/* ===== 变量与重置 ===== */
:root {
  --color-bg: #0a0a0f;
  --color-bg-alt: #12121a;
  --color-surface: #1a1a26;
  --color-text: #e8e6e3;
  --color-text-muted: #9a9690;
  --color-accent: #c9a227;
  --color-accent-light: #e8c547;
  --color-accent-dark: #9a7b1a;
  --font-main: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --header-h: 72px;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-main);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  overflow-x: hidden;
}

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

img.img-fallback {
  object-fit: cover;
  background: linear-gradient(135deg, #1a1a26 0%, #2a2418 50%, #1a1a26 100%);
}

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

ul, ol {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: 50px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-dark));
  color: #0a0a0f;
  border-color: var(--color-accent);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-accent-light), var(--color-accent));
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(201, 162, 39, 0.35);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: rgba(255, 255, 255, 0.4);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn-block {
  width: 100%;
}

/* ===== 区块标题 ===== */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header--light .section-label,
.section-header--light h2,
.section-header--light p {
  color: var(--color-text);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--color-accent);
  margin-bottom: 12px;
  font-weight: 600;
}

.section-header h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-header p {
  color: var(--color-text-muted);
  font-size: 1rem;
}

/* ===== 导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  transition: var(--transition);
}

.header.scrolled {
  background: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-dark));
  color: #0a0a0f;
  font-size: 1.25rem;
  font-weight: 700;
  border-radius: 10px;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-text strong {
  font-size: 1rem;
}

.logo-text small {
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  color: var(--color-text-muted);
}

.nav {
  display: flex;
  gap: 36px;
}

.nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition);
}

.nav a:hover,
.nav a.active {
  color: var(--color-text);
}

.nav a:hover::after,
.nav a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}

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

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

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

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--header-h);
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(10, 10, 15, 0.88) 0%,
    rgba(10, 10, 15, 0.6) 50%,
    rgba(10, 10, 15, 0.85) 100%
  );
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 80px 24px 120px;
}

.hero-tag {
  display: inline-block;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: 20px;
  padding: 6px 16px;
  border: 1px solid rgba(201, 162, 39, 0.4);
  border-radius: 50px;
}

.hero h1 {
  font-size: clamp(2.25rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 24px;
}

.hero h1 span {
  background: linear-gradient(135deg, var(--color-accent-light), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  max-width: 520px;
  font-size: 1.1rem;
  color: var(--color-text-muted);
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  width: 28px;
  height: 44px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.hero-scroll span {
  width: 4px;
  height: 8px;
  background: var(--color-accent);
  border-radius: 2px;
  animation: scrollBounce 2s infinite;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(8px); opacity: 0.3; }
}

/* ===== 数据 ===== */
.stats {
  background: var(--color-surface);
  padding: 48px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item strong {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--color-accent);
}

.stat-item span {
  font-size: 1.5rem;
  color: var(--color-accent);
}

.stat-item p {
  margin-top: 8px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ===== 关于 ===== */
.about {
  background: var(--color-bg-alt);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-image {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.about-image img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

.about-badge {
  position: absolute;
  bottom: 24px;
  left: 24px;
  display: flex;
  gap: 12px;
}

.about-badge span {
  padding: 8px 16px;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(8px);
  border-radius: 50px;
  font-size: 0.85rem;
  border: 1px solid rgba(201, 162, 39, 0.3);
  color: var(--color-accent);
}

.about-content h3 {
  font-size: 1.5rem;
  margin-bottom: 20px;
}

.about-content p {
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.about-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-top: 16px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.about-list svg {
  width: 22px;
  height: 22px;
  flex-shrink: 0;
  color: var(--color-accent);
  margin-top: 2px;
}

/* ===== 服务 ===== */
.services {
  background: var(--color-bg);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  background: var(--color-surface);
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: var(--transition);
}

.service-card:hover {
  transform: translateY(-6px);
  border-color: rgba(201, 162, 39, 0.3);
  box-shadow: var(--shadow);
}

.service-img {
  aspect-ratio: 16/10;
  overflow: hidden;
}

.service-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.service-card:hover .service-img img {
  transform: scale(1.06);
}

.service-body {
  padding: 24px;
}

.service-num {
  font-size: 0.75rem;
  color: var(--color-accent);
  font-weight: 600;
  letter-spacing: 0.1em;
}

.service-body h3 {
  font-size: 1.15rem;
  margin: 8px 0 12px;
}

.service-body p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ===== 优势 ===== */
.advantages {
  background: var(--color-bg-alt);
  padding: 100px 0;
}

.advantages-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.advantages-text h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 12px 0 32px;
}

.advantages-text ul li {
  margin-bottom: 24px;
  padding-left: 20px;
  border-left: 3px solid var(--color-accent);
}

