/* ============================================================
   中传筑时企业官网 - 主样式文件
   Design Tokens: 墨玉 #0A0F1C / 朱砂 #C8372D / 暖金 #C9A96E / 月白 #F5F2EB
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --color-ink: #0A0F1C;
  --color-ink-light: #131a2e;
  --color-vermilion: #C8372D;
  --color-vermilion-dark: #a82c24;
  --color-gold: #C9A96E;
  --color-gold-light: #d9c08e;
  --color-moon: #F5F2EB;
  --color-stone: #8B8680;
  --color-white: #FFFFFF;
  --color-gray-100: #f5f5f5;
  --color-gray-200: #e5e5e5;
  --color-gray-300: #d4d4d4;
  --color-gray-400: #a3a3a3;
  --color-gray-500: #737373;
  --color-gray-600: #525252;
  --color-gray-700: #404040;
  --color-gray-800: #262626;
  --color-gray-900: #171717;

  --font-serif: "Noto Serif SC", "Songti SC", "SimSun", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-en: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  --max-width: 1280px;
  --gutter: 32px;

  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

  --nav-height: 80px;
  --nav-height-scrolled: 64px;
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-sans);
  color: var(--color-gray-800);
  background-color: var(--color-white);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.3s var(--ease-out);
}

ul {
  list-style: none;
}

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

/* ---------- 通用布局 ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.section {
  padding: 120px 0;
}

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

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

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

/* ---------- Section Header ---------- */
.section-header {
  text-align: center;
  margin-bottom: 80px;
}

.section-en {
  display: inline-block;
  font-family: var(--font-en);
  font-size: 14px;
  letter-spacing: 4px;
  color: var(--color-gold);
  margin-bottom: 16px;
  text-transform: uppercase;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 42px;
  font-weight: 600;
  color: var(--color-ink);
  line-height: 1.3;
  margin-bottom: 24px;
  letter-spacing: -0.5px;
}

.title-divider {
  width: 60px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-gold), transparent);
  margin: 0 auto 24px;
}

.section-desc {
  font-size: 17px;
  color: var(--color-gray-500);
  max-width: 600px;
  margin: 0 auto;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 15px;
  font-weight: 500;
  border-radius: 2px;
  transition: all 0.4s var(--ease-out);
  cursor: pointer;
  border: 1px solid transparent;
  letter-spacing: 1px;
}

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

.btn-primary:hover {
  background-color: var(--color-vermilion-dark);
  border-color: var(--color-vermilion-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(200, 55, 45, 0.3);
}

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

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

.btn-full {
  width: 100%;
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  transition: all 0.4s var(--ease-out);
  background: transparent;
}

.navbar.scrolled {
  background-color: rgba(10, 15, 28, 0.95);
  backdrop-filter: blur(20px);
  height: var(--nav-height-scrolled);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
  max-width: var(--max-width);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  flex-direction: column;
  align-items: center;
  line-height: 1.2;
  transition: all 0.3s var(--ease-out);
}

.logo-cn {
  font-family: var(--font-serif);
  font-size: 26px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 4px;
}

.logo-en {
  font-family: var(--font-en);
  font-size: 10px;
  color: var(--color-gold);
  letter-spacing: 3px;
  margin-top: 2px;
}

.navbar.scrolled .logo-cn {
  font-size: 22px;
}

.nav-menu {
  display: flex;
  gap: 40px;
  align-items: center;
}

.nav-link {
  color: var(--color-white);
  font-size: 15px;
  font-weight: 400;
  position: relative;
  padding: 8px 0;
  opacity: 0.9;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 1px;
  background-color: var(--color-gold);
  transition: all 0.3s var(--ease-out);
  transform: translateX(-50%);
}

.nav-link:hover {
  opacity: 1;
  color: var(--color-gold);
}

.nav-link:hover::after {
  width: 100%;
}

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

.nav-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
  transition: all 0.3s var(--ease-out);
  border-radius: 1px;
}

