/* a2613 — 现代门户（slate/zinc + teal 强调）*/
:root {
  --bg: #f1f5f9;
  --bg-elevated: #ffffff;
  --ink: #18181b;
  --ink-soft: #3f3f46;
  --muted: #64748b;
  --faint: #94a3b8;
  --line: #e2e8f0;
  --line-strong: #cbd5e1;
  --accent: #0d9488;
  --accent-hover: #0f766e;
  --accent-soft: #ccfbf1;
  --accent-ink: #115e59;
  --brand-bar: #18181b;
  --brand-bar-soft: #27272a;
  --shadow-sm: 0 1px 2px rgba(24, 24, 27, .05);
  --shadow-md: 0 4px 12px rgba(24, 24, 27, .08);
  --shadow-lg: 0 12px 28px rgba(24, 24, 27, .12);
  --radius-xl: .75rem;
  --radius-2xl: 1rem;
  --radius-3xl: 1.25rem;
  --font-sans: "Manrope", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --max-w: 72rem;
  --transition: all .3s ease-in-out;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #09090b;
    --bg-elevated: #18181b;
    --ink: #f4f4f5;
    --ink-soft: #d4d4d8;
    --muted: #a1a1aa;
    --faint: #71717a;
    --line: #27272a;
    --line-strong: #3f3f46;
    --accent: #2dd4bf;
    --accent-hover: #5eead4;
    --accent-soft: #134e4a;
    --accent-ink: #99f6e4;
    --brand-bar: #000000;
    --brand-bar-soft: #18181b;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .35);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, .4);
    --shadow-lg: 0 12px 28px rgba(0, 0, 0, .5);
  }
}

*, *::before, *::after { box-sizing: border-box }
html { line-height: 1.5; -webkit-text-size-adjust: 100% }
body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--ink);
  min-height: 100vh;
}
a { color: inherit; text-decoration: none }
img { max-width: 100%; display: block }
ul, ol { margin: 0; padding: 0; list-style: none }
h1, h2, h3, p { margin: 0 }

/* utility mirrors used by views */
.text-ink { color: var(--ink) }
.text-accent, .hover\:text-accent:hover, .group:hover .group-hover\:text-accent { color: var(--accent) }
.accent-bg { background: var(--accent); color: #fff }
.accent-soft { background: var(--accent-soft); color: var(--accent-ink) }
.accent-text { color: var(--accent); font-weight: 800 }
.bg-surface { background: var(--bg-elevated) }
.bg-page { background: var(--bg) }
.bg-brand { background: var(--brand-bar); color: #fff }
.bg-brand-soft { background: var(--brand-bar-soft) }
.bg-slate-50 { background: var(--bg) }
.bg-slate-100 { background: var(--line) }
.bg-white { background: var(--bg-elevated) }
.bg-white\/20 { background: rgba(255,255,255,.2) }
.bg-white\/90 { background: color-mix(in srgb, var(--bg-elevated) 90%, transparent) }
.bg-white\/95 { background: color-mix(in srgb, var(--bg-elevated) 95%, transparent) }
.text-white { color: #fff }
.text-white\/70 { color: rgba(255,255,255,.7) }
.text-white\/85 { color: rgba(255,255,255,.85) }
.text-slate-300 { color: var(--line-strong) }
.text-slate-400 { color: var(--faint) }
.text-slate-500 { color: var(--muted) }
.text-slate-600 { color: var(--ink-soft) }
.text-slate-700 { color: var(--ink-soft) }
.text-slate-800 { color: var(--ink) }

.min-h-screen { min-height: 100vh }
.flex { display: flex }
.flex-col { flex-direction: column }
.flex-wrap { flex-wrap: wrap }
.flex-1 { flex: 1 1 0% }
.flex-grow { flex-grow: 1 }
.flex-shrink-0 { flex-shrink: 0 }
.grid { display: grid }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)) }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)) }
.hidden { display: none }
.block { display: block }
.inline-block { display: inline-block }
.relative { position: relative }
.absolute { position: absolute }
.fixed { position: fixed }
.sticky { position: sticky }
.inset-0 { inset: 0 }
.inset-x-0 { left: 0; right: 0 }
.top-0 { top: 0 }
.bottom-0 { bottom: 0 }
.z-40 { z-index: 40 }
.z-50 { z-index: 50 }
.items-center { align-items: center }
.items-start { align-items: flex-start }
.items-stretch { align-items: stretch }
.justify-between { justify-content: space-between }
