/* ============ 重置与变量 ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --clr-blue: #00E5FF;
  --clr-red: #FF3D3D;
  --clr-silver: #A8A9AD;
  --clr-night: #121212;
  --clr-deep-blue: #0A1A2F;
  --clr-pearl: #F5F5F5;
  --clr-gray: #B0B0B0;
  --clr-orange: #FFB020;
  --grad-blue: linear-gradient(90deg, #00E5FF 0%, #00BCD4 100%);
  --grad-red: linear-gradient(90deg, #FF3D3D 0%, #C22727 100%);
  --font-display: Impact, "Arial Narrow", "Microsoft YaHei", "PingFang SC", sans-serif;
  --font-body: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  --fs-h1: 48px;
  --fs-h2: 32px;
  --fs-h3: 24px;
  --fs-body: 16px;
  --fs-small: 12px;
  --lh-body: 1.6;
  --lh-heading: 1.2;
  --container-w: 1200px;
  --header-h: 72px;
  --header-h-mobile: 60px;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --radius-pill: 999px;
  --skew: -5deg;
  --sp-1: 8px;
  --sp-2: 16px;
  --sp-3: 24px;
  --sp-4: 32px;
  --sp-5: 48px;
  --sp-6: 64px;
  --sp-7: 96px;
  --z-skip: 200;
  --z-progress: 180;
  --z-header: 100;
  --z-nav: 90;
  --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-btn: 0 4px 16px rgba(0, 229, 255, 0.25);
  --glow-blue: 0 0 20px rgba(0, 229, 255, 0.3);
}

/* ============ 基础 ============ */
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--clr-pearl);
  background-color: var(--clr-night);
  background-image:
    radial-gradient(ellipse 700px 220px at 50% -10%, rgba(0, 229, 255, 0.07) 0%, transparent 70%),
    linear-gradient(160deg, var(--clr-deep-blue) 0%, var(--clr-night) 35%, var(--clr-night) 100%);
  background-attachment: fixed;
  min-height: 100vh;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease;
}

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

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

::selection {
  background: rgba(0, 229, 255, 0.3);
  color: var(--clr-pearl);
}

/* ============ 布局基础 ============ */
.container {
  width: 100%;
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 var(--sp-3);
}

.main-content {
  position: relative;
  z-index: 1;
  min-height: 60vh;
}

/* ============ 通用按钮 ============ */
.btn {
  display: inline-block;
  padding: 10px 28px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  text-align: center;
  white-space: nowrap;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn--primary {
  background: var(--grad-blue);
  color: var(--clr-night);
  box-shadow: var(--shadow-btn);
  transform: skewX(-3deg);
}

.btn--primary:hover {
  box-shadow: 0 8px 28px rgba(0, 229, 255, 0.4);
  transform: skewX(-3deg) translateY(-2px);
}

.btn--primary:active {
  transform: skewX(-3deg) translateY(0);
  box-shadow: 0 4px 12px rgba(0, 229, 255, 0.25);
}

.btn--ghost {
  border-color: rgba(168, 169, 173, 0.4);
  color: var(--clr-silver);
  background: transparent;
}

.btn--ghost:hover {
  border-color: var(--clr-blue);
  color: var(--clr-blue);
}

.btn--danger {
  background: var(--grad-red);
  color: var(--clr-pearl);
  box-shadow: 0 4px 16px rgba(255, 61, 61, 0.3);
  transform: skewX(-3deg);
}

.btn--danger:hover {
  transform: skewX(-3deg) translateY(-2px);
  box-shadow: 0 8px 24px rgba(255, 61, 61, 0.4);
}

/* ============ 跳转链接 ============ */
.skip-link {
  position: fixed;
  top: -100%;
  left: 50%;
  transform: translateX(-50%) translateY(-12px);
  background: var(--grad-blue);
  color: var(--clr-night);
  padding: 10px 28px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  font-size: 14px;
  z-index: var(--z-skip);
  transition: top 0.3s ease, transform 0.3s ease;
  box-shadow: var(--shadow-btn);
}