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

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

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

/* ---------- Hero 首屏 ---------- */
.hero {
  position: relative;
  height: 100vh;
  min-height: 700px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: var(--color-white);
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-bg::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #0A0F1C 0%, #1a2238 40%, #0f1628 100%);
  z-index: 0;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse at 20% 30%, rgba(200, 55, 45, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 70%, rgba(201, 169, 110, 0.12) 0%, transparent 50%),
    linear-gradient(to bottom, rgba(10, 15, 28, 0.3) 0%, rgba(10, 15, 28, 0.8) 100%);
  z-index: 1;
}

.hero-grid {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    linear-gradient(rgba(201, 169, 110, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(201, 169, 110, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 1;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  padding: 0 24px;
}

.hero-label {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 40px;
}

.label-line {
  width: 60px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-gold));
}

.label-line:last-child {
  background: linear-gradient(90deg, var(--color-gold), transparent);
}

.label-text {
  font-family: var(--font-en);
  font-size: 13px;
  letter-spacing: 6px;
  color: var(--color-gold);
  text-transform: uppercase;
}

.hero-title {
  font-family: var(--font-serif);
  font-size: 72px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 32px;
  letter-spacing: 8px;
}

.title-line {
  display: block;
  opacity: 0;
  transform: translateY(30px);
  animation: fadeUp 1s var(--ease-out) forwards;
}

.title-line:nth-child(1) {
  animation-delay: 0.2s;
}

.title-line:nth-child(2) {
  animation-delay: 0.4s;
}

@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 300;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 48px;
  letter-spacing: 2px;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.6s forwards;
}

.hero-tags {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 56px;
  flex-wrap: wrap;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 0.8s forwards;
}

.hero-tag {
  font-family: var(--font-serif);
  font-size: 16px;
  color: var(--color-gold);
  letter-spacing: 4px;
}

.hero-tag-dot {
  width: 4px;
  height: 4px;
  background-color: var(--color-gold);
  border-radius: 50%;
  opacity: 0.5;
}

.hero-cta {
  display: flex;
  gap: 20px;
  justify-content: center;
  opacity: 0;
  animation: fadeUp 1s var(--ease-out) 1s forwards;
}

/* 滚动指示器 */
.scroll-indicator {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  z-index: 2;
}

.scroll-text {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 4px;
  color: rgba(255, 255, 255, 0.5);
  writing-mode: vertical-rl;
}

.scroll-line {
  width: 1px;
  height: 60px;
  background: linear-gradient(to bottom, var(--color-gold), transparent);
  animation: scrollLine 2s ease-in-out infinite;
}

@keyframes scrollLine {
  0%, 100% {
    transform: scaleY(0.5);
    transform-origin: top;
    opacity: 0.5;
  }
  50% {
    transform: scaleY(1);
    opacity: 1;
  }
}

/* ---------- About 关于我们 ---------- */
.about {
  background-color: var(--color-moon);
}

.about-content {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 80px;
  align-items: center;
  margin-bottom: 100px;
}

.about-lead {
  font-family: var(--font-serif);
  font-size: 22px;
  line-height: 1.8;
  color: var(--color-ink);
  margin-bottom: 28px;
  font-weight: 500;
}

.about-desc {
  font-size: 16px;
  line-height: 2;
  color: var(--color-gray-600);
  margin-bottom: 20px;
}

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

.stat-item {
  text-align: center;
  padding: 40px 24px;
  background-color: var(--color-white);
  border: 1px solid rgba(201, 169, 110, 0.2);
  position: relative;
  transition: all 0.4s var(--ease-out);
}

.stat-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 24px;
  height: 24px;
  border-top: 2px solid var(--color-gold);
  border-left: 2px solid var(--color-gold);
}

