@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=IBM+Plex+Mono:wght@400;500&display=swap');

*, *::before, *::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-body);
  font-size: var(--size-md);
  line-height: 1.6;
  color: var(--fg);
  background:
    radial-gradient(circle at 24% 32%, var(--bg-gradient-1), transparent 30%),
    radial-gradient(circle at 76% 20%, var(--bg-gradient-2), transparent 28%),
    radial-gradient(circle at 50% 78%, var(--bg-gradient-3), transparent 30%),
    var(--bg-base);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

button, input, textarea, select {
  font: inherit;
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-6);
  background: transparent;
  backdrop-filter: none;
  border-bottom: none;
  z-index: 10;
  transition: opacity var(--transition);
}

.site-header > * {
  opacity: 0.18;
  transition: opacity var(--transition);
}

.site-header:hover > * {
  opacity: 1;
}

.logo {
  height: 44px;
  width: 44px;
  display: block;
  cursor: pointer;
  transition: transform var(--transition);
  color: var(--fg);
}

.logo-mark {
  width: 100%;
  height: 100%;
  display: block;
}

.logo-mark path {
  fill: currentColor;
}

.logo:hover {
  transform: translateY(-2px);
}

.theme-toggle {
  background: var(--paper);
  border: var(--border);
  color: var(--fg);
  padding: var(--space-2);
  border-radius: 50%;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: var(--space-3);
}

.theme-toggle:hover {
  background: var(--paper);
  transform: translateY(-1px);
}

.theme-icon {
  font-size: 18px;
  line-height: 1;
}

.nav-trigger {
  background: var(--paper);
  border: var(--border);
  color: var(--fg);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition), transform var(--transition);
}

.nav-trigger:hover {
  background: var(--paper);
  transform: translateY(-1px);
}

.nav-overlay {
  position: absolute;
  right: var(--space-6);
  top: calc(100% + 12px);
  z-index: 20;
}

.nav-panel {
  min-width: 220px;
  padding: var(--space-4);
  border-radius: var(--radius);
  border: var(--border);
  background: rgba(245, 243, 237, 0.9);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(12px);
}

html[data-theme="dark"] .nav-panel {
  background: rgba(15, 16, 17, 0.9);
}

.nav-kicker {
  text-transform: uppercase;
  font-size: var(--size-sm);
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: var(--space-3);
}

.nav-links {
  list-style: none;
  display: grid;
  gap: var(--space-2);
}

.nav-links a {
  color: var(--fg);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  border-radius: 10px;
  transition: background var(--transition), color var(--transition);
  display: inline-block;
}

.nav-links a:hover {
  background: var(--paper);
}

.site-header:hover {
  opacity: 1;
}

.site-footer {
  padding: var(--space-4) var(--space-6);
  border-top: none;
  background: transparent;
  text-align: center;
  color: var(--muted);
  font-size: var(--size-sm);
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 1;
  opacity: 0;
  pointer-events: none;
  transition: opacity 10000ms ease;
}

.site-header:hover ~ main .site-footer {
  opacity: 1;
  transition: opacity 1000ms ease;
}

/* Constellation Design logo in footer */
.constellation-link {
  display: block;
  margin: 0 auto var(--space-4);
  width: fit-content;
  opacity: 0;
  transition: opacity 1000ms ease;
  pointer-events: none;
  text-decoration: none;
}

.constellation-logo {
  display: block;
  width: 240px;
  height: auto;
  margin: 0 auto;
  pointer-events: none; /* Images don't intercept hover events */
}

/* Theme-specific logo visibility */
.constellation-logo-light {
  display: block;
}

.constellation-logo-dark {
  display: none;
}

html[data-theme="dark"] .constellation-logo-light {
  display: none;
}

html[data-theme="dark"] .constellation-logo-dark {
  display: block;
}

/* Show logo on header hover */
.site-header:hover ~ main .site-footer .constellation-link {
  opacity: 1;
  transition: opacity 1000ms ease;
  pointer-events: auto;
}

/* Logo hover: show at full opacity with smooth transition */
.constellation-link:hover {
  opacity: 1 !important;
  transition: opacity 180ms ease !important;
}

.container-block {
  padding: var(--space-8) var(--space-6);
  border-top: var(--border);
  transition: opacity 220ms ease, transform 220ms ease;
}

.container-inner {
  max-width: var(--content-max);
  margin: 0 auto;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: var(--size-sm);
  color: var(--muted);
  margin-bottom: var(--space-2);
}

.lede {
  color: var(--muted);
  margin-top: var(--space-3);
}

.container-block.active {
  opacity: 1;
  transform: translateY(0);
}

.container-overlay {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  padding: var(--space-6);
  background: rgba(245, 243, 237, 0.78);
  backdrop-filter: blur(12px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 240ms ease;
  z-index: 30;
  will-change: opacity;
}

html[data-theme="dark"] .container-overlay {
  background: rgba(5, 6, 7, 0.78);
}

.container-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.container-overlay.container-mode {
  background: transparent;
  backdrop-filter: none;
  pointer-events: none;
}

.container-overlay.container-mode .container-card {
  width: min(1100px, 92vw);
  height: min(78vh, 780px);
  overflow: auto;
  pointer-events: auto;
}

.container-overlay.is-essay .container-card {
  background: rgba(245, 243, 237, 1);
}

html[data-theme="dark"] .container-overlay.is-essay .container-card {
  background: rgba(13, 14, 15, 1);
}

.container-overlay.is-curiosity .eyebrow {
  display: none;
}

.container-card {
  width: min(720px, 94vw);
  background: rgba(245, 243, 237, 0.92);
  border: var(--border);
  border-radius: var(--radius);
  padding: var(--space-6);
  position: relative;
  box-shadow: var(--shadow-lg);
  content-visibility: auto;
  contain-intrinsic-size: 720px 500px;
}

html[data-theme="dark"] .container-card {
  background: rgba(13, 14, 15, 0.92);
}

.container-overlay.is-curiosity.container-mode .container-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.container-close {
  position: sticky;
  top: var(--space-4);
  left: 100%;
  margin-left: auto;
  margin-right: var(--space-4);
  margin-bottom: calc(-40px - var(--space-4));
  width: 40px;
  height: 40px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: var(--paper);
  border: var(--border);
  color: var(--fg);
  cursor: pointer;
  font-size: 1.5rem;
  line-height: 1;
  z-index: 100;
  transition: background var(--transition), transform var(--transition), opacity var(--transition);
}

.container-close:hover {
  background: var(--paper);
  transform: translateY(-1px);
}

@media (max-width: 640px) {
  .site-header {
    padding: 0 var(--space-4);
  }

  .site-footer {
    padding: var(--space-6) var(--space-4);
  }
}