/* ============================================================
   GuGuMur — Personal Universe
   Pure CSS · no build step
   ============================================================ */

:root {
  --bg: #04050d;
  --ink: #eef4ff;
  --muted: rgba(216, 228, 255, .62);
  --faint: rgba(190, 208, 255, .38);
  --line: rgba(156, 186, 255, .14);
  --line-strong: rgba(156, 186, 255, .26);
  --violet: #7a6bff;
  --cyan: #73dcff;
  --gold: #e8d6a8;

  --font-latin: "Space Grotesk", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  --ease: cubic-bezier(.22, 1, .36, 1);
  --header-h: 84px;
}

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

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

body {
  margin: 0;
  min-height: 100svh;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-weight: 300;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body.page--home {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
}

img,
svg {
  display: block;
}

::selection {
  background: rgba(115, 220, 255, .28);
  color: #fff;
}

:focus-visible {
  outline: 2px solid rgba(140, 205, 255, .8);
  outline-offset: 4px;
  border-radius: 6px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================================
   Sky / nebula
   ============================================================ */

.sky {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  background:
    radial-gradient(120% 95% at 76% 46%, #0d1536 0%, #080b24 36%, #04050e 68%, #02030a 100%),
    #04050d;
}

.sky::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.55'/%3E%3C/svg%3E");
  opacity: .045;
  mix-blend-mode: soft-light;
}

.sky__band {
  position: absolute;
  left: -20%;
  top: 34%;
  width: 150%;
  height: 22vmax;
  transform: rotate(-19deg);
  background: linear-gradient(
    180deg,
    transparent 0%,
    rgba(92, 122, 220, .05) 28%,
    rgba(130, 158, 255, .1) 50%,
    rgba(84, 190, 220, .05) 72%,
    transparent 100%
  );
  filter: blur(26px);
  opacity: .8;
}

.nebula {
  position: absolute;
  border-radius: 50%;
  filter: blur(72px);
  will-change: transform;
}

.nebula--violet {
  width: 64vmax;
  height: 64vmax;
  left: -20vmax;
  top: -26vmax;
  background: radial-gradient(circle at 50% 50%, rgba(92, 62, 196, .34), rgba(92, 62, 196, 0) 68%);
  animation: nebula-drift 28s ease-in-out infinite alternate;
}

.nebula--cyan {
  width: 58vmax;
  height: 58vmax;
  right: -22vmax;
  top: 2vh;
  background: radial-gradient(circle at 50% 50%, rgba(26, 132, 176, .26), rgba(26, 132, 176, 0) 68%);
  animation: nebula-drift 34s ease-in-out infinite alternate-reverse;
}

.nebula--rose {
  width: 48vmax;
  height: 48vmax;
  left: 26vw;
  bottom: -32vmax;
  background: radial-gradient(circle at 50% 50%, rgba(154, 60, 126, .16), rgba(154, 60, 126, 0) 68%);
  animation: nebula-drift 40s ease-in-out infinite alternate;
}

@keyframes nebula-drift {
  from { transform: translate3d(-2%, -1%, 0) scale(1); }
  to   { transform: translate3d(3%, 2%, 0) scale(1.08); }
}

/* ============================================================
   Cosmic canvas
   ============================================================ */

.stage {
  position: fixed;
  inset: 0;
  z-index: 1;
  overflow: hidden;
  pointer-events: none;
}

.cosmos-canvas {
  position: fixed;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 1.6s var(--ease);
}

.cosmos-ready .cosmos-canvas {
  opacity: 1;
}


/* soft vignette that gives the shower depth */
.stage::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background:
    radial-gradient(ellipse 82% 74% at 52% 46%, transparent 42%, rgba(2, 3, 10, .16) 70%, rgba(1, 2, 7, .62) 100%),
    linear-gradient(180deg, rgba(2, 3, 10, .22) 0%, transparent 18%, transparent 82%, rgba(2, 3, 10, .28) 100%);
}

/* ============================================================
   Header
   ============================================================ */

.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  padding: 0 clamp(20px, 4.5vw, 68px);
  animation: header-in 1.1s var(--ease) both;
}

.topbar::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(3, 5, 14, .84) 0%, rgba(3, 5, 14, .4) 58%, transparent 100%);
  -webkit-backdrop-filter: blur(9px);
  backdrop-filter: blur(9px);
  -webkit-mask-image: linear-gradient(180deg, #000 44%, transparent 100%);
  mask-image: linear-gradient(180deg, #000 44%, transparent 100%);
  transition: background .3s ease;
}

.topbar.is-scrolled::before {
  background: linear-gradient(180deg, rgba(3, 5, 14, .94) 0%, rgba(3, 5, 14, .68) 58%, transparent 100%);
}

