/* /belajar/ — "drawing set": tiap catatan = lembar bernomor, index = daftar lembar. Light mode only. */
@import url('https://fonts.googleapis.com/css2?family=Archivo:wdth,wght@62..125,100..900&family=JetBrains+Mono:wght@400;500&display=swap');

:root{
  --ground:#F3F6FB; --sheet:#fff; --ink:#0B1220; --ink2:#2A3347; --mute:#5A6478; --faint:#7C8599;
  --rule:#D5DBE6; --rule-soft:#E3E8F0; --tint:#EEF2FF;
  --cobalt:#1736E8; --cobalt-deep:#0F27B8; --rev:#D9421C; --rev-bg:#FFF0EB;
  --font:'Archivo',system-ui,-apple-system,'Segoe UI',sans-serif;
  --mono:'JetBrains Mono',ui-monospace,Menlo,monospace;
  --r:2px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-padding-top:72px;-webkit-text-size-adjust:100%}
html.lenis,html.lenis body{height:auto}
.lenis.lenis-smooth{scroll-behavior:auto!important}
html:not(.lenis){scroll-behavior:smooth}
body{overflow-x:clip;font-family:var(--font);background:var(--ground);color:var(--ink);line-height:1.6;font-size:15px;min-height:100vh;-webkit-font-smoothing:antialiased;font-variant-numeric:tabular-nums;caret-color:var(--cobalt)}
::selection{background:var(--cobalt);color:#fff}
img{max-width:100%;height:auto}
a{color:var(--cobalt-deep);text-underline-offset:3px}
:focus-visible{outline:2px solid var(--cobalt);outline-offset:2px}
*{scrollbar-width:thin;scrollbar-color:#B9C2D6 transparent}

/* progress + efek */
#progress{position:fixed;top:0;left:0;height:3px;width:0;background:var(--rev);z-index:120}
#fx-toggle{position:fixed;right:14px;bottom:14px;z-index:90;display:flex;align-items:center;gap:.5rem;font:600 .72rem/1 var(--font);font-stretch:80%;letter-spacing:.06em;text-transform:uppercase;color:var(--ink);background:var(--sheet);border:1px solid var(--ink);border-radius:var(--r);padding:.55rem .75rem;cursor:pointer}
#fx-toggle i{width:8px;height:8px;background:var(--cobalt);display:block}
#fx-toggle.off i{background:transparent;border:1px solid var(--faint)}
#fx-toggle:hover{background:var(--tint)}
#pv{position:fixed;z-index:95;left:0;top:0;width:280px;pointer-events:none;opacity:0;transform:translate(0,0) scale(.97);transition:opacity .14s ease-out;background:var(--sheet);border:1px solid var(--ink);border-radius:var(--r);box-shadow:0 18px 40px -12px rgba(11,18,32,.28)}
#pv.on{opacity:1}
#pv .h{display:flex;justify-content:space-between;align-items:center;background:var(--cobalt);color:#fff;font-size:.7rem;font-weight:700;letter-spacing:.05em;padding:.32rem .6rem;font-stretch:80%;text-transform:uppercase}
#pv .b{padding:.6rem .7rem .7rem}
#pv .t{font-weight:700;font-size:.86rem;line-height:1.3}
#pv .s{font-size:.76rem;color:var(--mute);margin-top:.3rem;line-height:1.45;display:-webkit-box;-webkit-line-clamp:4;-webkit-box-orient:vertical;overflow:hidden}
.fx-off *{scroll-behavior:auto}

/* ---------- halaman topik ---------- */
.wrap{max-width:780px;margin:0 auto;padding:1.4rem 20px 5rem}
.wrap.wide{max-width:1040px}
a.back{font-size:.82rem;color:var(--mute);text-decoration:none}
h1{font-size:clamp(1.55rem,4.6vw,2.3rem);font-weight:800;letter-spacing:-.02em;line-height:1.12;margin-top:1.1rem;text-wrap:balance;font-stretch:96%}
.lede{font-size:1rem;color:var(--ink2);margin-top:.9rem;line-height:1.7;max-width:68ch}
h2{font-size:1.14rem;font-weight:750;letter-spacing:-.005em;margin:2.6rem 0 .8rem;padding:0 0 .55rem;border-bottom:1px solid var(--ink);position:relative;display:flex;align-items:baseline;gap:.55rem}
