/* Articles / docs center */
:root {
  --art-ink: #122033;
  --art-muted: #5b6b7c;
  --art-line: rgba(18, 32, 51, 0.1);
  --art-panel: rgba(255, 255, 255, 0.78);
  --art-accent: #0f766e;
  --art-accent-2: #0369a1;
  --art-glow: rgba(15, 118, 110, 0.18);
  --art-font: "Sora", "Noto Sans SC", sans-serif;
  --art-display: "Fraunces", "Noto Serif SC", Georgia, serif;
}

.art-page {
  min-height: 100vh;
  color: var(--art-ink);
  font-family: var(--art-font);
  background:
    radial-gradient(ellipse 70% 45% at 8% -5%, rgba(3, 105, 161, 0.16), transparent 55%),
    radial-gradient(ellipse 55% 40% at 92% 8%, rgba(15, 118, 110, 0.14), transparent 50%),
    linear-gradient(165deg, #f4f7fb 0%, #e8eef5 42%, #f7faf8 100%);
  position: relative;
  overflow-x: hidden;
}

.art-page::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(18, 32, 51, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 32, 51, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.35), transparent 70%);
}

.art-shell {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.25rem 0 3.5rem;
  position: relative;
  z-index: 1;
}

.art-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1rem;
  margin-bottom: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.65);
  border-radius: 1.15rem;
  background: rgba(255, 255, 255, 0.55);
  backdrop-filter: blur(14px);
  box-shadow: 0 10px 40px rgba(18, 32, 51, 0.05);
  animation: art-rise 0.55s ease both;
}

.art-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: inherit;
}

.art-brand__mark {
  width: 2.35rem;
  height: 2.35rem;
  border-radius: 0.75rem;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: #fff;
  background: linear-gradient(145deg, #0f766e, #0369a1);
  box-shadow: 0 8px 18px var(--art-glow);
}

.art-brand__text {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}

.art-brand__title {
  font-weight: 700;
  font-size: 0.98rem;
  line-height: 1.2;
}

.art-brand__sub {
  font-size: 0.72rem;
  color: var(--art-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.art-nav__actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.art-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.35rem;
  padding: 0.45rem 0.95rem;
  border-radius: 999px;
  border: 1px solid transparent;
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 600;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

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

.art-btn--ghost {
  color: var(--art-ink);
  background: rgba(255, 255, 255, 0.7);
  border-color: var(--art-line);
}

.art-btn--ghost:hover {
  border-color: rgba(15, 118, 110, 0.35);
  box-shadow: 0 8px 18px rgba(18, 32, 51, 0.06);
}

.art-btn--primary {
  color: #fff;
  background: linear-gradient(135deg, #0f766e, #0e7490 55%, #0369a1);
  box-shadow: 0 10px 22px rgba(3, 105, 161, 0.22);
}

.art-btn--primary:hover {
  box-shadow: 0 14px 28px rgba(3, 105, 161, 0.28);
}

.art-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.9fr);
  gap: 1.25rem;
  margin-bottom: 1.35rem;
  animation: art-rise 0.65s 0.05s ease both;
}

.art-hero__copy {
  padding: 1.6rem 1.7rem 1.7rem;
  border-radius: 1.4rem;
  border: 1px solid rgba(255, 255, 255, 0.7);
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.88), rgba(240, 249, 255, 0.72)),
    radial-gradient(circle at 90% 10%, rgba(15, 118, 110, 0.12), transparent 45%);
  box-shadow: 0 18px 50px rgba(18, 32, 51, 0.06);
}

.art-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0 0 0.75rem;
  padding: 0.28rem 0.65rem;
  border-radius: 999px;
  background: rgba(15, 118, 110, 0.1);
  color: var(--art-accent);
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0.04em;
}

.art-hero__title {
  margin: 0 0 0.65rem;
  font-family: var(--art-display);
  font-size: clamp(1.8rem, 3.4vw, 2.55rem);
  font-weight: 650;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

.art-hero__desc {
  margin: 0;
  max-width: 34rem;
  color: var(--art-muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

.art-hero__visual {
  position: relative;
  min-height: 11rem;
  border-radius: 1.4rem;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.65);
  background:
    radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.35), transparent 40%),
    linear-gradient(145deg, #0f766e 0%, #0e7490 48%, #0c4a6e 100%);
  box-shadow: 0 18px 50px rgba(15, 118, 110, 0.18);
}

.art-hero__visual::before,
.art-hero__visual::after {
  content: "";
  position: absolute;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  animation: art-float 6s ease-in-out infinite;
}

.art-hero__visual::before {
  width: 9rem;
  height: 9rem;
  top: -2rem;
  right: -1.5rem;
}

.art-hero__visual::after {
  width: 5.5rem;
  height: 5.5rem;
  left: 1.2rem;
  bottom: 1rem;
  animation-delay: 1.2s;
}

.art-hero__visual-inner {
  position: absolute;
  inset: auto 1.25rem 1.25rem 1.25rem;
  color: #fff;
}

.art-hero__visual-inner strong {
  display: block;
  font-family: var(--art-display);
  font-size: 1.35rem;
  font-weight: 650;
  margin-bottom: 0.25rem;
}

.art-hero__visual-inner span {
  opacity: 0.85;
  font-size: 0.86rem;
}

.art-layout {
  display: grid;
  grid-template-columns: 15rem minmax(0, 1fr);
  gap: 1.15rem;
  align-items: start;
  animation: art-rise 0.7s 0.1s ease both;
}

.art-aside {
  position: sticky;
  top: 1rem;
  padding: 1rem;
  border-radius: 1.2rem;
  border: 1px solid rgba(255, 255, 255, 0.7);
  background: var(--art-panel);
  backdrop-filter: blur(12px);
  box-shadow: 0 12px 36px rgba(18, 32, 51, 0.05);
}

