/* Layout: ledger-style workspace — left rail of sections on desktop, scrolling tab strip on phones;
   content is ruled tables and quiet panels, figures in mono. */
:root{
  --paper:#f3f5f2; --surface:#ffffff; --sunken:#eaeeea; --ink:#18211c; --muted:#5d6a62; --line:#d8dfd9;
  --accent:#27684a; --accent-soft:#e2efe7; --on-accent:#ffffff;
  --amber:#9a620f; --amber-soft:#f8ecd8; --good:#27684a; --bad:#b0412e; --bad-soft:#f7e3de;
  --f-display:"Newsreader",Georgia,"Times New Roman",serif;
  --f-body:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --f-mono:"IBM Plex Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){:root{
  --paper:#0f1512; --surface:#161e1a; --sunken:#121915; --ink:#e3ebe5; --muted:#9aa9a0; --line:#2a3530;
  --accent:#72c39a; --accent-soft:#1d3328; --on-accent:#0f1512;
  --amber:#e3a650; --amber-soft:#3a2c17; --good:#72c39a; --bad:#ef8a73; --bad-soft:#3b211b; color-scheme:dark}}

*{box-sizing:border-box}
html,body{margin:0}
body{background:var(--paper);color:var(--ink);font:15px/1.55 var(--f-body);-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{font-family:var(--f-display);font-weight:600;line-height:1.2;margin:0;text-wrap:balance}
a{color:var(--accent)}
button,input,select,textarea{font:inherit;color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
[hidden]{display:none!important}
.mono,.num{font-family:var(--f-mono);font-variant-numeric:tabular-nums}
.label{font-size:11.5px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:500}
.muted{color:var(--muted)}
.small{font-size:13px}
.pos{color:var(--good)} .neg{color:var(--bad)}

/* shell */
.shell{display:grid;grid-template-columns:220px minmax(0,1fr);min-height:100vh}
.rail{position:sticky;top:0;height:100vh;border-right:1px solid var(--line);padding:22px 14px;display:flex;flex-direction:column;gap:18px;background:var(--paper)}
.brand{font-family:var(--f-display);font-size:22px;font-weight:600;padding:0 8px}
.brand small{display:block;font-family:var(--f-body);font-size:12px;color:var(--muted);font-weight:400;margin-top:2px}
.nav{display:flex;flex-direction:column;gap:2px}
.nav a{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:6px;text-decoration:none;color:var(--muted);font-weight:500}
.nav a:hover{background:var(--sunken);color:var(--ink)}
.nav a[aria-current="page"]{background:var(--accent-soft);color:var(--accent)}
.nav svg{width:18px;height:18px;flex:none;stroke:currentColor;fill:none;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.rail .who{margin-top:auto;font-size:13px;color:var(--muted);padding:0 8px;display:grid;gap:6px}
.main{min-width:0;padding:28px max(24px,env(safe-area-inset-right,0px)) 80px max(24px,env(safe-area-inset-left,0px))}
.page{max-width:1120px;margin:0 auto;display:grid;gap:24px}
.page-head{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:flex-end;gap:10px 20px}
.page-head h1{font-size:32px}
.page-head p{margin:4px 0 0;color:var(--muted)}

@media (max-width:900px){
  .shell{grid-template-columns:minmax(0,1fr)}
  .rail{position:sticky;top:0;z-index:20;height:auto;flex-direction:row;align-items:center;padding:10px max(12px,env(safe-area-inset-left,0px)) 0;border-right:0;border-bottom:1px solid var(--line);gap:12px;overflow:hidden}
  .brand{display:none}
  .nav{flex-direction:row;overflow-x:auto;scrollbar-width:none;gap:0;flex:1}
  .nav a{padding:8px 10px 10px;border-radius:0;border-bottom:2px solid transparent;white-space:nowrap}
  .nav a[aria-current="page"]{background:none;border-bottom-color:var(--accent)}
  .nav svg{display:none}
  .rail .who{display:none}
  .main{padding:20px max(16px,env(safe-area-inset-right,0px)) 64px max(16px,env(safe-area-inset-left,0px))}
  .page-head h1{font-size:26px}
}

/* building blocks */
.panel{background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:18px}
.panel > h2,.panel > header h2{font-size:19px}
.panel > header{display:flex;justify-content:space-between;align-items:baseline;gap:10px;margin-bottom:12px;flex-wrap:wrap}
.grid{display:grid;gap:18px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.gside{grid-template-columns:minmax(0,1fr) 320px;align-items:start}
@media (max-width:980px){.g3{grid-template-columns:repeat(2,minmax(0,1fr))}.gside{grid-template-columns:minmax(0,1fr)}}
@media (max-width:640px){.g2,.g3{grid-template-columns:minmax(0,1fr)}}

