/* ============================================================
   5电竞主站 — /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 页头 / 页脚 / 通用组件
   ============================================================ */

/* ---------- 0. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body { margin: 0; }

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }

ul, ol { padding: 0; list-style: none; }

img, svg, video { display: block; max-width: 100%; }

button, input, select, textarea { font: inherit; color: inherit; }

a { color: inherit; }

[hidden] { display: none !important; }

/* ---------- 1. 变量 ---------- */
:root {
  --k5-carbon: #0B0D10;
  --k5-ink: #141923;
  --k5-paper: #F4F7FA;
  --k5-steel: #C7D1DB;
  --k5-cyan: #00E5FF;
  --k5-cyan-deep: #007C8A;
  --k5-violet: #7C4DFF;
  --k5-yellow: #E6FF00;
  --k5-red: #FF4D6D;
  --k5-green: #42F5A7;

  --k5-line: rgba(199, 209, 219, .16);
  --k5-line-strong: rgba(199, 209, 219, .34);
  --k5-cyan-a: rgba(0, 229, 255, .14);
  --k5-violet-a: rgba(124, 77, 255, .18);

  --k5-wrap: 1240px;
  --k5-gutter: clamp(1.15rem, 4vw, 3.25rem);
  --k5-h-header: 84px;
  --k5-radius: 2px;

  --k5-font-display: "K5 Display", Impact, "Arial Black", "Noto Sans SC", "PingFang SC", sans-serif;
  --k5-font-editorial: "K5 Editorial", "Noto Serif SC", "Songti SC", Georgia, serif;
  --k5-font-body: "K5 Sans", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --k5-font-mono: "K5 Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --k5-dur: 220ms;
  --k5-ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 2. 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--k5-h-header);
  background-color: var(--k5-carbon);
  background-image:
    radial-gradient(58% 42% at 88% -6%, rgba(124, 77, 255, .20), transparent 68%),
    radial-gradient(52% 40% at -4% 2%, rgba(0, 229, 255, .14), transparent 70%);
  background-repeat: no-repeat;
  color: var(--k5-paper);
  font-family: var(--k5-font-body);
  font-size: 1rem;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--k5-font-display);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.01em;
  text-wrap: balance;
}

h1 { font-size: clamp(2.4rem, 5vw, 4.6rem); }
h2 { font-size: clamp(1.8rem, 3vw, 2.8rem); }
h3 { font-size: clamp(1.15rem, 1.6vw, 1.5rem); }

p { text-wrap: pretty; }

strong { color: var(--k5-paper); font-weight: 700; }

a { text-decoration-color: rgba(0, 229, 255, .55); text-underline-offset: .22em; }

:focus-visible {
  outline: 2px solid var(--k5-yellow);
  outline-offset: 3px;
  border-radius: var(--k5-radius);
}

::selection {
  background: var(--k5-cyan);
  color: #04141A;
}

/* ---------- 3. 容器与章节 ---------- */
.k5-wrap {
  width: min(100% - (var(--k5-gutter) * 2), var(--k5-wrap));
  margin-inline: auto;
}

.k5-section {
  position: relative;
  padding-block: clamp(2.6rem, 6vw, 5.2rem);
}

.k5-section--ink {
  background: var(--k5-ink);
  border-block: 1px solid var(--k5-line);
}

.k5-section--paper {
  --k5-line: rgba(11, 13, 16, .14);
  --k5-line-strong: rgba(11, 13, 16, .32);
  background: var(--k5-paper);
  color: var(--k5-carbon);
}

.k5-section--paper h1,
.k5-section--paper h2,
.k5-section--paper h3 { color: var(--k5-carbon); }

.k5-section--paper strong { color: #000; }

.k5-section--paper .k5-eyebrow { color: var(--k5-cyan-deep); }

.k5-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .62rem;
  font-family: var(--k5-font-mono);
  font-size: .72rem;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--k5-cyan);
}

.k5-eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: linear-gradient(90deg, currentColor, transparent);
}

.k5-lede {
  max-width: 62ch;
  font-size: clamp(1rem, 1.35vw, 1.14rem);
  color: var(--k5-steel);
}

