-scrollbar-track{background:transparent;}
.sidebar::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px;}
.sidebar-title{font-family:'DM Mono',monospace;font-size:.65rem;text-transform:uppercase;
letter-spacing:2px;color:var(--muted);padding:16px 16px 8px;}
.cat-btn{display:flex;align-items:center;gap:10px;width:100%;background:none;border:none;
padding:10px 16px;color:var(--muted);font-family:'DM Sans',sans-serif;font-size:.875rem;
font-weight:500;cursor:pointer;text-align:left;transition:all .15s;border-left:3px solid transparent;}
.cat-btn:hover{color:var(--text);background:var(--surface2);}
.cat-btn.active-cat{color:var(--accent);background:rgba(0,229,176,.07);border-left-color:var(--accent);}
.cat-icon{font-size:1rem;width:20px;text-align:center;}

/* ── MAIN PANEL ── */
.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;}
.panel-header{padding:24px 28px 20px;border-bottom:1px solid var(--border);
background:linear-gradient(135deg,rgba(0,229,176,.05),rgba(91,106,240,.05));}

/* ── BREADCRUMB ── */
.breadcrumb{font-size:.72rem;color:var(--muted);font-family:'DM Mono',monospace;
margin-bottom:8px;display:flex;align-items:center;gap:6px;flex-wrap:wrap;}
.breadcrumb a{color:var(--muted);text-decoration:none;transition:color .15s;}
.breadcrumb a:hover{color:var(--accent);}
.bc-sep{opacity:.4;}

/* ── H1 ── */
.panel-h1{font-family:'Syne',sans-serif;font-size:1.6rem;font-weight:800;color:var(--text);margin:0;}
.panel-h1 span{color:var(--accent);}
.panel-sub{font-size:.8rem;color:var(--muted);margin-top:4px;font-family:'DM Mono',monospace;}

/* ── CONVERTER ── */
.conversion-area{padding:28px;}
.convertor-row{display:grid;grid-template-columns:1fr auto 1fr;gap:16px;align-items:end;}
.unit-box{display:flex;flex-direction:column;gap:8px;}
.unit-label{font-family:'DM Mono',monospace;font-size:.68rem;text-transform:uppercase;letter-spacing:1.5px;color:var(--muted);}
.input-wrap{position:relative;}
.unit-input{width:100%;background:var(--surface2);border:2px solid var(--border);border-radius:10px;
padding:14px 16px;font-family:'DM Mono',monospace;font-size:1.4rem;font-weight:500;color:var(--text);
outline:none;transition:border-color .2s,box-shadow .2s;-moz-appearance:textfield;}
.unit-input::-webkit-outer-spin-button,.unit-input::-webkit-inner-spin-button{-webkit-appearance:none;}
.unit-input:focus{border-color:var(--accent);box-shadow:0 0 0 4px rgba(0,229,176,.1);}
.unit-input.input-right:focus{border-color:var(--accent2);box-shadow:0 0 0 4px rgba(91,106,240,.1);}
.copy-btn{position:absolute;right:10px;top:50%;transform:translateY(-50%);
background:none;border:none;color:var(--muted);cursor:pointer;padding:4px;border-radius:4px;
font-size:.8rem;transition:color .2s;opacity:0;}
.input-wrap:hover .copy-btn{opacity:1;}
.copy-btn:hover{color:var(--accent);}
.unit-select{width:100%;background:var(--surface2);border:1px solid var(--border);border-radius:8px;
padding:9px 32px 9px 12px;color:var(--text);font-family:'DM Sans',sans-serif;font-size:.875rem;
outline:none;cursor:pointer;transition:border-color .2s;appearance:none;
background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236b7190' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
background-repeat:no-repeat;background-position:right 12px center;}
.unit-select:focus{border-color:var(--accent);outline:none;}
.swap-col{display:flex;flex-direction:column;align-items:center;justify-content:flex-end;padding-bottom:2px;gap:8px;}
.swap-btn{background:var(--surface2);border:1px solid var(--border);border-radius:50%;width:44px;height:44px;
display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--text);
font-size:1.1rem;transition:all .2s;flex-shrink:0;}
.swap-btn:hover{background:var(--accent);border-color:var(--accent);color:#0d0f14;transform:rotate(180deg);}

/* ── FORMULA BAR ── */
.formula-bar{margin:16px 28px;background:rgba(0,229,176,.05);border:1px solid rgba(0,229,176,.15);
border-radius:8px;padding:12px 16px;font-family:'DM Mono',monospace;font-size:.8rem;color:var(--accent);
min-height:40px;display:flex;align-items:center;gap:8px;}
.formula-label{color:var(--muted);font-size:.68rem;text-transform:uppercase;letter-spacing:1px;white-space:nowrap;}

