:root{color-scheme:light;--paper:#f6f7f3;--white:#fff;--ink:#17373c;--muted:#4b6266;--line:#cadad6;--accent:#126960}
*{box-sizing:border-box}
html{scroll-padding-top:1.25rem;scrollbar-gutter:stable}
body{margin:0;background:var(--paper);color:var(--ink);font:1rem/1.65 "Instrument Sans",system-ui,"Microsoft JhengHei",sans-serif}
a{color:var(--accent);text-underline-offset:.2em}
:focus-visible{outline:3px solid #a14f2c;outline-offset:3px}
.wrap{width:min(1140px,calc(100% - 2rem));margin-inline:auto}
header,footer{background:var(--white);border-block:1px solid var(--line)}
.bar{padding-block:.85rem;display:flex;gap:.5rem 1.5rem;flex-wrap:wrap;justify-content:space-between;font-size:.93rem}
.hero{padding:clamp(1.05rem,2.5vw,1.65rem) 0 .8rem}
.eyebrow{letter-spacing:.15em;font-weight:700;text-transform:uppercase;font-size:.79rem;color:var(--accent)}
h1,h2,h3{line-height:1.23;margin:.15em 0 .6em}
h1{font-size:clamp(1.8rem,1.55rem + 1.1vw,2.35rem);font-weight:700;letter-spacing:.01em}
h2{font-size:clamp(1.35rem,1.2rem + .55vw,1.65rem);font-weight:700}
h3{font-size:1.14rem}
p{margin:.5rem 0 1rem}
.hero>p:not(.eyebrow){max-width:48rem;margin:.5rem 0;font-size:1rem;color:var(--muted)}
nav,.tab-row,.actions{display:flex;flex-wrap:wrap;gap:.5rem}
nav a,button,.download-link{border:1px solid var(--line);border-radius:.35rem;background:white;color:var(--ink);text-decoration:none;font:inherit;font-weight:650;padding:.5rem .8rem}
button{cursor:pointer}
button[aria-pressed=true],.download-link{background:var(--accent);color:white;border-color:var(--accent)}
nav a:hover,button:hover,.download-link:hover{border-color:var(--accent)}
section{padding:2.35rem 0;border-bottom:1px solid var(--line)}
.principles,.download-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.8rem}
.panel,.principles article,.download-grid article{background:white;border:1px solid var(--line);border-radius:.65rem;padding:1.15rem;min-width:0}
.principles article p,.panel p:last-child{margin-bottom:0}
details{padding:.8rem 0;border-bottom:1px solid var(--line)}
summary{cursor:pointer;font-weight:700}
.math{overflow:auto;white-space:nowrap;background:#e8f2ee;padding:.8rem;font-family:Georgia,serif}
.tab-row{margin-bottom:1.2rem}
.note{padding:.65rem .85rem;border-left:3px solid #9b592e;background:#fcf2e6}
.metrics{display:flex;gap:.65rem 1.5rem;flex-wrap:wrap;margin-block:.8rem}
.metrics dt{color:var(--muted);font-size:.85rem}
.metrics dd{margin:0;font-weight:700;font-variant-numeric:tabular-nums}
.lab{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.55fr);gap:.85rem;margin-top:1rem}
form{display:grid;gap:.5rem;margin:1rem 0}
form label{display:flex;gap:.5rem;align-items:center;justify-content:space-between;font-weight:600}
select{font:inherit;color:inherit;background:white;border:1px solid #9ab6ae;border-radius:.35rem;padding:.28rem .5rem}
.posterior-row{margin:.8rem 0}
.posterior-row>div:first-child{display:flex;justify-content:space-between;gap:.5rem}
.track{height:.65rem;background:#e8efec;border-radius:1rem;overflow:hidden}
.track span{display:block;height:100%;width:var(--value);background:var(--ink)}
.profile{margin-top:.85rem}
.table{overflow:auto;margin:.65rem 0}
table{border-collapse:collapse;width:100%;white-space:nowrap;font-variant-numeric:tabular-nums}
th,td{padding:.4rem .6rem;border-bottom:1px solid var(--line);text-align:right}
th:first-child{text-align:left}
thead th{background:#edf4f1}
.best{background:#d8ede2;font-weight:800}
.mini{position:relative;isolation:isolate;min-width:3.4rem;padding:.05rem .22rem}
.mini span{position:absolute;left:0;top:0;bottom:0;z-index:-1;width:var(--value);background:var(--ink);opacity:.16}
#references li{margin:.65rem 0}
footer .wrap{padding-block:1.5rem}
@media(max-width:720px){.principles,.download-grid,.lab{grid-template-columns:1fr}}

