/* Photography 101 design system
   Shared by every lesson: tokens, type, header, footer and common components.
   Page-specific styles live in their own file (see `pageCss` in each page). */

/* Tokens */
:root{
  --paper:#ECEEEA;--paper-2:#E1E4DF;--ink:#1B1E21;--muted:#5B6268;--rule:#C6CBC5;
  --body:#26292D;--body-2:#1D2023;--amber:#F5A623;--amber-dim:#8C6A2E;--lcd:#E9E4D6;
  /* Colours used inside dark instrument panels */
  --on-body:#E7E9E4;--on-body-muted:#A7ADB2;--on-body-rule:#ffffff1f;
  --sharp:#7FD6BC;--hyper:#B9A2F5;
  --sans:"Archivo",system-ui,sans-serif;--serif:"Source Serif 4",Georgia,serif;
  --header-h:60px;
}
@media (prefers-color-scheme:dark){
  :root{--paper:#16181B;--paper-2:#1E2125;--ink:#E7E9E4;--muted:#9AA1A6;--rule:#33383D;--body:#0E1012;--body-2:#08090A}
}
body.has-subnav{--header-h:104px}

/* Base */
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:no-preference){html{scroll-behavior:smooth}}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--serif);font-size:18px;line-height:1.6}
.wrap{max-width:1180px;margin:0 auto;padding:0 24px}
:focus-visible{outline:2px solid var(--amber);outline-offset:3px}
[id]{scroll-margin-top:calc(var(--header-h) + 16px)}
main h2{font-family:var(--sans);font-stretch:75%;font-weight:800;font-size:40px;line-height:1.05;margin:0 0 18px}
main h3{font-family:var(--sans);font-size:20px;font-weight:700;margin:0 0 10px}

/* Header */
.site-header{position:sticky;top:0;z-index:30;background:var(--paper);border-bottom:1px solid var(--rule)}
@supports (backdrop-filter:blur(1px)){.site-header{background:color-mix(in srgb,var(--paper) 86%,transparent);backdrop-filter:blur(12px)}}
.nav-in{display:flex;align-items:center;gap:16px;height:60px}
.brand{display:flex;align-items:center;gap:10px;flex:none;white-space:nowrap;font-family:var(--sans);font-weight:800;font-stretch:80%;font-size:20px;color:var(--ink);text-decoration:none}
.brand svg{width:26px;height:26px;flex:none}
.crumb{display:flex;gap:8px;min-width:0;margin:0 auto 0 4px;font-family:var(--sans);font-size:14px;font-weight:600;color:var(--muted);white-space:nowrap;overflow:hidden}
.crumb span:first-child{overflow:hidden;text-overflow:ellipsis}
.crumb span:last-child{color:var(--ink)}
.brand+.toc-btn{margin-left:auto}
/* Tools: a second destination beside the contents */
.tools-link{display:flex;align-items:center;gap:7px;flex:none;height:40px;padding:0 14px 0 11px;border-radius:999px;color:var(--ink);font-family:var(--sans);font-size:15px;font-weight:700;text-decoration:none}
.tools-link:hover{background:var(--paper-2)}
.tools-link[aria-current="page"]{background:var(--paper-2)}
.tools-link i{font-size:16px;color:var(--amber)}
.brand+.tools-link{margin-left:auto}
.toc-btn{display:flex;align-items:center;gap:8px;flex:none;height:40px;padding:0 16px 0 12px;border:1.5px solid var(--rule);border-radius:999px;background:transparent;color:var(--ink);font-family:var(--sans);font-size:15px;font-weight:700;cursor:pointer}
.toc-btn:hover{border-color:var(--ink)}
.toc-btn i{font-size:17px}
.subnav{border-top:1px solid var(--rule)}
.subnav-links{display:flex;gap:4px;height:44px;align-items:center;list-style:none;margin:0 auto;overflow-x:auto;scrollbar-width:none}
.subnav-links a{display:block;padding:5px 12px;border-radius:999px;font-family:var(--sans);font-size:14px;font-weight:600;color:var(--muted);text-decoration:none;white-space:nowrap}
.subnav-links li:first-child a{margin-left:-12px}
.subnav-links a:hover{color:var(--ink)}
.subnav-links a[aria-current="true"]{color:var(--ink);background:var(--paper-2)}