/* ── REFERENCE TABLE ── */
.ref-table-wrap{margin:0 28px 28px;}
.ref-title{font-family:'DM Mono',monospace;font-size:.65rem;text-transform:uppercase;letter-spacing:2px;color:var(--muted);margin-bottom:10px;}
.ref-table{width:100%;border-collapse:collapse;font-size:.82rem;}
.ref-table th{text-align:left;color:var(--muted);font-weight:500;padding:6px 10px;
border-bottom:1px solid var(--border);font-family:'DM Mono',monospace;font-size:.7rem;}
.ref-table td{padding:7px 10px;border-bottom:1px solid rgba(42,47,66,.5);
font-family:'DM Mono',monospace;font-size:.8rem;color:var(--text);cursor:pointer;transition:background .15s;}
.ref-table tr:hover td{background:var(--surface2);}
.ref-table tr:last-child td{border-bottom:none;}
.ref-table td:nth-child(2){color:var(--accent);}

/* ── SEO CONTENT SECTION ── */
.seo-section{margin-top:24px;background:var(--surface);border:1px solid var(--border);
border-radius:var(--radius);overflow:hidden;}
.seo-tabs{display:flex;border-bottom:1px solid var(--border);overflow-x:auto;scrollbar-width:none;}
.seo-tabs::-webkit-scrollbar{display:none;}
.seo-tab{flex:0 0 auto;padding:12px 20px;background:none;border:none;
font-family:'DM Sans',sans-serif;font-size:.82rem;font-weight:600;color:var(--muted);
cursor:pointer;border-bottom:2px solid transparent;transition:all .15s;white-space:nowrap;}
.seo-tab.active-tab{color:var(--accent);border-bottom-color:var(--accent);}
.seo-tab:hover:not(.active-tab){color:var(--text);}
.seo-panel{display:none;padding:24px 28px;}
.seo-panel.show{display:block;animation:fadeUp .2s ease;}
@keyframes fadeUp{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:translateY(0);}}

/* ── HOW TO ── */
.how-to-answer{background:rgba(0,229,176,.06);border:1px solid rgba(0,229,176,.2);
border-radius:10px;padding:16px 20px;font-size:.92rem;line-height:1.65;margin-bottom:20px;color:var(--text);}
.how-to-answer strong{color:var(--accent);}
.how-to-steps{list-style:none;display:flex;flex-direction:column;gap:12px;margin-bottom:20px;}
.how-to-steps li{display:flex;align-items:flex-start;gap:12px;font-size:.88rem;color:var(--text);line-height:1.6;}
.step-num{flex-shrink:0;width:26px;height:26px;background:var(--accent2);border-radius:50%;
display:flex;align-items:center;justify-content:center;font-family:'DM Mono',monospace;
font-size:.75rem;font-weight:700;color:#fff;margin-top:1px;}

/* ── COMMON VALUES TABLE ── */
.common-vals-table{width:100%;border-collapse:collapse;font-size:.85rem;margin-top:12px;}
.common-vals-table th{text-align:left;padding:9px 14px;background:var(--surface);color:var(--muted);
font-family:'DM Mono',monospace;font-size:.7rem;text-transform:uppercase;letter-spacing:.8px;
border-bottom:1px solid var(--border);}
.common-vals-table td{padding:9px 14px;border-bottom:1px solid rgba(42,47,66,.4);font-family:'DM Mono',monospace;}
.common-vals-table td:first-child{color:var(--muted);}
.common-vals-table td:last-child{color:var(--accent);font-weight:500;}
.common-vals-table tr:hover td{background:var(--surface2);}
.common-vals-table tr:last-child td{border-bottom:none;}

/* ── FAQ ── */
.faq-list{display:flex;flex-direction:column;gap:10px;}
.faq-item{background:var(--surface2);border:1px solid var(--border);border-radius:10px;overflow:hidden;}
.faq-q{width:100%;background:none;border:none;padding:14px 16px;text-align:left;color:var(--text);
font-family:'DM Sans',sans-serif;font-size:.88rem;font-weight:600;cursor:pointer;
display:flex;align-items:center;justify-content:space-between;transition:color .15s;}
.faq-q:hover{color:var(--accent);}
.faq-arrow{font-size:.75rem;color:var(--muted);transition:transform .2s;}
.faq-item.open .faq-arrow{transform:rotate(180deg);}
.faq-a{display:none;padding:0 16px 14px;font-size:.85rem;color:var(--muted);line-height:1.65;}
.faq-item.open .faq-a{display:block;}

/* ── ABOUT ── */
.cat-info{font-size:.875rem;color:var(--muted);line-height:1.7;}
.cat-info h2{font-family:'Syne',sans-serif;font-size:1rem;font-weight:700;color:var(--text);margin-bottom:8px;}
.cat-info h3{font-size:.85rem;font-weight:700;color:var(--text);margin:14px 0 6px;}
.cat-info p{margin-bottom:10px;}