.figure{font-family:var(--f-mono);font-variant-numeric:tabular-nums;font-size:26px;line-height:1.15;margin-top:6px}
.figure small{font-size:13px;color:var(--muted);margin-left:4px}
.sub{font-size:13px;color:var(--muted);margin-top:4px}
.meter{height:8px;background:var(--sunken);border-radius:4px;overflow:hidden}
.meter > span{display:block;height:100%;background:var(--accent);width:0}

.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);background:var(--surface);padding:7px 13px;border-radius:6px;cursor:pointer;font-weight:500;text-decoration:none;color:var(--ink);white-space:nowrap}
.btn:hover{border-color:var(--accent)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--on-accent)}
.btn.ghost{border-color:transparent;background:none;color:var(--muted)}
.btn.ghost:hover{color:var(--ink);border-color:var(--line)}
.btn.danger{color:var(--bad)}
.btn.small{padding:3px 9px;font-size:13px}
.btn[disabled]{opacity:.5;cursor:default}

.chip{display:inline-block;font-size:12px;padding:1px 9px;border-radius:999px;background:var(--sunken);color:var(--muted);font-weight:500;white-space:nowrap}
.chip.accent{background:var(--accent-soft);color:var(--accent)}
.chip.amber{background:var(--amber-soft);color:var(--amber)}
.chip.bad{background:var(--bad-soft);color:var(--bad)}
.chips{display:flex;flex-wrap:wrap;gap:6px}
button.chip{border:1px solid transparent;cursor:pointer}
button.chip[aria-pressed="true"]{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}

.subtabs{display:flex;gap:4px;border-bottom:1px solid var(--line);overflow-x:auto;scrollbar-width:none}
.subtabs button{background:none;border:0;border-bottom:2px solid transparent;padding:8px 12px;cursor:pointer;color:var(--muted);font-weight:500;white-space:nowrap}
.subtabs button[aria-selected="true"]{color:var(--ink);border-bottom-color:var(--accent)}

/* forms */
form.inline{display:grid;grid-template-columns:repeat(auto-fit,minmax(140px,1fr));gap:12px;align-items:end}
form.inline .wide{grid-column:1/-1}
.field{display:grid;gap:4px;min-width:0}
.field > span{font-size:13px;font-weight:500}
.field small{color:var(--muted);font-size:12px}
input[type=text],input[type=number],input[type=date],input[type=password],input[type=url],input:not([type]),select,textarea{
  background:var(--surface);border:1px solid var(--line);border-radius:6px;padding:8px 10px;width:100%;min-width:0}
textarea{min-height:90px;resize:vertical}
input[type=checkbox]{width:18px;height:18px;accent-color:var(--accent);flex:none}
.form-actions{display:flex;gap:10px;align-items:center;justify-content:flex-end;flex-wrap:wrap}
.error{color:var(--bad);font-size:13px}

/* tables */
.tablebox{overflow-x:auto;border:1px solid var(--line);border-radius:8px;background:var(--surface)}
table{border-collapse:collapse;width:100%;font-size:14px}
th,td{padding:9px 12px;text-align:left;border-bottom:1px solid var(--line);vertical-align:top}
tbody tr:last-child td{border-bottom:0}
th{font-weight:500;color:var(--muted);font-size:12px;white-space:nowrap;background:var(--sunken)}
td.r,th.r{text-align:right}
td.num{white-space:nowrap}
td .t{font-weight:500}
td .s{font-size:12.5px;color:var(--muted)}
.wrap-cell{min-width:220px;max-width:420px;color:var(--muted);font-size:13px}

/* lists */
.list{display:grid}
.item{display:grid;grid-template-columns:auto minmax(0,1fr) auto;gap:12px;align-items:start;padding:10px 2px;border-bottom:1px solid var(--line)}
.item:last-child{border-bottom:0}
.item .t{font-weight:500}
.item .s{font-size:13px;color:var(--muted)}
.item.done .t{text-decoration:line-through;color:var(--muted)}
.group-title{margin:14px 0 2px}

.empty{border:1px dashed var(--line);border-radius:8px;padding:22px;color:var(--muted)}
.empty h3{color:var(--ink);font-size:18px;margin-bottom:4px}
.notice{border:1px solid var(--amber);background:var(--amber-soft);color:var(--ink);border-radius:8px;padding:12px 14px;font-size:14px}
.notice b{color:var(--amber)}