/* Contents drawer: slides in from the right, full screen on phones */
.toc{position:fixed;inset:0 0 0 auto;width:min(440px,100vw);max-width:none;height:100dvh;max-height:none;margin:0;padding:0 0 32px;border:0;border-left:1px solid var(--rule);background:var(--paper);color:var(--ink);overflow-y:auto;overscroll-behavior:contain}
.toc::backdrop{background:#0008}
.toc[open]{animation:toc-in .18s ease-out}
@keyframes toc-in{from{transform:translateX(24px);opacity:0}}
.toc-head{position:sticky;top:0;z-index:1;display:flex;justify-content:space-between;align-items:center;height:60px;padding:0 12px 0 24px;background:var(--paper);border-bottom:1px solid var(--rule)}
.toc-head h2{margin:0;font-family:var(--sans);font-size:17px;font-weight:800}
.toc-close{display:grid;place-items:center;width:44px;height:44px;border:0;border-radius:10px;background:transparent;color:var(--ink);cursor:pointer}
.toc-close i{font-size:20px}
.toc-search{position:relative;margin:16px 24px 4px}
.toc-search i{position:absolute;left:16px;top:50%;font-size:16px;transform:translateY(-50%);color:var(--muted)}
.toc-search input{width:100%;height:46px;padding:0 14px 0 44px;border:1.5px solid var(--rule);border-radius:12px;background:var(--paper-2);color:var(--ink);font:500 16px var(--sans)}
.toc-search input:focus{outline:none;border-color:var(--ink)}
.toc-empty{margin:16px 24px;font-family:var(--sans);font-size:15px;color:var(--muted)}
.toc-part{padding:20px 24px 0}
.toc-part[hidden]{display:none}
.toc-part h3 a{color:inherit;text-decoration:none}
.toc-part h3 i{color:var(--amber);margin-right:2px}
.toc-icon{display:grid;justify-items:center;padding-top:2px;font-size:18px}
.toc-part h3{margin:0 0 6px;font-family:var(--sans);font-size:13px;font-weight:700;color:var(--muted)}
.toc-part ol,.toc-topics{list-style:none;margin:0;padding:0}
.toc-ch>a{display:flex;gap:14px;padding:10px 10px;margin:0 -10px;border-radius:10px;color:var(--ink);text-decoration:none}
.toc-ch>a:hover{background:var(--paper-2)}
.toc-ch>a[aria-current="page"]{background:var(--paper-2)}
.toc-num{flex:none;width:28px;font-family:var(--sans);font-stretch:75%;font-weight:800;font-size:26px;line-height:1;color:var(--amber);font-variant-numeric:tabular-nums}
.toc-title{font-family:var(--sans);font-size:16px;font-weight:700;line-height:1.3}
.toc-title small{display:block;margin-top:3px;font-size:14px;font-weight:500;color:var(--muted)}
.toc-topics{display:none;margin:0 0 6px 42px;border-left:1.5px solid var(--rule)}
.toc-ch.is-current .toc-topics,.toc.searching .toc-topics{display:block}
.toc-topics a{display:block;padding:6px 12px;font-family:var(--sans);font-size:14px;font-weight:600;color:var(--muted);text-decoration:none}
.toc-topics a:hover{color:var(--ink)}
.toc-ch[hidden],.toc-topics li[hidden]{display:none}

/* Hero */
.hero{padding:48px 0 32px}
.course{font-family:var(--sans);font-size:15px;font-weight:600;color:var(--muted);margin:0 0 10px}
h1{font-family:var(--sans);font-stretch:68%;font-weight:800;font-size:clamp(48px,8.5vw,104px);line-height:.9;letter-spacing:-.02em;margin:0 0 20px}
.lead{max-width:46em;margin:0;color:var(--muted);font-size:19px}

