/* ============================================================
   Nick Shu — Academic Homepage
   Quiet · Mathematical · Editorial · Precise · Exploratory
   ============================================================ */

/* ---------- Design tokens ---------- */
:root {
  /* Color — light */
  --bg: #F7F7F4;
  --bg-elevated: #F0F0EB;
  --text: #161616;
  --muted: #6A6A66;
  --faint: #9A9A93;
  --border: #DADAD4;
  --border-strong: #C6C6BF;
  --accent: #243A4B;
  --accent-soft: rgba(36, 58, 75, 0.10);

  /* Typography */
  --font-ui: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
             "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: "STIX Two Text", "Times New Roman", "Noto Serif SC",
                "Songti SC", "SimSun", serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono",
               Menlo, Consolas, monospace;

  /* Layout */
  --content-width: 1160px;
  --article-width: 720px;
  --page-padding: clamp(1.25rem, 4vw, 2.5rem);
  --section-gap: clamp(4.5rem, 10vw, 8rem);
  --header-height: 4rem;

  /* Motion */
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 0.45s;
}

html[data-theme="dark"] {
  --bg: #111210;
  --bg-elevated: #171714;
  --text: #ECECE8;
  --muted: #9B9B94;
  --faint: #6E6E68;
  --border: #30302C;
  --border-strong: #41413B;
  --accent: #A5BCCB;
  --accent-soft: rgba(165, 188, 203, 0.10);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-ui);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease;
}

::selection { background: var(--accent); color: var(--bg); }

img, svg { display: block; max-width: 100%; }
a { color: inherit; }

/* ---------- Language visibility ---------- */
html[data-lang="zh"] [data-lang="en"] { display: none !important; }
html[data-lang="en"] [data-lang="zh"] { display: none !important; }

/* ---------- CV download ---------- */
.cv-trigger {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 1.75rem;
  padding: 0.75rem 1.1rem;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  background: var(--bg);
  color: var(--accent);
  font: inherit;
  font-size: 0.9rem;
  cursor: pointer;
}
.cv-trigger svg { width: 1.15rem; height: 1.15rem; }
.cv-trigger:hover, .cv-option:hover { background: var(--accent-soft); border-color: var(--accent); }
.cv-trigger:focus-visible, .cv-option:focus-visible, .cv-close:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}
html:has(.cv-dialog[open]) { overflow: hidden; }
.cv-dialog {
  margin: auto;
  width: min(28rem, calc(100% - 2.5rem));
  max-height: calc(100dvh - 2.5rem);
  overflow-y: auto;
  padding: clamp(1.25rem, 5vw, 2rem);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.2);
}
.cv-dialog::backdrop { background: rgba(0, 0, 0, 0.45); backdrop-filter: blur(4px); }
.cv-dialog h2 { font-size: 1.8rem; }
.cv-dialog p { margin-top: 0.85rem; color: var(--muted); font-size: 0.9rem; }
.cv-options { display: grid; gap: 0.75rem; margin: 1.5rem 0; }
.cv-option {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  text-decoration: none;
  font-size: 0.9rem;
}
.cv-format { flex-shrink: 0; color: var(--muted); font-family: var(--font-mono); font-size: 0.75rem; }
.cv-dialog form { text-align: right; }
.cv-close {
  min-height: 44px;
  padding: 0.5rem 0.75rem;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  cursor: pointer;
}
.cv-close:hover { color: var(--text); }

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

.display {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(3rem, 9vw, 7rem);
  line-height: 0.98;
  letter-spacing: -0.02em;
}

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: var(--content-width);
  margin: 0 auto;
  padding-left: var(--page-padding);
  padding-right: var(--page-padding);
}

.page {
  padding-top: calc(var(--header-height) + 3rem);
  padding-bottom: 6rem;
}

.section {
  padding-top: var(--section-gap);
  scroll-margin-top: calc(var(--header-height) + 1rem);
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin-bottom: 2.75rem;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
}

.section-title {
  font-size: clamp(1.6rem, 3.4vw, 2.3rem);
  font-weight: 500;
}