.derivation{margin-block:1.35rem}
.derivation .math,details .math{margin-block:.55rem;border-left:3px solid #94bfb2}
.syntax-layout{display:grid;grid-template-columns:minmax(0,1fr);align-items:start;gap:1rem;margin-top:1rem}
.syntax-settings:not([open]){justify-self:start;padding:.6rem .95rem}
.syntax-settings label{display:block;font-weight:650;margin:.8rem 0 .25rem}
.syntax-settings select{display:block;width:100%;min-width:0}
.syntax-settings p{margin:.8rem 0 0}
.syntax-note{font-size:.9rem;color:#793c21}
.code-stack{min-width:0}
.code-panel + .code-panel{margin-top:.85rem}
.code-panel label{display:block;margin:.7rem 0 .25rem;font-weight:650}
.code-panel textarea{display:block;width:100%;min-height:12rem;resize:vertical;border:1px solid var(--line);border-radius:.35rem;background:#f8fbfa;color:var(--ink);padding:.75rem;font: .89rem/1.6 ui-monospace,Consolas,monospace}
.run-command{overflow-wrap:anywhere;margin:.65rem 0}
.run-command code{background:#e8f2ee;padding:.12rem .28rem}
#syntax-status:empty{display:none}
button:disabled{opacity:.55;cursor:default}

.profile-charts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 13rem), 1fr));
  gap: .65rem;
  margin-block: .8rem;
}
.profile-charts:has(> .profile-chart:nth-child(5)) {
  grid-template-columns: repeat(5, minmax(10.5rem, 1fr));
  overflow-x: auto;
}
.profile-chart {
  margin: 0;
  max-width: 23rem;
  padding: .55rem;
  border: 1px solid var(--line);
  border-radius: .35rem;
}
.profile-chart figcaption {
  font-weight: 650;
  text-align: center;
}
.profile-chart svg {
  display: block;
  width: 100%;
  fill: currentColor;
  font-size: 13px;
}

nav[aria-label="課程單元"] {
  padding-block: .8rem;
  border-bottom: 1px solid var(--line);
}
nav[aria-label="課程單元"] a[aria-current="location"] {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.model-overview {
  display: grid;
  grid-template-columns: minmax(15rem, 2fr) minmax(0, 3fr);
  align-items: center;
  gap: clamp(1rem, 4vw, 3rem);
  padding: clamp(1rem, 4vw, 2.25rem);
  margin-block: 1.25rem;
}
.model-overview figure { margin: 0; text-align: center; }
.model-overview img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto .65rem;
}
.model-overview figcaption { color: var(--muted); }
.lesson-notes { margin: .75rem 0; }
.lesson-notes dt { font-weight: 700; color: var(--accent); }
.lesson-notes dd { margin: 0 0 .85rem; }
.lesson-notes dd:last-child { margin-bottom: 0; }
@media (max-width: 680px) {
  .model-overview { grid-template-columns: 1fr; }
}

.software-comparison { display: grid; gap: 1rem; align-items: start; }
.software-comparison > * { min-width: 0; }
.software-results { padding: .7rem .85rem; border: 1px solid var(--line); border-radius: .35rem; }
.software-results h4 { margin: 0; }
.software-results p { font-size: .9rem; margin: .45rem 0; }
.software-results pre {
  overflow: auto;
  max-height: 27rem;
  margin: .7rem 0;
  padding: .6rem;
  background: var(--paper);
  font: .83rem/1.6 ui-monospace, Consolas, monospace;
}
@media (min-width: 800px) {
  .software-comparison { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

