:root {
  color-scheme: dark;
  --pointer-x: 0px;
  --pointer-y: 0px;
  --white: #ffffff;
  --mtr-red: #e2232e;
  --background-deep: #092536;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
}

body {
  overflow: hidden;
  background: var(--background-deep);
  color: var(--white);
  /* Helvetica/Arial are used on many Hong Kong transport interfaces;
     CJK fallbacks keep Chinese glyphs stable on Windows, macOS and Android. */
  font-family:
    "Helvetica Neue", Helvetica, Arial, "Noto Sans HK", "PingFang HK",
    "Microsoft JhengHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.maintenance-page {
  position: relative;
  display: grid;
  min-height: 100svh;
  place-items: center;
  isolation: isolate;
  overflow: hidden;
}

.liquid-field {
  position: absolute;
  z-index: -1;
  inset: 0;
  overflow: hidden;
  background:
    radial-gradient(circle at 18% 20%, rgba(45, 222, 214, 0.38), transparent 30%),
    radial-gradient(circle at 82% 18%, rgba(113, 95, 255, 0.42), transparent 32%),
    radial-gradient(circle at 72% 86%, rgba(255, 102, 119, 0.26), transparent 31%),
    linear-gradient(132deg, #092536 0%, #0c5363 44%, #241c5b 100%);
  background-size: 140% 140%;
  animation: liquid-colour-flow 18s linear infinite alternate;
  will-change: background-position;
}

/* Decorative liquid forms only; the content remains transparent and unobstructed. */
.liquid-field::before,
.liquid-field::after {
  position: absolute;
  display: block;
  content: "";
  pointer-events: none;
  border-radius: 50%;
  filter: blur(70px);
}

.liquid-field::before {
  top: -18%;
  left: 28%;
  width: 52vw;
  height: 52vw;
  min-width: 360px;
  min-height: 360px;
  background: rgba(29, 207, 205, 0.32);
  animation: liquid-current-one 20s linear infinite alternate;
}

.liquid-field::after {
  right: -12%;
  bottom: -28%;
  width: 58vw;
  height: 58vw;
  min-width: 420px;
  min-height: 420px;
  background: rgba(113, 71, 247, 0.32);
  animation: liquid-current-two 25s linear infinite alternate;
}

.liquid-blob {
  position: absolute;
  display: block;
  width: clamp(300px, 34vw, 620px);
  aspect-ratio: 1;
  border-radius: 50%;
  opacity: 0.72;
  filter: blur(28px);
  pointer-events: none;
  will-change: transform;
}

.liquid-blob--cyan {
  top: -16%;
  left: -10%;
  background:
    radial-gradient(circle at 42% 42%, rgba(163, 255, 246, 0.92) 0 6%, transparent 28%),
    radial-gradient(circle at 50% 50%, #25d7d3 0 30%, rgba(37, 215, 211, 0) 69%);
  animation: blob-cyan 18s linear infinite alternate;
}

.liquid-blob--violet {
  top: -15%;
  right: -12%;
  background:
    radial-gradient(circle at 45% 50%, rgba(220, 203, 255, 0.86) 0 5%, transparent 27%),
    radial-gradient(circle at 50% 50%, #735bff 0 31%, rgba(115, 91, 255, 0) 70%);
  animation: blob-violet 21s linear infinite alternate;
}

.liquid-blob--coral {
  right: 2%;
  bottom: -28%;
  width: clamp(260px, 30vw, 530px);
  background:
    radial-gradient(circle at 42% 40%, rgba(255, 218, 209, 0.88) 0 5%, transparent 26%),
    radial-gradient(circle at 50% 50%, #ff647e 0 30%, rgba(255, 100, 126, 0) 70%);
  animation: blob-coral 19s linear infinite alternate;
}

.liquid-blob--blue {
  bottom: -22%;
  left: -11%;
  width: clamp(280px, 32vw, 580px);
  background:
    radial-gradient(circle at 54% 42%, rgba(189, 233, 255, 0.82) 0 5%, transparent 24%),
    radial-gradient(circle at 50% 50%, #287fc9 0 30%, rgba(40, 127, 201, 0) 70%);
  animation: blob-blue 24s linear infinite alternate;
}