.k5-section--paper .k5-lede { color: #3C4652; }

.k5-chapter {
  display: inline-flex;
  align-items: baseline;
  gap: .5rem;
  font-family: var(--k5-font-mono);
  font-size: .74rem;
  letter-spacing: .18em;
  color: var(--k5-steel);
}

.k5-chapter::before {
  content: "";
  width: 10px;
  height: 10px;
  background: var(--k5-yellow);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}

/* ---------- 4. 通用按钮 ---------- */
.k5-btn {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  padding: .76rem 1.28rem;
  border: 1px solid var(--k5-line-strong);
  border-radius: var(--k5-radius);
  background: transparent;
  color: var(--k5-paper);
  font-family: var(--k5-font-body);
  font-size: .92rem;
  font-weight: 600;
  letter-spacing: .04em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--k5-dur) var(--k5-ease),
    color var(--k5-dur) var(--k5-ease),
    border-color var(--k5-dur) var(--k5-ease),
    transform var(--k5-dur) var(--k5-ease),
    box-shadow var(--k5-dur) var(--k5-ease);
}

.k5-btn:hover { transform: translateY(-2px); }

.k5-btn--primary {
  border-color: var(--k5-cyan);
  background: var(--k5-cyan);
  color: #04141A;
  box-shadow: 0 14px 34px -20px rgba(0, 229, 255, .95);
}

.k5-btn--primary:hover {
  background: #6FF2FF;
  border-color: #6FF2FF;
  box-shadow: 0 18px 40px -20px rgba(0, 229, 255, 1);
}

.k5-btn--ghost:hover {
  border-color: var(--k5-cyan);
  color: var(--k5-cyan);
}

.k5-btn--yellow {
  border-color: var(--k5-yellow);
  background: var(--k5-yellow);
  color: #0B0D10;
}

/* ---------- 5. 跳转链接 ---------- */
.k5-skip {
  position: fixed;
  top: .7rem;
  left: .7rem;
  z-index: 400;
  padding: .72rem 1.15rem;
  background: var(--k5-yellow);
  color: #0B0D10;
  font-family: var(--k5-font-mono);
  font-size: .8rem;
  letter-spacing: .1em;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform var(--k5-dur) var(--k5-ease);
}

.k5-skip:focus {
  transform: translateY(0);
  outline: 2px solid var(--k5-cyan);
  outline-offset: 2px;
}

/* ---------- 6. 页头 ---------- */
.k5-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 200;
  color: var(--k5-paper);
  background: linear-gradient(180deg, rgba(11, 13, 16, .94) 0%, rgba(11, 13, 16, .72) 58%, rgba(11, 13, 16, 0) 100%);
  transition:
    background-color var(--k5-dur) var(--k5-ease),
    box-shadow var(--k5-dur) var(--k5-ease),
    backdrop-filter var(--k5-dur) var(--k5-ease);
}

.k5-header[data-scrolled] {
  background: rgba(11, 13, 16, .95);
  backdrop-filter: blur(14px) saturate(130%);
  box-shadow:
    0 1px 0 0 rgba(0, 229, 255, .38),
    0 22px 48px -34px rgba(0, 229, 255, .9);
}

.k5-header__bar {
  display: flex;
  align-items: center;
  gap: clamp(.7rem, 2vw, 2rem);
  width: min(100% - (var(--k5-gutter) * 2), var(--k5-wrap));
  margin-inline: auto;
  padding-block: 1.05rem;
  transition: padding-block var(--k5-dur) var(--k5-ease);
}

.k5-header[data-scrolled] .k5-header__bar { padding-block: .5rem; }

/* 品牌 */
.k5-brand {
  display: inline-flex;
  align-items: center;
  gap: .72rem;
  margin-inline-end: auto;
  text-decoration: none;
  color: var(--k5-paper);
}

