:root {
  --black: #0A0A0A;
  --white: #FFFFFF;
  --gray-900: #141414;
  --gray-700: #3A3A3A;
  --gray-400: #A6A6A6;
  --gray-200: #E0E0E0;
  --brand: #FF4B2B;
  --brand-hover: #D93A1D;
  --gold: #FFD700;
  --focus-ring: #FF6B4A;
  --navy: #0D1B2A;
  --navy-light: #1B263B;
  --body-font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --display-font: "Arial Black", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container-max: 1200px;
  --header-h: 76px;
  --header-h-mobile: 64px;
  --radius: 0px;
  --transition: 200ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --shadow-1: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-2: 0 8px 30px rgba(0,0,0,0.12);
  --shadow-brand: 0 4px 20px rgba(255,75,43,0.25);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--body-font);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--black);
  background-color: var(--white);
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul,
li {
  list-style: none;
}

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

:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

::selection {
  background: var(--brand);
  color: var(--white);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 9999;
  padding: 12px 24px;
  background: var(--black);
  color: var(--white);
  font-weight: 700;
  clip-path: polygon(0 0, calc(100% - 8px) 0, 100% 100%, 8px 100%);
  transition: top var(--transition);
}

.skip-link:focus {
  top: 16px;
  color: var(--white);
}

/* ========== 阅读进度条 ========== */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--brand), var(--gold));
  z-index: 2000;
  transition: width 60ms linear;
}

/* ========== 头部 ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  background: transparent;
  color: var(--white);
  transition: background var(--transition), box-shadow var(--transition), height var(--transition);
}

.site-header.is-scrolled {
  background: rgba(10, 10, 10, 0.96);
  backdrop-filter: blur(8px);
  color: var(--white);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.site-header.is-open {
  background: rgba(10, 10, 10, 0.98);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  transition: transform var(--transition);
}

.brand-logo:hover {
  transform: scale(1.02);
}

.brand-mark {
  display: inline-flex;
  color: var(--brand);
  flex-shrink: 0;
}

.brand-mark svg {
  filter: drop-shadow(0 0 8px rgba(255, 75, 43, 0.3));
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--display-font);
  font-weight: 900;
  font-size: 1.15rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  white-space: nowrap;
}

.brand-tagline {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--brand);
}

.nav-list {
  display: flex;
  gap: 4px;
}

.nav-list a {
  display: inline-block;
  padding: 10px 16px;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  position: relative;
  clip-path: polygon(6px 0, 100% 0, calc(100% - 6px) 100%, 0 100%);
  transition: background var(--transition), color var(--transition);
}

.nav-list a::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 4px;
  height: 2px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.nav-list a:hover {
  color: var(--brand);
}

.nav-list a:hover::after,
.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-list a[aria-current="page"] {
  color: var(--brand);
}

.nav-toggle {
  display: none;
  width: 48px;
  height: 48px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  clip-path: polygon(6px 0, 100% 0, calc(100% - 6px) 100%, 0 100%);
  transition: border-color var(--transition);
}

.nav-toggle:hover {
  border-color: var(--brand);
}

.toggle-line {
  width: 22px;
  height: 2px;
  background: var(--white);
  transition: transform var(--transition), opacity var(--transition), background var(--transition);
}

.nav-toggle.is-active .toggle-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
  background: var(--brand);
}

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

.nav-toggle.is-active .toggle-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
  background: var(--brand);
}

/* ========== 页脚 ========== */
.site-footer {
  background: var(--black);
  color: var(--gray-400);
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--brand) 0%, var(--black) 30%, var(--black) 70%, var(--brand) 100%);
}

.site-footer::after {
  content: "";
  position: absolute;
  bottom: -80px;
  right: -40px;
  width: 300px;
  height: 300px;
  border: 2px solid rgba(255, 75, 43, 0.08);
  transform: rotate(45deg);
  pointer-events: none;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.6fr;
  gap: 48px;
  padding-top: 72px;
  padding-bottom: 48px;
  position: relative;
  z-index: 1;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  font-family: var(--display-font);
  font-weight: 900;
  font-size: 1.05rem;
}