/* ── TOAST ── */
.toast{position:fixed;bottom:24px;left:50%;transform:translateX(-50%) translateY(80px);
background:var(--accent);color:#0d0f14;padding:10px 20px;border-radius:8px;font-weight:600;
font-size:.85rem;z-index:9999;transition:transform .3s cubic-bezier(.34,1.56,.64,1);pointer-events:none;}
.toast.show{transform:translateX(-50%) translateY(0);}

/* ── MOBILE CATEGORY ── */
.mobile-cat-header{display:none;align-items:center;justify-content:space-between;
padding:14px 16px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);
cursor:pointer;font-weight:600;font-size:.9rem;color:var(--text);}
.mobile-cat-header span{color:var(--accent);}

/* ── RESPONSIVE ── */
@media(max-width:768px){
  .main{grid-template-columns:1fr;padding:16px 12px 60px;gap:12px;}
  .sidebar{position:static;max-height:none;overflow:visible;display:none;}
  .sidebar.open{display:block;}
  .mobile-cat-header{display:flex;}
  .convertor-row{grid-template-columns:1fr;gap:12px;}
  .swap-col{flex-direction:row;justify-content:center;padding-bottom:0;}
  .swap-btn{transform:rotate(90deg);}
  .swap-btn:hover{transform:rotate(270deg);}
  .panel-header{padding:18px 18px 14px;}
  .panel-h1{font-size:1.3rem;}
  .conversion-area{padding:18px;}
  .formula-bar{margin:12px 18px;}
  .ref-table-wrap{margin:0 18px 18px;}
  .history-wrap{padding:16px 18px 20px;}
  .unit-input{font-size:1.2rem;padding:12px 14px;}
  .header-search{display:none;}
  .seo-panel{padding:18px;}
  .home-btn .home-txt{display:none;}
}
@media(max-width:400px){
  .unit-input{font-size:1rem;}
  .panel-h1{font-size:1.1rem;}
}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px);}to{opacity:1;transform:translateY(0);}}
.panel{animation:fadeIn .4s ease;}
::-webkit-scrollbar{width:6px;}
::-webkit-scrollbar-track{background:transparent;}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px;}

/* ── UNIT DEFINITIONS ── */
.defs-search-wrap{margin-bottom:16px;position:relative;}
.defs-search{width:100%;background:var(--surface2);border:1px solid var(--border);border-radius:8px;
padding:9px 12px 9px 34px;color:var(--text);font-family:"DM Sans",sans-serif;font-size:.85rem;outline:none;transition:border-color .2s;}
.defs-search:focus{border-color:var(--accent);}
.defs-search::placeholder{color:var(--muted);}
.defs-search-icon{position:absolute;left:10px;top:50%;transform:translateY(-50%);color:var(--muted);font-size:.85rem;pointer-events:none;}
.def-card{background:var(--surface2);border:1px solid var(--border);border-radius:10px;margin-bottom:10px;overflow:hidden;transition:border-color .2s;}
.def-card:hover{border-color:rgba(0,229,176,.3);}
.def-header{display:flex;align-items:center;gap:12px;padding:13px 16px;cursor:pointer;}
.def-symbol{font-family:"DM Mono",monospace;font-size:1rem;font-weight:700;color:var(--accent);
min-width:56px;background:rgba(0,229,176,.08);border:1px solid rgba(0,229,176,.18);border-radius:6px;
padding:4px 8px;text-align:center;white-space:nowrap;}
.def-name{font-size:.9rem;font-weight:600;color:var(--text);flex:1;}
.def-std{font-family:"DM Mono",monospace;font-size:.68rem;color:var(--muted);white-space:nowrap;
background:var(--surface);border:1px solid var(--border);border-radius:4px;padding:2px 7px;}
.def-arrow{font-size:.72rem;color:var(--muted);transition:transform .2s;margin-left:6px;}
.def-card.open .def-arrow{transform:rotate(180deg);}
.def-body{display:none;padding:0 16px 14px 16px;border-top:1px solid var(--border);}
.def-card.open .def-body{display:block;}
.def-body p{font-size:.85rem;color:var(--muted);line-height:1.7;margin-top:10px;}
.def-body p strong{color:var(--text);}
.def-body .def-formula{font-family:"DM Mono",monospace;font-size:.82rem;color:var(--accent2);
background:rgba(91,106,240,.08);border:1px solid rgba(91,106,240,.2);border-radius:6px;
padding:8px 12px;margin:10px 0;display:block;}
.def-body .def-equiv{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px;}
.def-body .def-equiv span{font-family:"DM Mono",monospace;font-size:.75rem;color:var(--muted);
background:var(--surface);border:1px solid var(--border);border-radius:4px;padding:3px 8px;}
.def-body .def-equiv span strong{color:var(--accent);font-weight:600;}
.defs-none{text-align:center;color:var(--muted);padding:32px 0;font-size:.85rem;}
.def-source{font-size:.7rem;color:var(--muted);opacity:.6;margin-top:8px;font-family:"DM Mono",monospace;}

