/* SwiftUI Quest — shared styles for the calendar page and the day pages.
   Palette: near-black graphite ground, warm white text, the Swift logo's orange as the
   single accent. Type: Spectral SC for headings and labels, Spectral for text. */
:root{
  --paper:#1b1c20;
  --panel:#24252b;
  --ink:#e9e6df;
  --ink2:#a6a49c;
  --rule:rgba(233,230,223,.16);
  --swift:#f05138;
  --swiftsoft:#f2745f;
  --codebg:#16171b;
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0; background:var(--paper); color:var(--ink);
  font-family:"Spectral",serif; font-weight:400; font-size:17px; line-height:1.62;
}
::selection{background:rgba(240,81,56,.35);}
a{color:var(--swiftsoft); text-decoration:none; border-bottom:1px solid rgba(242,116,95,.35);}
a:hover{border-bottom-color:var(--swiftsoft);}
.sheet{max-width:920px; margin:0 auto; padding:56px 34px 100px;}
p{margin:0 0 14px;}
b{font-weight:600;}
code{
  font-family:ui-monospace,"SF Mono",SFMono-Regular,Menlo,Consolas,monospace;
  font-size:.86em; background:rgba(233,230,223,.08); padding:1px 5px; border-radius:3px;
}

/* ---------- headings ---------- */
.kicker{
  font-family:"Spectral SC"; font-weight:500; font-size:12.5px; letter-spacing:.3em;
  text-indent:.3em; color:var(--swift); text-align:center; margin:0 0 16px;
}
.bird{display:block; margin:0 auto 10px; width:110px; height:48px;}
h1{
  font-family:"Spectral SC"; font-weight:500; font-size:52px; letter-spacing:.04em;
  text-align:center; margin:0 0 12px; line-height:1.1;
}
.mastrule{display:flex; align-items:center; gap:14px; max-width:380px; margin:0 auto 16px;}
.mastrule .ln{flex:1; height:1px; background:var(--rule);}
.mastrule .gl{color:var(--swift); font-size:16px; line-height:1;}
.sub{font-style:italic; font-weight:300; color:var(--ink2); text-align:center; max-width:600px; margin:0 auto;}
h2{
  font-family:"Spectral SC"; font-weight:500; font-size:25px; letter-spacing:.04em;
  margin:52px 0 12px; line-height:1.25;
}
h3{font-family:"Spectral SC"; font-weight:500; font-size:20px; letter-spacing:.03em; margin:0 0 8px; line-height:1.3;}
.label{
  font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.24em;
  color:var(--swiftsoft); margin:20px 0 6px; display:block;
}
.dim{color:var(--ink2);}

/* ---------- today banner & counters ---------- */
.today{
  margin:34px 0 0; border:1.6px solid var(--swift); padding:16px 20px; background:rgba(240,81,56,.06);
}
.today .label{margin-top:0;}
.today p{margin:0;}
.glance{display:grid; grid-template-columns:1.3fr .7fr; gap:30px; margin-top:34px; align-items:start;}
.gtable{width:100%; border-collapse:collapse;}
.gtable td{padding:8px 0; border-bottom:1px solid var(--rule); vertical-align:top;}
.gtable tr:last-child td{border-bottom:none;}
.gtable .k{font-family:"Spectral SC"; font-weight:500; font-size:12px; letter-spacing:.2em; color:var(--ink2); width:150px; padding-right:14px;}
.gtable .v{font-weight:300;}
.counters{display:flex; flex-direction:column; gap:18px; align-items:center;}
.stamp{
  border:2.5px solid var(--swift); outline:1px solid var(--swift); outline-offset:3px;
  color:var(--swift); padding:12px 22px; text-align:center; background:rgba(240,81,56,.05);
}
.stamp .k{font-family:"Spectral SC"; font-weight:500; font-size:11px; letter-spacing:.26em;}
.stamp .v{font-family:"Spectral SC"; font-weight:600; font-size:25px; letter-spacing:.1em; margin-top:2px;}
.how{margin-top:30px; padding:0; counter-reset:how;}
.how li{list-style:none; counter-increment:how; position:relative; padding:0 0 10px 34px; font-weight:300;}
.how li::before{
  content:counter(how); position:absolute; left:0; top:1px; width:22px; height:22px; border:1px solid var(--swift);
  color:var(--swift); border-radius:50%; text-align:center; font-family:"Spectral SC"; font-size:13px; line-height:20px;
}

