/* UnixTime. Reference-matched, restrained single-purpose layout. */
:root{color-scheme:light;--paper:#fcfcfd;--ink:#0c1324;--muted:#4a5366;--line:#d9dfe8;--blue:#155cf2;--blue-pale:#e8f2ff;--panel:#f2f4f6;--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;--sans:Inter,system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.5 var(--sans);-webkit-font-smoothing:antialiased}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:var(--blue);text-underline-offset:3px}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #77a5ff;outline-offset:3px}
.container{width:calc(100% - 48px);max-width:1280px;margin:0 auto}
.skip{position:absolute;top:-150px;left:16px;background:white;padding:10px;z-index:5}
.skip:focus{top:8px}
.topbar{height:78px;display:grid;grid-template-columns:1fr 1fr 1fr;align-items:start}
.brand{margin-top:15px;font-size:22px;letter-spacing:-1.05px;color:var(--ink);font-weight:400;text-decoration:none}
.brand strong,.footer-brand strong{font-weight:840}
.brand{display:flex;flex-direction:column;justify-content:center;align-items:flex-start;gap:2px;margin-top:8px;line-height:1.12}
.brand-main{font-size:22px;letter-spacing:-1.05px}
.brand-signature{font-size:10px;letter-spacing:1.17px;color:#697587;font-weight:400;line-height:1.4;white-space:nowrap}
.nav-links{height:56px;display:flex;gap:37px;align-items:stretch;justify-content:center}
.nav-links a{display:grid;align-items:center;font-size:13px;text-decoration:none;color:#4c5669;border-bottom:2px solid transparent;font-weight:500;white-space:nowrap}
.nav-links a.active{font-weight:680;color:var(--ink);border-color:var(--blue)}
.nav-links a:hover,.footer-links a:hover{color:var(--blue)}
.locale-label{display:flex;align-items:start;justify-content:flex-end;color:var(--muted)}
.lang-menu{margin-top:13px;max-width:144px;border:1px solid transparent;border-radius:4px;background:transparent;color:#333d4f;font-size:13px;font-weight:600;padding:8px 10px}
.lang-menu:hover{border-color:var(--line)}
.hero{height:226px;border-bottom:1px solid var(--line);text-align:center;padding:22px 0 26px}
.kicker{font-size:12px;font-family:var(--mono);letter-spacing:.17em;text-transform:uppercase;color:#4b566b;margin:0 0 10px;font-weight:480}
.hero-time{display:flex;justify-content:center;align-items:center;gap:26px}
.live-dot{width:13px;height:13px;background:#266bff;border-radius:50%;flex:0 0 auto}
.timestamp{font:760 clamp(53px,5.6vw,88px)/1.22 var(--mono);letter-spacing:-.035em;margin:0;white-space:nowrap;font-variant-numeric:tabular-nums}
.copy-time{border:1px solid #2865ff;color:#1158ef;background:white;font-size:13px;font-weight:580;display:inline-flex;align-items:center;gap:9px;border-radius:5px;padding:10px 15px;white-space:nowrap}
.copy-time:hover,.inline-copy:hover{background:var(--blue-pale)}
.copy-time svg,.inline-copy svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.9;stroke-linejoin:round;stroke-linecap:round}
.hero-readable{font-size:18px;letter-spacing:.025em;margin:4px 0 0;font-weight:490}
.hero-caption{margin:0;color:#667083;font:12px/1.7 var(--mono)}
.converter{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);border-bottom:1px solid var(--line);min-height:354px}
.convert-col{min-width:0;padding:26px 39px 26px 0}
.convert-col+.convert-col{border-left:1px solid var(--line);padding:26px 0 26px 38px}
.col-head h2{margin:0 0 4px;font-size:29px;letter-spacing:-.047em;font-weight:745;line-height:1.25}
.arrow{font-weight:350}
.col-head p{margin:0;color:var(--muted);font-size:13px}
.col-head{margin-bottom:20px}
.timestamp-input,.date-time-inputs input,.timezone-select{border:1px solid #d6dce6;border-radius:5px;background:#f5f6f8;color:var(--ink);min-height:50px}