.justify-center { justify-content: center }
.gap-0\.5 { gap: .125rem }
.gap-1 { gap: .25rem }
.gap-1\.5 { gap: .375rem }
.gap-2 { gap: .5rem }
.gap-3 { gap: .75rem }
.gap-4 { gap: 1rem }
.gap-x-1 { column-gap: .25rem }
.gap-x-3 { column-gap: .75rem }
.gap-x-4 { column-gap: 1rem }
.gap-y-1 { row-gap: .25rem }
.gap-y-1\.5 { row-gap: .375rem }
.space-y-3 > :not([hidden]) ~ :not([hidden]) { margin-top: .75rem }
.space-y-5 > :not([hidden]) ~ :not([hidden]) { margin-top: 1.25rem }
.space-y-8 > :not([hidden]) ~ :not([hidden]) { margin-top: 2rem }
.w-1\.5 { width: .375rem }
.w-2 { width: .5rem }
.w-5 { width: 1.25rem }
.w-6 { width: 1.5rem }
.w-20 { width: 5rem }
.w-full { width: 100% }
.w-fit { width: fit-content }
.max-w-6xl { max-width: var(--max-w) }
.max-w-none { max-width: none }
.max-w-xs { max-width: 20rem }
.max-w-xl { max-width: 36rem }
.max-w-\[4rem\] { max-width: 4rem }
.min-w-0 { min-width: 0 }
.h-2 { height: .5rem }
.h-5 { height: 1.25rem }
.h-6 { height: 1.5rem }
.h-7 { height: 1.75rem }
.h-14 { height: 3.5rem }
.h-16 { height: 4rem }
.h-40 { height: 10rem }
.h-48 { height: 12rem }
.h-auto { height: auto }
.h-full { height: 100% }
.m-0 { margin: 0 }
.mx-auto { margin-left: auto; margin-right: auto }
.ml-1 { margin-left: .25rem }
.mt-1\.5 { margin-top: .375rem }
.mt-2 { margin-top: .5rem }
.mt-3 { margin-top: .75rem }
.mt-4 { margin-top: 1rem }
.mt-6 { margin-top: 1.5rem }
.mt-8 { margin-top: 2rem }
.mt-auto { margin-top: auto }
.mb-1 { margin-bottom: .25rem }
.mb-2 { margin-bottom: .5rem }
.mb-3 { margin-bottom: .75rem }
.mb-4 { margin-bottom: 1rem }
.mb-5 { margin-bottom: 1.25rem }
.mb-6 { margin-bottom: 1.5rem }
.mb-8 { margin-bottom: 2rem }
.p-3 { padding: .75rem }
.p-4 { padding: 1rem }
.p-5 { padding: 1.25rem }
.p-6 { padding: 1.5rem }
.p-10 { padding: 2.5rem }
.px-1 { padding-left: .25rem; padding-right: .25rem }
.px-3 { padding-left: .75rem; padding-right: .75rem }
.px-3\.5 { padding-left: .875rem; padding-right: .875rem }
.px-4 { padding-left: 1rem; padding-right: 1rem }
.px-5 { padding-left: 1.25rem; padding-right: 1.25rem }
.px-6 { padding-left: 1.5rem; padding-right: 1.5rem }
.py-1 { padding-top: .25rem; padding-bottom: .25rem }
.py-1\.5 { padding-top: .375rem; padding-bottom: .375rem }
.py-2 { padding-top: .5rem; padding-bottom: .5rem }
.py-2\.5 { padding-top: .625rem; padding-bottom: .625rem }
.py-5 { padding-top: 1.25rem; padding-bottom: 1.25rem }
.py-6 { padding-top: 1.5rem; padding-bottom: 1.5rem }
.pb-5 { padding-bottom: 1.25rem }
.pb-16 { padding-bottom: 4rem }
.pt-2 { padding-top: .5rem }
.pt-5 { padding-top: 1.25rem }
.pt-7 { padding-top: 1.75rem }
.rounded-xl { border-radius: var(--radius-xl) }
.rounded-2xl { border-radius: var(--radius-2xl) }
.rounded-3xl { border-radius: var(--radius-3xl) }
.rounded-full { border-radius: 9999px }
.border-b { border-bottom: 1px solid var(--line) }
.border-t { border-top: 1px solid var(--line) }
.border-slate-100 { border-color: var(--line) }
.ring-1 { box-shadow: 0 0 0 1px var(--tw-ring-color, var(--line)) }
.ring-slate-100 { --tw-ring-color: var(--line) }
.ring-slate-200 { --tw-ring-color: var(--line-strong) }
.shadow-sm { box-shadow: var(--shadow-sm) }
.shadow-lg { box-shadow: var(--shadow-lg) }
.shadow-\[0_-2px_10px_rgba\(0\,0\,0\,0\.06\)\] { box-shadow: 0 -2px 10px rgba(0,0,0,.06) }
.overflow-hidden { overflow: hidden }
.whitespace-nowrap { white-space: nowrap }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap }
.line-clamp-2 { overflow: hidden; display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 2 }
.object-cover { object-fit: cover }
.opacity-10 { opacity: .1 }
.cursor-pointer { cursor: pointer }
.backdrop-blur { -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px) }
.font-normal { font-weight: 400 }
.font-medium { font-weight: 500 }
.font-semibold { font-weight: 600 }