/* Page sections separated by a heavy rule */
.section{border-top:2px solid var(--ink);padding:48px 0 80px}
.section-intro{max-width:52em;margin:0 0 32px}

/* Dark instrument panel: viewfinders, diagrams, dials */
.instrument{background:var(--body);color:var(--on-body);border-radius:22px;padding:14px;box-shadow:inset 0 1px 0 #ffffff14,0 24px 48px -28px #000a}
.instrument svg text{font-family:var(--sans)}

/* Controls: label + live value, then a slider */
.control{padding:20px 0 16px;border-bottom:1px solid var(--rule)}
.control-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;font-family:var(--sans)}
.control-head label,.control-head .label{font-size:17px;font-weight:700}
.control-head output{font-size:28px;font-weight:800;font-stretch:75%;font-variant-numeric:tabular-nums;margin-left:8px}
.control-head .delta{font-size:15px;font-weight:600;color:var(--muted);font-variant-numeric:tabular-nums}
.hint{margin:4px 0 0;font-family:var(--sans);font-size:13px;line-height:1.5;color:var(--muted)}

input[type=range]{display:block;width:100%;margin:6px 0 0;height:28px;background:transparent;-webkit-appearance:none;appearance:none;cursor:pointer}
input[type=range]::-webkit-slider-runnable-track{height:3px;background:var(--ink);border-radius:2px}
input[type=range]::-moz-range-track{height:3px;background:var(--ink);border-radius:2px}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:24px;height:24px;margin-top:-10.5px;border-radius:50%;background:var(--ink);border:4px solid var(--paper);box-shadow:0 0 0 1.5px var(--ink)}
input[type=range]::-moz-range-thumb{width:16px;height:16px;border-radius:50%;background:var(--ink);border:4px solid var(--paper);box-shadow:0 0 0 1.5px var(--ink)}
input[type=range]:focus-visible{outline:none}
input[type=range]:focus-visible::-webkit-slider-thumb{box-shadow:0 0 0 1.5px var(--ink),0 0 0 5px var(--amber)}
input[type=range]:focus-visible::-moz-range-thumb{box-shadow:0 0 0 1.5px var(--ink),0 0 0 5px var(--amber)}

/* Buttons */
.btn{font-family:var(--sans);font-size:16px;font-weight:700;color:var(--paper);background:var(--ink);border:0;border-radius:999px;padding:12px 22px;cursor:pointer}
.btn:hover{background:var(--muted)}
.chip{font-family:var(--sans);font-size:15px;font-weight:600;color:var(--ink);background:transparent;border:1.5px solid var(--rule);border-radius:999px;padding:8px 14px;cursor:pointer}
.chip:hover{border-color:var(--ink)}
.chip[aria-pressed="true"]{border-color:var(--ink);background:var(--ink);color:var(--paper)}

/* Segmented control: a row of pressable options, one on at a time */
.segmented{display:grid;grid-auto-flow:column;grid-auto-columns:minmax(0,1fr);gap:4px;padding:4px;background:var(--paper-2);border-radius:999px}
.segmented button{font:700 15px var(--sans);color:var(--muted);background:transparent;border:0;border-radius:999px;padding:9px 4px;cursor:pointer;white-space:nowrap}
.segmented button:hover{color:var(--ink)}
.segmented button[aria-pressed="true"]{color:var(--paper);background:var(--ink)}
.control .segmented{margin-top:10px}
@media (max-width:560px){.segmented button{font-size:14px}}

/* Readouts: a row of labelled values split by rules */
.readouts{display:grid;grid-template-columns:repeat(var(--cols,3),minmax(0,1fr));margin:18px 0 0;border-top:1px solid var(--rule)}
.readouts>div{padding:12px 14px 0 0}
.readouts>div+div{padding-left:14px;border-left:1px solid var(--rule)}
.readouts dt{font-family:var(--sans);font-size:13px;font-weight:600;color:var(--muted)}
.readouts dd{margin:2px 0 0;font-family:var(--sans);font-size:18px;font-weight:700;font-stretch:90%;line-height:1.3;font-variant-numeric:tabular-nums}