h2::before{content:'';width:9px;height:9px;background:var(--cobalt);flex:none;transform:translateY(-1px)}
h2 .anc{position:absolute;left:-1.1rem;color:var(--cobalt);text-decoration:none;opacity:0;font-weight:500}
h2:hover .anc,h2 .anc:focus{opacity:.9}
h3{font-size:.98rem;font-weight:700;margin:1.5rem 0 .35rem}
p,li{font-size:.97rem;color:var(--ink2);line-height:1.7;max-width:72ch}
p{margin-top:.65rem}
ul,ol{margin:.6rem 0 0 1.2rem;display:flex;flex-direction:column;gap:.42rem}
ul li::marker{color:var(--cobalt)}
ol li::marker{color:var(--cobalt);font-weight:700}
b,strong{color:var(--ink);font-weight:650}
pre{background:#EDF1F9;color:var(--ink);border:1px solid var(--rule);border-radius:var(--r);padding:.85rem 1rem;font-size:.8rem;line-height:1.6;overflow-x:auto;white-space:pre-wrap;word-break:break-word;font-family:var(--mono);margin:.8rem 0}
code{background:#EDF1F9;border:1px solid var(--rule-soft);border-radius:var(--r);padding:.04rem .32rem;font-size:.82em;font-family:var(--mono);color:#1B2A8A;overflow-wrap:anywhere}
pre code{background:none;border:0;padding:0;color:inherit}
table{width:100%;border-collapse:collapse;font-size:.85rem;margin:.8rem 0;background:var(--sheet);border:1px solid var(--ink)}
th,td{border:1px solid var(--rule);padding:.5rem .65rem;text-align:left;vertical-align:top;overflow-wrap:break-word}
th{background:var(--tint);font-weight:700;color:var(--ink);font-size:.76rem;letter-spacing:.04em;font-stretch:85%;text-transform:uppercase}
td.n{text-align:right;white-space:nowrap}
.tscroll{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:.5rem 0}
.tscroll table{margin:0;min-width:520px}
.rc,.box{background:var(--sheet);border:1px solid var(--rule);border-radius:var(--r);padding:1rem 1.1rem;margin:.8rem 0}
.rc h3{margin-top:0}
.rc .row{font-size:.82rem;color:var(--mute);margin-top:.3rem}
.box.hi{border-color:var(--cobalt);background:var(--tint)}
.tag{display:inline-block;font-size:.64rem;font-weight:750;font-stretch:80%;letter-spacing:.07em;text-transform:uppercase;padding:.1rem .42rem;border:1px solid currentColor;border-radius:var(--r);color:var(--mute);vertical-align:middle;white-space:nowrap;line-height:1.5}
.tag.ok{color:var(--cobalt-deep)}
.tag.warn{color:var(--rev)}
.tag.no{color:#fff;background:var(--rev);border-color:var(--rev)}
.tag.blue,.tag.new{color:#fff;background:var(--cobalt);border-color:var(--cobalt)}
.next{background:var(--rev-bg);border:1px solid var(--rev);border-radius:var(--r);padding:.8rem 1rem;font-size:.92rem;color:var(--ink2);margin:1.2rem 0;position:relative}
.next b:first-child{color:var(--rev)}
.galeri{display:flex;gap:.75rem;flex-wrap:wrap;align-items:flex-start;margin:.9rem 0}
figure{margin:0}
figure.g{flex:1 1 175px;max-width:185px}
figure img{width:100%;border:1px solid var(--ink);border-radius:var(--r);display:block}
figure figcaption{font-size:.75rem;color:var(--mute);margin-top:.3rem}
footer{font-size:.8rem;color:var(--mute);border-top:1px solid var(--ink);padding-top:1rem;margin-top:2.6rem;line-height:1.65}

/* bar atas */
.topbar{position:sticky;top:0;z-index:50;background:var(--cobalt);color:#fff}
.topbar .in{max-width:780px;margin:0 auto;padding:.55rem 20px;display:flex;align-items:center;gap:.8rem;font-size:.8rem}
.topbar a{color:#fff;text-decoration:none;font-weight:650}
.topbar a:hover{text-decoration:underline}