.stat-item::after {
  content: "";
  position: absolute;
  bottom: 0;
  right: 0;
  width: 24px;
  height: 24px;
  border-bottom: 2px solid var(--color-gold);
  border-right: 2px solid var(--color-gold);
}

.stat-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.stat-number {
  font-family: var(--font-serif);
  font-size: 52px;
  font-weight: 700;
  color: var(--color-vermilion);
  line-height: 1;
}

.stat-unit {
  font-size: 18px;
  color: var(--color-gold);
  margin-left: 4px;
  font-weight: 500;
}

.stat-label {
  display: block;
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-gray-500);
  letter-spacing: 2px;
}

/* 核心优势 */
.advantages {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 24px;
}

.adv-item {
  text-align: center;
  padding: 48px 24px;
  background-color: var(--color-white);
  transition: all 0.4s var(--ease-out);
  border: 1px solid rgba(201, 169, 110, 0.15);
  position: relative;
  overflow: hidden;
}

.adv-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background: var(--color-vermilion);
  transition: all 0.4s var(--ease-out);
  transform: translateX(-50%);
}

.adv-item:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.adv-item:hover::before {
  width: 100%;
}

.adv-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 24px;
  color: var(--color-gold);
  display: flex;
  align-items: center;
  justify-content: center;
}

.adv-icon svg {
  width: 48px;
  height: 48px;
}

.adv-title {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 8px;
}

.adv-en {
  font-family: var(--font-en);
  font-size: 12px;
  letter-spacing: 3px;
  color: var(--color-gold);
  margin-bottom: 16px;
  text-transform: uppercase;
}

.adv-desc {
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-gray-500);
}

/* ---------- Services 业务板块 ---------- */
.service-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.service-card {
  position: relative;
  background-color: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(201, 169, 110, 0.15);
  overflow: hidden;
  transition: all 0.5s var(--ease-out);
}

.service-card:hover {
  transform: translateY(-8px);
  border-color: rgba(201, 169, 110, 0.4);
}

.service-image {
  position: relative;
  height: 240px;
  overflow: hidden;
}

.service-img-placeholder {
  width: 100%;
  height: 100%;
  transition: transform 0.8s var(--ease-out);
}

.service-card:hover .service-img-placeholder {
  transform: scale(1.08);
}

.service-img-1 {
  background: linear-gradient(135deg, #1a2a4a 0%, #2d3a5c 50%, #0f1830 100%);
  position: relative;
}

.service-img-1::after {
  content: "园";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(201, 169, 110, 0.15);
  font-weight: 700;
}

.service-img-2 {
  background: linear-gradient(135deg, #2a1a1a 0%, #4a2d2d 50%, #1a0f0f 100%);
  position: relative;
}

.service-img-2::after {
  content: "博";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(200, 55, 45, 0.2);
  font-weight: 700;
}

.service-img-3 {
  background: linear-gradient(135deg, #2a2518 0%, #4a3f28 50%, #1a1710 100%);
  position: relative;
}

.service-img-3::after {
  content: "文";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(201, 169, 110, 0.2);
  font-weight: 700;
}

.service-img-4 {
  background: linear-gradient(135deg, #1a1f2a 0%, #2d344a 50%, #0f1218 100%);
  position: relative;
}

.service-img-4::after {
  content: "展";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(201, 169, 110, 0.15);
  font-weight: 700;
}

.service-img-5 {
  background: linear-gradient(135deg, #0a1a2a 0%, #1a3a5a 50%, #050d18 100%);
  position: relative;
}

.service-img-5::after {
  content: "数";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(201, 169, 110, 0.2);
  font-weight: 700;
}

.service-img-6 {
  background: linear-gradient(135deg, #1a0a2a 0%, #3a1a5a 50%, #0d0518 100%);
  position: relative;
}

.service-img-6::after {
  content: "空";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-family: var(--font-serif);
  font-size: 120px;
  color: rgba(200, 55, 45, 0.2);
  font-weight: 700;
}