.font-bold { font-weight: 700 }
.font-extrabold { font-weight: 800 }
.text-xs { font-size: .75rem; line-height: 1rem }
.text-sm { font-size: .875rem; line-height: 1.25rem }
.text-lg { font-size: 1.125rem; line-height: 1.75rem }
.text-xl { font-size: 1.25rem; line-height: 1.75rem }
.text-2xl { font-size: 1.5rem; line-height: 2rem }
.text-\[11px\] { font-size: 11px }
.text-center { text-align: center }
.leading-none { line-height: 1 }
.leading-6 { line-height: 1.5rem }
.leading-snug { line-height: 1.375 }
.leading-relaxed { line-height: 1.625 }
.decoration-2 { text-decoration-thickness: 2px }
.underline-offset-4 { text-underline-offset: 4px }
.transition-all { transition: var(--transition) }
.transition-colors { transition: color .3s ease-in-out, background-color .3s ease-in-out, border-color .3s ease-in-out }
.transition-transform { transition: transform .3s ease-in-out }
.transition-opacity { transition: opacity .3s ease-in-out }
.duration-300 { transition-duration: .3s }
.hover\:text-white:hover { color: #fff }
.hover\:accent-bg:hover { background: var(--accent); color: #fff }
.hover\:opacity-90:hover { opacity: .9 }
.hover\:shadow-lg:hover { box-shadow: var(--shadow-lg) }
.hover\:shadow-md:hover { box-shadow: var(--shadow-md) }
.hover\:-translate-y-0\.5:hover { transform: translateY(-.125rem) }
.hover\:ring-accent:hover { --tw-ring-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) }
.group:hover .group-hover\:underline { text-decoration: underline }
.group:hover .group-hover\:scale-\[1\.03\] { transform: scale(1.03) }
.focus\:outline-none:focus { outline: none }
.focus\:ring-2:focus { box-shadow: 0 0 0 2px var(--accent-soft) }

/* a2613-specific layout pieces */
.a13-shell { min-height: 100vh; display: flex; flex-direction: column; padding-bottom: 4rem }
.a13-header {
  position: sticky; top: 0; z-index: 40;
  background: color-mix(in srgb, var(--bg-elevated) 88%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.a13-brand {
  font-size: 1.35rem; font-weight: 800; letter-spacing: -.02em;
  color: var(--ink); white-space: nowrap;
}
.a13-brand span { color: var(--accent) }
.a13-nav-link {
  padding: .35rem .85rem; border-radius: 999px; font-size: .875rem;
  color: var(--ink-soft); transition: var(--transition); white-space: nowrap; flex-shrink: 0;
}
.a13-nav-link:hover { background: var(--accent); color: #fff }
/* 手机：频道横滑；桌面：自然换行 */
.a13-channel-nav { position: relative }
.a13-nav-scroll {
  display: flex; flex-wrap: nowrap; align-items: center;
  gap: .25rem; overflow-x: auto; overflow-y: hidden;
  -webkit-overflow-scrolling: touch; overscroll-behavior-x: contain;
  scrollbar-width: none; scroll-snap-type: x proximity;
  mask-image: linear-gradient(90deg, #000 0%, #000 calc(100% - 1.75rem), transparent 100%);
  -webkit-mask-image: linear-gradient(90deg, #000 0%, #000 calc(100% - 1.75rem), transparent 100%);
}
.a13-nav-scroll::-webkit-scrollbar { display: none; width: 0; height: 0 }
.a13-nav-scroll .a13-nav-link { scroll-snap-align: start }
.a13-masthead {
  background: linear-gradient(145deg, var(--brand-bar) 0%, var(--brand-bar-soft) 55%, #134e4a 100%);
  color: #fff; border-radius: var(--radius-3xl); padding: 1.75rem 1.5rem;
  box-shadow: var(--shadow-lg); margin-bottom: 1.5rem;
  position: relative; overflow: hidden;
}
.a13-masthead::after {
  content: ""; position: absolute; right: -10%; top: -40%;
  width: 55%; height: 160%; border-radius: 50%;
  background: radial-gradient(circle, rgba(45,212,191,.28), transparent 65%);
  pointer-events: none;
}
.a13-masthead-inner { position: relative; z-index: 1 }
.a13-masthead-kicker {
  display: inline-flex; align-items: center; gap: .4rem;
  font-size: .7rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase;
  color: #99f6e4; margin-bottom: .75rem;
}
