@font-face{font-family:'Source Serif 4';font-style:normal;font-weight:600;font-display:swap;src:url(/static/fonts/source-serif-4-latin-ext-600-normal.woff2) format('woff2');unicode-range:U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:'Source Serif 4';font-style:normal;font-weight:600;font-display:swap;src:url(/static/fonts/source-serif-4-latin-600-normal.woff2) format('woff2');unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
:root{--valley:#1E4A3A;--valley-deep:#163A2D;--sand:#B98A4E;--sand-soft:#F6EEE2;--ink:#1C2430;--muted:#55606B;
--stone:#ECEFEC;--card:#FFFFFF;--line:#D5DBD7;--bad:#B42318;--bad-soft:#FDECEA;--ok:#067647;--ok-soft:#E5F4EC;
--serif:'Source Serif 4',Georgia,'Times New Roman',serif;--sans:system-ui,-apple-system,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
--mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;font:16px/1.55 var(--sans);color:var(--ink);background:var(--stone);min-height:100vh;display:flex;flex-direction:column}
a{color:var(--valley);text-underline-offset:3px}a:hover{color:var(--valley-deep)}
:focus-visible{outline:2px solid var(--valley);outline-offset:2px;border-radius:3px}
.sandbox{background:repeating-linear-gradient(135deg,#F6EEE2 0 12px,#EFE3D0 12px 24px);color:#5A4320;text-align:center;font-size:12.5px;padding:4px 12px;border-bottom:1px solid #E2D2B8}
.top{background:var(--valley);color:#fff}
.top-inner{max-width:760px;margin:0 auto;padding:14px 20px;display:flex;align-items:center;gap:12px}
body.narrow .top-inner{max-width:500px}
body.app .top-inner{max-width:440px}
.brand{color:#fff;text-decoration:none;display:inline-flex;align-items:center;gap:11px}
.brand:hover{color:#fff}
.brand svg{width:34px;height:26px;flex:none;color:var(--sand)}
.brand .wordmark{font:600 21px/1 var(--serif);letter-spacing:.005em}
.brand .tag{display:block;font:500 11.5px/1.2 var(--sans);color:#C9D9D1;letter-spacing:.02em;margin-top:4px}
.top :focus-visible{outline-color:#fff}
main{width:100%;max-width:760px;margin:0 auto;padding:28px 20px 48px;flex:1}
body.narrow main{max-width:500px}
h1,h2{font-family:var(--serif);font-weight:600;color:var(--ink);letter-spacing:-.005em}
h1{font-size:30px;line-height:1.2;margin:4px 0 16px}
h2{font-size:21px;line-height:1.3;margin:28px 0 10px}
h3{font-size:16px;margin:22px 0 6px}
.card{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:22px 24px;margin:16px 0}
.card > h2:first-child{margin-top:0}
.card > :last-child{margin-bottom:0}
label{display:block;font-weight:600;font-size:15px;margin:16px 0 6px}
input[type=text],input[type=password],input[type=email],input[type=number],input[type=file],textarea,select{width:100%;padding:11px 12px;border:1px solid #AEB8B2;border-radius:8px;font:inherit;background:#fff;color:var(--ink)}
input:focus-visible,textarea:focus-visible,select:focus-visible{outline:2px solid var(--valley);outline-offset:0;border-color:var(--valley)}
input[type=checkbox]{width:18px;height:18px;accent-color:var(--valley)}
textarea{min-height:130px;line-height:1.5}
button,.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:var(--valley);color:#fff;border:1px solid var(--valley);border-radius:8px;padding:11px 20px;font:inherit;font-weight:600;cursor:pointer;text-decoration:none;margin-top:18px;min-height:46px}
button:hover,.btn:hover{background:var(--valley-deep);color:#fff}
button.secondary,.btn.secondary{background:#fff;color:var(--valley);border-color:#AEB8B2}
button.secondary:hover,.btn.secondary:hover{border-color:var(--valley);background:#fff;color:var(--valley-deep)}
button.danger{background:#fff;color:var(--bad);border-color:var(--bad)}
button.danger:hover{background:var(--bad-soft);color:var(--bad)}
.actions{display:flex;flex-wrap:wrap;gap:0 10px}
.alert,.info{border-radius:8px;padding:11px 14px;margin:12px 0;border:1px solid}
.alert{background:var(--bad-soft);border-color:#F1B7B1;color:var(--bad)}
.info{background:var(--ok-soft);border-color:#B4DCC6;color:#0B4A30}
.muted{color:var(--muted);font-size:14.5px}
dl.kv{display:grid;grid-template-columns:max-content 1fr;gap:9px 18px;margin:4px 0}
dl.kv dt{color:var(--muted)}dl.kv dd{margin:0;font-weight:600;overflow-wrap:anywhere}
code,.mono{font-family:var(--mono);font-size:.9em}
pre{background:#14201B;color:#E4EEE8;padding:14px 16px;border-radius:8px;overflow:auto;font-size:13.5px;line-height:1.5}
table{border-collapse:collapse;width:100%;font-size:14.5px}
th,td{border-bottom:1px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
th{font-weight:600;color:var(--muted);font-size:13px;background:#F5F7F5}
.table-scroll{overflow-x:auto}
.secret{font:500 17px/1.5 var(--mono);padding:14px;background:#14201B;color:#BFF0D6;border-radius:8px;word-break:break-all;user-select:all}
.foot{color:var(--muted);font-size:12.5px;text-align:center;padding:18px 16px 22px}
.badge{display:inline-block;border-radius:999px;padding:2px 10px;font-size:13px;font-weight:600;border:1px solid}
.badge.ok{background:var(--ok-soft);color:var(--ok);border-color:#B4DCC6}
.badge.warn{background:var(--sand-soft);color:#7A5524;border-color:#E2CDAE}
.badge.bad{background:var(--bad-soft);color:var(--bad);border-color:#F1B7B1}
nav.tabs{display:flex;flex-wrap:wrap;gap:4px 22px;border-bottom:1px solid var(--line);margin:0 0 20px}
nav.tabs a{padding:8px 0;color:var(--muted);text-decoration:none;border-bottom:2px solid transparent;margin-bottom:-1px}
nav.tabs a:hover{color:var(--ink)}nav.tabs a[aria-current]{color:var(--ink);border-bottom-color:var(--sand)}

