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

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 7.5rem;
}

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

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

a {
  color: inherit;
}

:root {
  --ink: #050B14;
  --abyss: #0A1626;
  --deep: #0E2A47;
  --cyan: #24D6E8;
  --cyan-soft: #A8F4FA;
  --signal: #FF6A2A;
  --paper: #F4F7FA;
  --mist: #E6EDF4;
  --stone: #5D7186;
  --white: #FFFFFF;

  --hair: rgba(120, 170, 200, 0.22);
  --hair-cyan: rgba(36, 214, 232, 0.28);
  --footer-rule: rgba(120, 170, 200, 0.16);

  --font-display: "Barlow Condensed", "DIN Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --shell: 1240px;
  --gutter: clamp(1.15rem, 4vw, 3.5rem);
  --radius: 14px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.75;
  letter-spacing: 0.02em;
  color: var(--ink);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 300;
  line-height: 1.08;
  letter-spacing: 0.005em;
}

h3,
h4,
h5,
h6 {
  font-weight: 400;
  line-height: 1.25;
}

::selection {
  background-color: var(--cyan);
  color: var(--ink);
}

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ============ 布局基座 ============ */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

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

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(1.25rem, 3vw, 2.5rem);
}

.divider {
  height: 1px;
  border: 0;
  margin: clamp(2rem, 4vw, 3rem) 0;
  background: var(--mist);
}

.surface {
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--mist);
  border-radius: 18px;
  background: var(--paper);
}

/* ============ 通用文字组件 ============ */
.mono {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
}

.index-no {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  color: var(--stone);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.24em;
  color: var(--signal);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--hair);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--deep);
}

.prose {
  max-width: 720px;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--ink);
}

.prose p + p {
  margin-top: 1.1em;
}

.prose h3 {
  margin-top: 2em;
  font-size: 1.4rem;
}

.prose ul {
  margin-top: 1em;
  padding-left: 1.1em;
  list-style: disc;
}

.prose li + li {
  margin-top: 0.4em;
}

/* ============ 面包屑 ============ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--stone);
}

.breadcrumb a {
  text-decoration: none;
  color: var(--deep);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.breadcrumb a:hover {
  color: var(--signal);
  border-bottom-color: currentColor;
}

.breadcrumb__sep {
  color: var(--stone);
  opacity: 0.55;
}

.breadcrumb [aria-current="page"] {
  color: var(--signal);
}

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.2rem;
  border: 1px solid transparent;
  border-radius: 8px;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1.3;
  text-align: center;
  text-decoration: none;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease),
    border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.btn--signal {
  background-color: var(--signal);
  color: var(--ink);
  box-shadow: 0 8px 22px rgba(255, 106, 42, 0.28);
}

.btn--signal:hover {
  background-color: #ff8149;
  transform: translateY(-2px);
}

.btn--cyan {
  background-color: var(--cyan);
  color: var(--ink);
}

.btn--cyan:hover {
  background-color: var(--cyan-soft);
  transform: translateY(-2px);
}

.btn--ghost {
  border-color: rgba(36, 214, 232, 0.45);
  background-color: rgba(36, 214, 232, 0.06);
  color: var(--cyan-soft);
}

.btn--ghost:hover {
  border-color: var(--cyan);
  background-color: rgba(36, 214, 232, 0.14);
  color: var(--white);
}

/* ============ 图片容器基座 ============ */
.media-frame {
  position: relative;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--hair-cyan);
  border-radius: 18px;
  background-color: var(--abyss);
  background-image: linear-gradient(145deg, var(--deep) 0%, var(--abyss) 55%, var(--ink) 100%);
}

.media-frame img,
.media-frame video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--16x9 {
  aspect-ratio: 16 / 9;
}

.media-frame--4x3 {
  aspect-ratio: 4 / 3;
}

.media-frame--1x1 {
  aspect-ratio: 1 / 1;
}

.media-frame--21x9 {
  aspect-ratio: 21 / 9;
}

.media-frame__caption {
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  color: var(--stone);
}