.skip-link:focus-visible {
  top: 16px;
  transform: translateX(-50%) translateY(0);
}

/* ============ 滚动进度 ============ */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: var(--grad-blue);
  box-shadow: 0 0 12px rgba(0, 229, 255, 0.6);
  z-index: var(--z-progress);
  pointer-events: none;
  border-radius: 0 4px 4px 0;
}

/* ============ 品牌标识 ============ */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand__mark {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 26px;
  line-height: 1;
  font-weight: 700;
  color: var(--clr-pearl);
  background: var(--grad-red);
  border-radius: 10px;
  padding: 7px 12px 6px;
  transform: skewX(var(--skew));
  box-shadow: 0 4px 16px rgba(255, 61, 61, 0.4);
  letter-spacing: 1.5px;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
}

.brand__cn {
  font-size: 20px;
  font-weight: 700;
  color: var(--clr-pearl);
  letter-spacing: 1px;
  white-space: nowrap;
}

/* ============ 头部 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  background: rgba(18, 18, 18, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(168, 169, 173, 0.18);
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--clr-red) 0%, var(--clr-blue) 55%, transparent 100%);
  z-index: 1;
  pointer-events: none;
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  min-height: var(--header-h);
  position: relative;
}

.site-nav {
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  display: inline-block;
  position: relative;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--clr-silver);
  border-radius: var(--radius-pill);
  transition: color 0.25s ease, background-color 0.25s ease;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 0;
  height: 2px;
  background: var(--clr-blue);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--clr-pearl);
  background: rgba(0, 229, 255, 0.08);
}

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

.site-nav__link[aria-current="page"] {
  color: var(--clr-blue);
  background: rgba(0, 229, 255, 0.1);
  text-shadow: 0 0 12px rgba(0, 229, 255, 0.25);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--clr-blue);
  box-shadow: 0 0 8px rgba(0, 229, 255, 0.6);
}

.site-header__cta {
  margin-left: var(--sp-2);
}

/* ============ 移动导航 ============ */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 6px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border-radius: var(--radius-sm);
  background: rgba(0, 229, 255, 0.08);
  border: 1px solid rgba(0, 229, 255, 0.15);
  margin-left: auto;
  flex-shrink: 0;
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.nav-toggle:hover {
  background: rgba(0, 229, 255, 0.14);
  border-color: rgba(0, 229, 255, 0.3);
}

.nav-toggle__bar {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--clr-blue);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.is-active {
  border-color: rgba(0, 229, 255, 0.35);
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-active .nav-toggle__bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  background: linear-gradient(180deg, var(--clr-night) 0%, var(--clr-deep-blue) 120%);
  border-top: 1px solid rgba(168, 169, 173, 0.15);
  margin-top: var(--sp-7);
  padding-top: var(--sp-6);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent 0%, var(--clr-red) 15%, var(--clr-blue) 60%, transparent 100%);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 480px;
  height: 120px;
  background: radial-gradient(ellipse, rgba(0, 229, 255, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: var(--sp-5);
  padding-bottom: var(--sp-5);
}

.site-footer__brand .brand__mark {
  font-size: 30px;
  padding: 8px 14px 7px;
}

.site-footer__brand .brand__cn {
  font-size: 24px;
}

.site-footer__tagline {
  margin-top: var(--sp-3);
  font-size: 17px;
  font-weight: 600;
  color: var(--clr-blue);
  letter-spacing: 0.5px;
}

.site-footer__trust {
  margin-top: var(--sp-2);
  font-size: 13px;
  color: var(--clr-gray);
  line-height: 1.7;
  max-width: 340px;
}

.site-footer__title {
  font-size: 13px;
  font-weight: 700;
  color: var(--clr-silver);
  text-transform: uppercase;
  letter-spacing: 2.5px;
  margin-bottom: var(--sp-3);
}