.topbar .crumb{margin-left:auto;color:#C9D2FF;font-weight:600}
.titleblock{display:grid;grid-template-columns:auto 1fr auto;border:1px solid var(--ink);background:var(--sheet);margin-top:1rem;font-size:.8rem}
.titleblock>div{padding:.45rem .8rem;border-right:1px solid var(--ink);min-width:0}
.titleblock>div:last-child{border-right:0;display:flex;gap:.45rem;align-items:center;flex-wrap:wrap}
.titleblock small{display:block;font-size:.62rem;font-weight:700;font-stretch:78%;letter-spacing:.09em;text-transform:uppercase;color:var(--faint)}
.titleblock .no{font-size:1.5rem;font-weight:800;color:var(--cobalt);line-height:1.1;font-stretch:90%}
.titleblock a{color:var(--ink);font-weight:650;text-decoration:none}
.titleblock a:hover{color:var(--cobalt)}
.btn{font:inherit;font-size:.76rem;font-weight:650;color:var(--ink);background:var(--sheet);border:1px solid var(--ink);border-radius:var(--r);padding:.3rem .65rem;cursor:pointer}
.btn:hover{background:var(--cobalt);border-color:var(--cobalt);color:#fff}
details.toc{background:var(--sheet);border:1px solid var(--rule);border-radius:var(--r);margin:1.2rem 0 0;padding:.1rem 1rem}
details.toc summary{cursor:pointer;font-size:.84rem;font-weight:700;color:var(--ink2);padding:.65rem 0}
details.toc ol{margin:0 0 .8rem 1.2rem;gap:.25rem}
details.toc li{font-size:.9rem}
details.toc a{text-decoration:none;color:var(--ink2)}
details.toc a:hover{color:var(--cobalt);text-decoration:underline}
.pn{display:grid;grid-template-columns:1fr 1fr;gap:0;margin-top:2.6rem;border:1px solid var(--ink);background:var(--sheet)}
.pn a{display:block;padding:.8rem 1rem;text-decoration:none;color:var(--ink);transition:background .15s}
.pn a+a{border-left:1px solid var(--ink)}
.pn a:hover{background:var(--tint)}
.pn a small{display:block;font-size:.68rem;font-weight:700;color:var(--cobalt);margin-bottom:.15rem;letter-spacing:.04em}
.pn a span{font-size:.9rem;font-weight:650;line-height:1.4;display:block}
.pn a.nx{text-align:right;grid-column:2}
.pn a.pv:only-child{grid-column:1}
.related{margin-top:1.8rem}
.related h4{font-size:.72rem;font-weight:750;font-stretch:80%;letter-spacing:.09em;text-transform:uppercase;color:var(--mute);margin-bottom:.3rem}
.related a{display:flex;gap:.6rem;font-size:.9rem;padding:.4rem 0;text-decoration:none;color:var(--ink2);border-bottom:1px solid var(--rule)}
.related a:hover{color:var(--cobalt)}
.related a b{font-weight:700;color:var(--cobalt);min-width:2.6rem}

/* ---------- index ---------- */
.masthead{display:grid;grid-template-columns:1fr auto;gap:1.5rem;align-items:end;padding:2.2rem 0 1.4rem}
.masthead h1{font-size:clamp(2.6rem,9vw,5.2rem);line-height:.92;letter-spacing:-.035em;font-weight:850;font-stretch:100%;margin:0}
.masthead p{color:var(--ink2);margin-top:.8rem;max-width:44ch;font-size:.97rem}
.masthead .tb{border:1px solid var(--ink);background:var(--sheet);min-width:250px}
.masthead .tb div{display:flex;justify-content:space-between;gap:1.5rem;padding:.4rem .75rem;border-bottom:1px solid var(--rule);font-size:.8rem}
.masthead .tb div:last-child{border-bottom:0}
.masthead .tb span{color:var(--faint);font-size:.66rem;font-weight:700;font-stretch:78%;letter-spacing:.09em;text-transform:uppercase;align-self:center}
.masthead .tb b{font-weight:700}
.tools{position:sticky;top:3px;z-index:40;background:rgba(243,246,251,.95);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);padding:.65rem 0;border-top:1px solid var(--ink);border-bottom:1px solid var(--rule)}