/* Text helpers */
.note{margin:14px 0 0;font-family:var(--sans);font-size:13px;line-height:1.5;color:var(--muted);max-width:52em}
.ratio{font-family:var(--sans);font-weight:700;white-space:nowrap;font-variant-numeric:tabular-nums}
.eq{font-family:var(--serif);font-size:24px;padding:4px 0 4px 16px;border-left:3px solid var(--amber);font-variant-numeric:lining-nums}
.eq var{font-style:italic}
.eq var+sup{margin-left:2px}
.steps{counter-reset:step;list-style:none;padding:0;margin:0 0 20px}
.steps li{counter-increment:step;position:relative;padding:0 0 16px 48px}
.steps li::before{content:counter(step);position:absolute;left:0;top:-2px;width:32px;height:32px;border-radius:50%;border:1.5px solid var(--ink);display:grid;place-items:center;font-family:var(--sans);font-weight:700;font-size:15px}

/* Lab: sliders on top, then several live views of the same settings.
   Large screens show every view at once; phones pick one view with tabs,
   kept in view above the sliders. Pages place their own views on the grid. */
.lab{display:grid;gap:16px;padding-bottom:64px}
.lab-head{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px 24px}
.lab-title{margin:0}
.lab-controls{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0 28px;border-top:1px solid var(--rule)}
.lab-controls .control{border-bottom:0;padding:14px 0 0}
.lab-controls output{font-size:24px}
.chip-row{display:flex;flex-wrap:wrap;gap:8px}
.lab-views{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:16px}
.view-tabs{display:none}
.view{display:flex;flex-direction:column;gap:10px;padding:14px 16px 16px;min-width:0;grid-column:span 6}
.view-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px;font-family:var(--sans)}
.view-head h3{margin:0;font-size:16px;font-weight:700;color:var(--on-body)}
.view-head p{margin:0;font-size:14px;font-weight:600;color:var(--on-body-muted);text-align:right;font-variant-numeric:tabular-nums}
.view-head strong{font-size:18px;font-weight:800;font-stretch:85%;color:var(--amber);margin-left:4px}
.view-foot{margin:auto 0 0;font-family:var(--sans);font-size:13px;line-height:1.45;color:var(--on-body-muted)}
.view-stats{display:grid;grid-template-columns:repeat(var(--cols,3),minmax(0,1fr));margin:auto 0 0;border-top:1px solid var(--on-body-rule);font-family:var(--sans)}
.view-stats>div{padding:10px 12px 0 0}
.view-stats>div+div{padding-left:12px;border-left:1px solid var(--on-body-rule)}
.view-stats dt{font-size:12px;font-weight:600;color:var(--on-body-muted)}
.view-stats dd{margin:2px 0 0;font-size:17px;font-weight:700;font-stretch:90%;color:var(--on-body);font-variant-numeric:tabular-nums}
.diagram{display:block;width:100%;height:auto}
.text-link{color:inherit;text-decoration-color:var(--amber);text-underline-offset:3px}
@media (max-width:1023px){
  .lab-controls{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:760px){
  .lab{gap:12px}
  .lab-head{display:contents}
  .lab-title{order:0}
  .lab-views{display:block;order:1}
  .lab-controls{order:2;grid-template-columns:1fr}
  .chip-row{order:3}
  .lab-controls .control{border-bottom:1px solid var(--rule);padding:16px 0 14px}
  .view-tabs{display:grid;grid-auto-flow:column;grid-auto-columns:minmax(0,1fr);gap:4px;padding:4px;margin-bottom:8px;background:var(--paper-2);border-radius:999px}
  .view-tabs button{font:600 14px var(--sans);color:var(--muted);background:transparent;border:0;border-radius:999px;padding:9px 4px;cursor:pointer;white-space:nowrap}
  .view-tabs button[aria-selected="true"]{color:var(--paper);background:var(--ink)}
  .view[hidden]{display:none}
  .view-head{flex-wrap:wrap;row-gap:2px}
  .view-head h3{font-size:15px}
  .view-head p{text-align:left}
}
@media (max-width:760px) and (min-height:620px){
  .lab-views{position:sticky;top:calc(var(--header-h) + 8px);z-index:10;background:var(--paper);box-shadow:0 0 0 8px var(--paper),0 18px 24px -18px #0009}
}
@media (max-width:380px){
  .view-tabs button{font-size:13px}
  .view-stats dd{font-size:15px}
}