.service-number {
  position: absolute;
  top: 20px;
  right: 20px;
  font-family: var(--font-serif);
  font-size: 48px;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.1);
  z-index: 2;
}

.service-content {
  padding: 32px;
}

.service-title {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 8px;
}

.service-en {
  font-family: var(--font-en);
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--color-gold);
  margin-bottom: 20px;
  text-transform: uppercase;
}

.service-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.service-list li {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
  padding-left: 20px;
  position: relative;
}

.service-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  background-color: var(--color-gold);
  opacity: 0.6;
}

.service-border {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.service-border::before,
.service-border::after {
  content: "";
  position: absolute;
  width: 24px;
  height: 24px;
  border: 1px solid var(--color-gold);
  opacity: 0;
  transition: all 0.4s var(--ease-out);
}

.service-border::before {
  top: 12px;
  left: 12px;
  border-right: none;
  border-bottom: none;
}

.service-border::after {
  bottom: 12px;
  right: 12px;
  border-left: none;
  border-top: none;
}

.service-card:hover .service-border::before,
.service-card:hover .service-border::after {
  opacity: 1;
  top: 16px;
  left: 16px;
  bottom: 16px;
  right: 16px;
}

/* ---------- Cases 项目案例 ---------- */
.case-filter {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 10px 24px;
  font-size: 14px;
  color: var(--color-gray-500);
  border: 1px solid var(--color-gray-200);
  background-color: transparent;
  transition: all 0.3s var(--ease-out);
  border-radius: 2px;
  letter-spacing: 1px;
}

.filter-btn:hover {
  color: var(--color-vermilion);
  border-color: var(--color-vermilion);
}

.filter-btn.active {
  background-color: var(--color-vermilion);
  color: var(--color-white);
  border-color: var(--color-vermilion);
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.case-item {
  overflow: hidden;
  transition: all 0.5s var(--ease-out);
}

.case-item.hidden {
  display: none;
}

.case-image {
  position: relative;
  height: 280px;
  overflow: hidden;
  margin-bottom: 20px;
}

.case-img {
  width: 100%;
  height: 100%;
  transition: transform 0.8s var(--ease-out);
}

.case-item:hover .case-img {
  transform: scale(1.08);
}

.case-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to bottom, transparent 50%, rgba(10, 15, 28, 0.8) 100%);
  display: flex;
  align-items: flex-end;
  padding: 20px;
}

.case-category {
  font-size: 13px;
  color: var(--color-gold);
  letter-spacing: 2px;
}

/* 案例图片占位 */
.case-img-1 { background: linear-gradient(135deg, #1a2a4a, #2d4a6a); }
.case-img-2 { background: linear-gradient(135deg, #2a2a3a, #4a4a5a); }
.case-img-3 { background: linear-gradient(135deg, #0a1a3a, #1a3a6a); }
.case-img-4 { background: linear-gradient(135deg, #3a2a1a, #5a4a2a); }
.case-img-5 { background: linear-gradient(135deg, #2a1a3a, #4a2a5a); }
.case-img-6 { background: linear-gradient(135deg, #1a3a2a, #2a5a4a); }
.case-img-7 { background: linear-gradient(135deg, #2a1a1a, #5a2a2a); }
.case-img-8 { background: linear-gradient(135deg, #1a1a2a, #3a3a5a); }
.case-img-9 { background: linear-gradient(135deg, #0a2a3a, #1a4a6a); }

.case-info {
  padding: 0 4px;
}

.case-title {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 6px;
  transition: color 0.3s var(--ease-out);
}

.case-item:hover .case-title {
  color: var(--color-vermilion);
}

.case-subtitle {
  font-family: var(--font-en);
  font-size: 12px;
  color: var(--color-gold);
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.case-desc {
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-gray-500);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------- Partners 合作伙伴 ---------- */
.partners-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.partner-item {
  padding: 40px 32px;
  text-align: center;
  border: 1px solid rgba(201, 169, 110, 0.15);
  background-color: rgba(255, 255, 255, 0.02);
  transition: all 0.4s var(--ease-out);
}

