/* ============================================================
   skyyang.net v2 — "Thinking Machines" style
   (rollback to v1 neolee style: git tag v1-neolee-style)
   ============================================================ */

:root {
  --content-pad: 1.3rem;
  --content-max: calc(660px + 2 * var(--content-pad));
  --bg: #ffffff;
  --bg-code: #f3f3f2;
  --fg: #282828;
  --fg1: #3c3836;
  --fg2: #504945;
  --fg3: #6b6866;
  --fg4: #676767;
  --fg5: #969696;
  --red: #AD2111;
  --hover-bg: rgba(128, 128, 128, 0.12);
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-serif: 'Iowan Old Style', 'Iowan Old Style BT', Georgia, serif;
  --font-brand: 'Chakra Petch', sans-serif;
  --site-header-height: 54px;
}

* { box-sizing: border-box; }

html {
  overflow-y: scroll;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: var(--fg4) var(--bg);
  scroll-padding-top: calc(var(--site-header-height) + 1rem);
}

body {
  font-family: var(--font-serif);
  font-size: 17px;
  line-height: 1.6;
  background-color: var(--bg);
  color: var(--fg);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  overflow-x: clip;
}

/* ---------- fixed header + nav ---------- */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: fixed;
  top: 0;
  left: 1rem;
  right: 1rem;
  z-index: 1002;
  height: var(--site-header-height);
  padding: 0 1rem;
  background: var(--bg);
}

.navbar-spacer { flex: 0 0 auto; }

/* small brand wordmark in header (inner pages) */
.navbar-logo a,
.navbar-logo a:link,
.navbar-logo a:visited {
  font-family: var(--font-brand);
  font-weight: 500;
  font-size: 17px;
  line-height: 25px;
  letter-spacing: 1.7px;
  text-transform: uppercase;
  color: var(--fg4);
  text-decoration: none;
  transition: opacity 0.3s ease-in-out;
}
.navbar-logo a:hover { opacity: 0.8; }

.top-nav {
  display: flex;
  gap: 1.75rem;
  align-items: center;
  font-family: var(--font-sans);
}

.top-nav a {
  font-family: var(--font-sans);
  font-weight: 400;
  color: var(--fg1);
  text-decoration: none;
  font-size: 15px;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  height: 100%;
}

.top-nav a:hover {
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg) 20%, transparent);
  text-underline-offset: 2px;
}

/* ---------- hero wordmark ---------- */

.logo-container {
  margin-top: calc(var(--site-header-height) + 2.5rem);
  margin-inline: auto;
  padding-block: 1rem 1.35rem;
  text-align: center;
  animation: fadeIn 0.6s ease-in-out;
}

.logo {
  position: relative;
  overflow: hidden;
  background: var(--bg);
  border: solid 1px var(--bg);
  color: black;
  backface-visibility: hidden;
  animation: float 7s ease-in-out infinite;
  display: inline-block;
  font-family: var(--font-brand);
  font-size: clamp(3em, 8vw, 3.4em);
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  line-height: 1.3;
  text-decoration: none;
}

.logo::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 150%;
  aspect-ratio: 1;
  background: linear-gradient(90deg, #565151, #d2caca);
  mix-blend-mode: screen;
  animation: gradRotate 8s linear infinite;
  pointer-events: none;
  transform-origin: center;
  transform: translate(-50%, -50%);
}

/* ---------- announcement pill row ---------- */

.home-announcement {
  margin-top: 1.6rem;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  max-width: 660px;
  margin-left: auto;
  margin-right: auto;
}

.pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
  height: 26px;
  font-family: var(--font-sans);
  font-weight: 450;
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--fg1);
  background: rgba(0, 0, 0, 0.04);
  border-radius: 100px;
  transition: background-color 0.2s ease;
}

.announcement-text {
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--fg);
  text-wrap: balance;
}

.home-announcement:hover .announcement-text {
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg) 20%, transparent);
  text-underline-offset: 2px;
}
.home-announcement:hover .pill { background: rgba(0, 0, 0, 0.06); }

/* ---------- main content column ---------- */

main.content {
  max-width: var(--content-max);
  margin-inline: auto;
  padding: 0.5rem var(--content-pad) 0;
}

/* inner pages (no hero): clear the fixed header */
main.content.page {
  padding-top: calc(var(--site-header-height) + 2rem);
}

.content p { margin: 0 0 1.333rem; }

.content a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--fg4) 30%, transparent);
  transition: color 0.3s ease-in-out, text-decoration-color 0.3s ease-in-out;
}

.content a:hover {
  color: var(--fg2);
  text-decoration-color: color-mix(in srgb, var(--fg2) 30%, transparent);
}

.content ul {
  list-style: square;
  margin: 1rem 0 1.2rem 1.5rem;
  padding: 0;
}
.content ul > li { margin-bottom: 0.2rem; }

.content h1 {
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.4;
  margin: 0 0 0.6em;
}

.content h2 {
  font-size: 1.45rem;
  font-weight: 600;
  line-height: 1.4;
  margin: 1.6em 0 0.6em;
}

.content code {
  color: var(--red);
  font-family: SFMono-Regular, 'SF Mono', ui-monospace, Menlo, Monaco, Consolas, monospace;
  font-size: 0.9em;
  padding: 0 0.2rem;
}

.content pre {
  background-color: var(--bg-code);
  border-radius: 0.45rem;
  font-family: 'SF Mono', Monaco, Inconsolata, 'Fira Code', monospace;
  overflow-x: auto;
  padding: 1rem;
}

/* ---------- blog catalog ---------- */

.post-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.post-list li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid color-mix(in srgb, var(--fg4) 20%, transparent);
}

.post-list .post-date {
  font-family: var(--font-sans);
  font-size: 14px;
  color: var(--fg4);
  white-space: nowrap;
}

.empty-state {
  color: var(--fg4);
  font-style: italic;
  margin-top: 1.5rem;
}

/* ---------- footer ---------- */

.site-footer {
  max-width: var(--content-max);
  margin: 4rem auto 0;
  padding: 1.5rem var(--content-pad) 2rem;
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--fg4);
  text-align: center;
}

/* ---------- animations ---------- */

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes float {
  0%   { transform: translateY(5px); }
  50%  { transform: translateY(-5px); }
  100% { transform: translateY(5px); }
}

@keyframes gradRotate {
  0%   { transform: translate(-50%, -50%) rotate(0deg); }
  100% { transform: translate(-50%, -50%) rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .logo, .logo::after, .logo-container { animation: none; }
}

/* ---------- mobile ---------- */

@media (max-width: 640px) {
  .site-header { left: 0; right: 0; padding: 0 1rem; }
  .top-nav { gap: 1.2rem; }
  .logo-container { margin-top: calc(var(--site-header-height) + 1.2rem); }
}