/* Two columns of text under a section intro */
.cols{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:40px 56px;align-items:start;margin-top:40px}
.cols p{margin:0 0 14px;max-width:34em}
.cols h3:not(:first-child){margin-top:24px}
/* Label and value rows */
.rules{margin:0}
.rules div{display:flex;justify-content:space-between;gap:16px;padding:10px 0;border-bottom:1px solid var(--rule);font-family:var(--sans);font-size:16px}
.rules dt{font-weight:600}
.rules dd{margin:0;font-weight:800;white-space:nowrap;font-variant-numeric:tabular-nums}
@media (max-width:900px){.cols{grid-template-columns:1fr;gap:32px}}

/* Bullet tips, and a boxed "common mistake" note */
.tips{margin:0;padding:0 0 0 20px}
.tips li{margin:0 0 12px}
.myth{padding:18px 20px;border:1.5px solid var(--ink);border-radius:16px}
.myth p{margin:0 0 12px}
.myth-def{margin:0!important;padding-left:14px;border-left:3px solid var(--amber);font-family:var(--sans);font-weight:700}

/* Two-view lab: two live views side by side, then the controls beside their results */
.duo-lab{display:grid;gap:24px;padding-bottom:64px}
.duo-views{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.duo-views .view{grid-column:auto;display:flex;flex-direction:column;gap:10px;padding:14px 16px 16px}
.duo-side{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:24px 48px;align-items:start}
.duo-controls .control:first-child{padding-top:0}
.duo-out .readouts{margin-top:0}
@media (max-width:900px){.duo-side{grid-template-columns:1fr}}
/* Phones: first view, then the controls, then the second view, so the sliders sit next to a view */
@media (max-width:760px){
  .duo-views{display:contents}
  .duo-views>:first-child{order:1}
  .duo-side{order:2}
  .duo-views>:nth-child(2){order:3}
  .duo-lab>:not(.duo-views,.duo-side){order:4}
}

/* A part's cheat sheet and quiz: one section per chapter, headed by a link back to it */
.cheat h2 a,.quiz-chapter a{color:inherit;text-decoration:none}
.cheat h2 a:hover,.quiz-chapter a:hover{text-decoration:underline;text-decoration-color:var(--amber);text-underline-offset:4px}
.cheat h2 small,.quiz-chapter small{display:block;margin-bottom:6px;font-size:15px;font-weight:600;font-stretch:100%;color:var(--muted)}
.cheat{padding-bottom:56px}
.cheat-cols{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:40px 56px;align-items:start;margin-top:28px}
.cheat h4{margin:22px 0 2px;font-family:var(--sans);font-size:14px;font-weight:700;color:var(--muted)}
.cheat h3+h4{margin-top:0}
.formulas{margin:0;display:grid;gap:12px}
.formulas>div{padding:14px 16px 14px 18px;border-left:3px solid var(--amber);background:var(--paper-2);border-radius:0 12px 12px 0}
.formulas dt{font-family:var(--sans);font-size:14px;font-weight:700;color:var(--muted)}
.formula{margin:4px 0 0;font-family:var(--serif);font-size:21px;line-height:1.35;font-variant-numeric:lining-nums}
.formula var{font-style:italic}
.formula-ex{margin:4px 0 0;font-family:var(--sans);font-size:14px;line-height:1.45;color:var(--muted)}
.cheat-rules dt{font-weight:600}
.cheat-rules dd{white-space:normal;text-align:right}
@media (max-width:900px){.cheat-cols{grid-template-columns:1fr;gap:32px}}