.footer-blurb {
  font-size: 0.9rem;
  line-height: 1.7;
  max-width: 320px;
}

.footer-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 215, 0, 0.25);
  color: var(--gray-200);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  clip-path: polygon(8px 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
}

.badge-gold {
  color: var(--gold);
  font-size: 0.9rem;
}

.footer-heading {
  color: var(--white);
  font-family: var(--display-font);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin-bottom: 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid rgba(255, 75, 43, 0.5);
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--gray-400);
  transition: color var(--transition), padding-left var(--transition);
}

.footer-links a:hover {
  color: var(--brand);
  padding-left: 6px;
}

.contact-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 0.9rem;
}

.contact-list a {
  color: var(--gray-400);
  transition: color var(--transition);
}

.contact-list a:hover {
  color: var(--brand);
}

.trust-text {
  margin-top: 16px;
  font-size: 0.78rem;
  line-height: 1.6;
  color: var(--gray-700);
  border-left: 3px solid var(--brand);
  padding-left: 12px;
}

.footer-bottom {
  background: var(--gray-900);
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  padding: 20px 0;
  position: relative;
  z-index: 1;
}

.footer-bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.8rem;
}

.footer-flag {
  font-family: var(--display-font);
  font-weight: 800;
  text-transform: uppercase;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--gray-700);
}

/* ========== 基础组件 ========== */
.section {
  padding: 96px 0;
}

.section-dark {
  background: var(--black);
  color: var(--white);
}

.section-head {
  margin-bottom: 48px;
  max-width: 720px;
}

.section-head.is-center {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.section-head h2 {
  font-family: var(--display-font);
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.01em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-head p {
  color: var(--gray-700);
  font-size: 1.05rem;
}

.section-dark .section-head p {
  color: var(--gray-400);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--display-font);
  font-size: 0.8rem;
  font-weight: 900;
  font-style: italic;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--brand);
  margin-bottom: 12px;
}

.kicker::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 2px;
  background: var(--brand);
  transform: skewX(-30deg);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: 0.9rem;
  font-weight: 800;
  font-family: var(--display-font);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  clip-path: polygon(10px 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
  transition: background var(--transition), color var(--transition), transform var(--transition), box-shadow var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--brand);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--brand-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-brand);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border: 2px solid var(--white);
}

.btn-outline:hover {
  background: var(--white);
  color: var(--black);
  transform: translateY(-2px);
}

.btn-light {
  background: var(--white);
  color: var(--black);
}

.btn-light:hover {
  background: var(--gray-200);
  transform: translateY(-2px);
  box-shadow: var(--shadow-1);
}

.card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  padding: 28px;
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 0;
  height: 0;
  border-top: 40px solid var(--brand);
  border-right: 40px solid transparent;
  opacity: 0;
  transition: opacity var(--transition);
}

.card:hover {
  transform: translate(-3px, -3px);
  box-shadow: var(--shadow-2);
  border-color: var(--brand);
}

.card:hover::before {
  opacity: 1;
}

.card-accent {
  border-left: 4px solid var(--brand);
}

.card-dark {
  background: var(--gray-900);
  color: var(--white);
  border-color: var(--gray-900);
}

.chamfer-panel {
  background: var(--white);
  padding: 36px;
  position: relative;
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 20px 100%, 0 calc(100% - 20px));
  border: 1px solid var(--gray-200);
  transition: transform var(--transition), box-shadow var(--transition);
}

.chamfer-panel:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-2);
}

.divider {
  height: 4px;
  background: repeating-linear-gradient(
    -45deg,
    var(--brand) 0,
    var(--brand) 12px,
    var(--black) 12px,
    var(--black) 24px
  );
  border: none;
}

.field-grid {
  display: grid;
  gap: 24px;
}

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

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

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

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  font-size: 0.85rem;
  margin-bottom: 24px;
  color: var(--gray-400);
}

.breadcrumb a {
  color: var(--gray-700);
  transition: color var(--transition);
}