/* ---------- parts & the calendar ---------- */
.part{margin-top:70px;}
.part-head{display:flex; align-items:center; gap:14px;}
.part-head .ln{flex:1; height:1px; background:var(--rule);}
.part-head .glyph{color:var(--swift); font-size:14px;}
.part-head h2{margin:0; text-align:center; font-size:23px;}
.part-no{
  font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.3em; text-indent:.3em;
  color:var(--ink2); text-align:center; margin:0 0 4px;
}
.part-intro{max-width:640px; margin:10px auto 0; text-align:center; font-style:italic; font-weight:300; color:var(--ink2);}
.part-meta{max-width:640px; margin:14px auto 0; font-size:15px; font-weight:300;}
.part-meta p{margin:0 0 4px;}
.part-meta .label{display:inline; margin:0 6px 0 0;}
.days{margin-top:22px; border-top:1px solid var(--rule);}
.day{
  display:grid; grid-template-columns:118px 1fr auto; gap:18px; padding:16px 0;
  border-bottom:1px solid var(--rule); align-items:start;
}
.day .when{font-family:"Spectral SC"; font-weight:500; font-size:12.5px; letter-spacing:.14em; line-height:1.6;}
.day .when .date{color:var(--swiftsoft); display:block;}
.day .when .dn{color:var(--ink2); display:block;}
.day .what h3{font-size:18px; margin:0 0 3px;}
.day .what h3 a{color:var(--ink); border-bottom-color:transparent;}
.day .what h3 a:hover{border-bottom-color:var(--ink2);}
.day .what p{margin:0 0 3px; font-weight:300; font-size:15.5px; color:var(--ink2);}
.day .what .extra{font-size:14px; color:var(--swiftsoft); font-style:italic;}
.day .act{display:flex; flex-direction:column; gap:7px; align-items:flex-end; min-width:132px;}
.badge{
  font-family:"Spectral SC"; font-weight:500; font-size:10.5px; letter-spacing:.2em;
  border:1px solid var(--rule); color:var(--ink2); padding:2px 8px; white-space:nowrap;
}
.badge.tutorial{border-color:var(--swift); color:var(--swift);}
a.badge{padding:5px 12px; font-size:11.5px; letter-spacing:.18em; cursor:pointer; transition:background .12s, color .12s, border-color .12s;}
a.badge:hover{border-color:var(--ink2); color:var(--ink);}
a.badge.tutorial:hover{background:var(--swift); border-color:var(--swift); color:var(--paper);}
.day.is-today{background:rgba(240,81,56,.07); box-shadow:-10px 0 0 rgba(240,81,56,.07), 10px 0 0 rgba(240,81,56,.07);}
.day.is-today .when .dn::after{content:" · today"; color:var(--swift);}
.day.is-late .when .date{color:var(--ink2);}
.day.is-done .what h3 a{color:var(--ink2);}

button.toggle{
  background:none; cursor:pointer; color:var(--ink2); border:1px solid var(--rule); padding:5px 12px;
  font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.18em; white-space:nowrap;
}
button.toggle:hover{border-color:var(--ink2);}
button.toggle .on{display:none;}
button.toggle[aria-pressed="true"]{border-color:var(--swift); color:var(--swift);}
button.toggle[aria-pressed="true"] .on{display:inline;}
button.toggle[aria-pressed="true"] .off{display:none;}