.topbar::after {
  content: "";
  position: absolute;
  left: 5%;
  right: 5%;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(150, 184, 255, .17) 26%, rgba(150, 184, 255, .17) 74%, transparent);
}

.topbar__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  justify-self: start;
  padding: 6px 2px;
  color: #f3f7ff;
  font-family: var(--font-latin);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: .015em;
  transition: opacity .3s ease;
}

.brand:hover { opacity: .82; }

.brand__mark {
  display: grid;
  place-items: center;
  width: 31px;
  height: 31px;
  filter: drop-shadow(0 0 11px rgba(104, 168, 255, .42));
}

.brand__mark svg {
  width: 31px;
  height: 31px;
  overflow: visible;
}

.brand__name {
  background: linear-gradient(100deg, #fff 20%, #dbe8ff 60%, #a9c6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* center nav — text tabs with hover dropdown */
.nav {
  justify-self: center;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: 4px;
  min-height: 48px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav__group {
  position: relative;
}

.nav__group + .nav__group::before {
  content: "";
  position: absolute;
  left: -2px;
  top: 50%;
  width: 1px;
  height: 18px;
  background: linear-gradient(180deg, transparent, rgba(150, 185, 255, .16), transparent);
  transform: translateY(-50%);
}

.nav__tab {
  position: relative;
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 9px 17px;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: inherit;
  cursor: pointer;
  transition: background .25s ease;
}

.nav__tab::after {
  content: "";
  position: absolute;
  left: 17px;
  right: 17px;
  bottom: 2px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(130, 220, 255, .7), transparent);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform .35s var(--ease);
}

.nav__group:hover .nav__tab,
.nav__group.is-open .nav__tab {
  background: rgba(130, 165, 255, .055);
}

.nav__group:hover .nav__tab::after,
.nav__group.is-open .nav__tab::after,
.nav__group.is-current .nav__tab::after {
  transform: scaleX(1);
}

.nav__group.is-current .nav__tab::after {
  background: linear-gradient(90deg, transparent, rgba(115, 220, 255, .9), transparent);
}

.nav__tab-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
}

.nav__tab-title {
  color: rgba(228, 240, 255, .96);
  font-family: var(--font-latin);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: .24em;
  line-height: 1;
  text-transform: uppercase;
  transition: color .25s ease;
}

.nav__tab-display {
  color: rgba(248, 251, 255, .96);
  font-size: 14.5px;
  font-weight: 400;
  letter-spacing: .13em;
  line-height: 1.1;
  transition: color .25s ease;
}

.nav__group:hover .nav__tab-display,
.nav__group.is-open .nav__tab-display {
  color: #fff;
}

.nav__group:hover .nav__tab-title,
.nav__group.is-open .nav__tab-title {
  color: rgba(170, 215, 255, .7);
}

.nav__chevron {
  display: flex;
  width: 10px;
  height: 10px;
  margin-left: 2px;
  color: rgba(205, 224, 255, .82);
  transition: transform .3s var(--ease), color .25s ease;
}

.nav__chevron-glyph {
  width: 10px;
  height: 10px;
}

.nav__group.is-open .nav__chevron {
  color: #8fe6ff;
  transform: rotate(180deg);
}

.nav__dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  z-index: 60;
  padding-top: 14px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translate(-50%, 6px);
  transition: opacity .22s ease, transform .32s var(--ease), visibility .22s;
}

.nav__group.is-open .nav__dropdown {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translate(-50%, 0);
}

.nav__dropdown-panel {
  position: relative;
  min-width: 268px;
  padding: 10px;
  border: 1px solid rgba(166, 196, 255, .24);
  border-radius: 18px;
  background: linear-gradient(155deg, rgba(20, 28, 62, .97), rgba(7, 10, 26, .985));
  box-shadow:
    0 34px 90px rgba(0, 0, 0, .68),
    inset 0 1px 0 rgba(255, 255, 255, .06);
  -webkit-backdrop-filter: blur(24px) saturate(120%);
  backdrop-filter: blur(24px) saturate(120%);
}

.nav__dropdown-panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 24px;
  right: 24px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(120, 220, 255, .65), transparent);
}

.nav__dropdown-panel::after {
  content: "";
  position: absolute;
  top: -14px;
  left: 50%;
  width: 1px;
  height: 14px;
  background: linear-gradient(180deg, rgba(115, 220, 255, .45), transparent);
  transform: translateX(-50%);
}

.nav__dropdown-label {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 6px;
  padding: 6px 10px 10px;
  border-bottom: 1px solid rgba(156, 186, 255, .09);
  color: rgba(190, 216, 255, .8);
  font-family: var(--font-latin);
  font-size: 9.5px;
  letter-spacing: .22em;
  text-transform: uppercase;
}