.tools .r1{display:flex;gap:.6rem;align-items:center}
.search{position:relative;flex:1}
.search input{width:100%;font:inherit;font-size:.92rem;padding:.55rem 2.3rem .55rem 2.3rem;border:1px solid var(--ink);border-radius:var(--r);background:var(--sheet);color:var(--ink);outline:none}
.search input:focus{box-shadow:0 0 0 3px rgba(23,54,232,.22);border-color:var(--cobalt)}
.search svg{position:absolute;left:.75rem;top:50%;transform:translateY(-50%);width:15px;height:15px;stroke:var(--mute)}
.search kbd{position:absolute;right:.55rem;top:50%;transform:translateY(-50%);font:inherit;font-size:.7rem;font-weight:650;color:var(--mute);border:1px solid var(--rule);border-radius:var(--r);padding:0 .35rem;background:var(--ground)}
.seg{display:flex;border:1px solid var(--ink);border-radius:var(--r);flex:none;background:var(--sheet)}
.seg button{font:inherit;font-size:.8rem;font-weight:650;color:var(--ink);background:none;border:0;padding:.5rem .8rem;cursor:pointer}
.seg button+button{border-left:1px solid var(--ink)}
.seg button.on{background:var(--cobalt);color:#fff}
.seg button:not(.on):hover{background:var(--tint)}

.csa-outer{perspective:1100px;padding:1.6rem 0 .6rem}
.csa-card{transform-origin:center top;will-change:transform;background:var(--sheet);border:1.5px solid var(--ink);box-shadow:0 26px 50px -24px rgba(11,18,32,.35);position:relative}
.csa-card::before,.csa-card::after{content:'';position:absolute;width:13px;height:13px;border:solid var(--cobalt);border-width:0}
.csa-card::before{left:-8px;top:-8px;border-width:0 1.5px 1.5px 0}
.csa-card::after{right:-8px;bottom:-8px;border-width:1.5px 0 0 1.5px}
.csa-head{display:flex;justify-content:space-between;align-items:baseline;padding:.55rem .9rem;border-bottom:1px solid var(--ink);background:var(--tint);font-size:.74rem;font-weight:750;font-stretch:80%;letter-spacing:.08em;text-transform:uppercase}
.csa-head span{color:var(--mute);font-weight:600}
.disc{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr))}
.disc button{display:flex;align-items:center;gap:.6rem;text-align:left;font:inherit;font-size:.84rem;color:var(--ink);background:var(--sheet);border:0;border-right:1px solid var(--rule);border-bottom:1px solid var(--rule);padding:.55rem .8rem;cursor:pointer;min-width:0}
.disc button:hover{background:var(--tint)}
.disc button.on{background:var(--cobalt);color:#fff}
.disc .cd{flex:none;width:2.1rem;text-align:center;font-weight:800;font-size:.78rem;border:1px solid currentColor;border-radius:var(--r);padding:.12rem 0;color:var(--cobalt);background:transparent;letter-spacing:.03em}
.disc button.on .cd{color:#fff}
.disc .nm{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-weight:550}
.disc .ct{font-weight:700;color:var(--mute);font-size:.8rem}
.disc button.on .ct{color:#C9D2FF}

details.plan{margin:1.1rem 0 .2rem;background:var(--sheet);border:1px solid var(--rule);border-radius:var(--r)}
details.plan summary{cursor:pointer;padding:.65rem 1rem;font-size:.86rem;font-weight:700;color:var(--ink);display:flex;gap:.6rem;align-items:center}
details.plan summary small{font-weight:500;color:var(--mute)}
details.plan ol{margin:0;padding:.2rem 1rem 1rem 2.4rem;gap:.85rem}
details.plan li{font-size:.9rem;max-width:none}
details.plan li span{display:block;color:var(--mute);font-size:.84rem;margin-top:.15rem}
