/* How to RSI — Jev-inspired: warm paper, ink borders, Grotesk display, Mono labels */

:root {
  --canvas: #f3f1ea;
  --surface: #faf9f4;
  --ink: #171717;
  --ink-soft: rgba(23, 23, 23, 0.62);
  --ink-faint: rgba(23, 23, 23, 0.42);
  --divider: rgba(23, 23, 23, 0.10);
  --divider-strong: #171717;
  --acc: #394a66;
  --code-bg: #eceae2;
  --sans: "Inter", -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
          "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --disp: "Space Grotesk", var(--sans);
  --mono: "Space Mono", ui-monospace, "SF Mono", "Cascadia Code", Consolas,
          "Sarasa Mono SC", monospace;
  --measure: 42rem;
}
[data-theme="dark"] {
  --canvas: #000;
  --surface: #1d1d1d;
  --ink: #f8f8f2;
  --ink-soft: rgba(248, 248, 242, 0.62);
  --ink-faint: rgba(248, 248, 242, 0.42);
  --divider: rgba(255, 255, 255, 0.12);
  --divider-strong: #f8f8f2;
  --acc: #7aa2f7;
  --code-bg: #1d1d1d;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: var(--sans);
  background: var(--canvas);
  color: var(--ink);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--ink); color: var(--canvas); }

a { color: var(--ink); text-decoration: underline; text-underline-offset: 3px; }
a:hover { color: var(--acc); }

code {
  font-family: var(--mono); font-size: 0.82em;
  background: var(--code-bg); border-radius: 3px; padding: 0.08em 0.4em;
}

/* ---------- header ---------- */
.site-head {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 12px;
  padding: 0 clamp(20px, 6vw, 72px);
  height: 60px;
  background: var(--canvas);
  border-bottom: 1px solid var(--divider);
}
.brand {
  font-family: var(--disp); font-weight: 700; font-size: 1.02rem;
  letter-spacing: -0.02em; color: var(--ink); text-decoration: none;
}
.brand:hover { color: var(--acc); }
.brand-sub {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--ink-faint);
}

/* ---------- page ---------- */
.page {
  flex: 1; min-width: 0;
  padding: 64px clamp(20px, 6vw, 72px) 96px;
}

/* Markdown output */
h1, h2, h3 {
  font-family: var(--disp);
  letter-spacing: -0.03em;
  color: var(--ink);
  scroll-margin-top: 76px;
}
h1 {
  font-size: clamp(2.4rem, 5vw, 3.4rem); line-height: 1.06;
  margin: 0 0 18px; font-weight: 700;
}
h2 {
  font-size: 1.5rem; font-weight: 700;
  margin: 56px 0 14px;
}
h3 { font-size: 1.12rem; margin: 30px 0 8px; font-weight: 500; }

p { margin: 12px 0; max-width: var(--measure); }
.lede, .page > article > p:first-of-type {
  font-size: 1.08rem; color: var(--ink-soft);
}
ul, ol { padding-left: 1.4em; max-width: var(--measure); }
li { margin: 6px 0; }
li::marker { color: var(--ink-faint); }
strong { font-weight: 600; }

hr { border: 0; height: 1px; background: var(--divider); margin: 48px 0; }

blockquote {
  margin: 18px 0; padding: 2px 0 2px 16px;
  border-left: 2px solid var(--divider-strong);
  color: var(--ink-soft);
}
blockquote p { margin: 4px 0; }

pre {
  background: var(--surface); border: 1px solid var(--divider);
  border-radius: 6px; padding: 16px 18px; margin: 16px 0;
  max-width: var(--measure); overflow-x: auto;
}
pre code { background: none; padding: 0; font-size: 0.85rem; line-height: 1.7; }

table {
  border-collapse: collapse; width: 100%; margin: 20px 0;
  font-size: 0.88rem;
}
th, td { padding: 10px 16px 10px 0; border-bottom: 1px solid var(--divider); text-align: left; vertical-align: top; }
th {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.12em;
  text-transform: uppercase; font-weight: 700;
  border-bottom: 1.5px solid var(--ink);
}
tbody tr:hover { background: var(--surface); }

/* ---------- sidebar layout ---------- */
.layout {
  display: flex;
  gap: 0;
  max-width: 1200px;
  margin: 0 auto;
}
.side {
  flex: none;
  width: 220px;
  padding: 40px 28px 60px clamp(20px, 6vw, 72px);
  border-right: 1px solid var(--divider);
  min-height: calc(100vh - 60px);
  position: sticky;
  top: 60px;
  align-self: flex-start;
  font-family: var(--sans);
}
.side-group { margin-bottom: 28px; }
.side-label {
  font-family: var(--mono); font-size: 0.62rem; font-weight: 700;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--ink-faint); margin-bottom: 8px;
}
.side-item, .side-step {
  display: block;
  padding: 5px 0;
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.88rem;
  line-height: 1.5;
}
.side-item:hover, .side-step:hover { color: var(--ink); }
.side-item.on, .side-step.on { color: var(--acc); font-weight: 600; }
.side-num {
  display: inline-block; min-width: 20px;
  font-family: var(--mono); font-size: 0.68rem; color: var(--ink-faint);
}
.side-step.on .side-num { color: var(--acc); }