.syntax-selectors {
  display: flex;
  flex-wrap: wrap;
  gap: 0 1rem;
}
.syntax-selectors > :first-child { min-width: min(100%, 15rem); }
.threshold-legend {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1.2rem;
  margin: 0 0 .9rem;
  padding: 0;
  list-style: none;
}
.threshold-legend li { display: flex; align-items: center; gap: .5rem; }
.threshold-legend span { width: 2rem; border-top: 3px solid #126960; }
.threshold-legend li + li span { border-top: 3px dashed #a14f2c; }

nav[aria-label="課程單元"],
.lesson-links {
  gap: .25rem;
  padding: 0;
  border-bottom: 1px solid var(--line);
}
nav[aria-label="課程單元"] a,
.lesson-links a {
  margin-bottom: -1px;
  padding: .65rem clamp(.6rem, 1.5vw, 1.05rem);
  background: transparent;
  border: 1px solid transparent;
  border-top: 3px solid transparent;
  border-radius: .45rem .45rem 0 0;
  white-space: nowrap;
}
nav[aria-label="課程單元"] a[aria-current="location"],
.lesson-links a[aria-current="location"] {
  background: var(--white);
  border-color: var(--line);
  border-top-color: var(--accent);
  border-bottom-color: var(--white);
  color: var(--accent);
}
.lesson-frame {
  padding: clamp(.75rem, 2.6vw, 1.8rem);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: .7rem;
}
.lesson-panel {
  padding: clamp(1rem, 2.5vw, 1.65rem) 0 0;
  border: 0;
}

.lesson-panel > .model-overview { background: var(--paper); }
@media (max-width: 620px) {
  nav[aria-label="課程單元"], .lesson-links {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding: .2rem .2rem 0;
  }
  nav[aria-label="課程單元"] a, .lesson-links a { margin-bottom: 0; }
}

.fit-topic {
  padding: 1.2rem 0;
  border: 0;
  border-top: 1px solid var(--line);
}
.fit-topic h4 { margin: 0 0 .55rem; font-size: 1.12rem; }
.fit-equation {
  margin: .55rem 0;
  border-left: 3px solid var(--accent);
  white-space: normal;
  overflow-wrap: anywhere;
}
.fit-index { margin: .5rem 0 1.35rem; }
.fit-index caption { padding: .5rem 0; text-align: left; font-weight: 650; }
.fit-index th, .fit-index td { text-align: left; }

.assignment-lead { max-width: 65ch; font-size: 1.05rem; }
.assignment-cards {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  margin: 1.2rem 0;
}
.assignment-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: .55rem;
  padding: clamp(.85rem, 2.4vw, 1.3rem);
}
.assignment-card h4, .assignment-step h4 { margin: 0 0 .55rem; font-size: 1.12rem; }
.assignment-card p { margin: .55rem 0; }
.assignment-weights {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: .4rem;
  margin: .8rem 0;
  font-variant-numeric: tabular-nums;
  text-align: center;
}
.assignment-weights span {
  padding: .32rem .2rem;
  border: 1px solid var(--line);
  border-radius: .3rem;
  background: var(--white);
}
.assignment-weights span:nth-child(2) {
  background: var(--accent);
  color: white;
  font-weight: 700;
}
.assignment-step { border-top: 1px solid var(--line); padding-top: 1rem; margin-top: 1rem; }
.assignment-table table { max-width: 38rem; }
@media (max-width: 620px) {
  .assignment-cards { grid-template-columns: minmax(0, 1fr); }
}

.tcs-background { margin-block: 1rem; }
.tcs-background h4 { margin: 1.1rem 0 .35rem; }
.tcs-background p { margin-block: .45rem .8rem; }
.tcs-background ol { padding-left: 1.45rem; }
.tcs-background li + li { margin-top: .55rem; }
.tcs-indicators caption { text-align: left; font-weight: 650; margin-bottom: .4rem; }
.tcs-indicators th, .tcs-indicators td { white-space: normal; }
.tcs-indicators th:nth-child(2), .tcs-indicators td:nth-child(2) { text-align: left; }