.k5-brand__mark {
  display: grid;
  place-items: center;
  min-width: 2.9rem;
  height: 2.9rem;
  padding-inline: .45rem;
  font-family: var(--k5-font-display);
  font-size: 1.02rem;
  letter-spacing: .08em;
  color: var(--k5-cyan);
  border: 1px solid rgba(0, 229, 255, .75);
  background: linear-gradient(140deg, rgba(0, 229, 255, .20), rgba(124, 77, 255, .22));
  clip-path: polygon(0 0, 100% 0, 100% 68%, 76% 100%, 0 100%);
  text-shadow: 0 0 14px rgba(0, 229, 255, .8);
}

.k5-brand__text { display: grid; gap: .06rem; }

.k5-brand__name {
  font-family: var(--k5-font-display);
  font-size: 1.06rem;
  letter-spacing: .04em;
  line-height: 1.1;
}

.k5-brand__domain {
  font-family: var(--k5-font-mono);
  font-size: .64rem;
  letter-spacing: .16em;
  color: var(--k5-steel);
}

/* 导航（桌面） */
.k5-nav { display: flex; align-items: center; }

.k5-nav__list {
  display: flex;
  align-items: center;
  gap: .1rem;
}

.k5-nav__item { display: block; }

.k5-nav__link {
  position: relative;
  display: inline-block;
  padding: .55rem .72rem;
  color: var(--k5-steel);
  font-size: .94rem;
  letter-spacing: .02em;
  text-decoration: none;
  transition: color var(--k5-dur) var(--k5-ease);
}

.k5-nav__link::after {
  content: "";
  position: absolute;
  left: .72rem;
  right: .72rem;
  bottom: .26rem;
  height: 2px;
  background: linear-gradient(90deg, var(--k5-cyan), var(--k5-violet));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--k5-dur) var(--k5-ease);
}

.k5-nav__link:hover,
.k5-nav__link:focus-visible { color: var(--k5-paper); }

.k5-nav__link:hover::after,
.k5-nav__link:focus-visible::after { transform: scaleX(1); }

.k5-nav__link[aria-current="page"] { color: var(--k5-cyan); }

.k5-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--k5-cyan);
  box-shadow: 0 0 12px rgba(0, 229, 255, .85);
}

.k5-nav__foot { display: none; }

/* 右侧操作区 */
.k5-header__end {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.k5-header__cta { padding: .62rem 1.05rem; font-size: .86rem; }

/* 菜单按钮 */
.k5-nav-toggle {
  display: none;
  align-items: center;
  gap: .55rem;
  padding: .55rem .7rem;
  border: 1px solid rgba(0, 229, 255, .5);
  border-radius: var(--k5-radius);
  background: rgba(20, 25, 35, .8);
  color: var(--k5-paper);
  font-family: var(--k5-font-mono);
  font-size: .72rem;
  letter-spacing: .14em;
  cursor: pointer;
  transition: border-color var(--k5-dur) var(--k5-ease), background-color var(--k5-dur) var(--k5-ease);
}

.k5-nav-toggle:hover { border-color: var(--k5-cyan); background: rgba(0, 229, 255, .12); }

.k5-nav-toggle__bars { display: grid; gap: 3px; width: 16px; }

.k5-nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--k5-cyan);
  transition: transform var(--k5-dur) var(--k5-ease), opacity var(--k5-dur) var(--k5-ease);
}

.k5-nav-toggle[aria-expanded="true"] .k5-nav-toggle__bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}

.k5-nav-toggle[aria-expanded="true"] .k5-nav-toggle__bars span:nth-child(2) {
  opacity: 0;
  transform: scaleX(.2);
}

.k5-nav-toggle[aria-expanded="true"] .k5-nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

/* 阅读进度 */
.k5-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  overflow: hidden;
  background: rgba(199, 209, 219, .12);
}

.k5-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--k5-cyan), var(--k5-violet) 62%, var(--k5-yellow));
  transition: transform 120ms linear;
}

/* ---------- 7. 页头移动端抽屉 ---------- */
@media (max-width: 1023px) {
  .k5-header__cta { display: none; }