/* article outline (h2/h3 extracted from the page) */
.side-outline {
  display: block;
  padding: 4px 0;
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.85rem;
  line-height: 1.45;
}
.side-outline:hover { color: var(--ink); }
.side-outline.d3 {
  padding-left: 14px;
  font-size: 0.8rem;
  color: var(--ink-faint);
}
.side-outline.d3:hover { color: var(--ink-soft); }

@media (max-width: 900px) {
  .layout { flex-direction: column; }
  .side {
    width: auto; border-right: 0; border-bottom: 1px solid var(--divider);
    padding: 20px clamp(20px, 6vw, 72px);
    position: static; min-height: 0;
  }
}

/* footer */
.foot {
  margin-top: 72px; padding-top: 20px;
  border-top: 1px solid var(--divider);
  font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--ink-faint);
}

/* ---------- module cards ---------- */
.mod-head {
  font-family: var(--mono); font-size: 0.68rem; font-weight: 700;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--ink-faint); margin: 56px 0 0;
}
.mod-list { border-top: 1px solid var(--divider); }
.mod-card {
  display: grid; grid-template-columns: 1fr auto; gap: 4px 20px;
  padding: 18px 0; border-bottom: 1px solid var(--divider);
  text-decoration: none; color: var(--ink);
}
.mod-card:hover { text-decoration: none; }
.mod-card:hover .mod-name { color: var(--acc); }
.mod-name { font-family: var(--disp); font-weight: 700; font-size: 1.1rem; letter-spacing: -0.02em; }
.mod-desc { grid-column: 1; color: var(--ink-soft); font-size: 0.92rem; max-width: 34rem; }
.mod-count {
  grid-column: 2; grid-row: 1; align-self: start;
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink-faint); white-space: nowrap;
}

/* ---------- steps ---------- */
.step-toc { border-top: 1px solid var(--divider); margin-top: 28px; }
.step-item {
  display: flex; align-items: baseline; gap: 14px;
  padding: 13px 0; border-bottom: 1px solid var(--divider);
  text-decoration: none; color: var(--ink);
}
.step-item:hover .step-name { color: var(--acc); }
.step-num {
  flex: none; min-width: 26px;
  font-family: var(--mono); font-size: 0.72rem; color: var(--ink-faint);
}
.step-name { font-weight: 500; }
.step-item.on .step-name { color: var(--acc); font-weight: 600; }
.step-item.on .step-num { color: var(--acc); }

.step-nav {
  display: flex; justify-content: space-between; gap: 20px;
  margin-top: 48px; padding-top: 18px;
  border-top: 1px solid var(--divider);
}
.step-link {
  font-family: var(--mono); font-size: 0.8rem; color: var(--ink-soft);
  text-decoration: none; max-width: 46%;
}
.step-link:hover { color: var(--acc); }
.step-link.next { text-align: right; margin-left: auto; }

.step-kicker {
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.14em;
  text-transform: uppercase; color: var(--ink-faint);
  margin: 0 0 14px;
}

.crumb {
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em;
  text-transform: uppercase; margin-bottom: 24px;
}
.crumb a { color: var(--ink-faint); text-decoration: none; }
.crumb a:hover { color: var(--acc); }

/* ---------- motion ---------- */
#progress {
  position: fixed; top: 0; left: 0; height: 2px; width: 0;
  background: var(--acc); z-index: 100;
  opacity: 0; transition: width 0.25s ease, opacity 0.3s ease;
}
#progress.run { width: 62%; opacity: 1; transition: width 1.6s cubic-bezier(0.1, 0.6, 0.2, 1); }
#progress.done { width: 100%; opacity: 0; transition: width 0.28s ease, opacity 0.35s ease 0.1s; }

.rise {
  opacity: 0;
  animation: rise 0.55s cubic-bezier(0.16, 0.6, 0.2, 1) forwards;
}
@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* link underline draws in */
.step-item .step-name, .mod-card .mod-name, .step-link, .crumb a {
  background-image: linear-gradient(currentColor, currentColor);
  background-size: 0 1px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  transition: background-size 0.3s ease;
  padding-bottom: 1px;
}
.step-item:hover .step-name, .mod-card:hover .mod-name, .step-link:hover, .crumb a:hover {
  background-size: 100% 1px;
}

@media (prefers-reduced-motion: reduce) {
  .rise { animation: none; opacity: 1; }
  #progress { display: none; }
}