/* ---------- figures ---------- */
figure.plate{margin:34px 0 8px;}
.plateframe{border:1.6px solid var(--ink); padding:7px; background:var(--panel);}
.plateframe .in{border:.6px solid rgba(233,230,223,.55);}
.plateframe svg{display:block; width:100%; height:auto;}
figcaption{font-family:"Spectral SC"; font-weight:500; font-size:13px; letter-spacing:.12em; text-align:center; margin-top:12px; color:var(--ink2);}

/* ---------- day pages ---------- */
.crumbs{font-family:"Spectral SC"; font-weight:500; font-size:12px; letter-spacing:.18em; display:flex; justify-content:space-between; gap:12px; flex-wrap:wrap;}
.crumbs a{border-bottom:none; color:var(--ink2);}
.crumbs a:hover{color:var(--swiftsoft);}
.dayhead{margin:38px 0 0; text-align:center;}
.dayhead .kicker{margin-bottom:10px;}
.dayhead h1{font-size:40px;}
.dayhead .sub{max-width:640px;}
.intro{border:1px solid var(--rule); background:var(--panel); padding:20px 24px; margin:34px 0 0;}
.intro p{margin:0 0 8px; font-weight:300;}
.intro p:last-child{margin-bottom:0;}
.intro .label{display:inline; margin:0 8px 0 0;}
.lesson{margin-top:50px;}
.lesson > .lno{font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.28em; color:var(--ink2); margin:0 0 2px;}
.lesson > h2{margin:0 0 14px;}
.lesson p, .step p{font-weight:300;}
ol.questions, ul.built, ul.reslist{margin:0 0 14px; padding-left:22px; font-weight:300;}
ol.questions li, ul.built li, ul.reslist li{margin-bottom:6px;}
.notice{border-left:2px solid var(--swift); padding:6px 0 6px 16px; margin:30px 0 0; color:var(--ink2); font-style:italic; font-weight:300;}

