/* 19216811ip.org — light, flat, text-first */
:root{
  --bg:#fff;--soft:#f5f7fa;--ink:#1f2328;--ink-2:#4a5260;--muted:#6b7280;--line:#e5e7eb;
  --accent:#0b57d0;--accent-ink:#fff;--accent-soft:#eaf1fd;--ok:#15803d;--bad:#c62828;
  --note:#fff8e1;--note-line:#f3d98a;
  --font:system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans",Arial,sans-serif;
  --mono:ui-monospace,"SF Mono",Consolas,"Liberation Mono",monospace;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:64px}
body{margin:0;background:var(--bg);color:var(--ink);font:16.5px/1.65 var(--font)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto;display:block;margin:14px 0}
code,kbd{font-family:var(--mono);font-size:.9em;background:var(--soft);padding:.05em .35em;border-radius:4px;word-break:break-all}
kbd{border:1px solid var(--line)}
strong{font-weight:650}
.wrap{max-width:1140px;margin:0 auto;padding:0 16px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0)}
.skip{position:absolute;left:-999px}.skip:focus{left:16px;top:8px;z-index:9;background:#fff;padding:8px}

/* header */
.site-head{background:var(--bg);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:20}
.head-row{display:flex;align-items:center;gap:16px;min-height:56px}
.logo{display:flex;align-items:center;gap:8px;color:var(--ink);font-weight:750;font-size:18px;letter-spacing:-.01em}
.logo:hover{text-decoration:none}
.logo svg{color:var(--accent)}
.logo span{display:flex;flex-direction:column;line-height:1.05}
.logo small{font-size:10.5px;font-weight:600;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}
.nav{margin-left:auto;display:flex;gap:2px}
.nav a{color:var(--ink-2);font-size:14.5px;padding:8px 11px;border-radius:6px}
.nav a:hover{background:var(--soft);color:var(--ink);text-decoration:none}
.nav-btn{display:none;margin-left:auto;background:none;border:0;padding:10px;cursor:pointer}
.nav-btn span{display:block;width:22px;height:2px;background:var(--ink);margin:4px 0;border-radius:2px}
@media (max-width:820px){
  .nav-btn{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:56px;background:var(--bg);flex-direction:column;padding:6px 16px 14px;border-bottom:1px solid var(--line)}
  .nav.open{display:flex}
}

/* layout */
.grid{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:48px;align-items:start;padding-top:18px;padding-bottom:48px}
@media (max-width:960px){.grid{grid-template-columns:minmax(0,1fr);gap:28px}}
.content{min-width:0;max-width:760px}
.crumbs{font-size:13.5px;color:var(--muted);margin-bottom:6px}
.crumbs a{color:var(--muted)}
.crumbs span{margin:0 3px}
h1{font-size:clamp(28px,4vw,36px);line-height:1.2;margin:.1em 0 .2em;letter-spacing:-.015em;font-weight:700}
.meta{font-size:13.5px;color:var(--muted);margin:0 0 12px}
.content h2{font-size:clamp(21px,2.6vw,24px);line-height:1.3;margin:1.7em 0 .5em;font-weight:650}
.content h3{font-size:18.5px;margin:1.4em 0 .4em;font-weight:650}
.content h4{font-size:16.5px;margin:1.2em 0 .3em}
.content ol,.content ul{padding-left:1.4em}
.content li{margin:.25em 0}
.intro{font-size:17px;margin:10px 0 6px}
.small{font-size:13.5px;color:var(--muted)}
.callout{background:var(--note);border:1px solid var(--note-line);padding:10px 14px;border-radius:6px}
ol.steps{padding-left:1.4em}
ol.steps>li{margin:.45em 0;padding-left:4px}
.steps-list li{margin:.45em 0}
.typos{display:flex;flex-wrap:wrap;gap:6px 14px;list-style:none;padding:0!important}
.typos li{color:var(--bad);font-family:var(--mono);font-size:15px;margin:0}
.btns{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
.feat{width:100%;border-radius:8px;margin:8px 0 14px}