/* TAN challenge: the card coordinate, set like a stamp in sandstone */
.tan-box{display:flex;align-items:center;gap:18px;background:var(--sand-soft);border:1px solid #E2CDAE;border-left:5px solid var(--sand);border-radius:10px;padding:14px 18px;margin:14px 0}
.tan{font:600 46px/1 var(--serif);letter-spacing:.06em;color:var(--ink);margin:0}
.tan-box .muted{margin:0}

/* landing */
.hero{position:relative;overflow:hidden;background:var(--valley);color:#fff;border-radius:14px;padding:34px 30px 132px;margin:4px 0 22px}
.hero h1{color:#fff;font-size:34px;margin:0 0 12px;max-width:14em;position:relative}
.hero p{color:#D6E4DD;max-width:34em;margin:0;position:relative}
.hero svg{position:absolute;left:0;right:0;bottom:-2px;width:100%;height:118px;color:var(--sand);opacity:.75}
.dest{list-style:none;margin:0;padding:0}
.dest li{border-top:1px solid var(--line)}.dest li:first-child{border-top:0}
.dest a{display:block;padding:14px 0;text-decoration:none;color:var(--ink)}
.dest a b{display:block;font:600 18px/1.3 var(--serif);color:var(--valley)}
.dest a span{color:var(--muted);font-size:14.5px}
.dest a:hover b{text-decoration:underline}

/* instructions article */
.md{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:30px 34px}
.md h1{font-size:32px;margin-top:0}
.md h2{padding-top:18px;border-top:1px solid var(--line);margin-top:34px}
.md p,.md li{max-width:70ch}
.md li{margin:4px 0}
.md table{margin:14px 0;font-size:14.5px;display:block;overflow-x:auto}
.md :not(pre) > code{background:#EEF2EF;border-radius:4px;padding:1px 5px}

@media (max-width:600px){
  main{padding:20px 16px 40px}
  h1{font-size:26px}.hero h1{font-size:28px}.hero{padding-bottom:96px}.hero svg{height:84px}
  .card{padding:18px 16px}.md{padding:20px 16px}
  .top-inner{padding:12px 16px}
  dl.kv{grid-template-columns:1fr;gap:2px}dl.kv dt{margin-top:8px}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important}}