/* convert — mock v1 (12/10/2026). Một cột, phẳng, tương phản cao, không bóng đổ, không font ngoài. */
:root{
  --bg:#ffffff; --surface:#f4f6f8; --fg:#15202b; --muted:#3f4f63; --line:#c9d3df; --line-strong:#7d8b9d;
  --accent:#0a58b0; --accent-fg:#ffffff; --ok:#1f7a3a;
  --w-page:1080px; --w-tool:760px; --radius:6px;
  --f:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  color-scheme:light;
}
/* Sáng là mặc định (owner 12/10); tối chỉ khi người dùng bật nút trong header (localStorage cv_theme, script sớm trong <head>). */
:root[data-theme="dark"]{--bg:#0f1419;--surface:#161d25;--fg:#e6ebf0;--muted:#aab6c3;--line:#2c3a48;--line-strong:#6b7c90;--accent:#6fb0ff;--accent-fg:#0b1a2b;--ok:#6fcf8a;color-scheme:dark}
*{box-sizing:border-box}
html{font-size:16px}
body{margin:0;background:var(--bg);color:var(--fg);font-family:var(--f);font-size:16px;line-height:1.5;padding-inline:16px;padding-block:0 40px}
a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}
h1,h2,h3{line-height:1.2;margin:0}
/* header */
.hd{max-width:var(--w-page);margin:0 auto;height:56px;display:flex;align-items:center;gap:16px;border-bottom:1px solid var(--line)}
.brand{display:inline-flex;align-items:center;gap:8px;font-weight:700;font-size:20px;color:var(--fg);letter-spacing:-.01em;text-decoration:none}
.brand .mark{width:26px;height:26px;flex:none;color:var(--accent)}
.brand b{font-weight:700;color:var(--accent)}
.brand:hover{text-decoration:none}
.hd nav{display:flex;gap:18px;margin-left:8px;font-size:15px}
.hd .sp{flex:1}
.btn-ghost{height:44px;padding:0 12px;border:1px solid var(--line);border-radius:var(--radius);background:transparent;color:var(--fg);font:inherit;font-size:15px;cursor:pointer;display:inline-flex;align-items:center;gap:8px}
.btn-ghost:hover{border-color:var(--line-strong)}
.btn-ghost svg{width:20px;height:20px;flex:none}
.icon-btn{width:44px;padding:0;justify-content:center}
.hd-actions{display:flex;align-items:center;gap:8px}
/* theme toggle: moon in light mode, sun in dark mode */
:root[data-theme="dark"] .i-moon{display:none}
:root:not([data-theme="dark"]) .i-sun{display:none}
/* language menu (details) — closes on outside click/Escape via the inline header script in Base.astro */
.hd .language-menu{position:relative;border:0;padding:0;margin:0}
.hd .language-menu summary{height:44px;display:inline-flex;align-items:center;gap:6px;padding:0 10px;border:1px solid var(--line);border-radius:var(--radius);font-size:15px;font-weight:600;list-style:none;cursor:pointer;color:var(--fg)}
.hd .language-menu summary::-webkit-details-marker{display:none}
.hd .language-menu summary::after{content:none}
.hd .language-menu summary:hover,.hd .language-menu[open] summary{border-color:var(--line-strong)}
.hd .language-menu[open] summary{border-color:var(--accent)}
.hd .language-menu summary svg{width:20px;height:20px;flex:none}
.hd .language-menu summary svg.chev{width:16px;height:16px;color:var(--muted)}
.hd .language-menu>div{position:absolute;inset-inline-end:0;top:calc(100% + 6px);z-index:30;min-width:260px;padding:6px 0;background:var(--bg);border:1px solid var(--line-strong);border-radius:var(--radius)}
.hd .language-menu>div span[aria-current]{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:44px;padding:0 14px;font-weight:600}
.hd .language-menu>div span[aria-current]::after{content:'✓';color:var(--accent)}
.hd .language-menu>div a small{margin-inline-start:auto;padding-inline-start:12px;color:var(--muted);font-size:13px;white-space:nowrap}
.hd .language-menu>div a{display:flex;align-items:center;min-height:44px;padding:0 14px;color:var(--fg);font-size:16px;text-decoration:none;white-space:nowrap}
.hd .language-menu>div a:hover,.hd .language-menu>div a:focus-visible{background:var(--surface)}
/* layout */
.wrap{max-width:var(--w-page);margin:0 auto}
.narrow{max-width:var(--w-tool)}
.crumb{font-size:14px;color:var(--muted);margin:18px 0 10px}
.crumb a{color:var(--muted)}
.crumb span{margin:0 6px}
h1{font-size:32px;font-weight:700;margin-bottom:6px}
.lead{color:var(--muted);margin:0 0 18px;font-size:16px}
/* tool */
