/* HTTP Error Pages — unified theme */
:root {
  --bg-0: #0b141c;
  --bg-1: #12202c;
  --bg-2: #1a2d3d;
  --ink: #e8f0f5;
  --muted: #8aa0b2;
  --line: rgba(148, 180, 204, 0.18);
  --accent: #3ecfba;
  --accent-soft: rgba(62, 207, 186, 0.14);
  --warn: #f0b429;
  --warn-soft: rgba(240, 180, 41, 0.14);
  --danger: #ff7a6e;
  --danger-soft: rgba(255, 122, 110, 0.14);
  --shadow: 0 24px 64px rgba(0, 0, 0, 0.35);
  --radius: 20px;
  --font: "Segoe UI Variable", "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  --mono: "Cascadia Code", "Consolas", "SF Mono", "Menlo", monospace;
}

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

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

body {
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 700px at 12% -10%, rgba(62, 207, 186, 0.16), transparent 55%),
    radial-gradient(900px 600px at 88% 110%, rgba(240, 180, 41, 0.1), transparent 50%),
    linear-gradient(160deg, var(--bg-0), var(--bg-1) 48%, var(--bg-2));
  background-attachment: fixed;
  display: grid;
  place-items: center;
  padding: 32px 20px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, black 20%, transparent 75%);
  opacity: 0.45;
}

.page {
  position: relative;
  width: min(920px, 100%);
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: center;
  animation: rise 0.7s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.visual {
  display: grid;
  place-items: center;
  min-height: 280px;
}

.visual svg {
  width: min(360px, 100%);
  height: auto;
  filter: drop-shadow(0 18px 40px rgba(0, 0, 0, 0.35));
}

.content {
  max-width: 440px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 14px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(18, 32, 44, 0.55);
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--tone, var(--accent));
  box-shadow: 0 0 0 4px var(--tone-soft, var(--accent-soft));
}

.code {
  margin: 0;
  font-family: var(--mono);
  font-size: clamp(4.5rem, 12vw, 6.5rem);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.04em;
  background: linear-gradient(135deg, var(--ink) 20%, var(--tone, var(--accent)));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.title {
  margin: 18px 0 10px;
  font-size: clamp(1.55rem, 3.4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.desc {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 1.02rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  appearance: none;
  border: 0;
  border-radius: 12px;
  padding: 12px 18px;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  color: #062018;
  background: linear-gradient(135deg, #66e6d2, var(--accent));
}

.btn-primary:hover {
  background: linear-gradient(135deg, #7aedd9, #4ad9c3);
}

.btn-ghost {
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
}

.btn-ghost:hover {
  border-color: rgba(62, 207, 186, 0.45);
  background: rgba(62, 207, 186, 0.08);
}

.meta {
  margin-top: 28px;
  color: color-mix(in srgb, var(--muted) 85%, transparent);
  font-size: 0.85rem;
}

.meta code {
  font-family: var(--mono);
  color: var(--tone, var(--accent));
}

/* tone variants */
.tone-warn {
  --tone: var(--warn);
  --tone-soft: var(--warn-soft);
}

.tone-danger {
  --tone: var(--danger);
  --tone-soft: var(--danger-soft);
}

.tone-accent {
  --tone: var(--accent);
  --tone-soft: var(--accent-soft);
}

/* svg motion helpers */
.float {
  animation: float 4.8s ease-in-out infinite;
}

.pulse {
  animation: pulse 2.8s ease-in-out infinite;
}

.spin-slow {
  transform-origin: center;
  animation: spin 14s linear infinite;
}

.dash {
  stroke-dasharray: 6 8;
  animation: dash 1.8s linear infinite;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

@keyframes pulse {
  0%,
  100% {
    opacity: 0.55;
  }
  50% {
    opacity: 1;
  }
}

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

@keyframes dash {
  to {
    stroke-dashoffset: -28;
  }
}

@media (max-width: 760px) {
  .page {
    grid-template-columns: 1fr;
    text-align: center;
    justify-items: center;
  }

  .content {
    order: 1;
  }

  .visual {
    order: 0;
    min-height: 220px;
  }

  .visual svg {
    width: min(280px, 86vw);
  }

  .actions {
    justify-content: center;
  }

  .eyebrow {
    margin-left: auto;
    margin-right: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}