.grp{display:flex;align-items:baseline;gap:.6rem;margin:1.9rem 0 .5rem;font-size:.74rem;font-weight:750;font-stretch:80%;letter-spacing:.1em;text-transform:uppercase;color:var(--ink)}
.grp::before{content:'';width:9px;height:9px;background:var(--cobalt);align-self:center}
.grp .ct{margin-left:auto;color:var(--mute);font-weight:600}
.grp.cat{font-size:.9rem;letter-spacing:.04em}
.grp-sub{font-size:.84rem;color:var(--mute);margin:0 0 .5rem;max-width:80ch}
.list{border:1px solid var(--ink);background:var(--sheet)}
a.row{display:grid;grid-template-columns:3.4rem 2.6rem 1fr auto;gap:.15rem 1rem;align-items:start;padding:.8rem 1rem;text-decoration:none;color:var(--ink);border-top:1px solid var(--rule);transition:background .12s}
a.row:first-child{border-top:0}
a.row:hover{background:var(--tint)}
a.row .num{font-size:.92rem;font-weight:800;color:var(--ink);font-stretch:90%}
a.row:hover .num{color:var(--cobalt)}
a.row .cd{font-size:.7rem;font-weight:800;text-align:center;border:1px solid var(--cobalt);color:var(--cobalt);border-radius:var(--r);padding:.1rem 0;margin-top:.1rem;letter-spacing:.03em}
a.row .ttl{font-size:.97rem;font-weight:700;line-height:1.35;display:block}
a.row .sum{font-size:.84rem;color:var(--mute);line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin-top:.2rem;max-width:80ch}
a.row .meta{display:flex;flex-direction:column;align-items:flex-end;gap:.3rem;font-size:.76rem;color:var(--mute);white-space:nowrap;padding-top:.15rem}
a.row:hover .ttl{text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
.empty{font-size:.92rem;color:var(--mute);padding:2.5rem 0;text-align:center}
.idx-foot{font-size:.78rem;color:var(--mute);margin-top:2.2rem;padding-top:1rem;border-top:1px solid var(--ink)}


/* ---------- Tanya AI ---------- */
.ask{border:1px solid var(--ink);background:var(--sheet);margin:0 0 1.3rem}
.ask-head{display:flex;justify-content:space-between;align-items:center;background:var(--cobalt);color:#fff;padding:.4rem .85rem;font-size:.72rem;font-weight:750;font-stretch:80%;letter-spacing:.09em;text-transform:uppercase}
.ask-head span{font-weight:600;color:#C9D2FF;letter-spacing:.04em;text-transform:none;font-stretch:100%}
.ask-row{display:flex;gap:.5rem;padding:.8rem .85rem .5rem}
.ask-row input{flex:1;min-width:0;font:inherit;font-size:.95rem;padding:.6rem .8rem;border:1px solid var(--ink);border-radius:var(--r);background:var(--sheet);color:var(--ink);outline:none}
.ask-row input:focus{box-shadow:0 0 0 3px rgba(23,54,232,.22);border-color:var(--cobalt)}
.ask-row button{font:inherit;font-size:.88rem;font-weight:700;color:#fff;background:var(--cobalt);border:0;border-radius:var(--r);padding:.6rem 1.1rem;cursor:pointer}
.ask-row button:hover{background:var(--cobalt-deep)}
.ask-row button:disabled{background:var(--faint);cursor:wait}
.ask-chips{display:flex;flex-wrap:wrap;gap:.4rem;padding:0 .85rem .8rem}
.ask-chips button{font:inherit;font-size:.78rem;color:var(--ink2);background:var(--sheet);border:1px solid var(--rule);border-radius:var(--r);padding:.3rem .6rem;cursor:pointer}
.ask-chips button:hover{border-color:var(--cobalt);color:var(--cobalt)}
.thread{border-top:1px solid var(--ink);display:none}
.thread.has{display:block}
.turn{padding:.85rem .95rem;border-bottom:1px solid var(--rule)}
.turn:last-child{border-bottom:0}