.section-desc {
  max-width: 56ch;
  color: var(--muted);
  font-size: 1rem;
}

/* ---------- Header / Navigation ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--header-height);
  z-index: 100;
  background: rgba(247, 247, 244, 0.82);
  -webkit-backdrop-filter: blur(10px) saturate(1.4);
  backdrop-filter: blur(10px) saturate(1.4);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background-color 0.3s ease;
}

html[data-theme="dark"] .site-header {
  background: rgba(17, 18, 16, 0.82);
}

.site-header.scrolled {
  border-bottom-color: var(--border);
}

.header-inner {
  height: var(--header-height);
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--page-padding);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 3vw, 2.25rem);
}

.nav a {
  position: relative;
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--muted);
  padding: 0.3rem 0;
  transition: color 0.2s ease;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}

.nav a:hover { color: var(--text); }
.nav a:hover::after { transform: scaleX(1); }
.nav a.active { color: var(--text); }
.nav a.active::after { transform: scaleX(1); }

.header-right {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2.5vw, 2rem);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Theme toggle */
.theme-toggle {
  width: 2.2rem;
  height: 2.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.theme-toggle:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--accent-soft);
}

.theme-toggle svg { width: 1rem; height: 1rem; }
html[data-theme="light"] .icon-sun { display: none; }
html[data-theme="dark"] .icon-moon { display: none; }

/* Language toggle */
.lang-toggle {
  height: 2.2rem;
  padding: 0 0.7rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.lang-toggle:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--accent-soft);
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  width: 2.2rem;
  height: 2.2rem;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
}

.nav-toggle svg { width: 1.05rem; height: 1.05rem; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 3rem 0 2.5rem;
  color: var(--muted);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-brand {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--text);
}

.footer-meta {
  font-size: 0.85rem;
  color: var(--faint);
}

.footer-tagline {
  font-size: 0.85rem;
  color: var(--faint);
  font-style: italic;
}

/* ---------- Links ---------- */
.link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  text-decoration: none;
  color: var(--text);
  border-bottom: 1px solid var(--border-strong);
  padding-bottom: 1px;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.link:hover { color: var(--accent); border-color: var(--accent); }
.link .arrow { transition: transform var(--dur) var(--ease); }
.link:hover .arrow { transform: translateX(3px); }

.arrow-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--text);
}

.arrow-link .arrow {
  transition: transform var(--dur) var(--ease);
  color: var(--muted);
}

.arrow-link:hover .arrow { transform: translateX(3px); }
.arrow-link:hover { color: var(--accent); }

/* ---------- Eyebrow / tags ---------- */
.tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* Status labels */
.status {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--border-strong);
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  white-space: nowrap;
}

/* ---------- Hero ---------- */
.hero {
  min-height: 92vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  padding: calc(var(--header-height) + 2rem) 0 4rem;
  overflow: hidden;
}

.hero-inner {
  position: relative;
  z-index: 2;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.75rem;
}

.hero-name {
  margin-bottom: 1.5rem;
}

.hero-name .line {
  display: block;
}

.hero-sub {
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  color: var(--muted);
  max-width: 46ch;
  margin-bottom: 1.25rem;
}

.hero-meta {
  font-size: 0.92rem;
  color: var(--faint);
  line-height: 1.8;
}

.hero-meta a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}

.hero-meta a:hover { color: var(--text); border-color: var(--border-strong); }

.hero-viz {
  position: absolute;
  right: -6%;
  top: 50%;
  transform: translateY(-50%);
  width: clamp(20rem, 44vw, 40rem);
  opacity: 0.16;
  z-index: 1;
  pointer-events: none;
}

/* ---------- Two-column split ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: clamp(2rem, 6vw, 5rem);
  align-items: start;
}

.split-left { display: flex; flex-direction: column; gap: 1.25rem; }
.split-left p { color: var(--muted); max-width: 58ch; }

/* ---------- Timeline ---------- */
.timeline {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--border);
}

.tl-item {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 1.5rem;
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}