/* ============ 跳转链接 ============ */
.skip-link {
  position: fixed;
  top: 0;
  left: 50%;
  z-index: 200;
  padding: 0.7rem 1.4rem;
  border-radius: 0 0 10px 10px;
  background-color: var(--signal);
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transform: translate(-50%, -120%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus-visible {
  transform: translate(-50%, 0);
  outline-offset: -3px;
}

/* ============ 页头 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  font-family: var(--font-body);
}

.header-utility {
  background-color: var(--ink);
  border-bottom: 1px solid rgba(36, 214, 232, 0.16);
  color: rgba(244, 247, 250, 0.66);
}

.header-utility__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: 2.5rem;
}

.header-motto {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: var(--cyan-soft);
  white-space: nowrap;
}

.header-motto__dot {
  flex: none;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--cyan);
  box-shadow: 0 0 10px rgba(36, 214, 232, 0.9);
}

.header-quick {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.header-quick__link {
  display: inline-block;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  font-size: 0.76rem;
  letter-spacing: 0.1em;
  color: rgba(244, 247, 250, 0.62);
  text-decoration: none;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.header-quick__link:hover,
.header-quick__link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.header-main {
  background-color: var(--abyss);
  background-image: linear-gradient(180deg, #0b1829 0%, #081120 100%);
  border-bottom: 1px solid var(--hair);
  color: var(--white);
}

.header-main__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  min-height: 4.75rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  flex: none;
  color: var(--white);
  text-decoration: none;
}

.brand__mark {
  position: relative;
  flex: none;
  width: 1.75rem;
  height: 1.75rem;
  overflow: hidden;
  border: 1px solid rgba(36, 214, 232, 0.5);
  border-radius: 7px;
}

.brand__mark i {
  position: absolute;
  left: 3px;
  width: 15px;
  height: 2px;
  border-radius: 2px;
  transform: rotate(-30deg);
}

.brand__mark i:first-child {
  top: 9px;
  background-color: var(--cyan);
}

.brand__mark i:last-child {
  top: 18px;
  background-color: var(--signal);
}

.brand__text {
  display: block;
}

.brand__name {
  display: block;
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.06em;
}

.brand__sub {
  display: block;
  margin-top: 0.15rem;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.3em;
  color: rgba(168, 244, 250, 0.66);
}

.primary-nav {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2vw, 1.9rem);
}

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.6rem, 1.6vw, 1.5rem);
}

.primary-nav__link {
  position: relative;
  display: inline-block;
  padding: 0.55rem 0.15rem;
  font-size: 0.94rem;
  letter-spacing: 0.04em;
  color: rgba(244, 247, 250, 0.76);
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.primary-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background-color: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.2s var(--ease), background-color 0.2s var(--ease);
}

.primary-nav__link:hover {
  color: var(--white);
}

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

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

.primary-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background-color: var(--signal);
}

.primary-nav__cta {
  flex: none;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  padding: 0.5rem 0.8rem;
  border: 1px solid rgba(36, 214, 232, 0.4);
  border-radius: 8px;
  color: var(--cyan-soft);
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background-color: currentColor;
  transition: transform 0.2s var(--ease);
}

.nav-toggle__label {
  line-height: 1;
}

.site-header[data-open] .nav-toggle {
  border-color: var(--signal);
  color: var(--signal);
}

.site-header[data-open] .nav-toggle__bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}

.site-header[data-open] .nav-toggle__bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  padding-top: clamp(2.5rem, 5vw, 4rem);
  background-color: var(--ink);
  color: rgba(244, 247, 250, 0.72);
  font-size: 0.92rem;
}

.footer-rail {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-image: linear-gradient(90deg, var(--cyan) 0%, rgba(36, 214, 232, 0.12) 46%, var(--signal) 100%);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.9fr) minmax(0, 1.1fr) minmax(0, 1.1fr);
  gap: clamp(1.6rem, 3vw, 3rem);
}

.footer-brand .brand__name {
  color: var(--white);
}

.footer-motto {
  margin-top: 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.22em;
  color: var(--cyan-soft);
}