.turn .who{display:inline-block;font-size:.62rem;font-weight:800;font-stretch:78%;letter-spacing:.1em;text-transform:uppercase;color:var(--cobalt);border:1px solid var(--cobalt);border-radius:var(--r);padding:.05rem .35rem;margin-bottom:.35rem}
.turn.a .who{color:#fff;background:var(--cobalt)}
.turn .t{font-size:.95rem;line-height:1.65;color:var(--ink2);max-width:75ch}
.turn.q .t{font-weight:650;color:var(--ink)}
.turn .t p{margin:.45rem 0 0}
.turn .t ul,.turn .t ol{margin:.4rem 0 0 1.1rem}
.turn .t a.ref{font-weight:750;color:var(--cobalt-deep);background:var(--tint);padding:0 .25rem;border-radius:var(--r);text-decoration:none}
.turn .t a.ref:hover{background:var(--cobalt);color:#fff}
.turn.err .t{color:var(--rev)}
.dots{display:inline-flex;gap:4px;vertical-align:middle}
.dots i{width:7px;height:7px;background:var(--cobalt);animation:blk 1s infinite steps(2)}
.dots i:nth-child(2){animation-delay:.2s}.dots i:nth-child(3){animation-delay:.4s}
@keyframes blk{0%{opacity:1}50%{opacity:.15}}
.fx-off .dots i{animation:none}
@media (max-width:700px){.ask-row{flex-wrap:wrap}.ask-row button{width:100%}}

/* ---------- PIN ---------- */
#pin-screen{position:fixed;inset:0;display:flex;align-items:center;justify-content:center;background:var(--ground);z-index:130}
.pin-card{width:100%;max-width:340px;background:var(--sheet);border:1.5px solid var(--ink);padding:1.6rem 1.6rem 1.4rem;text-align:left}
.pin-card h1{font-size:2rem;margin:0;color:var(--ink);line-height:1}
.pin-card p{font-size:.85rem;color:var(--mute);margin:.4rem 0 1.3rem}
.pin-input-wrap{position:relative;margin-bottom:.7rem}
.pin-input-wrap input{width:100%;font:inherit;font-size:1.1rem;letter-spacing:.35em;text-align:center;padding:.7rem 2.75rem;border:1px solid var(--ink);border-radius:var(--r);background:var(--sheet);color:var(--ink);outline:none}
.pin-input-wrap input:focus{box-shadow:0 0 0 3px rgba(23,54,232,.22);border-color:var(--cobalt)}
.pin-eye{position:absolute;right:10px;top:50%;transform:translateY(-50%);background:none;border:none;cursor:pointer;color:var(--mute);font-size:1.05rem;padding:.25rem}
.pin-error{font-size:.8rem;color:var(--rev);height:1.1rem;margin-bottom:.7rem}
.pin-submit{width:100%;padding:.7rem;border:0;border-radius:var(--r);background:var(--cobalt);color:#fff;font:inherit;font-size:.92rem;font-weight:700;cursor:pointer}
.pin-submit:hover{background:var(--cobalt-deep)}
@keyframes shake{0%,100%{transform:translateX(0)}20%,60%{transform:translateX(-8px)}40%,80%{transform:translateX(8px)}}
.shake{animation:shake .35s ease}

@media (max-width:700px){
  .masthead{grid-template-columns:1fr}
  .masthead .tb{min-width:0}
  .seg button{padding:.5rem .6rem}
  .search kbd{display:none}
  h2 .anc{display:none}
  .disc{grid-template-columns:1fr 1fr}
  .disc button{padding:.5rem .55rem}
  .disc .ct{display:none}
  a.row{grid-template-columns:2.6rem 1fr;padding:.75rem .85rem}
  a.row .num{grid-column:1}
  a.row .cd{display:none}
  a.row .main{grid-column:2}
  a.row .meta{grid-column:2;flex-direction:row;align-items:center;gap:.6rem}
  .titleblock{grid-template-columns:auto 1fr}
  .titleblock>div:last-child{grid-column:1/-1;border-right:0;border-top:1px solid var(--ink)}
  .pn{grid-template-columns:1fr}
  .pn a+a{border-left:0;border-top:1px solid var(--ink)}
  .pn a.nx{grid-column:1}
  #fx-toggle span{display:none}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}