  .k5-nav-toggle { display: inline-flex; }

  .k5-nav {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 5;
    display: flex;
    flex-direction: column;
    max-height: 82vh;
    overflow-y: auto;
    padding: 1.1rem var(--k5-gutter) calc(1.5rem + env(safe-area-inset-bottom, 0px));
    background: linear-gradient(180deg, rgba(20, 25, 35, .99), rgba(11, 13, 16, .99));
    border-top: 1px solid rgba(0, 229, 255, .45);
    box-shadow: 0 -34px 70px -34px rgba(0, 229, 255, .75);
    transform: translateY(104%);
    visibility: hidden;
    transition: transform 260ms var(--k5-ease), visibility 260ms;
  }

  .k5-nav[data-open] {
    transform: translateY(0);
    visibility: visible;
    transition: transform 260ms var(--k5-ease), visibility 0s;
  }

  .k5-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    counter-reset: k5nav;
  }

  .k5-nav__item {
    counter-increment: k5nav;
    border-bottom: 1px solid var(--k5-line);
  }

  .k5-nav__link {
    display: block;
    padding: .92rem .2rem;
    font-family: var(--k5-font-display);
    font-size: 1.12rem;
    color: var(--k5-paper);
  }

  .k5-nav__link::before {
    content: "0" counter(k5nav) " / ";
    margin-inline-end: .6rem;
    font-family: var(--k5-font-mono);
    font-size: .7rem;
    letter-spacing: .16em;
    color: var(--k5-steel);
    vertical-align: middle;
  }

  .k5-nav__link::after { display: none; }

  .k5-nav__link[aria-current="page"] {
    color: var(--k5-cyan);
    text-shadow: 0 0 16px rgba(0, 229, 255, .55);
  }

  .k5-nav__link[aria-current="page"]::before { color: var(--k5-yellow); }

  .k5-nav__foot {
    display: flex;
    flex-direction: column;
    gap: .85rem;
    margin-top: 1.2rem;
  }

  .k5-nav__hint {
    font-family: var(--k5-font-mono);
    font-size: .7rem;
    letter-spacing: .12em;
    color: var(--k5-steel);
  }

  .k5-nav__cta { justify-content: center; }
}

body.k5-drawer-open { overflow: hidden; }

@media (max-width: 1023px) {
  :root { --k5-h-header: 72px; }
}

@media (max-width: 640px) {
  :root { --k5-h-header: 64px; }

  .k5-header__bar { padding-block: .78rem; }

  .k5-brand__mark { min-width: 2.45rem; height: 2.45rem; font-size: .92rem; }

  .k5-brand__name { font-size: .98rem; }

  .k5-brand__domain { font-size: .58rem; letter-spacing: .12em; }
}

/* ---------- 8. 页脚 ---------- */
.k5-footer {
  position: relative;
  margin-top: clamp(3rem, 7vw, 6rem);
  padding-block: clamp(2.4rem, 5vw, 4rem) 1.4rem;
  overflow: hidden;
  background: var(--k5-ink);
  color: var(--k5-paper);
  border-top: 1px solid rgba(0, 229, 255, .32);
}

.k5-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--k5-cyan), var(--k5-violet) 42%, transparent 82%);
}

.k5-footer::after {
  content: "";
  position: absolute;
  top: -46%;
  right: -14%;
  width: 54vw;
  height: 54vw;
  background: radial-gradient(circle, rgba(124, 77, 255, .26), transparent 62%);
  pointer-events: none;
}

.k5-footer__top {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.7rem, 3vw, 3rem);
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1.4fr) minmax(0, 1fr);
}

.k5-footer__brand { display: grid; align-content: start; gap: .8rem; }

.k5-footer__logo {
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  text-decoration: none;
}

.k5-footer__mark {
  display: grid;
  place-items: center;
  min-width: 2.6rem;
  height: 2.6rem;
  padding-inline: .4rem;
  font-family: var(--k5-font-display);
  font-size: .95rem;
  letter-spacing: .08em;
  color: var(--k5-cyan);
  border: 1px solid rgba(0, 229, 255, .7);
  background: linear-gradient(140deg, rgba(0, 229, 255, .18), rgba(124, 77, 255, .22));
  clip-path: polygon(0 0, 100% 0, 100% 68%, 76% 100%, 0 100%);
}