.nav__dropdown-code {
  color: rgba(220, 234, 255, .96);
}

.nav__dropdown-separator {
  color: rgba(150, 190, 255, .25);
}

.nav__dropdown-zh {
  color: rgba(190, 216, 255, .74);
  font-family: var(--font-body);
  font-size: 10px;
  letter-spacing: .18em;
}

.nav__sublist {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav__subitem {
  margin: 0;
}

.nav__sublink {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 9px 10px;
  border-radius: 11px;
  color: rgba(244, 248, 255, .96);
  transition: background .22s ease, color .22s ease;
}

.nav__sublink-icon {
  display: grid;
  place-items: center;
  flex: none;
  width: 30px;
  height: 30px;
  border: 1px solid rgba(156, 186, 255, .16);
  border-radius: 9px;
  background: rgba(130, 165, 255, .09);
  color: rgba(194, 218, 255, .82);
  transition: color .22s ease, border-color .22s ease, background .22s ease, box-shadow .22s ease;
}

.nav__sublink-glyph {
  width: 14px;
  height: 14px;
}

.nav__sublink-text {
  font-size: 13px;
  letter-spacing: .05em;
}

.nav__sublink-arrow {
  display: flex;
  width: 12px;
  height: 12px;
  margin-left: auto;
  color: rgba(160, 195, 255, .4);
  opacity: 0;
  transform: translate(-4px, 4px);
  transition: opacity .25s ease, transform .25s ease;
}

.nav__sublink-arrow-glyph {
  width: 12px;
  height: 12px;
}

.nav__sublink:hover {
  background: rgba(130, 165, 255, .085);
  color: #fff;
}

.nav__sublink:hover .nav__sublink-icon {
  color: #8fe6ff;
  border-color: rgba(115, 220, 255, .3);
  background: rgba(115, 220, 255, .1);
  box-shadow: 0 0 18px rgba(90, 180, 255, .12);
}

.nav__sublink:hover .nav__sublink-arrow {
  opacity: 1;
  transform: none;
}

.nav__sublink[aria-current="page"] .nav__sublink-text::after {
  content: "";
  display: inline-block;
  width: 4px;
  height: 4px;
  margin-left: 8px;
  border-radius: 50%;
  background: #8fe6ff;
  box-shadow: 0 0 8px rgba(143, 230, 255, .9);
  vertical-align: middle;
}

/* social icons */
.socials {
  display: flex;
  align-items: center;
  gap: 9px;
  justify-self: end;
}

.social-link {
  position: relative;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 1px solid rgba(160, 190, 255, .18);
  border-radius: 50%;
  background: rgba(255, 255, 255, .025);
  color: rgba(226, 238, 255, .82);
  transition:
    color .28s ease,
    border-color .28s ease,
    background .28s ease,
    box-shadow .28s ease,
    transform .28s var(--ease);
}

.social-link svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.social-link::after {
  content: attr(data-label);
  position: absolute;
  top: calc(100% + 11px);
  left: 50%;
  padding: 5px 9px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(8, 12, 28, .92);
  color: rgba(236, 243, 255, .86);
  font-size: 11px;
  letter-spacing: .06em;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, -4px);
  transition: opacity .2s ease, transform .2s ease;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.social-link:hover {
  color: #fff;
  border-color: rgba(146, 194, 255, .42);
  background: rgba(118, 152, 255, .12);
  box-shadow: 0 0 26px rgba(92, 142, 255, .24);
  transform: translateY(-2px);
}

.social-link:hover::after {
  opacity: 1;
  transform: translate(-50%, 0);
}

.social-link--bilibili:hover {
  color: #6fe3ff;
  border-color: rgba(80, 204, 255, .45);
}

.social-link--github:hover {
  color: #eef5ff;
}

.social-link--orcid:hover {
  color: #b8e35a;
  border-color: rgba(166, 206, 57, .5);
  background: rgba(166, 206, 57, .1);
  box-shadow: 0 0 26px rgba(166, 206, 57, .2);
}

.social-link--steam:hover {
  color: #7fd9ff;
  border-color: rgba(102, 192, 244, .5);
  background: rgba(102, 192, 244, .1);
  box-shadow: 0 0 26px rgba(102, 192, 244, .2);
}

/* mobile menu button */
.nav__toggle {
  position: relative;
  display: none;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: rgba(255, 255, 255, .03);
  cursor: pointer;
  transition: border-color .25s ease, background .25s ease;
}

.nav__toggle:hover {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, .055);
}

.nav__toggle span {
  position: absolute;
  left: 11px;
  width: 15px;
  height: 1.5px;
  border-radius: 2px;
  background: #dbe7ff;
  transition: transform .3s var(--ease), top .3s var(--ease), opacity .2s ease;
}