.partner-item:hover {
  border-color: rgba(201, 169, 110, 0.4);
  background-color: rgba(255, 255, 255, 0.05);
  transform: translateY(-4px);
}

.partner-logo {
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.partner-name {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  color: var(--color-white);
}

.partner-role {
  font-size: 13px;
  color: var(--color-gray-400);
  letter-spacing: 1px;
}

/* ---------- Contact 联系我们 ---------- */
.contact {
  background-color: var(--color-moon);
}

.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 80px;
  align-items: start;
}

.contact-info .section-en {
  display: block;
  margin-bottom: 16px;
}

.contact-title {
  font-family: var(--font-serif);
  font-size: 42px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: 20px;
  line-height: 1.3;
}

.contact-info .title-divider {
  margin: 0 0 28px 0;
}

.contact-desc {
  font-size: 16px;
  line-height: 2;
  color: var(--color-gray-600);
  margin-bottom: 48px;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact-icon {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
  background-color: var(--color-white);
  border: 1px solid rgba(201, 169, 110, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gold);
}

.contact-icon svg {
  width: 20px;
  height: 20px;
}

.contact-label {
  font-size: 13px;
  color: var(--color-gray-500);
  margin-bottom: 4px;
}

.contact-value {
  font-size: 16px;
  color: var(--color-ink);
  font-weight: 500;
}

/* 表单 */
.contact-form {
  background-color: var(--color-white);
  padding: 48px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.06);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-gray-700);
  margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  font-family: inherit;
  border: 1px solid var(--color-gray-200);
  background-color: var(--color-white);
  color: var(--color-gray-800);
  transition: all 0.3s var(--ease-out);
  border-radius: 2px;
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-gold);
  box-shadow: 0 0 0 3px rgba(201, 169, 110, 0.1);
}

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

.contact-form .btn {
  margin-top: 8px;
}

.contact-form .btn svg {
  width: 18px;
  height: 18px;
  transition: transform 0.3s var(--ease-out);
}

.contact-form .btn:hover svg {
  transform: translateX(4px);
}

/* ---------- Footer 页脚 ---------- */
.footer {
  background-color: var(--color-ink);
  color: var(--color-white);
  padding: 80px 0 0;
  border-top: 1px solid rgba(201, 169, 110, 0.1);
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 80px;
  padding-bottom: 60px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand {
  max-width: 360px;
}

.footer-logo {
  margin-bottom: 20px;
  display: inline-block;
}

.footer-logo .logo-cn {
  font-size: 32px;
}

.footer-logo .logo-en {
  font-size: 12px;
}

.footer-slogan {
  font-family: var(--font-serif);
  font-size: 18px;
  color: var(--color-gold);
  margin-bottom: 12px;
}

.footer-tagline {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.5);
  letter-spacing: 1px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.footer-col h4 {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 24px;
  position: relative;
  padding-bottom: 12px;
}

.footer-col h4::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 1px;
  background-color: var(--color-gold);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col li {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.5);
}

.footer-col a {
  color: rgba(255, 255, 255, 0.5);
  transition: all 0.3s var(--ease-out);
}

.footer-col a:hover {
  color: var(--color-gold);
  padding-left: 4px;
}

.footer-bottom {
  padding: 28px 0;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.4);
}

.footer-bottom p:first-child {
  margin-bottom: 4px;
}

.footer-bottom p:last-child {
  font-family: var(--font-en);
  font-size: 11px;
  letter-spacing: 1px;
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  width: 48px;
  height: 48px;
  background-color: var(--color-vermilion);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.4s var(--ease-out);
  z-index: 999;
  border-radius: 2px;
}