.footer-note {
  max-width: 24em;
  margin-top: 0.7rem;
  font-size: 0.86rem;
  line-height: 1.8;
  color: rgba(244, 247, 250, 0.6);
}

.footer-col__title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.22em;
  color: var(--cyan-soft);
}

.footer-col__list {
  display: grid;
  gap: 0.55rem;
}

.footer-col__list a {
  color: rgba(244, 247, 250, 0.74);
  font-size: 0.9rem;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-col__list a:hover,
.footer-col__list a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.footer-index__card {
  display: block;
  padding: 1.1rem 1.2rem;
  border: 1px solid rgba(36, 214, 232, 0.35);
  border-radius: 14px;
  background-color: rgba(36, 214, 232, 0.07);
  background-image: linear-gradient(150deg, rgba(36, 214, 232, 0.16) 0%, rgba(14, 42, 71, 0.22) 100%);
  color: var(--white);
  text-decoration: none;
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.footer-index__card:hover {
  border-color: var(--signal);
  transform: translateY(-2px);
}

.footer-index__code {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  color: var(--signal);
}

.footer-index__title {
  display: block;
  margin-top: 0.4rem;
  font-size: 1.02rem;
  letter-spacing: 0.03em;
}

.footer-index__meta {
  display: block;
  margin-top: 0.4rem;
  font-size: 0.76rem;
  letter-spacing: 0.06em;
  color: rgba(168, 244, 250, 0.72);
}

.footer-contact__list {
  display: grid;
  gap: 0.8rem;
}

.footer-contact__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.2em;
  color: var(--stone);
}

.footer-contact__value {
  display: block;
  font-size: 0.9rem;
  line-height: 1.6;
  word-break: break-word;
  color: rgba(244, 247, 250, 0.84);
}

.footer-base {
  margin-top: clamp(2rem, 4vw, 3rem);
}

.footer-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem 1.5rem;
  padding: 1.1rem 0 1.6rem;
  border-top: 1px solid var(--footer-rule);
  font-size: 0.78rem;
  color: rgba(244, 247, 250, 0.55);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 1.1rem;
}

.footer-legal a {
  color: rgba(244, 247, 250, 0.7);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-legal a:hover,
.footer-legal a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.footer-icp {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
}

/* ============ 滚动进度 ============ */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 120;
  width: 100%;
  height: 3px;
  background-image: linear-gradient(90deg, var(--cyan) 0%, var(--signal) 100%);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
}

/* ============ 内容淡入 ============ */
[data-reveal] {
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}

.reveal-ready [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ============ 平板 ============ */
@media (max-width: 959px) {
  html {
    scroll-padding-top: 5.5rem;
  }

  .header-utility {
    display: none;
  }

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

  .header-main__inner {
    min-height: 4rem;
    gap: 1rem;
  }

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 1rem;
    max-height: calc(100vh - 4rem);
    overflow-y: auto;
    padding: 1rem var(--gutter) 1.6rem;
    background-color: var(--abyss);
    border-top: 1px solid var(--hair-cyan);
    border-bottom: 1px solid var(--hair);
    box-shadow: 0 24px 48px rgba(0, 0, 0, 0.45);
  }

  .site-header[data-open] .primary-nav {
    display: flex;
  }

  .primary-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }

  .primary-nav__list > li {
    width: 100%;
  }

  .primary-nav__link {
    display: block;
    width: 100%;
    padding: 0.9rem 0.25rem;
    font-size: 1rem;
  }

  .primary-nav__cta {
    width: 100%;
    margin-top: 0.25rem;
  }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .grid-2 {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ============ 手机 ============ */
@media (max-width: 639px) {
  body {
    font-size: 1rem;
  }

  .brand__name {
    font-size: 0.98rem;
  }

  .brand__sub {
    font-size: 0.58rem;
    letter-spacing: 0.24em;
  }

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

  .footer-base__inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-legal {
    gap: 0.9rem;
  }
}

/* ============ 减少动效 ============ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

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

  .btn:hover,
  .footer-index__card:hover {
    transform: none;
  }
}