.nav__toggle span:first-child { top: 15px; }
.nav__toggle span:last-child  { top: 21px; }

.nav__toggle[aria-expanded="true"] span:first-child {
  top: 18px;
  transform: rotate(45deg);
}

.nav__toggle[aria-expanded="true"] span:last-child {
  top: 18px;
  transform: rotate(-45deg);
}

@keyframes header-in {
  from { opacity: 0; transform: translateY(-14px); }
  to   { opacity: 1; transform: none; }
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 960px) {
  :root { --header-h: 72px; }

  .topbar { padding: 0 20px; }

  .topbar__inner {
    display: flex;
    height: var(--header-h);
  }

  .brand { font-size: 17px; gap: 9px; }
  .brand__mark,
  .brand__mark svg { width: 28px; height: 28px; }

  .nav {
    order: 3;
    margin-left: 9px;
  }

  .socials {
    order: 2;
    gap: 7px;
    margin-left: auto;
  }

  .social-link {
    width: 36px;
    height: 36px;
  }

  .social-link svg { width: 17px; height: 17px; }
  .social-link::after { display: none; }

  .nav__toggle { display: block; }

  .nav__list {
    position: fixed;
    top: calc(var(--header-h) + 10px);
    left: 16px;
    right: 16px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    min-height: 0;
    max-height: calc(100svh - var(--header-h) - 26px);
    overflow-y: auto;
    padding: 10px;
    border: 1px solid rgba(160, 190, 255, .17);
    border-radius: 20px;
    background: rgba(7, 11, 27, .975);
    box-shadow: 0 26px 70px rgba(0, 0, 0, .52), inset 0 1px 0 rgba(255, 255, 255, .05);
    -webkit-backdrop-filter: blur(24px);
    backdrop-filter: blur(24px);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px) scale(.985);
    transform-origin: top center;
    transition: opacity .25s ease, transform .3s var(--ease), visibility .25s;
  }

  .nav__list.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav__group {
    position: static;
  }

  .nav__group + .nav__group::before {
    display: none;
  }

  .nav__tab {
    width: 100%;
    padding: 12px 13px;
    border-radius: 12px;
  }

  .nav__tab:hover,
  .nav__group.is-open .nav__tab {
    background: rgba(130, 165, 255, .07);
  }

  .nav__tab::after {
    display: none;
  }

  .nav__tab-copy {
    flex-direction: row;
    align-items: baseline;
    gap: 9px;
  }

  .nav__tab-title {
    font-size: 10px;
  }

  .nav__tab-display {
    font-size: 15px;
  }

  .nav__chevron {
    margin-left: auto;
  }

  .nav__dropdown {
    position: static;
    display: grid;
    grid-template-rows: 0fr;
    padding: 0 0 4px;
    opacity: 1;
    visibility: hidden;
    pointer-events: none;
    transform: none;
    transition: grid-template-rows .32s var(--ease), visibility .32s;
  }

  .nav__group.is-open .nav__dropdown {
    grid-template-rows: 1fr;
    visibility: visible;
    pointer-events: auto;
    transform: none;
  }

  .nav__dropdown-panel {
    min-width: 0;
    min-height: 0;
    padding: 0 0 6px 12px;
    overflow: hidden;
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  .nav__dropdown-panel::before,
  .nav__dropdown-panel::after {
    display: none;
  }

  .nav__dropdown-label {
    display: none;
  }

  .nav__sublink {
    padding: 9px 12px;
  }

  .nav__sublink-icon {
    width: 28px;
    height: 28px;
  }

}

@media (max-width: 430px) {
  .brand__name { font-size: 16px; }

  .social-link {
    width: 32px;
    height: 32px;
  }

  .nav__toggle {
    width: 36px;
    height: 36px;
  }

  .nav__toggle span { left: 10px; }

  .topbar { padding: 0 16px; }

}


@media (max-width: 350px) {
  .topbar { padding: 0 14px; }

  .brand { gap: 7px; font-size: 15px; }

  .brand__mark,
  .brand__mark svg { width: 25px; height: 25px; }

  .socials { gap: 5px; }

  .social-link {
    width: 30px;
    height: 30px;
  }

  .social-link svg { width: 15px; height: 15px; }

  .nav { margin-left: 7px; }

  .nav__toggle {
    width: 34px;
    height: 34px;
  }

  .nav__toggle span { left: 9px; width: 14px; }
  .nav__toggle span:first-child { top: 13px; }
  .nav__toggle span:last-child { top: 19px; }
  .nav__toggle[aria-expanded="true"] span:first-child,
  .nav__toggle[aria-expanded="true"] span:last-child { top: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }

  .nebula { animation: none; }
}