.breadcrumb a:hover {
  color: var(--brand);
}

.breadcrumb span[aria-current="page"] {
  color: var(--brand);
  font-weight: 700;
}

.page-header {
  padding: calc(var(--header-h) + 64px) 0 48px;
  background: var(--black);
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.page-header::after {
  content: "";
  position: absolute;
  bottom: -40px;
  right: 10%;
  width: 260px;
  height: 260px;
  border: 2px solid rgba(255, 75, 43, 0.12);
  transform: rotate(45deg);
  pointer-events: none;
}

.page-header .page-title {
  font-family: var(--display-font);
  font-style: italic;
  font-size: clamp(2.4rem, 6vw, 4.2rem);
  font-weight: 900;
  line-height: 0.95;
  text-transform: uppercase;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.page-header .page-subtitle {
  font-size: 1.1rem;
  color: var(--gray-400);
  max-width: 560px;
  position: relative;
  z-index: 1;
}

.stat-number {
  font-family: var(--display-font);
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 900;
  font-style: italic;
  line-height: 1;
  color: var(--brand);
  display: inline-block;
}

.img-ratio {
  position: relative;
  background: var(--gray-900);
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

.img-ratio img,
.img-ratio .ratio-content {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(100%) contrast(1.1);
  transition: filter var(--transition), transform var(--transition);
}

.img-ratio:hover img,
.img-ratio:hover .ratio-content {
  filter: grayscale(0%) contrast(1);
  transform: scale(1.02);
}

.img-ratio-widescreen {
  aspect-ratio: 16 / 9;
}

.img-ratio .ratio-label {
  position: absolute;
  left: 12px;
  bottom: 12px;
  background: rgba(10, 10, 10, 0.8);
  color: var(--white);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 10px;
  clip-path: polygon(4px 0, 100% 0, calc(100% - 4px) 100%, 0 100%);
}

/* 技能树式服务路径 */
.skill-path {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  position: relative;
  align-items: stretch;
}

.skill-path-item {
  flex: 1 1 260px;
  padding: 24px;
  position: relative;
}

.skill-path-item .step-number {
  font-family: var(--display-font);
  font-size: 3rem;
  font-weight: 900;
  font-style: italic;
  color: transparent;
  -webkit-text-stroke: 2px var(--brand);
  line-height: 1;
  display: block;
  margin-bottom: 12px;
}

.skill-path-item h3 {
  font-family: var(--display-font);
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.skill-path-item p {
  font-size: 0.9rem;
  color: var(--gray-700);
}

.skill-path-item::before {
  content: "";
  position: absolute;
  top: 42px;
  right: -10px;
  width: 20px;
  height: 2px;
  background: var(--brand);
  opacity: 0.4;
}

.skill-path-item:last-child::before {
  display: none;
}

/* ========== 动效显现 ========== */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 500ms ease, transform 500ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }

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

@media (max-width: 768px) {
  :root {
    --header-h: var(--header-h-mobile);
  }

  .site-header {
    background: rgba(10, 10, 10, 0.9);
  }

  .header-inner {
    padding: 0 16px;
  }

  .brand-tagline {
    display: none;
  }

  .brand-name {
    font-size: 0.95rem;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: var(--header-h-mobile);
    left: 0;
    right: 0;
    background: rgba(10, 10, 10, 0.98);
    border-bottom: 3px solid var(--brand);
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
    pointer-events: none;
  }

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

  .nav-list {
    flex-direction: column;
    padding: 16px 0;
  }

  .nav-list a {
    display: block;
    padding: 14px 24px;
    font-size: 1rem;
    border-left: 3px solid transparent;
  }

  .nav-list a:hover,
  .nav-list a[aria-current="page"] {
    border-left-color: var(--brand);
  }

  .nav-list a::after {
    display: none;
  }

  .section {
    padding: 64px 0;
  }

  .field-grid.cols-2,
  .field-grid.cols-3,
  .field-grid.cols-4 {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
    padding-top: 48px;
  }

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

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .page-header {
    padding: calc(var(--header-h) + 40px) 0 36px;
  }

  .card,
  .chamfer-panel {
    padding: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

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