.k5-footer__name {
  font-family: var(--k5-font-display);
  font-size: 1.15rem;
  letter-spacing: .04em;
}

.k5-footer__summary {
  max-width: 34ch;
  font-size: .92rem;
  line-height: 1.75;
  color: var(--k5-steel);
}

.k5-footer__domain {
  font-family: var(--k5-font-mono);
  font-size: .74rem;
  letter-spacing: .16em;
  color: var(--k5-cyan);
}

.k5-footer__nav {
  display: grid;
  gap: clamp(1.1rem, 2.2vw, 2rem);
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.k5-footer__col { display: grid; align-content: start; gap: .7rem; }

.k5-footer__title {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--k5-font-mono);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--k5-cyan);
}

.k5-footer__title::before {
  content: "";
  width: 16px;
  height: 2px;
  background: var(--k5-cyan);
}

.k5-footer__list { display: grid; gap: .45rem; }

.k5-footer__link {
  display: inline-block;
  padding-block: .12rem;
  color: var(--k5-steel);
  font-size: .94rem;
  text-decoration: none;
  transition: color var(--k5-dur) var(--k5-ease), transform var(--k5-dur) var(--k5-ease);
}

.k5-footer__link:hover,
.k5-footer__link:focus-visible {
  color: var(--k5-cyan);
  transform: translateX(3px);
}

.k5-footer__link[aria-current="page"] { color: var(--k5-yellow); }

.k5-footer__contact { display: grid; align-content: start; gap: .7rem; }

.k5-footer__row {
  display: grid;
  gap: .1rem;
  padding-block: .35rem;
  border-bottom: 1px dashed rgba(199, 209, 219, .16);
}

.k5-footer__label {
  font-family: var(--k5-font-mono);
  font-size: .68rem;
  letter-spacing: .14em;
  color: rgba(199, 209, 219, .72);
}

.k5-footer__value {
  margin: 0;
  font-family: var(--k5-font-mono);
  font-size: .86rem;
  color: var(--k5-paper);
  word-break: break-word;
}

.k5-footer__note {
  font-size: .76rem;
  line-height: 1.7;
  color: rgba(199, 209, 219, .78);
}

.k5-footer__bottom {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem 1.6rem;
  margin-top: clamp(1.8rem, 3vw, 2.6rem);
  padding-top: 1.1rem;
  border-top: 1px solid var(--k5-line);
  font-family: var(--k5-font-mono);
  font-size: .74rem;
  letter-spacing: .08em;
  color: rgba(199, 209, 219, .78);
}

.k5-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1.1rem;
  margin-inline-start: auto;
}

.k5-footer__legal a {
  color: var(--k5-steel);
  text-decoration: none;
  transition: color var(--k5-dur) var(--k5-ease);
}

.k5-footer__legal a:hover,
.k5-footer__legal a:focus-visible { color: var(--k5-yellow); }

.k5-footer__icp { color: rgba(199, 209, 219, .62); }

@media (max-width: 1023px) {
  .k5-footer__top { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .k5-footer__contact { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .k5-footer__top { grid-template-columns: minmax(0, 1fr); }
  .k5-footer__nav { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .k5-footer__bottom { font-size: .7rem; }
  .k5-footer__legal { margin-inline-start: 0; }
}

/* ---------- 9. 网格与卡片 ---------- */
.k5-grid {
  display: grid;
  gap: clamp(.85rem, 1.5vw, 1.35rem);
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.k5-span-3 { grid-column: span 3; }
.k5-span-4 { grid-column: span 4; }
.k5-span-5 { grid-column: span 5; }
.k5-span-6 { grid-column: span 6; }
.k5-span-7 { grid-column: span 7; }
.k5-span-8 { grid-column: span 8; }
.k5-span-9 { grid-column: span 9; }
.k5-span-12 { grid-column: span 12; }