/* tutorial steps */
.step{margin-top:54px;}
.step > .sno{font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.28em; color:var(--swift); margin:0 0 2px;}
.step > h2{margin:0 0 14px;}
.where{
  font-family:"Spectral SC"; font-weight:500; font-size:11px; letter-spacing:.2em; color:var(--ink2);
  margin:16px 0 0; padding:6px 12px; background:var(--panel); border:1px solid var(--rule); border-bottom:none; display:inline-block;
}
.where code{font-size:12px; background:none; padding:0; color:var(--ink); letter-spacing:0;}
pre.code{
  font-family:ui-monospace,"SF Mono",SFMono-Regular,Menlo,Consolas,monospace; font-size:13px; line-height:1.6;
  background:var(--codebg); border:1px solid var(--rule); padding:14px 16px; margin:0 0 16px;
  overflow-x:auto; color:#dcd9d1; tab-size:4; max-width:100%;
}
pre.code code{font-family:inherit; font-size:inherit; background:none; padding:0; border-radius:0;}
pre.code .c{color:#85827a;}
pre.sh{border-left:3px solid var(--swift);}
pre.out{background:#101114; border-color:rgba(240,81,56,.4); color:#f0ede6; margin-top:0;}
pre.err{background:#1d1314; border-color:rgba(240,81,56,.6); color:#f6b4a8; white-space:pre-wrap; margin-top:0;}
.outlabel{
  font-family:"Spectral SC"; font-weight:500; font-size:11px; letter-spacing:.2em; color:var(--swiftsoft);
  margin:0; padding:6px 0 5px;
}
/* numbered things to do in Xcode */
ol.ui{margin:18px 0 20px; padding:0; counter-reset:ui; list-style:none;}
ol.ui > li{counter-increment:ui; position:relative; padding:0 0 2px 40px; margin:0 0 12px; min-width:0;}
ol.ui > li::before{
  content:counter(ui); position:absolute; left:0; top:2px; width:25px; height:25px; border:1px solid var(--swift);
  color:var(--swift); border-radius:50%; text-align:center; font-family:"Spectral SC"; font-size:13.5px; line-height:23px;
}
ol.ui > li > p{margin:0 0 10px;}
ol.ui > li > :last-child{margin-bottom:0;}
/* an example of Xcode's console: real output, in a small window */
.console{border:1px solid rgba(233,230,223,.24); background:#0e0f12; border-radius:8px; overflow:hidden; margin:0 0 16px; max-width:100%;}
.console-bar{display:flex; align-items:center; gap:10px; padding:7px 11px; background:#25262d; border-bottom:1px solid var(--rule);}
.console .lights{display:flex; gap:5px;}
.console .lights i{display:block; width:9px; height:9px; border-radius:50%; background:rgba(233,230,223,.24);}
.console-title{font-family:"Spectral SC"; font-weight:500; font-size:10.5px; letter-spacing:.26em; color:var(--ink2);}
pre.console-out{
  font-family:ui-monospace,"SF Mono",SFMono-Regular,Menlo,Consolas,monospace; font-size:13px; line-height:1.55;
  margin:0; padding:12px 14px 13px; color:#f0ede6; white-space:pre-wrap; overflow-wrap:anywhere; tab-size:4;
}
pre.console-out code{font-family:inherit; font-size:inherit; background:none; padding:0; border-radius:0;}
.console .exit{color:#7f7d76;}
/* a screenshot of the app, from a real run in the simulator */
figure.shot{margin:20px 0 24px; text-align:center;}
figure.shot img{
  display:block; margin:0 auto; width:250px; max-width:64%; height:auto; background:#fff;
  border:6px solid #050506; border-radius:34px; outline:1px solid rgba(233,230,223,.3);
}
figure.shot figcaption{letter-spacing:.1em;}
figure.shot .device{display:block; font-size:10.5px; letter-spacing:.22em; margin-top:3px; opacity:.75;}
/* something folded away until wanted */
details.fold{border:1px solid var(--rule); background:var(--panel); margin:0 0 12px; min-width:0;}
details.fold summary{cursor:pointer; list-style:none; padding:9px 14px; font-weight:300; color:var(--ink2); font-size:15px;}
details.fold summary::-webkit-details-marker{display:none;}
details.fold summary::before{content:"▸\00a0\00a0"; color:var(--swift);}
details.fold[open] summary::before{content:"▾\00a0\00a0";}
details.fold pre.code{margin:0; border-width:1px 0 0 0;}
.note{border:1px solid var(--rule); background:var(--panel); padding:16px 20px; margin:18px 0;}
.note .label{margin-top:0;}
.note p{margin:0;}
.note + pre.code, .note + .where{margin-top:0;}
table.map{width:100%; border-collapse:collapse; margin:0 0 16px; font-weight:300;}
table.map td, table.map th{padding:7px 10px 7px 0; border-bottom:1px solid var(--rule); text-align:left; vertical-align:top;}
table.map th{font-family:"Spectral SC"; font-weight:500; font-size:12px; letter-spacing:.2em; color:var(--ink2);}

/* ---------- flash cards ---------- */
.cards-head{display:flex; align-items:baseline; justify-content:space-between; gap:12px; flex-wrap:wrap; margin-top:60px;}
.cards-head h2{margin:0;}
.cards-tools{display:flex; gap:8px; flex-wrap:wrap;}
.cards-intro{font-weight:300; color:var(--ink2); margin:8px 0 18px;}
.pile{display:grid; grid-template-columns:1fr 1fr; gap:14px; align-items:start; grid-auto-flow:row dense;}
details.card{border:1px solid var(--rule); background:var(--panel); min-width:0;}
details.card[open]{grid-column:1 / -1; border-color:rgba(240,81,56,.55);}
details.card summary{cursor:pointer; list-style:none; padding:14px 16px 16px; display:block;}
details.card summary::-webkit-details-marker{display:none;}
details.card .tag{
  display:block; font-family:"Spectral SC"; font-weight:500; font-size:10.5px; letter-spacing:.2em;
  color:var(--ink2); margin-bottom:6px;
}
details.card.trick .tag{color:var(--swift);}
details.card .front{display:block; font-size:16.5px;}
details.card summary::after{
  content:"tap to show"; display:block; margin-top:9px; font-family:"Spectral SC"; font-size:10.5px;
  letter-spacing:.2em; color:var(--ink2);
}
details.card[open] summary::after{content:"tap to hide";}
details.card .back{padding:0 16px 14px; border-top:1px solid var(--rule); margin-top:0; padding-top:14px;}
details.card .back p{font-weight:300; margin:0 0 10px;}
details.card .back p:last-child{margin-bottom:0;}