.hero > h1 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: .28rem .7rem;
  margin: 0;
}
.course-title-en {
  color: var(--muted);
  font-size: clamp(1rem, .85rem + .6vw, 1.45rem);
  font-weight: 500;
  letter-spacing: 0;
}
.history-timeline {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
}
.history-timeline li {
  display: grid;
  grid-template-columns: 7.5rem minmax(0, 1fr);
  gap: .35rem 1.3rem;
  padding: 1rem 0;
  border-top: 1px solid var(--line);
}
.history-years { color: var(--accent); font-weight: 700; font-variant-numeric: tabular-nums; }
.history-timeline h3 { margin: 0 0 .35rem; font-size: 1.15rem; }
.history-timeline p { margin: 0; max-width: 72ch; }
@media (max-width: 600px) {
  .history-timeline li { grid-template-columns: minmax(0, 1fr); }
}

nav[aria-label="課程單元"] a:not([aria-current]),
.lesson-links a:not([aria-current]) { color: var(--muted); }
.lesson-links a { font-size: .94rem; font-weight: 600; }
.lesson-links a[aria-current] { font-weight: 600; }
main > section:not(#principles) {
  padding: clamp(.75rem, 2.6vw, 1.8rem);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: .7rem;
}
main > section { margin-block: clamp(.8rem, 2vw, 1.4rem) 1.4rem; }
#principles { padding: 0; border: 0; }

.history-portraits {
  display: flex;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: .55rem;
  grid-column: 2;
}
.history-portraits a {
  display: grid;
  gap: .25rem;
  justify-items: center;
  width: 6.75rem;
  padding: .35rem;
  border: 1px solid var(--line);
  border-radius: .45rem;
  background: var(--paper);
  text-align: center;
  font-size: .8rem;
}
.history-portraits img {
  display: block;
  width: 72px;
  height: 88px;
  object-fit: cover;
  object-position: center top;
  border-radius: .25rem;
}
@media (min-width: 850px) {
  .history-timeline li:has(.history-portraits) {
    grid-template-columns: 7.5rem minmax(0, 1fr) auto;
  }
  .history-portraits { grid-column: 3; }
}
@media (max-width: 600px) {
  .history-portraits { grid-column: 1; }
}

.history-timeline {
  --timeline-line: #bfd7ce;
  position: relative;
}
.history-timeline > li {
  position: relative;
  padding-block: 1.2rem 1.4rem;
}
.history-years {
  position: relative;
  justify-self: start;
  align-self: start;
  display: inline-flex;
  margin-left: 1.1rem;
  padding: .15rem .48rem;
  border-radius: .35rem;
  background: var(--paper);
  font-size: .88rem;
}
.history-years::before {
  content: '';
  position: absolute;
  top: .6rem;
  left: -1.1rem;
  width: .58rem;
  height: .58rem;
  border: 2px solid var(--accent);
  border-radius: 50%;
  background: var(--white);
}
.history-timeline > li::before {
  content: '';
  position: absolute;
  left: .34rem;
  top: 0;
  bottom: 0;
  border-left: 2px solid var(--timeline-line);
}
.history-timeline > li:first-child::before { top: 1.8rem; }
.history-timeline > li:last-child::before { bottom: auto; height: 1.8rem; }
.history-milestones {
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  gap: .45rem .65rem;
  margin: .8rem 0 0;
  padding: .75rem .8rem;
  background: var(--paper);
  border-radius: .45rem;
}
.history-milestones dt { color: var(--accent); font-weight: 700; }
.history-milestones dd { grid-column: 2; margin: 0; }
@media (max-width: 600px) {
  .history-timeline > li { padding-left: 1.1rem; }
  .history-years { margin-left: 0; }
}

.research-checklist { padding: 0; list-style: none; }
.research-checklist > li { border-top: 1px solid var(--line); padding: .9rem 0; }
.research-checklist h3 { margin: 0 0 .45rem; }
.research-checklist label { display: flex; align-items: baseline; gap: .45rem; cursor: pointer; }
.research-checklist input { accent-color: var(--accent); flex: none; }
.research-checklist p { margin: .3rem 0 0; max-width: 78ch; }
.checklist-status { display: inline-block; border-radius: .25rem; padding-inline: .35rem; background: #e5eff7; color: #205577; font-size: .88em; }
.checklist-status[data-status="已具備"] { background: #e3f2e8; color: #235b39; }
.checklist-status[data-status="待補強"] { background: #faeee2; color: #833d25; }

.research-checklist > li {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: .7rem 1.25rem;
  align-items: start;
}
.checklist-example {
  padding: .6rem .8rem;
  border-left: 2px solid var(--line);
  background: var(--paper);
}
.checklist-example p { margin: 0; }
@media (max-width: 620px) {
  .research-checklist > li { grid-template-columns: minmax(0, 1fr); }
}