.k5-card {
  position: relative;
  display: grid;
  align-content: start;
  gap: .7rem;
  padding: clamp(1.05rem, 2vw, 1.7rem);
  border: 1px solid var(--k5-line);
  border-radius: var(--k5-radius);
  background:
    linear-gradient(160deg, rgba(20, 25, 35, .96), rgba(11, 13, 16, .96));
  transition:
    transform var(--k5-dur) var(--k5-ease),
    border-color var(--k5-dur) var(--k5-ease),
    box-shadow var(--k5-dur) var(--k5-ease);
}

.k5-card:hover {
  transform: translateY(-3px);
  border-color: rgba(0, 229, 255, .7);
  box-shadow: 0 26px 54px -34px rgba(0, 229, 255, .95);
}

.k5-card__title {
  font-family: var(--k5-font-display);
  font-size: 1.1rem;
  letter-spacing: .01em;
}

.k5-card__meta {
  font-family: var(--k5-font-mono);
  font-size: .72rem;
  letter-spacing: .12em;
  color: var(--k5-steel);
}

.k5-card--paper {
  background: var(--k5-paper);
  color: var(--k5-carbon);
  border-color: rgba(11, 13, 16, .16);
}

.k5-card--paper .k5-card__meta { color: #4C5866; }

.k5-card--accent {
  border-color: rgba(124, 77, 255, .65);
  box-shadow: inset 3px 0 0 0 var(--k5-violet);
}

.k5-card--flat { background: transparent; }

@media (max-width: 1023px) {
  .k5-span-3,
  .k5-span-4,
  .k5-span-5 { grid-column: span 6; }
}

@media (max-width: 640px) {
  .k5-span-3,
  .k5-span-4,
  .k5-span-5,
  .k5-span-6,
  .k5-span-7,
  .k5-span-8,
  .k5-span-9 { grid-column: span 12; }
}

/* ---------- 10. 标签 ---------- */
.k5-tag {
  display: inline-flex;
  align-items: center;
  gap: .38rem;
  padding: .22rem .58rem;
  border: 1px solid rgba(0, 229, 255, .5);
  border-radius: 1px;
  background: var(--k5-cyan-a);
  color: var(--k5-cyan);
  font-family: var(--k5-font-mono);
  font-size: .68rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  line-height: 1.5;
}

.k5-tag--yellow {
  border-color: var(--k5-yellow);
  background: var(--k5-yellow);
  color: #0B0D10;
}

.k5-tag--violet {
  border-color: rgba(124, 77, 255, .65);
  background: rgba(124, 77, 255, .18);
  color: #D6C8FF;
}

.k5-tag--red {
  border-color: rgba(255, 77, 109, .7);
  background: rgba(255, 77, 109, .16);
  color: #FFB3C1;
}

.k5-tag--green {
  border-color: rgba(66, 245, 167, .6);
  background: rgba(66, 245, 167, .14);
  color: #9BFFD2;
}

/* ---------- 11. 面包屑 ---------- */
.k5-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  font-family: var(--k5-font-mono);
  font-size: .72rem;
  letter-spacing: .1em;
  color: var(--k5-steel);
}

.k5-crumbs a {
  color: var(--k5-steel);
  text-decoration: none;
  transition: color var(--k5-dur) var(--k5-ease);
}

.k5-crumbs a:hover,
.k5-crumbs a:focus-visible { color: var(--k5-cyan); }

.k5-crumbs__sep { color: rgba(199, 209, 219, .45); }

.k5-crumbs [aria-current="page"] { color: var(--k5-yellow); }

/* ---------- 12. 图片容器 ---------- */
.k5-media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--k5-line);
  border-radius: var(--k5-radius);
  background:
    radial-gradient(120% 90% at 12% 8%, rgba(0, 229, 255, .24), transparent 58%),
    radial-gradient(95% 85% at 88% 92%, rgba(124, 77, 255, .30), transparent 62%),
    var(--k5-ink);
}

.k5-media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(199, 209, 219, .10) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(199, 209, 219, .10) 1px, transparent 1px);
  background-size: 30px 30px;
}

.k5-media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: relative;
  z-index: 1;
}