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

.back-to-top:hover {
  background-color: var(--color-vermilion-dark);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ---------- Fade Up 动画 ---------- */
.fade-up {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

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

/* ============================================================
   响应式设计
   ============================================================ */

/* 平板尺寸 768px - 1023px */
@media (max-width: 1023px) {
  :root { --gutter: 24px; }

  .section { padding: 80px 0; }
  .section-title { font-size: 36px; }
  .section-header { margin-bottom: 60px; }

  .hero-title { font-size: 56px; letter-spacing: 6px; }

  .about-content { grid-template-columns: 1fr; gap: 60px; }
  .advantages { grid-template-columns: repeat(3, 1fr); gap: 16px; }

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

  .contact-wrapper { grid-template-columns: 1fr; gap: 60px; }
  .footer-top { grid-template-columns: 1fr; gap: 48px; }
}

/* 手机尺寸 < 768px */
@media (max-width: 767px) {
  :root {
    --gutter: 16px;
    --nav-height: 60px;
    --nav-height-scrolled: 56px;
  }

  .section { padding: 60px 0; }
  .section-title { font-size: 28px; }
  .section-desc { font-size: 15px; }
  .section-header { margin-bottom: 48px; }

  /* 导航 */
  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background-color: rgba(10, 15, 28, 0.98);
    backdrop-filter: blur(20px);
    padding: 20px 0;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s var(--ease-out);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-menu li { width: 100%; text-align: center; }
  .nav-link { display: block; padding: 16px 24px; font-size: 16px; }
  .nav-toggle { display: flex; }

  .logo-cn { font-size: 20px; letter-spacing: 3px; }
  .logo-en { font-size: 9px; letter-spacing: 2px; }

  /* Hero */
  .hero { min-height: 600px; }
  .hero-title { font-size: 36px; letter-spacing: 4px; }
  .hero-subtitle { font-size: 16px; }
  .hero-tags { gap: 12px; }
  .hero-tag { font-size: 14px; letter-spacing: 2px; }
  .hero-tag-dot { display: none; }
  .hero-cta { flex-direction: column; gap: 12px; padding: 0 24px; }
  .btn { width: 100%; }
  .hero-label { gap: 12px; }
  .label-line { width: 30px; }
  .label-text { font-size: 11px; letter-spacing: 3px; }

  /* About */
  .about-lead { font-size: 18px; }
  .about-stats { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .stat-item { padding: 24px 16px; }
  .stat-number { font-size: 36px; }
  .stat-label { font-size: 12px; }
  .advantages { grid-template-columns: 1fr; gap: 16px; }
  .adv-item { padding: 32px 24px; }

  /* Services */
  .service-grid { grid-template-columns: 1fr; gap: 24px; }
  .service-image { height: 200px; }
  .service-content { padding: 24px; }

  /* Cases */
  .case-filter { gap: 8px; }
  .filter-btn { padding: 8px 16px; font-size: 13px; }
  .case-grid { grid-template-columns: 1fr; gap: 24px; }
  .case-image { height: 220px; }

  /* Partners */
  .partners-grid { grid-template-columns: 1fr; gap: 20px; }

  /* Contact */
  .contact-title { font-size: 32px; }
  .contact-form { padding: 32px 24px; }
  .form-row { grid-template-columns: 1fr; gap: 0; }

  /* Footer */
  .footer { padding-top: 60px; }
  .footer-top { grid-template-columns: 1fr; gap: 40px; padding-bottom: 40px; }
  .footer-links { grid-template-columns: repeat(2, 1fr); gap: 32px; }
  .footer-col h4 { font-size: 15px; }

  .back-to-top { bottom: 24px; right: 24px; width: 44px; height: 44px; }
}

/* 小屏幕手机 < 480px */
@media (max-width: 479px) {
  .hero-title { font-size: 30px; letter-spacing: 3px; }
  .section-title { font-size: 24px; }
  .footer-links { grid-template-columns: 1fr; }
}