/* login box — one centred button */
.login-box{text-align:center;margin:18px 0 8px;padding:4px 0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--accent);color:var(--accent-ink);font-weight:650;border:0;border-radius:6px;padding:10px 18px;font-size:15.5px;cursor:pointer;font-family:inherit}
.btn:hover{filter:brightness(1.08);text-decoration:none}
.btn-lg{font-size:17px;padding:13px 34px;min-width:230px}
.btn-ghost{background:transparent;color:var(--accent);border:1.5px solid var(--accent)}
.btn-sm{font-size:13.5px;padding:7px 12px}
.creds{margin:12px 0 0;font-size:15.5px;color:var(--ink-2)}
.creds span{color:var(--muted)}
.creds code{font-size:15px;color:var(--ink);font-weight:600}
.alts{margin:6px 0 0;font-size:14px;color:var(--muted)}
.linkish{background:none;border:0;padding:0;color:var(--accent);font:inherit;cursor:pointer}
.linkish:hover{text-decoration:underline}

/* contents */
.toc{border:1px solid var(--line);border-radius:6px;padding:8px 14px;margin:18px 0;font-size:15px}
.toc summary{font-weight:650;cursor:pointer;color:var(--ink-2)}
.toc ol{margin:8px 0 4px;padding-left:1.3em}
.toc li{margin:.15em 0}

/* tables */
.tbl{overflow-x:auto;margin:14px 0}
table{border-collapse:collapse;width:100%;font-size:15px}
th,td{text-align:left;padding:9px 10px;border-bottom:1px solid var(--line);vertical-align:top}
thead th{font-size:13px;text-transform:uppercase;letter-spacing:.04em;color:var(--muted);border-bottom:2px solid var(--line);font-weight:650}
tbody tr:hover{background:#fafbfc}
table.kv th{width:40%;font-weight:600;color:var(--ink-2)}
@media (max-width:600px){th,td{padding:8px 6px;font-size:14px}}

/* link chips + cards (in-content) */
.chips{display:flex;flex-wrap:wrap;gap:6px 8px;list-style:none;padding:0!important;margin:10px 0}
.chips li{margin:0}
.chips a,.chips span{display:inline-block;padding:4px 10px;border:1px solid var(--line);border-radius:4px;font-size:14.5px;color:var(--accent)}
.chips span{color:var(--ink-2)}
.chips a:hover{border-color:var(--accent);text-decoration:none}
.cards-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(190px,1fr));gap:8px;list-style:none;padding:0!important;margin:10px 0}
.cards-list li{margin:0}
.cards-list a{display:flex;flex-direction:column;padding:10px 12px;border:1px solid var(--line);border-radius:6px;color:var(--ink);height:100%}
.cards-list a strong{color:var(--accent);font-weight:600}
.cards-list a:hover{border-color:var(--accent);text-decoration:none}
.cards-list span{font-size:13px;color:var(--muted)}

/* faq */
.faq details{border-bottom:1px solid var(--line);padding:0 2px}
.faq summary{cursor:pointer;font-weight:600;padding:11px 0}
.faq details p{margin:0 0 12px;color:var(--ink-2)}

/* sidebar */
.side{position:sticky;top:72px;font-size:15px}
@media (max-width:960px){.side{position:static;border-top:1px solid var(--line);padding-top:8px}}
.note{background:var(--note);border:1px solid var(--note-line);border-radius:6px;padding:12px 14px;font-size:14px;line-height:1.55;color:var(--ink-2)}
.goto{margin:18px 0 4px}
.goto label{display:block;font-weight:650;font-size:15px;margin-bottom:6px}
.goto div{display:flex;gap:6px}
.goto input{flex:1;min-width:0;font:600 15px var(--mono);padding:8px 10px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink)}
.goto button{background:var(--accent);color:#fff;border:0;border-radius:6px;padding:0 14px;font-weight:650;cursor:pointer}
.side-h{font-size:17px;font-weight:600;margin:22px 0 6px;color:var(--ink)}
.side-list{list-style:none;padding:0;margin:0}
.side-list li{margin:0}
.side-list a{display:flex;align-items:center;gap:8px;padding:6px 0}
.bi{width:18px;height:18px;border-radius:4px;background:var(--accent-soft);color:var(--accent);font-size:11px;font-weight:800;display:grid;place-items:center}
.more{display:inline-block;margin-top:6px;font-size:12.5px;font-weight:650;border:1.5px solid var(--accent);border-radius:4px;padding:3px 9px}
.more:hover{background:var(--accent);color:#fff;text-decoration:none}
.ext{margin-top:22px;border:1px solid var(--line);border-radius:6px;padding:12px 14px;font-size:14px;color:var(--ink-2)}
.ext p{margin:0 0 8px}
.ext strong{color:var(--ink)}