/* ── CONCENTRATION PANEL ── */
.conc-panel{padding:20px 28px 26px;background:rgba(0,229,176,.025);border-top:1px solid var(--border);}
.conc-section-title{font-family:'DM Mono',monospace;font-size:.65rem;text-transform:uppercase;
letter-spacing:2px;color:var(--accent);margin-bottom:14px;}
.conc-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:12px;}
@media(max-width:700px){.conc-grid{grid-template-columns:1fr 1fr;}}
@media(max-width:440px){.conc-grid{grid-template-columns:1fr;}}
.conc-group{display:flex;flex-direction:column;gap:5px;}
.conc-label{font-family:'DM Mono',monospace;font-size:.65rem;text-transform:uppercase;
letter-spacing:1px;color:var(--muted);}
.conc-input{background:var(--surface2);border:1.5px solid var(--border);border-radius:8px;
padding:9px 11px;font-family:'DM Mono',monospace;font-size:.95rem;font-weight:500;
color:var(--text);outline:none;width:100%;transition:border-color .2s,box-shadow .2s;
-moz-appearance:textfield;}
.conc-input::-webkit-outer-spin-button,.conc-input::-webkit-inner-spin-button{-webkit-appearance:none;}
.conc-input:focus{border-color:var(--accent);box-shadow:0 0 0 3px rgba(0,229,176,.1);}
.conc-input.highlight{border-color:var(--accent2);}
.conc-density-row{display:grid;grid-template-columns:1fr 1fr 1fr;gap:10px;
background:rgba(91,106,240,.05);border:1px solid rgba(91,106,240,.2);
border-radius:8px;padding:12px 14px;margin-bottom:12px;}
@media(max-width:600px){.conc-density-row{grid-template-columns:1fr 1fr;}}
.conc-density-label{font-family:'DM Mono',monospace;font-size:.62rem;text-transform:uppercase;
letter-spacing:1px;color:var(--accent2);margin-bottom:4px;}
.conc-density-input{background:var(--surface2);border:1.5px solid rgba(91,106,240,.3);border-radius:6px;
padding:7px 10px;font-family:'DM Mono',monospace;font-size:.9rem;color:var(--text);
outline:none;width:100%;transition:border-color .2s;-moz-appearance:textfield;}
.conc-density-input::-webkit-outer-spin-button,.conc-density-input::-webkit-inner-spin-button{-webkit-appearance:none;}
.conc-density-input:focus{border-color:var(--accent2);}
.conc-note{font-family:'DM Mono',monospace;font-size:.72rem;color:var(--muted);
background:rgba(0,229,176,.04);border:1px solid rgba(0,229,176,.12);border-radius:6px;
padding:8px 12px;line-height:1.6;margin-top:4px;}
.conc-note strong{color:var(--accent);}
.conc-mode-tabs{display:flex;gap:6px;margin-bottom:12px;}
.conc-mode-btn{background:var(--surface2);border:1px solid var(--border);border-radius:6px;
padding:5px 14px;font-family:'DM Mono',monospace;font-size:.72rem;color:var(--muted);
cursor:pointer;transition:all .15s;}
.conc-mode-btn.active{background:rgba(0,229,176,.12);border-color:var(--accent);color:var(--accent);}
.conc-mode-btn:hover:not(.active){color:var(--text);}

/* ── BRAND WATERMARK ── */
#mc-watermark{
  position:fixed;bottom:14px;right:16px;z-index:99999;
  font-family:'DM Mono',monospace;font-size:.68rem;font-weight:600;
  color:rgba(0,229,176,.55);letter-spacing:.5px;
  background:rgba(13,15,20,.7);border:1px solid rgba(0,229,176,.18);
  border-radius:6px;padding:4px 10px;pointer-events:none;user-select:none;
  white-space:nowrap;backdrop-filter:blur(4px);}
#mc-footer{
  text-align:center;padding:18px 12px;font-family:'DM Mono',monospace;
  font-size:.72rem;color:var(--muted);border-top:1px solid var(--border);
  position:relative;z-index:1;margin-top:8px;letter-spacing:.3px;}
#mc-footer a{color:var(--accent);text-decoration:none;font-weight:600;}
#mc-footer a:hover{text-decoration:underline;}
.panel-h1::after{
  content:'multicalci.com';
  font-family:'DM Mono',monospace;font-size:.58rem;font-weight:400;
  color:rgba(0,229,176,.35);margin-left:10px;vertical-align:middle;
  letter-spacing:.5px;}