.tool{border:1px solid var(--line);border-radius:var(--radius);padding:20px;background:var(--surface)}
.row{display:grid;grid-template-columns:1fr 1fr 48px 1fr;gap:12px;align-items:center}
.field{min-width:0;display:flex;flex-direction:column;gap:6px}
.field label{font-size:13px;font-weight:600;color:var(--muted);text-transform:uppercase;letter-spacing:.04em}
input.num,select.unit{height:56px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font:inherit;padding:0 14px;width:100%;margin:0}
input.num{font-size:24px;font-weight:600;font-variant-numeric:tabular-nums}
select.unit{font-size:17px}
/* Progressively enhanced unit picker; the original select remains form state. */
.unit-select{position:relative;min-width:0;width:100%;font-size:16px;text-align:start}
.unit-select--compact{display:inline-block;width:auto;max-width:100%;vertical-align:middle}
.unit-select[data-enhanced]>select{position:absolute!important;inset:0;width:100%!important;height:100%!important;min-height:0!important;opacity:0;pointer-events:none}
.unit-select-trigger{display:flex;align-items:center;justify-content:space-between;gap:10px;width:100%;height:56px;padding:0 14px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font:inherit;font-size:16px;text-align:start;cursor:pointer}
.unit-select-trigger>span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.unit-select-trigger>svg{flex:none;color:var(--muted)}
.unit-select-trigger[aria-expanded=true]{border-color:var(--accent)}
.unit-select-trigger:disabled{opacity:.65;cursor:default}
.unit-select--compact .unit-select-trigger{height:40px;padding-inline:10px}
.unit-select-panel{position:absolute;z-index:40;inset-block-start:calc(100% + 4px);inset-inline-start:0;display:flex;flex-direction:column;width:max(100%,270px);max-width:min(440px,calc(100vw - 32px));max-height:320px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);overflow:hidden}
.unit-select-top{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:8px 12px;border-bottom:1px solid var(--line);font-size:16px}
.unit-select-top strong{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.unit-select-close{flex:none;min-height:40px;padding:0 10px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font:inherit;font-size:16px;cursor:pointer}
.unit-select .unit-select-search{flex:none;width:calc(100% - 24px);min-height:44px;height:44px;margin:10px 12px;padding:8px 10px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font:inherit;font-size:16px}
.unit-select-list{min-height:0;overflow-y:auto;overscroll-behavior:contain;padding:4px 0}
.unit-select-group{padding:10px 12px 4px;font-size:15px;font-weight:600;color:var(--muted)}
.unit-select-option{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:44px;padding:10px 12px;font-size:16px;line-height:1.4;cursor:pointer;overflow-wrap:anywhere}
.unit-select-option[aria-selected=true]{background:var(--surface);font-weight:600}
.unit-select-option[aria-selected=true]::after{content:'✓';flex:none;color:var(--accent)}
.unit-select-option:hover,.unit-select-option[data-active]{background:var(--surface);outline:2px solid var(--accent);outline-offset:-2px}
.unit-select-option[aria-disabled=true]{opacity:.6;cursor:default}
.unit-select-empty{margin:0;padding:16px 12px;font-size:16px;color:var(--muted)}
.unit-select-backdrop{display:none}
.unit-select [hidden]{display:none!important}
@media(min-width:721px){.unit-select[data-align-end] .unit-select-panel{inset-inline-start:auto;inset-inline-end:0}}
@media(max-width:720px){
  body:has(.unit-select-panel:not([hidden])){overflow:hidden}
  .unit-select-backdrop{display:block;position:fixed;inset:0;z-index:49;background:#0006;touch-action:none}
  .unit-select-panel{position:fixed;inset:auto 0 0;z-index:50;width:100%;max-width:none;max-height:70vh;max-height:70dvh;border-radius:var(--radius) var(--radius) 0 0;padding-bottom:env(safe-area-inset-bottom)}
  .unit-select-top{padding:10px 16px}
  .unit-select-option{min-height:48px;padding-inline:16px}
  .unit-select-group{padding-inline:16px}
}
.swap{height:56px;width:48px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font-size:22px;cursor:pointer;align-self:end}