.art-aside__label {
  margin: 0 0 0.7rem 0.35rem;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #8090a1;
}

.art-cat {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.58rem 0.7rem;
  margin-bottom: 0.28rem;
  border-radius: 0.75rem;
  color: #334155;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 550;
  transition: background 0.16s ease, color 0.16s ease, transform 0.16s ease;
}

.art-cat:hover {
  background: rgba(15, 118, 110, 0.08);
  color: var(--art-accent);
  transform: translateX(2px);
}

.art-cat.is-active {
  background: linear-gradient(135deg, rgba(15, 118, 110, 0.14), rgba(3, 105, 161, 0.1));
  color: #0f5f5a;
  box-shadow: inset 0 0 0 1px rgba(15, 118, 110, 0.18);
}

.art-main {
  padding: 1.35rem 1.4rem 1.55rem;
  border-radius: 1.25rem;
  border: 1px solid rgba(255, 255, 255, 0.7);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(10px);
  box-shadow: 0 16px 44px rgba(18, 32, 51, 0.05);
}

.art-main__head {
  margin-bottom: 1.15rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--art-line);
}

.art-main__title {
  margin: 0 0 0.35rem;
  font-family: var(--art-display);
  font-size: clamp(1.35rem, 2.4vw, 1.75rem);
  font-weight: 650;
  letter-spacing: -0.01em;
}

.art-main__desc {
  margin: 0;
  color: var(--art-muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

.art-grid {
  display: grid;
  gap: 0.85rem;
}

.art-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.9rem;
  align-items: start;
  padding: 1rem 1.05rem;
  border-radius: 1rem;
  border: 1px solid var(--art-line);
  background: linear-gradient(180deg, #fff, #f8fafc);
  color: inherit;
  text-decoration: none;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.art-card:hover {
  transform: translateY(-3px);
  border-color: rgba(15, 118, 110, 0.28);
  box-shadow: 0 16px 34px rgba(18, 32, 51, 0.08);
}

.art-card__index {
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 0.7rem;
  display: grid;
  place-items: center;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--art-accent);
  background: rgba(15, 118, 110, 0.1);
}

.art-card__title {
  margin: 0 0 0.3rem;
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.35;
}

.art-card__meta {
  margin: 0;
  color: #8a97a8;
  font-size: 0.78rem;
}

.art-card__summary {
  margin: 0.45rem 0 0;
  color: var(--art-muted);
  font-size: 0.88rem;
  line-height: 1.55;
}

.art-card__arrow {
  align-self: center;
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 999px;
  display: grid;
  place-items: center;
  color: var(--art-accent);
  background: rgba(15, 118, 110, 0.08);
  transition: transform 0.18s ease, background 0.18s ease;
}

.art-card:hover .art-card__arrow {
  transform: translateX(3px);
  background: rgba(15, 118, 110, 0.16);
}

.art-empty {
  padding: 2.4rem 1.2rem;
  text-align: center;
  border-radius: 1rem;
  border: 1px dashed rgba(18, 32, 51, 0.16);
  background: rgba(248, 250, 252, 0.8);
}

.art-empty__icon {
  width: 3.2rem;
  height: 3.2rem;
  margin: 0 auto 0.85rem;
  border-radius: 1rem;
  display: grid;
  place-items: center;
  color: var(--art-accent);
  background: rgba(15, 118, 110, 0.1);
  font-size: 1.35rem;
}

.art-empty p {
  margin: 0;
  color: var(--art-muted);
  font-size: 0.92rem;
}

.art-detail__crumb {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 0.85rem;
  color: var(--art-accent);
  text-decoration: none;
  font-size: 0.84rem;
  font-weight: 600;
}

.art-detail__crumb:hover {
  text-decoration: underline;
}

.art-detail__title {
  margin: 0 0 0.55rem;
  font-family: var(--art-display);
  font-size: clamp(1.55rem, 3vw, 2.1rem);
  font-weight: 650;
  letter-spacing: -0.02em;
  line-height: 1.22;
}

.art-detail__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.85rem;
  margin: 0 0 1.25rem;
  color: #8090a1;
  font-size: 0.82rem;
}

.art-detail__chip {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  background: rgba(3, 105, 161, 0.08);
  color: var(--art-accent-2);
  font-weight: 600;
}

.art-detail__summary {
  margin: 0 0 1.25rem;
  padding: 0.9rem 1rem;
  border-radius: 0.9rem;
  border-left: 3px solid var(--art-accent);
  background: rgba(15, 118, 110, 0.06);
  color: #3d5166;
  font-size: 0.94rem;
  line-height: 1.65;
}

.art-detail__body {
  white-space: pre-wrap;
  word-break: break-word;
  color: #243447;
  font-size: 1rem;
  line-height: 1.85;
}

.art-detail__foot {
  margin-top: 1.75rem;
  padding-top: 1rem;
  border-top: 1px solid var(--art-line);
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}

@keyframes art-rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@media (max-width: 900px) {
  .art-hero {
    grid-template-columns: 1fr;
  }

  .art-hero__visual {
    min-height: 8.5rem;
  }

  .art-layout {
    grid-template-columns: 1fr;
  }

  .art-aside {
    position: static;
  }

  .art-aside__cats {
    display: flex;
    flex-wrap: wrap;
    gap: 0.35rem;
  }

  .art-cat {
    margin-bottom: 0;
  }

  .art-card {
    grid-template-columns: auto minmax(0, 1fr);
  }

  .art-card__arrow {
    display: none;
  }
}