/* ---------- interview problem ---------- */
.exam{margin:60px 0 12px; border:1.6px solid var(--ink); padding:7px; background:var(--panel); position:relative;}
.exam .in{border:.6px solid rgba(233,230,223,.55); padding:28px 26px 22px; min-width:0;}
.exam-kind{
  position:absolute; top:-14px; left:22px; transform:rotate(-2deg); background:var(--paper);
  border:2px solid var(--swift); outline:1px solid var(--swift); outline-offset:2px; color:var(--swift);
  font-family:"Spectral SC"; font-weight:600; font-size:11.5px; letter-spacing:.22em; padding:4px 13px;
}
.exam-no{font-family:"Spectral SC"; font-weight:500; font-size:11.5px; letter-spacing:.26em; color:var(--ink2); text-align:right; margin:0 0 4px;}
.exam h2{margin:0 0 9px; font-size:22px;}
.exam .ask{font-weight:300; font-style:italic; margin:0 0 14px;}
.exam .src{font-size:14.5px; color:var(--ink2); font-weight:300; margin:0 0 6px;}
details.seal{border-top:1px solid var(--rule); margin-top:14px; padding-top:13px;}
details.seal summary{cursor:pointer; list-style:none; font-family:"Spectral SC"; font-weight:500; font-size:12.5px; letter-spacing:.22em; color:var(--swift);}
details.seal summary::-webkit-details-marker{display:none;}
details.seal summary::before{content:"✦ \00a0";}
details.seal[open] summary{margin-bottom:14px;}
details.seal p{font-weight:300;}
.listen{color:var(--ink2);}
.exam button.toggle{margin-top:10px;}

/* ---------- footer nav ---------- */
.daynav{display:flex; justify-content:space-between; gap:14px; margin-top:70px; padding-top:20px; border-top:1px solid var(--rule); flex-wrap:wrap;}
.daynav a{border-bottom:none; max-width:46%;}
.daynav .dir{display:block; font-family:"Spectral SC"; font-weight:500; font-size:11px; letter-spacing:.24em; color:var(--ink2);}
.daynav .next{text-align:right; margin-left:auto;}
.donebar{margin-top:44px; text-align:center;}
.colophon{margin-top:80px; text-align:center; font-style:italic; font-weight:300; color:var(--ink2); font-size:14.5px;}

/* ---------- mobile ---------- */
@media(max-width:700px){
  body{font-size:16px;}
  .sheet{padding:40px 18px 70px;}
  h1{font-size:36px;}
  .dayhead h1{font-size:29px;}
  h2{font-size:21px;}
  .part-head h2{font-size:18px;}
  .glance{grid-template-columns:1fr;}
  .counters{flex-direction:row; flex-wrap:wrap; justify-content:flex-start;}
  .gtable .k{width:104px;}
  .day{grid-template-columns:1fr; gap:6px;}
  .day .when .date, .day .when .dn{display:inline;}
  .day .when .dn::before{content:" · ";}
  .day .act{flex-direction:row; align-items:center; justify-content:flex-start; min-width:0; margin-top:4px;}
  .pile{grid-template-columns:1fr;}
  .exam .in{padding:24px 14px 16px;}
  .exam-kind{left:12px;}
  pre.code{font-size:12px; padding:12px;}
  pre.console-out{font-size:12px; padding:11px 12px;}
  ol.ui > li{padding-left:34px;}
  ol.ui > li::before{width:23px; height:23px; line-height:21px; font-size:12.5px;}
  .intro{padding:16px;}
  .daynav a{max-width:100%;}
}