.site-footer__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.site-footer__list a {
  display: inline-block;
  color: var(--clr-gray);
  font-size: 14px;
  transition: color 0.2s ease, transform 0.2s ease;
}

.site-footer__list a:hover {
  color: var(--clr-blue);
  transform: translateX(4px);
}

.site-footer__phone {
  font-family: var(--font-display);
  font-size: 28px;
  line-height: 1.2;
  color: var(--clr-pearl);
  letter-spacing: 2px;
  margin-bottom: var(--sp-2);
  text-shadow: 0 0 16px rgba(0, 229, 255, 0.15);
}

.site-footer__email {
  color: var(--clr-blue);
  font-size: 14px;
  margin-bottom: var(--sp-2);
}

.site-footer__address {
  color: var(--clr-gray);
  font-size: 13px;
  line-height: 1.7;
  margin-bottom: var(--sp-1);
}

.site-footer__hours {
  color: var(--clr-gray);
  font-size: 13px;
  line-height: 1.7;
}

.site-footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-2);
  flex-wrap: wrap;
  border-top: 1px solid rgba(168, 169, 173, 0.15);
  padding: var(--sp-2) 0;
  margin-top: var(--sp-1);
}

.site-footer__copyright {
  font-size: 13px;
  color: var(--clr-gray);
}

.site-footer__icp {
  font-size: 13px;
  color: var(--clr-silver);
  transition: color 0.2s ease;
}

.site-footer__icp:hover {
  color: var(--clr-blue);
}

/* ============ 返回顶部 ============ */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: var(--z-header);
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--grad-blue);
  color: var(--clr-night);
  font-size: 22px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--glow-blue);
  border: 1px solid rgba(0, 229, 255, 0.5);
  opacity: 0;
  transform: translateY(16px) scale(0.9);
  pointer-events: none;
  transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
}

.back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.back-to-top:hover {
  box-shadow: 0 0 28px rgba(0, 229, 255, 0.5);
  transform: translateY(-3px) scale(1.05);
}

.back-to-top.is-visible:hover {
  transform: translateY(-3px) scale(1.05);
}

/* ============ 面包屑 ============ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-1);
  font-size: 14px;
  color: var(--clr-gray);
  margin-bottom: var(--sp-4);
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-1);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
}

.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--clr-silver);
  font-size: 12px;
}

.breadcrumb__link {
  color: var(--clr-gray);
  transition: color 0.2s ease;
}

.breadcrumb__link:hover {
  color: var(--clr-blue);
}

.breadcrumb__item[aria-current="page"] {
  color: var(--clr-pearl);
}

/* ============ 页面头部 ============ */
.page-header {
  padding: var(--sp-5) 0 var(--sp-4);
  margin-bottom: var(--sp-5);
  border-bottom: 1px solid rgba(168, 169, 173, 0.12);
}

.page-header__title {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  line-height: var(--lh-heading);
  color: var(--clr-pearl);
  transform: skewX(var(--skew));
  letter-spacing: 1px;
  text-transform: uppercase;
}

.page-header__desc {
  margin-top: var(--sp-2);
  color: var(--clr-gray);
  font-size: 16px;
  max-width: 720px;
}

/* ============ 章节 ============ */
.section {
  padding: var(--sp-6) 0;
}

.section__head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--sp-3);
  flex-wrap: wrap;
  margin-bottom: var(--sp-4);
}

.section__title {
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  line-height: var(--lh-heading);
  color: var(--clr-pearl);
  transform: skewX(var(--skew));
  letter-spacing: 0.5px;
  position: relative;
}

.section__subtitle {
  color: var(--clr-gray);
  font-size: 14px;
  margin-top: var(--sp-1);
  max-width: 600px;
}

/* ============ 栅格 ============ */
.grid {
  display: grid;
  gap: var(--sp-4);
}

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

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.grid--4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

/* ============ 卡片 ============ */
.card {
  position: relative;
  background: rgba(10, 26, 47, 0.6);
  border: 1px solid rgba(168, 169, 173, 0.15);
  border-radius: var(--radius-lg);
  padding: var(--sp-4);
  overflow: hidden;
  transition: border-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease;
}