.result{margin-top:18px;padding-top:16px;border-top:1px solid var(--line)}
.result .big{font-size:40px;font-weight:700;letter-spacing:-.01em;font-variant-numeric:tabular-nums;line-height:1.15;word-break:break-word;display:flex;flex-wrap:wrap;align-items:baseline;gap:0 10px}
.result input.big{font:inherit;font-size:40px;font-weight:700;border:0;border-bottom:2px solid var(--line-strong);background:transparent;color:var(--fg);padding:0;width:auto;min-width:2ch;max-width:100%;font-variant-numeric:tabular-nums}
/* width hugs the digits (+0.6ch breathing room) via inline style from SSR and convert.ts fitOutput() — owner 12/10 */
.result input.big:focus{outline:none;border-bottom-color:var(--accent)}
.result .big small{font-size:22px;font-weight:600;color:var(--muted)}
.result .alt{margin-top:8px;color:var(--muted);font-size:16px}
.result .alt b{color:var(--fg);font-weight:600}
.ctl{display:flex;flex-wrap:wrap;gap:12px 20px;align-items:center;margin-top:14px;font-size:15px}
.ctl>div{display:inline-flex;align-items:center;gap:10px;flex-wrap:wrap}
.ctl select{height:56px;border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg);color:var(--fg);font:inherit;font-size:16px;padding:0 10px}
.btn{height:40px;padding:0 14px;border:1px solid var(--accent);border-radius:var(--radius);background:var(--accent);color:var(--accent-fg);font:inherit;font-size:15px;font-weight:600;cursor:pointer}
/* sections */
section{margin-top:32px}
h2{font-size:22px;font-weight:700;margin-bottom:10px}
.formula{border-left:3px solid var(--accent);padding:10px 14px;background:var(--surface);font-size:17px}
.formula code{font-family:ui-monospace,Menlo,monospace;font-size:16px}
.defs{display:grid;grid-template-columns:1fr 1fr;gap:20px}
.defs p{margin:4px 0 0}
.defs h3{font-size:17px}
table{border-collapse:collapse;width:100%;font-variant-numeric:tabular-nums}
th,td{text-align:left;padding:9px 12px;border-bottom:1px solid var(--line);font-size:16px}
th{font-size:13px;text-transform:uppercase;letter-spacing:.04em;color:var(--muted)}
td.n{text-align:right}th.n{text-align:right}
.tables{display:grid;grid-template-columns:1fr 1fr;gap:28px}
details{border-top:1px solid var(--line);padding:12px 0}
details:last-of-type{border-bottom:1px solid var(--line)}
summary{cursor:pointer;font-weight:600;font-size:17px;list-style:none;display:flex;justify-content:space-between}
summary::after{content:"+";color:var(--muted);font-weight:400}
details[open] summary::after{content:"–"}
details p{margin:8px 0 0;color:var(--muted)}
.links{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:6px 24px;font-size:16px}
.links a{padding:6px 0;border-bottom:1px solid var(--line)}
.inline{display:flex;flex-wrap:wrap;gap:6px 18px;align-items:baseline}
footer{max-width:var(--w-page);margin:48px auto 0;padding-top:16px;border-top:1px solid var(--line);color:var(--muted);font-size:14px;display:flex;flex-wrap:wrap;gap:8px 20px}
/* home + hub */
.search{display:flex;gap:10px;max-width:var(--w-tool)}
.search input{flex:1;height:56px;border:1px solid var(--line-strong);border-radius:var(--radius);font:inherit;font-size:18px;padding:0 16px;background:var(--bg);color:var(--fg)}
.search button{height:56px}
.fams{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:10px 24px;margin-top:16px}
.fams a{display:block;padding:12px 0;border-bottom:1px solid var(--line);font-size:17px;font-weight:600}
.fams a small{display:block;font-weight:400;color:var(--muted);font-size:14px}
.matrix td,.matrix th{font-size:15px;padding:6px 10px}
@media (max-width:720px){
  h1{font-size:26px}
  .row{grid-template-columns:minmax(0,1fr) 48px minmax(0,1fr);align-items:end}
  .row .field:first-child{grid-column:1/-1}
  .swap{display:block;grid-column:2;grid-row:2;width:48px;height:48px;align-self:end;margin-bottom:4px}
  .result .big,.result input.big{font-size:32px}
  .defs,.tables{grid-template-columns:1fr}
  input.num,select.unit{font-size:18px}
  .hd nav{display:none}
}
@media (max-width:480px){
  .btn-ghost[data-search-open]{width:44px;padding:0;justify-content:center}
  .btn-ghost[data-search-open] span{display:none}
}