/* search */
.search input{width:100%;font-size:16px;padding:11px 12px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink)}
.search input:focus,.goto input:focus{outline:2px solid var(--accent);outline-offset:0;border-color:transparent}

/* blog */
.post-list{list-style:none;padding:0!important}
.post-list li{display:flex;gap:16px;align-items:flex-start;padding:14px 0;border-bottom:1px solid var(--line);margin:0}
.post-list p{margin:4px 0 0;color:var(--ink-2);font-size:15px}
.post-list .thumb{flex:0 0 160px}
.post-list .thumb img{margin:0;border-radius:6px;width:160px;height:auto}
@media (max-width:560px){.post-list .thumb{flex-basis:100px}.post-list .thumb img{width:100px}}

/* ads: reserve space only for the top unit (avoids layout shift without big empty gaps) */
.ad{margin:16px auto;text-align:center;clear:both}
.ad-top{max-width:100%;overflow:hidden;min-height:90px}
@media (max-width:760px){.ad-top{min-height:250px}}
.ad-side{margin-top:22px}

/* youtube */
.yt{position:relative;aspect-ratio:16/9;background:#000 center/cover;border-radius:8px;cursor:pointer;margin:14px 0}
.yt::after{content:"";position:absolute;inset:0;margin:auto;width:68px;height:48px;background:#f00;border-radius:12px}
.yt::before{content:"";position:absolute;inset:0;margin:auto;z-index:1;width:0;height:0;border-style:solid;border-width:10px 0 10px 18px;border-color:transparent transparent transparent #fff}
.yt iframe{position:absolute;inset:0;width:100%;height:100%;border:0;border-radius:8px}

/* footer */
.site-foot{background:var(--soft);border-top:1px solid var(--line);padding:28px 0 18px;font-size:14.5px;color:var(--ink-2)}
.foot-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:24px}
@media (max-width:760px){.foot-grid{grid-template-columns:1fr 1fr}}
.foot-brand,.foot-h{font-weight:700;color:var(--ink);margin:0 0 8px}
.site-foot ul{list-style:none;padding:0;margin:0}
.site-foot li{margin:4px 0}
.site-foot a{color:var(--ink-2)}
.copy{font-size:12.5px;color:var(--muted);margin-top:18px}
.toast{position:fixed;left:50%;bottom:24px;transform:translateX(-50%);background:var(--ink);color:#fff;padding:9px 16px;border-radius:6px;font-weight:600;z-index:50}

/* tools */
.tool{border:1px solid var(--line);border-radius:8px;padding:16px;margin:18px 0;background:var(--soft)}
.tool-row{display:flex;flex-wrap:wrap;gap:12px;align-items:flex-end;margin:8px 0}
.tool-row label{display:flex;flex-direction:column;gap:4px;font-weight:600;font-size:14px;color:var(--ink-2);flex:1;min-width:160px}
.tool-row.checks label{flex-direction:row;align-items:center;flex:0 0 auto;min-width:0;font-weight:500;gap:6px}
.tool input[name=ip],.tool select{font:600 16px var(--mono);padding:9px 10px;border:1px solid var(--line);border-radius:6px;background:#fff;color:var(--ink);width:100%}
.tool select{font-family:var(--font);font-weight:500}
.tool input[type=range]{width:100%}
.tool .tbl{background:#fff;border:1px solid var(--line);border-radius:6px}
.tool-err{color:var(--bad);font-weight:600;margin:4px 0}
.pw-out{display:flex;gap:10px;align-items:stretch;flex-wrap:wrap}
.pw-out output{flex:1;min-width:0;font:700 clamp(18px,3.4vw,23px)/1.3 var(--mono);background:#fff;border:1px solid var(--line);border-radius:6px;padding:11px 14px;word-break:break-all}
.pw-meter{height:6px;background:var(--line);border-radius:99px;overflow:hidden;margin:12px 0 4px}
.pw-meter span{display:block;height:100%;width:0;background:var(--ok);transition:width .2s}
.pw-meter span.weak{background:var(--bad)}
.pw-meter span.ok{background:#e6a500}
.src{font-size:12.5px;white-space:nowrap}