/* Cheat sheet and quiz rows at the end of each part, in the contents and on the home page */
.toc-extra .toc-title{font-weight:600}
.chapter-extra{border-style:dashed}
.tool-card-icon{font-size:30px;color:var(--amber);margin-bottom:6px}
.course-icon{margin-right:8px;color:var(--amber)}
.chapter-extra .chapter-title{margin-top:0}

/* Quiz: pick an option, see right or wrong and why. Questions are numbered through the whole part */
[data-quiz]{counter-reset:quiz}
.quiz-chapter{margin-bottom:28px}
[data-quiz] .section{padding-bottom:48px}
.quiz{list-style:none;margin:0;padding:0;display:grid;gap:32px;max-width:52em}
.quiz-q{counter-increment:quiz;position:relative;padding-left:48px}
.quiz-q::before{content:counter(quiz);position:absolute;left:0;top:0;width:32px;height:32px;border-radius:50%;border:1.5px solid var(--ink);display:grid;place-items:center;font-family:var(--sans);font-weight:700;font-size:15px}
.quiz-q.is-right::before{background:var(--sharp);border-color:var(--sharp);color:var(--body-2)}
.quiz-q.is-wrong::before{background:var(--amber);border-color:var(--amber);color:var(--body-2)}
.quiz-ask{margin:0 0 12px;font-family:var(--sans);font-size:18px;font-weight:700;line-height:1.4}
.quiz-opts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
.quiz-opt{position:relative;padding:12px 16px 12px 40px;border:1.5px solid var(--rule);border-radius:12px;background:transparent;color:var(--ink);font:500 16px/1.4 var(--sans);text-align:left;cursor:pointer}
.quiz-opt::before{content:"";position:absolute;left:14px;top:15px;width:14px;height:14px;border-radius:50%;border:1.5px solid var(--muted)}
.quiz-opt:hover{border-color:var(--ink)}
.quiz-q.answered .quiz-opt{cursor:default}
.quiz-q.answered .quiz-opt:hover{border-color:var(--rule)}
.quiz-q.answered .quiz-opt:not([data-right],[aria-pressed="true"]){opacity:.55}
.quiz-q.answered .quiz-opt[data-right]{border-color:var(--sharp);background:color-mix(in srgb,var(--sharp) 18%,transparent)}
.quiz-q.answered .quiz-opt[data-right]::before{content:"✓";border:0;top:11px;width:auto;height:auto;font-weight:800;color:inherit}
.quiz-opt[aria-pressed="true"]:not([data-right]){border-color:var(--amber);background:color-mix(in srgb,var(--amber) 16%,transparent)}
.quiz-opt[aria-pressed="true"]:not([data-right])::before{content:"✕";border:0;top:11px;width:auto;height:auto;font-weight:800;color:inherit}
.quiz-why{margin:12px 0 0;padding-left:14px;border-left:3px solid var(--rule);font-size:17px}
.quiz-q.is-right .quiz-why{border-color:var(--sharp)}
.quiz-q.is-wrong .quiz-why{border-color:var(--amber)}
.quiz-why strong{font-family:var(--sans)}
.quiz-score{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 24px;max-width:52em;margin:0 0 48px;padding:18px 20px;border:1.5px solid var(--ink);border-radius:16px;font-family:var(--sans)}
.quiz-score p{margin:0;font-size:20px;font-weight:800;font-stretch:85%}
.quiz-left{color:var(--muted);font-weight:600}
@media (max-width:560px){
  .quiz-q{padding-left:40px}
  .quiz-opts{grid-template-columns:1fr}
}