.timestamp-input{width:100%;padding:11px 17px;font:500 20px/1.3 var(--mono);letter-spacing:-.02em}
.unit-tabs{margin-top:22px;display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border:1px solid var(--line);border-radius:5px;overflow:hidden}
.unit-choice{background:transparent;border:0;border-right:1px solid var(--line);color:#414b60;padding:9px 8px;font-size:12px;min-height:38px;white-space:nowrap}
.unit-choice:last-child{border-right:0}
.unit-choice.is-active{background:var(--blue-pale);color:var(--blue);font-weight:650}
.unit-choice:hover:not(.is-active){background:#eff3f9}
.field-label{font-size:12px;color:#5a6475;font-weight:500;display:block}
.output-label{margin:23px 0 6px}
.result-surface{border-radius:5px;background:var(--panel);min-height:56px;padding:10px 15px 10px 20px;display:flex;gap:10px;align-items:center;justify-content:space-between}
.converted-value{color:#10192a;font-size:19px;line-height:1.5;overflow-wrap:anywhere}
.mono{font-family:var(--mono);font-variant-numeric:tabular-nums}
.inline-copy{border:0;background:transparent;color:#0e56ea;display:inline-flex;gap:9px;align-items:center;padding:7px;font-size:12px;flex:0 0 auto;border-radius:4px}
.feedback{font-size:12px;color:#5f6a7d;margin:5px 0 0;line-height:1.4}
.feedback:empty{display:none}
.feedback.error{color:#b42318}
.date-time-inputs{display:grid;grid-template-columns:1.35fr .92fr;gap:20px}
.date-time-inputs input{min-width:0;width:100%;padding:10px 14px;background:white;font-size:15px}
.timezone-label{margin:14px 0 6px}
.timezone-select{background:white;width:100%;padding:10px 13px;font-size:13px;min-height:39px}
.date-output-label{margin:17px 0 6px}
.below{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:0;border-bottom:1px solid var(--line);padding:26px 0 25px}
.explain{padding-right:44px}
.explain h2{font-size:28px;letter-spacing:-.046em;line-height:1.2;margin:0 0 9px}
.explain p{font-size:13px;line-height:1.65;color:var(--muted);margin:0 0 11px}
.explain p:last-child{margin-bottom:0}
.references{border-left:1px solid var(--line);padding:2px 0 0 47px;min-width:0}
.references h2{font-size:11px;line-height:1.35;letter-spacing:.13em;color:#5c677c;font-weight:700;text-transform:uppercase;margin:0 0 12px}
.reference-links{display:grid;grid-template-columns:1fr 1fr;column-gap:18px}
.reference-links details{min-width:0}
.reference-links summary{list-style:none;cursor:pointer;color:#0e59e9;font-size:12px;padding:3px 0;white-space:nowrap}
.reference-links summary::before{content:"↗";font-size:14px;font-weight:670;margin-right:9px}
.reference-links summary::-webkit-details-marker{display:none}
.reference-links details[open]{grid-column:1/-1}
.reference-links pre{white-space:pre-wrap;overflow:auto;word-break:break-word;color:#eaf0ff;background:#19243a;font:12px/1.7 var(--mono);padding:12px;border-radius:4px;margin:8px 0}
.footer{display:flex;justify-content:space-between;align-items:center;gap:12px;min-height:69px;font-size:11px;color:#5e6879}
.footer-brand{font-weight:350;color:var(--ink);text-decoration:none;font-size:12px;white-space:nowrap}
.footer-left{display:flex;align-items:center;flex-wrap:wrap}
.footer-divider{padding:0 16px;color:#c6cad2}
.footer-links{display:flex;align-items:center;gap:24px}
.footer-links a{color:#5a6577;text-decoration:none}
.sr-only{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(max-width:920px){.container{width:calc(100% - 38px)}.hero{height:auto;min-height:218px}.hero-time{gap:14px}.timestamp{font-size:clamp(46px,6.5vw,74px)}.convert-col{padding-right:22px}.convert-col+.convert-col{padding-left:22px}.date-time-inputs{gap:8px}.explain{padding-right:22px}.references{padding-left:24px}}