.tl-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--faint);
  text-transform: uppercase;
  padding-top: 0.15rem;
}

.tl-body h3 {
  font-family: var(--font-ui);
  font-weight: 500;
  font-size: 1.02rem;
  margin-bottom: 0.3rem;
}

.tl-body .role { color: var(--muted); font-size: 0.92rem; margin-bottom: 0.4rem; }
.tl-body ul { list-style: none; margin: 0.4rem 0 0; }
.tl-body li {
  position: relative;
  padding-left: 1rem;
  font-size: 0.88rem;
  color: var(--muted);
  margin: 0.25rem 0;
}
.tl-body li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border-strong);
}

/* ---------- Research index ---------- */
.r-index {
  border-top: 1px solid var(--border);
}

.r-block {
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: clamp(1rem, 3vw, 2.5rem);
  padding: clamp(1.75rem, 4vw, 3rem) 0;
  border-bottom: 1px solid var(--border);
}

.r-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--faint);
  letter-spacing: 0.1em;
  padding-top: 0.35rem;
}

.r-title {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 2.8vw, 2rem);
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 0.4rem;
}

.r-cn {
  font-size: 0.88rem;
  color: var(--faint);
  margin-bottom: 1.1rem;
}

.r-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  margin-bottom: 1rem;
}

.r-tags span {
  font-size: 0.85rem;
  color: var(--muted);
}

.r-tags span + span {
  position: relative;
}

.r-body { color: var(--muted); max-width: 68ch; }

.r-body p { margin-bottom: 1rem; }
.r-body p:last-child { margin-bottom: 0; }

.r-body ul {
  list-style: none;
  margin: 0.75rem 0 1rem;
}

.r-body li {
  position: relative;
  padding-left: 1.1rem;
  margin: 0.35rem 0;
  font-size: 0.94rem;
}

.r-body li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--faint);
}

/* ---------- Projects ---------- */
.project {
  border-top: 1px solid var(--border);
  padding: clamp(2rem, 5vw, 3.5rem) 0;
  display: grid;
  grid-template-columns: 5rem 1fr;
  gap: clamp(1rem, 3vw, 2.5rem);
}

.project:last-of-type { border-bottom: 1px solid var(--border); }

.project-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--faint);
  letter-spacing: 0.1em;
  padding-top: 0.35rem;
}

.project-head {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 0.9rem;
}

.project-title {
  font-family: var(--font-serif);
  font-size: clamp(1.2rem, 2.4vw, 1.7rem);
  font-weight: 500;
}

.project-kw {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.1rem;
  margin-bottom: 1.1rem;
}

.project-kw span {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.project-body { color: var(--muted); max-width: 72ch; }
.project-body p { margin-bottom: 1rem; }
.project-body p:last-child { margin-bottom: 0; }
.project-body ul { list-style: none; margin: 0.75rem 0 1rem; }
.project-body li {
  position: relative;
  padding-left: 1.1rem;
  margin: 0.32rem 0;
  font-size: 0.94rem;
}
.project-body li::before { content: "—"; position: absolute; left: 0; color: var(--faint); }

.project-body .formula {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  color: var(--text);
  margin: 1.1rem 0;
}

/* ---------- Blog list (journal / table of contents) ---------- */
.post-list { border-top: 1px solid var(--border); }

.post-year {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--faint);
  padding: 1.75rem 0 0.75rem;
}

.post-item {
  display: grid;
  grid-template-columns: 6.5rem 1fr auto;
  gap: 1.5rem;
  align-items: baseline;
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  transition: background-color 0.2s ease;
}

.post-item:hover { background: var(--accent-soft); }

.post-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--faint);
  text-transform: uppercase;
}

.post-main {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  transition: transform var(--dur) var(--ease);
}

.post-item:hover .post-main { transform: translateX(4px); }

.post-title {
  font-family: var(--font-serif);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  font-weight: 500;
  line-height: 1.3;
  color: var(--text);
}