.liquid-highlight {
  position: absolute;
  top: 50%;
  left: 50%;
  width: min(48vw, 680px);
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.12) 0,
    rgba(255, 255, 255, 0.035) 25%,
    transparent 69%
  );
  filter: blur(8px);
  pointer-events: none;
  transform: translate3d(
    calc(-50% + var(--pointer-x)),
    calc(-50% + var(--pointer-y)),
    0
  );
  transition: transform 1.2s cubic-bezier(0.22, 1, 0.36, 1);
}

.maintenance-notice {
  position: relative;
  z-index: 1;
  width: min(92vw, 760px);
  padding: 2rem;
  text-align: center;
  text-shadow: 0 3px 26px rgba(2, 15, 26, 0.28);
}

.mtr-rule {
  display: block;
  width: 46px;
  height: 4px;
  margin: 0 auto 2.25rem;
  background: var(--mtr-red);
  box-shadow: 0 0 22px rgba(226, 35, 46, 0.48);
}

h1 {
  margin: 0;
  font-size: clamp(2.35rem, 7vw, 5.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: 0.13em;
  text-indent: 0.13em;
}

.notice-chinese {
  margin: 1.45rem 0 0;
  font-size: clamp(1.05rem, 2.4vw, 1.55rem);
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: 0.16em;
  text-indent: 0.16em;
}

.notice-divider {
  width: 34px;
  height: 1px;
  margin: 2rem auto 1.75rem;
  background: rgba(255, 255, 255, 0.68);
}

.notice-english {
  margin: 0;
  font-size: clamp(0.9rem, 1.8vw, 1.1rem);
  font-weight: 400;
  line-height: 1.55;
  letter-spacing: 0.045em;
}

.notice-english span:last-child {
  color: rgba(255, 255, 255, 0.86);
  font-size: 0.92em;
}

@keyframes liquid-colour-flow {
  0% {
    background-position: 0% 42%;
  }
  50% {
    background-position: 100% 58%;
  }
  100% {
    background-position: 28% 0%;
  }
}

@keyframes liquid-current-one {
  0% {
    transform: translate3d(-8%, 6%, 0) scale(0.92) rotate(-8deg);
  }
  100% {
    transform: translate3d(17%, 23%, 0) scale(1.12) rotate(13deg);
  }
}

@keyframes liquid-current-two {
  0% {
    transform: translate3d(8%, -8%, 0) scale(0.95) rotate(10deg);
  }
  100% {
    transform: translate3d(-17%, -22%, 0) scale(1.16) rotate(-14deg);
  }
}

@keyframes blob-cyan {
  0% {
    transform: translate3d(0, 0, 0) rotate(-10deg) scale(0.95);
  }
  100% {
    transform: translate3d(10%, 17%, 0) rotate(18deg) scale(1.09);
  }
}

@keyframes blob-violet {
  0% {
    transform: translate3d(0, 0, 0) rotate(7deg) scale(0.98);
  }
  100% {
    transform: translate3d(-12%, 19%, 0) rotate(-16deg) scale(1.12);
  }
}

@keyframes blob-coral {
  0% {
    transform: translate3d(0, 0, 0) rotate(-12deg) scale(0.94);
  }
  100% {
    transform: translate3d(-15%, -16%, 0) rotate(15deg) scale(1.1);
  }
}

@keyframes blob-blue {
  0% {
    transform: translate3d(0, 0, 0) rotate(12deg) scale(0.97);
  }
  100% {
    transform: translate3d(18%, -12%, 0) rotate(-15deg) scale(1.08);
  }
}

@media (max-width: 560px) {
  .maintenance-notice {
    padding: 1.5rem;
  }

  .mtr-rule {
    margin-bottom: 1.75rem;
  }

  h1 {
    letter-spacing: 0.09em;
    text-indent: 0.09em;
  }

  .notice-chinese {
    letter-spacing: 0.1em;
    text-indent: 0.1em;
  }

  .notice-english {
    letter-spacing: 0.015em;
  }

  .liquid-highlight {
    width: 92vw;
  }
}