.k5-media--wide { aspect-ratio: 21 / 9; }
.k5-media--tall { aspect-ratio: 3 / 4; }
.k5-media--square { aspect-ratio: 1 / 1; }

.k5-media__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 2;
  padding: .34rem .68rem;
  background: var(--k5-yellow);
  color: #0B0D10;
  font-family: var(--k5-font-mono);
  font-size: .66rem;
  letter-spacing: .12em;
}

/* ---------- 13. 分段标签页 ---------- */
.k5-tabs { display: block; }

.k5-tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  padding-bottom: .8rem;
  border-bottom: 1px solid var(--k5-line);
}

.k5-tabs__btn {
  appearance: none;
  padding: .55rem .95rem;
  border: 1px solid var(--k5-line);
  border-radius: var(--k5-radius);
  background: rgba(20, 25, 35, .8);
  color: var(--k5-steel);
  font-family: var(--k5-font-mono);
  font-size: .76rem;
  letter-spacing: .1em;
  cursor: pointer;
  transition:
    color var(--k5-dur) var(--k5-ease),
    background-color var(--k5-dur) var(--k5-ease),
    border-color var(--k5-dur) var(--k5-ease),
    box-shadow var(--k5-dur) var(--k5-ease);
}

.k5-tabs__btn:hover { color: var(--k5-paper); border-color: var(--k5-line-strong); }

.k5-tabs__btn[aria-selected="true"] {
  border-color: var(--k5-cyan);
  background: var(--k5-cyan);
  color: #04141A;
  box-shadow: 0 12px 28px -18px rgba(0, 229, 255, .95);
}

.k5-tabs__panel {
  padding-top: 1.25rem;
  animation: k5-panel-in 240ms var(--k5-ease) both;
}

@keyframes k5-panel-in {
  from { opacity: 0; transform: translateX(14px); }
  to { opacity: 1; transform: translateX(0); }
}

/* ---------- 14. 折叠面板 ---------- */
.k5-fold {
  margin-bottom: .7rem;
  border: 1px solid var(--k5-line);
  border-radius: var(--k5-radius);
  background: rgba(20, 25, 35, .72);
}

.k5-fold__head {
  display: flex;
  align-items: center;
  gap: .8rem;
  padding: 1rem 1.15rem;
  cursor: pointer;
  list-style: none;
  font-family: var(--k5-font-display);
  font-size: 1.02rem;
  letter-spacing: .01em;
  color: var(--k5-paper);
}

.k5-fold__head::-webkit-details-marker { display: none; }

.k5-fold__head::after {
  content: "+";
  margin-inline-start: auto;
  font-family: var(--k5-font-mono);
  font-size: 1.15rem;
  color: var(--k5-cyan);
  transition: transform var(--k5-dur) var(--k5-ease);
}

.k5-fold[open] > .k5-fold__head { color: var(--k5-cyan); }

.k5-fold[open] > .k5-fold__head::after { transform: rotate(45deg); }

.k5-fold__body {
  padding: 0 1.15rem 1.15rem;
  color: var(--k5-steel);
  font-size: .95rem;
  line-height: 1.8;
}

/* ---------- 15. 正文长文 ---------- */
.k5-prose {
  max-width: 74ch;
  color: inherit;
  font-size: 1rem;
  line-height: 1.9;
}

.k5-prose > * + * { margin-top: 1rem; }

.k5-prose h2 {
  margin-top: 2rem;
  font-size: clamp(1.4rem, 2.2vw, 1.85rem);
}

.k5-prose h3 { margin-top: 1.5rem; }

.k5-prose ul,
.k5-prose ol {
  display: grid;
  gap: .45rem;
  padding-inline-start: 1.1rem;
  list-style: disc;
}

.k5-prose ol { list-style: decimal; }

.k5-prose a { color: var(--k5-cyan-deep); }

/* ---------- 16. 显现动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translate3d(-14px, 20px, 0);
  transition: opacity 480ms var(--k5-ease), transform 480ms var(--k5-ease);
  will-change: opacity, transform;
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
  will-change: auto;
}

/* ---------- 17. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .k5-card:hover,
  .k5-btn:hover { transform: none; }
}