.card:hover {
  border-color: rgba(0, 229, 255, 0.35);
  box-shadow: var(--shadow-card);
  transform: translateY(-4px);
}

.card--red-accent {
  border-top: 3px solid var(--clr-red);
}

.card--blue-accent {
  border-top: 3px solid var(--clr-blue);
}

.card--orange-accent {
  border-top: 3px solid var(--clr-orange);
}

.card__title {
  font-size: var(--fs-h3);
  line-height: var(--lh-heading);
  color: var(--clr-pearl);
  margin-bottom: var(--sp-2);
}

.card__text {
  font-size: 14px;
  color: var(--clr-gray);
  line-height: var(--lh-body);
}

/* ============ 标签 ============ */
.badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 1px;
  background: rgba(0, 229, 255, 0.12);
  color: var(--clr-blue);
  border: 1px solid rgba(0, 229, 255, 0.25);
  white-space: nowrap;
}

.badge--red {
  background: rgba(255, 61, 61, 0.12);
  color: var(--clr-red);
  border-color: rgba(255, 61, 61, 0.25);
}

.badge--orange {
  background: rgba(255, 176, 32, 0.12);
  color: var(--clr-orange);
  border-color: rgba(255, 176, 32, 0.25);
}

/* ============ 图片容器 ============ */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--clr-deep-blue) 0%, #1E3147 45%, #141E2E 100%);
  aspect-ratio: 16 / 9;
  min-height: 180px;
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(18, 18, 18, 0) 60%, rgba(18, 18, 18, 0.25) 100%);
  pointer-events: none;
}

.img-frame > img,
.img-frame > picture > img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.img-frame--portrait {
  aspect-ratio: 3 / 4;
}

.img-frame--wide {
  aspect-ratio: 21 / 9;
}

.img-frame--square {
  aspect-ratio: 1 / 1;
}

/* ============ 响应式：平板 ============ */
@media (max-width: 1024px) {
  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-4);
  }

  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .site-footer__trust {
    max-width: 100%;
  }
}

/* ============ 响应式：移动端 ============ */
@media (max-width: 900px) {
  :root {
    --fs-h1: 36px;
    --fs-h2: 26px;
    --fs-h3: 20px;
  }

  .site-header__inner {
    min-height: var(--header-h-mobile);
    gap: var(--sp-2);
  }

  .site-header__cta {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: var(--header-h-mobile);
    left: 0;
    right: 0;
    margin-left: 0;
    background: rgba(10, 26, 47, 0.98);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(0, 229, 255, 0.2);
    box-shadow: 0 20px 48px rgba(0, 0, 0, 0.5);
    padding: var(--sp-2) var(--sp-3) var(--sp-4);
    transform: translateY(-16px);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s ease, opacity 0.3s ease;
    z-index: var(--z-nav);
  }

  .site-nav[data-open="true"] {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }

  .site-nav__item {
    width: 100%;
  }

  .site-nav__link {
    display: block;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    font-size: 16px;
  }

  .site-nav__link::after {
    left: 16px;
    right: auto;
    width: 28px;
  }
}

/* ============ 响应式：小屏移动端 ============ */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--sp-2);
  }

  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: 1fr;
    gap: var(--sp-3);
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: var(--sp-4);
    padding-bottom: var(--sp-4);
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--sp-1);
  }

  .site-footer__phone {
    font-size: 24px;
  }

  .page-header {
    padding: var(--sp-4) 0 var(--sp-3);
    margin-bottom: var(--sp-4);
  }

  .section {
    padding: var(--sp-4) 0;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
    font-size: 18px;
  }
}

/* ============ 减少动态效果 ============ */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .card:hover,
  .btn--primary:hover,
  .btn--danger:hover,
  .back-to-top:hover,
  .back-to-top.is-visible:hover {
    transform: none;
  }
}