@media(max-width:680px){.container{width:calc(100% - 30px)}.topbar{height:60px;grid-template-columns:1fr auto}.nav-links{display:none}.brand{margin-top:6px}.lang-menu{margin-top:7px}.hero{padding:31px 0 28px}.kicker{font-size:11px}.hero-time{gap:9px;flex-wrap:wrap}.timestamp{font-size:clamp(29px,8.5vw,55px);letter-spacing:-.06em}.live-dot{width:9px;height:9px}.copy-time{padding:8px;font-size:0;gap:0}.copy-time svg{width:17px;height:17px}.hero-readable{font-size:14px;margin-top:8px}.hero-caption{font-size:11px}.converter{grid-template-columns:1fr}.convert-col{padding:24px 0 25px}.convert-col+.convert-col{padding:24px 0 25px;border-left:0;border-top:1px solid var(--line)}.col-head h2{font-size:26px}.col-head{margin-bottom:15px}.unit-choice{font-size:11px;padding:8px 3px}.output-label{margin-top:18px}.date-time-inputs{grid-template-columns:minmax(0,1.3fr) minmax(0,1fr)}.below{grid-template-columns:1fr;gap:22px;padding:25px 0}.explain{padding:0}.references{padding:18px 0 0;border-left:0;border-top:1px solid var(--line)}.explain h2{font-size:25px}.footer{flex-wrap:wrap;padding:19px 0;gap:9px}.footer-links{margin-left:auto}.footer-left{width:100%}}
@media(max-width:360px){.timestamp{font-size:28px}.date-time-inputs{gap:6px}.date-time-inputs input{font-size:13px;padding:8px}.converted-value{font-size:15px}.unit-choice{font-size:10px}.reference-links{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

/* Reference guide links share the exact visual rhythm of programming expanders. */
.reference-links a.reference-guide{color:#0e59e9;font-size:12px;padding:3px 0;text-decoration:none;white-space:normal;line-height:1.5}
.reference-links a.reference-guide::before{content:"↗";font-size:14px;font-weight:670;margin-right:9px}
.reference-links a.reference-guide:hover{text-decoration:underline}
/* Original research/reference pages: a separate reading layout, no homepage changes. */
.guide-main{max-width:880px;margin:0 auto;padding:35px 24px 54px}
.guide-eyebrow{text-transform:uppercase;letter-spacing:.11em;color:#4c5b76;font:12px var(--mono);margin:0 0 9px}
.guide-main h1{font-size:clamp(30px,4vw,43px);line-height:1.18;letter-spacing:-.045em;margin:0 0 10px}
.guide-deck{color:var(--muted);font-size:16px;line-height:1.65;margin:0 0 26px}
.guide-main h2{font-size:24px;letter-spacing:-.025em;margin:26px 0 10px}
.guide-main h3{font-size:18px;margin:21px 0 8px}
.guide-main p,.guide-main li{color:#3e4a5f;font-size:15px;line-height:1.75}
.guide-main ul,.guide-main ol{padding-left:23px}
.guide-main pre{background:#162139;color:#f5f9ff;padding:17px 20px;line-height:1.6;border-radius:7px;font-size:13px;overflow:auto;white-space:pre-wrap;overflow-wrap:anywhere}
.guide-main code{font-family:var(--mono);font-size:.9em}
.guide-main :not(pre)>code{background:#eaf0fa;border-radius:3px;padding:2px 4px;color:#122e60}
.guide-main table{width:100%;border-collapse:collapse;font-size:14px}
.guide-main td,.guide-main th{border-bottom:1px solid var(--line);padding:12px 10px;text-align:left;overflow-wrap:anywhere}
.guide-main th{background:#f4f7fb}
.guide-main .guide-action{background:#eff5ff;border:1px solid #cedfff;border-radius:7px;padding:16px 20px;margin:24px 0}
.guide-main .guide-action a{font-weight:720}
.guide-related{border-top:1px solid var(--line);padding-top:20px;margin-top:35px}
.guide-related ul{display:flex;gap:9px 22px;flex-wrap:wrap;list-style:none;padding:0}
.guide-related a{font-weight:620}
.guide-footer{max-width:880px;margin:0 auto;padding:22px 24px 35px;border-top:1px solid var(--line);display:flex;gap:20px;flex-wrap:wrap;font-size:13px}
@media(max-width:680px){.guide-main{padding:25px 17px 35px}.guide-footer{padding:20px 17px}}