/* lesson reader */
.lesson h2{font-size:30px;margin-top:10px}
.lesson .summary{font-size:17px;color:var(--muted);margin:8px 0 0;max-width:62ch}
.lesson-body{display:grid;gap:22px;margin-top:22px}
.lesson-body h3{font-size:20px;margin-bottom:6px}
.lesson-body p,.lesson-body ul{margin:0 0 10px;max-width:66ch}
.lesson-body ul{padding-left:20px}
.exercise{border:1px solid var(--amber);background:var(--amber-soft);border-radius:8px;padding:14px 16px}
.exercise .label{color:var(--amber)}
.exercise p{margin:6px 0 0;white-space:pre-wrap}
dl.terms{margin:0;border-top:1px solid var(--line)}
dl.terms div{display:grid;grid-template-columns:minmax(110px,170px) minmax(0,1fr);gap:12px;padding:8px 0;border-bottom:1px solid var(--line)}
dl.terms dt{font-weight:600} dl.terms dd{margin:0;color:var(--muted)}
@media (max-width:480px){dl.terms div{grid-template-columns:minmax(0,1fr);gap:2px}}
.lesson-index{display:grid;max-height:70vh;overflow:auto}
.lesson-index button{display:grid;grid-template-columns:52px minmax(0,1fr) 12px;gap:10px;align-items:center;text-align:left;background:none;border:0;border-bottom:1px solid var(--line);padding:9px 6px;cursor:pointer}
.lesson-index button:hover{background:var(--sunken)}
.lesson-index button[aria-current="true"]{background:var(--accent-soft)}
.dot{width:10px;height:10px;border-radius:50%;border:1.5px solid var(--muted)}
.dot.on{background:var(--accent);border-color:var(--accent)}

/* news */
.news{display:grid}
.news article{padding:14px 0;border-bottom:1px solid var(--line);display:grid;gap:4px}
.news article:last-child{border-bottom:0}
.news h3{font-family:var(--f-body);font-size:16px;font-weight:600;line-height:1.35}
.news h3 a{color:var(--ink);text-decoration:none}
.news h3 a:hover{text-decoration:underline}
.news p{margin:0;color:var(--muted);font-size:14px;max-width:80ch}
.news .meta{display:flex;flex-wrap:wrap;gap:8px;align-items:center;font-size:12.5px;color:var(--muted)}

/* charts */
.chart{width:100%;height:auto;display:block}
.chart text{fill:var(--muted);font-family:var(--f-mono);font-size:11px}
.chart .grid line{stroke:var(--line)}
.chart .line{fill:none;stroke:var(--accent);stroke-width:2}
.chart .area{fill:var(--accent-soft)}
.chart .pt{fill:var(--accent)}
.chart .bar{fill:var(--accent)}
.chart .bar.off{fill:var(--sunken)}

.habit{display:grid;grid-template-columns:auto minmax(0,1fr) auto;gap:12px;align-items:center;padding:10px 2px;border-bottom:1px solid var(--line)}
.habit:last-child{border-bottom:0}
.habit input[type=number]{width:96px}
.datebar{display:flex;gap:6px;align-items:center;flex-wrap:wrap}
.datebar input[type=date]{width:auto}
.chips input:not([type=checkbox]):not([type=range]){width:auto;flex:1 1 140px}
.habit .chips input[type=number]{flex:0 0 100px;width:100px}

/* toast & modal */
.toast{position:fixed;left:50%;transform:translateX(-50%);bottom:calc(22px + env(safe-area-inset-bottom,0px));background:var(--ink);color:var(--paper);padding:9px 16px;border-radius:6px;font-size:14px;opacity:0;transition:opacity .2s;pointer-events:none;z-index:50;max-width:calc(100% - 32px)}
.toast.show{opacity:1}
.modal{position:fixed;inset:0;background:rgba(10,15,12,.55);display:grid;place-items:center;padding:16px;z-index:40}
.modal .panel{width:min(440px,100%);display:grid;gap:14px}
.secret{font-family:var(--f-mono);font-size:13px;background:var(--sunken);border:1px solid var(--line);border-radius:6px;padding:10px;word-break:break-all;user-select:all}
pre.code{font-family:var(--f-mono);font-size:12.5px;background:var(--sunken);border:1px solid var(--line);border-radius:6px;padding:10px 12px;overflow-x:auto;margin:0}

/* login */
.login-wrap{min-height:100vh;display:grid;place-items:center;padding:24px 16px}
.login{width:min(380px,100%);display:grid;gap:18px}
.login h1{font-size:34px}
.login p{margin:0;color:var(--muted)}
.login form{display:grid;gap:14px}
.login .btn{justify-content:center;padding:10px}

@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}