.advantages-text strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 6px;
}

.advantages-text p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.advantages-image {
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.advantages-image img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}

/* ===== 案例 ===== */
.cases {
  background: var(--color-bg);
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: auto auto;
  gap: 20px;
}

.case-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
}

.case-item--large {
  grid-row: span 2;
}

.case-item img {
  width: 100%;
  height: 100%;
  min-height: 220px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.case-item--large img {
  min-height: 100%;
}

.case-item:hover img {
  transform: scale(1.05);
}

.case-item figcaption {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 24px;
  background: linear-gradient(transparent 40%, rgba(10, 10, 15, 0.9));
}

.case-item figcaption span {
  font-size: 0.75rem;
  color: var(--color-accent);
  letter-spacing: 0.1em;
  margin-bottom: 6px;
}

.case-item figcaption h4 {
  font-size: 1.1rem;
}

/* ===== 流程 ===== */
.process {
  background: var(--color-surface);
  padding: 80px 0;
}

.process-steps {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.process-steps li {
  flex: 1;
  min-width: 140px;
  text-align: center;
  padding: 24px 16px;
  position: relative;
}

.process-steps li:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 36px;
  right: -8px;
  width: calc(100% - 60px);
  height: 2px;
  background: linear-gradient(90deg, var(--color-accent), transparent);
  transform: translateX(50%);
  opacity: 0.4;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-dark));
  color: #0a0a0f;
  font-weight: 700;
  font-size: 1.1rem;
  margin-bottom: 16px;
}

.process-steps h4 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.process-steps p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ===== 联系 ===== */
.contact {
  background: var(--color-bg-alt);
  padding-bottom: 0;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
  padding-bottom: 60px;
}

.contact-info h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  margin: 12px 0 16px;
}

.contact-info > p {
  color: var(--color-text-muted);
  margin-bottom: 32px;
}

.contact-list li {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
}

.contact-list svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  color: var(--color-accent);
  margin-top: 4px;
}

.contact-list strong {
  display: block;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.contact-form {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.contact-form h3 {
  margin-bottom: 24px;
  font-size: 1.25rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.contact-form label {
  display: block;
  margin-bottom: 16px;
}

.contact-form label span {
  display: block;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--color-bg);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  color: var(--color-text);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color var(--transition);
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--color-accent);
}

.contact-form textarea {
  resize: vertical;
  min-height: 100px;
}

.form-tip {
  margin-top: 12px;
  font-size: 0.85rem;
  text-align: center;
  min-height: 1.2em;
}

.form-tip.success {
  color: #4ade80;
}

.form-tip.error {
  color: #f87171;
}

.contact-map {
  width: 100%;
  height: 320px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.contact-map iframe {
  width: 100%;
  height: 100%;
  border: 0;
  filter: grayscale(0.6) invert(0.92) contrast(0.9);
}

/* ===== 页脚 ===== */
.footer {
  background: var(--color-bg);
  padding: 48px 0 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  padding-top: 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 6px;
}

.footer-bottom a {
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.footer-bottom a:hover {
  color: var(--color-accent);
}

/* ===== 返回顶部 ===== */
.back-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-accent);
  color: #0a0a0f;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: var(--transition);
  z-index: 999;
  box-shadow: 0 4px 16px rgba(201, 162, 39, 0.4);
}

.back-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top svg {
  width: 24px;
  height: 24px;
}

.back-top:hover {
  background: var(--color-accent-light);
}

/* ===== 动画 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .case-item--large {
    grid-row: span 1;
  }

  .process-steps li:not(:last-child)::after {
    display: none;
  }
}

@media (max-width: 768px) {
  :root {
    --header-h: 64px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: rgba(10, 10, 15, 0.98);
    flex-direction: column;
    padding: 24px;
    gap: 0;
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav a {
    padding: 16px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
  }

  .about-grid,
  .advantages-inner,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .advantages-image {
    order: -1;
  }

  .services-grid {
    grid-template-columns: 1fr;
  }

  .cases-grid {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-brand {
    flex-direction: column;
  }

  .footer-links {
    justify-content: center;
  }

  .process-steps {
    flex-direction: column;
  }

  .process-steps li {
    display: flex;
    align-items: center;
    gap: 20px;
    text-align: left;
    padding: 16px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .step-num {
    margin-bottom: 0;
    flex-shrink: 0;
  }

  .hero-content {
    padding-bottom: 100px;
  }

  .section {
    padding: 72px 0;
  }
}

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

  .hero-actions {
    flex-direction: column;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .contact-form {
    padding: 24px 20px;
  }

  .back-top {
    right: 16px;
    bottom: 16px;
    width: 44px;
    height: 44px;
  }
}