/* "Try it yourself": things to do with a camera, each with what to look for */
.try-list{list-style:none;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin:0;padding:0}
.try-list li{display:grid;gap:4px;padding:16px 18px;border:1.5px solid var(--rule);border-radius:14px}
.try-list strong{font:800 17px var(--sans);color:var(--ink)}
.try-list span{line-height:1.4}
.try-list small{font:600 14px/1.4 var(--sans);color:var(--muted)}
@media (max-width:620px){.try-list{grid-template-columns:1fr}}

/* Tables */
table{width:100%;border-collapse:collapse;margin-top:8px;font-family:var(--sans);font-size:16px;font-variant-numeric:tabular-nums}
th,td{text-align:left;padding:11px 10px 11px 0;border-bottom:1px solid var(--rule);vertical-align:top}
th{font-weight:600;color:var(--muted);font-size:14px}
td:first-child{font-weight:700}

/* Contents page: parts, each with a row of chapter cards */
.contents{padding-bottom:40px}
.tools-index{padding-bottom:64px}
.find{display:flex;align-items:center;gap:12px;width:min(520px,100%);height:52px;margin:0 0 16px;padding:0 12px 0 16px;border:1.5px solid var(--rule);border-radius:14px;background:var(--paper-2);color:var(--muted);font:500 17px var(--sans);text-align:left;cursor:pointer}
.find:hover{border-color:var(--ink)}
.find i{font-size:18px;flex:none}
.find span{flex:1}
.find kbd{padding:2px 9px;border:1.5px solid var(--rule);border-radius:6px;font:700 14px var(--sans)}
.part{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,2.4fr);gap:24px 48px;border-top:2px solid var(--ink);padding:36px 0 48px}
.part-head .course{margin-bottom:6px}
.part-head h2{margin-bottom:10px}
.part-head p{margin:0;color:var(--muted);font-size:17px}
.part-start{display:inline-flex;align-items:center;gap:8px;margin-top:18px;padding:10px 14px;border:1.5px solid var(--ink);border-radius:999px;color:var(--ink);font:700 14px var(--sans);text-decoration:none}
.part-start:hover{background:var(--ink);color:var(--paper)}
.chapters{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px;list-style:none;margin:0;padding:0}
.chapter-card{display:flex;flex-direction:column;border:1.5px solid var(--rule);border-radius:18px;overflow:hidden}
.chapter-card:hover{border-color:var(--ink)}
.chapter-card>a{display:grid;gap:4px;padding:18px 20px 14px;color:var(--ink);text-decoration:none;font-family:var(--sans)}
.chapter-num{font-stretch:70%;font-weight:800;font-size:44px;line-height:1;color:var(--amber);font-variant-numeric:tabular-nums}
.chapter-title{font-size:21px;font-weight:800;font-stretch:85%;line-height:1.2;margin-top:6px}
.chapter-summary{font-size:15px;line-height:1.45;color:var(--muted)}
.topics{display:flex;flex-wrap:wrap;gap:6px;list-style:none;margin:auto 0 0;padding:4px 20px 18px}
.topics a{display:block;padding:4px 10px;border-radius:999px;background:var(--paper-2);font-family:var(--sans);font-size:13px;font-weight:600;color:var(--muted);text-decoration:none}
.topics a:hover{color:var(--ink)}
@media (max-width:900px){
  .part{grid-template-columns:1fr}
}
@media (max-width:560px){
  .part{padding:28px 0 36px}
  .find kbd{display:none}
}

/* Previous and next chapter */
.pager{display:grid;grid-template-columns:1fr 1fr;gap:16px;border-top:2px solid var(--ink);padding:32px 0 56px}
.pager a{display:block;padding:18px 20px;border:1.5px solid var(--rule);border-radius:16px;color:var(--ink);text-decoration:none;font-family:var(--sans);font-size:20px;font-weight:800;font-stretch:85%;line-height:1.2}
.pager a:hover{border-color:var(--ink)}
.pager small{display:block;margin-bottom:4px;font-size:14px;font-weight:600;font-stretch:100%;color:var(--muted)}
.pager-next{grid-column:2;text-align:right}
@media (max-width:560px){
  .pager{grid-template-columns:1fr;gap:10px}
  .pager-next{grid-column:1}
}