.a13-masthead-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 800;
  letter-spacing: -.03em; line-height: 1.15; margin: 0;
}
.a13-masthead-desc {
  margin-top: .75rem; max-width: 36rem; font-size: .9rem;
  color: rgba(255,255,255,.78); line-height: 1.6;
}
.a13-card {
  background: var(--bg-elevated); border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-sm); outline: 1px solid var(--line);
  overflow: hidden; transition: var(--transition);
}
.a13-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px) }
.a13-section-mark {
  width: .4rem; height: 1.25rem; border-radius: 999px;
  background: var(--accent); display: inline-block;
}
.a13-badge {
  display: inline-flex; align-items: center; justify-content: center;
  width: 1.5rem; height: 1.5rem; border-radius: 999px;
  background: var(--accent); color: #fff; font-size: .7rem; font-weight: 700;
}
.a13-footer {
  margin-top: auto; background: var(--bg-elevated);
  border-top: 1px solid var(--line);
}
.a13-bottom-nav {
  position: fixed; bottom: 0; left: 0; right: 0; z-index: 50;
  height: 4rem; display: grid; grid-template-columns: repeat(3, 1fr);
  background: color-mix(in srgb, var(--bg-elevated) 95%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--line);
  box-shadow: 0 -2px 10px rgba(0,0,0,.06);
}
.a13-bottom-nav a {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .125rem; color: var(--muted); font-size: 11px; transition: color .3s ease-in-out;
}
.a13-bottom-nav a:hover { color: var(--accent) }
.a13-bottom-nav svg { width: 1.25rem; height: 1.25rem }

.prose { color: var(--ink-soft); max-width: 65ch }
.prose-sm { font-size: .875rem; line-height: 1.714 }
.prose :where(p) { margin-top: 1.142em; margin-bottom: 1.142em }
.prose :where(h2) { font-size: 1.25em; margin-top: 1.6em; margin-bottom: .6em; font-weight: 700; color: var(--ink) }
.prose :where(h3) { font-size: 1.1em; margin-top: 1.4em; margin-bottom: .5em; font-weight: 700; color: var(--ink) }
.prose :where(ul) { list-style: disc; padding-left: 1.5em; margin: 1em 0 }
.prose :where(ol) { list-style: decimal; padding-left: 1.5em; margin: 1em 0 }
.prose :where(li) { margin: .35em 0 }
.prose :where(img) { margin: 1.2em 0; border-radius: 1rem; height: auto }
.prose :where(a) { color: var(--accent); text-decoration: underline }
.prose :where(blockquote) { border-left: 3px solid var(--accent); padding-left: 1em; color: var(--muted); margin: 1.2em 0 }
.prose-headings\:font-bold :where(h1,h2,h3,h4) { font-weight: 700 }
.prose-a\:text-accent :where(a) { color: var(--accent) }
.prose-img\:rounded-2xl :where(img) { border-radius: 1rem }

@media (min-width: 640px) {
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)) }
  .sm\:col-span-2 { grid-column: span 2 / span 2 }
}
@media (min-width: 768px) {
  .md\:flex { display: flex }
  .md\:block { display: block }
  .md\:hidden { display: none }
  .md\:flex-row { flex-direction: row }
  .md\:w-1\/2 { width: 50% }
  .md\:w-2\/5 { width: 40% }
  .md\:w-3\/5 { width: 60% }
  .md\:h-64 { height: 16rem }
  .md\:h-auto { height: auto }
  .md\:p-8 { padding: 2rem }
  .md\:pb-0 { padding-bottom: 0 }
  .md\:text-xl { font-size: 1.25rem; line-height: 1.75rem }
  .md\:text-2xl { font-size: 1.5rem; line-height: 2rem }
  .md\:text-3xl { font-size: 1.875rem; line-height: 2.25rem }
  .a13-shell { padding-bottom: 0 }
  .a13-bottom-nav { display: none }
  .a13-nav-scroll {
    flex-wrap: wrap; overflow-x: visible; gap: .25rem .25rem;
    mask-image: none; -webkit-mask-image: none; scroll-snap-type: none;
  }
  .a13-masthead { padding: 2.25rem 2rem }
}
@media (min-width: 1024px) {
  .lg\:grid { display: grid }
  .lg\:grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)) }
  .lg\:col-span-3 { grid-column: span 3 / span 3 }
  .lg\:gap-6 { gap: 1.5rem }
  .lg\:mt-0 { margin-top: 0 }
  .lg\:block { display: block }
}