.post-desc { font-size: 0.88rem; color: var(--muted); }

.post-arrow {
  font-size: 1.1rem;
  color: var(--faint);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease),
              color 0.2s ease;
}

.post-item:hover .post-arrow {
  opacity: 1;
  transform: translateX(0);
  color: var(--accent);
}

/* ---------- Article (blog post) ---------- */
.article {
  max-width: var(--article-width);
  margin: 0 auto;
  font-family: var(--font-serif);
  font-size: 1.06rem;
  line-height: 1.85;
  color: var(--text);
}

.article-header {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.article-header h1 {
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  margin-bottom: 0.9rem;
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--faint);
}

.article h2 {
  font-size: 1.5rem;
  margin: 2.75rem 0 1.1rem;
}

.article h3 { font-size: 1.2rem; margin: 2rem 0 0.9rem; }

.article p { margin: 1.25rem 0; }

.article a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid var(--border-strong);
}

.article a:hover { border-color: var(--accent); }

.article strong { font-weight: 600; }

.article em { font-style: italic; }

.article blockquote {
  margin: 1.75rem 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 2px solid var(--border-strong);
  color: var(--muted);
  font-style: italic;
}

.article code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.article pre {
  overflow-x: auto;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin: 1.5rem 0;
  font-size: 0.85rem;
}

.article pre code { background: none; padding: 0; }

.article img {
  margin: 2rem auto;
  border-radius: 6px;
}

/* Long math must not break the layout */
mjx-container { max-width: 100%; }
mjx-container[display="true"] {
  display: block;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.25rem 0;
}

/* ---------- Social ---------- */
.social {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.social-icon {
  width: 2.4rem;
  height: 2.4rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.social-icon:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--accent-soft);
}

.social-icon svg { width: 1.05rem; height: 1.05rem; }

/* ---------- Copy button ---------- */
.copy-row {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.22rem 0.6rem;
  cursor: pointer;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.copy-btn:hover { color: var(--text); border-color: var(--border-strong); }

/* ---------- Divider ---------- */
.hr {
  height: 1px;
  background: var(--border);
  border: 0;
  margin: 0;
}

/* Inline decorative visualization */
.viz-inline {
  float: right;
  width: 9rem;
  margin: 0.25rem 0 1.1rem 1.75rem;
  opacity: 0.5;
  pointer-events: none;
}

@media (max-width: 768px) {
  .viz-inline { float: none; width: 7rem; margin: 0.75rem 0 1.25rem; }
}

/* ---------- Decorative visualization ---------- */
.viz {
  display: block;
  width: 100%;
  height: auto;
}

.viz-line {
  fill: none;
  stroke: var(--accent);
  stroke-width: 1;
}

.viz-fill { fill: var(--accent); }

.spin-slow {
  transform-origin: center;
  animation: spin 48s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .split { grid-template-columns: 1fr; }
  .hero-viz { opacity: 0.09; right: -18%; }
}

@media (max-width: 768px) {
  :root { --header-height: 3.5rem; }

  .nav {
    position: fixed;
    top: var(--header-height);
    right: 0;
    left: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem var(--page-padding) 1rem;
    transform: translateY(-120%);
    transition: transform var(--dur) var(--ease);
    box-shadow: 0 24px 40px -24px rgba(0,0,0,0.25);
  }

  .nav.open { transform: translateY(0); }

  .nav a {
    padding: 0.9rem 0;
    font-size: 1.05rem;
    border-bottom: 1px solid var(--border);
  }

  .nav a:last-child { border-bottom: none; }

  .nav-toggle { display: inline-flex; }

  .post-item { grid-template-columns: 1fr auto; gap: 0.5rem 1rem; }
  .post-date { grid-column: 1 / -1; }

  .tl-item { grid-template-columns: 1fr; gap: 0.35rem; }
  .r-block, .project { grid-template-columns: 1fr; }
  .r-num, .project-num { padding-top: 0; }

  .footer-top { flex-direction: column; gap: 0.5rem; }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .post-item:hover .post-main,
  .link:hover .arrow,
  .arrow-link:hover .arrow { transform: none; }
}