/* Footer */
.site-footer{background:var(--body);color:var(--on-body);margin-top:24px}
.site-footer a{color:inherit;text-decoration:none}
.site-footer a:hover{color:var(--amber)}
.foot-in{display:grid;grid-template-columns:minmax(0,1.7fr) minmax(0,1fr) minmax(0,1fr);gap:clamp(32px,6vw,96px);padding-top:56px;padding-bottom:54px}
.foot-eyebrow{display:block;margin-bottom:18px;color:var(--amber);font:700 11px/1.4 var(--sans);letter-spacing:.16em}
.foot-brand .brand{width:max-content;margin-bottom:14px;color:var(--on-body);font-size:25px}
.foot-brand .brand svg{width:30px;height:30px}
.foot-brand p{max-width:34ch;margin:0;color:var(--on-body-muted);font:400 16px/1.55 var(--sans)}
.foot-all{display:inline-flex;align-items:center;gap:10px;margin-top:23px;padding-bottom:4px;border-bottom:1px solid var(--amber);color:var(--on-body);font:700 15px/1.4 var(--sans)}
.foot-all span{color:var(--amber);font-size:20px;line-height:1}
.foot-links h2{margin:2px 0 15px;color:var(--on-body-muted);font:700 12px/1.4 var(--sans);letter-spacing:.12em;text-transform:uppercase}
.foot-links ul{list-style:none;margin:0;padding:0;font:600 15px/1.4 var(--sans)}
.foot-links li+li{margin-top:12px}
.foot-links a{display:inline-flex;align-items:baseline;gap:11px}
.foot-part-num{color:var(--amber);font-size:12px;font-variant-numeric:tabular-nums}
.foot-bar{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding-top:18px;padding-bottom:22px;border-top:1px solid var(--on-body-rule);font:500 13px/1.5 var(--sans);color:var(--on-body-muted)}
.foot-bar>a{white-space:nowrap}

@media (max-width:760px){
  .foot-in{grid-template-columns:repeat(2,minmax(0,1fr));gap:36px 24px;padding-top:44px;padding-bottom:40px}
  .foot-brand{grid-column:1/-1}
}
/* Phones and small tablets: this page's sections move into the contents drawer */
@media (max-width:760px){
  body.has-subnav{--header-h:60px}
  .subnav,.crumb{display:none}
  .brand+.toc-btn{margin-left:auto}
  .crumb+.toc-btn{margin-left:auto}
  .crumb+.tools-link{margin-left:auto}
}
/* Narrow phones: the Tools link keeps only its icon so the bar fits */
@media (max-width:480px){
  .nav-in{gap:8px}
  .tools-link{width:40px;padding:0;justify-content:center}
  .tools-link i{font-size:18px}
  .tools-link span{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
}
/* The smallest phones: Contents keeps only its menu icon too */
@media (max-width:380px){
  .toc-btn{width:40px;padding:0;justify-content:center}
  .toc-btn span{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}
}
@media (max-width:560px){
  .wrap{padding:0 16px}
  .hero{padding:28px 0 20px}
  .lead{font-size:18px}
  main h2{font-size:32px}
  .instrument{padding:10px;border-radius:16px}
  .readouts{grid-template-columns:1fr}
  .readouts>div,.readouts>div+div{padding:10px 0;border-left:0;border-bottom:1px solid var(--rule);display:flex;justify-content:space-between;gap:12px}
  .readouts dd{margin:0;text-align:right}
  .foot-in{padding-top:40px;padding-bottom:36px}
  .foot-bar{padding-top:16px;padding-bottom:24px}
}
@media (max-width:340px){
  .foot-in{grid-template-columns:1fr;gap:30px}
  .foot-brand{grid-column:auto}
}
@media (prefers-reduced-motion:reduce){
  *{transition:none!important;animation:none!important}
}