/* ============================================
   全局样式 - 软件技术开发公司官网
   纯 HTML + CSS（含少量原生 JS 控制移动菜单）
   ============================================ */

:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --accent: #06b6d4;
  --dark: #0f172a;
  --gray-900: #111827;
  --gray-700: #374151;
  --gray-500: #6b7280;
  --gray-300: #d1d5db;
  --gray-100: #f3f4f6;
  --gray-50: #f9fafb;
  --white: #ffffff;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--gray-700);
  line-height: 1.7;
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
}

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

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

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

/* ============ 按钮 ============ */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  transition: all 0.25s ease;
  border: 2px solid transparent;
}

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

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

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: var(--white);
}

.btn-ghost {
  background: var(--white);
  color: var(--primary);
  border-color: var(--gray-300);
}

.btn-ghost:hover {
  border-color: var(--primary);
  color: var(--primary-dark);
}

/* ============ 顶部导航 ============ */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--gray-100);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--dark);
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  padding: 8px 16px;
  border-radius: 8px;
  font-weight: 500;
  color: var(--gray-700);
  transition: all 0.2s ease;
}

.nav-links a:hover {
  color: var(--primary);
  background: var(--gray-100);
}

.nav-links a.active {
  color: var(--primary);
  font-weight: 600;
}

.nav-cta {
  margin-left: 8px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  width: 26px;
  height: 3px;
  background: var(--dark);
  border-radius: 3px;
  transition: 0.3s;
}

/* ============ Hero 区 ============ */
.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 55%, #2563eb 100%);
  color: var(--white);
  padding: 96px 0 110px;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  top: -120px;
  right: -120px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.35), transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 760px;
}

.hero .eyebrow {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  font-size: 13px;
  letter-spacing: 1px;
  margin-bottom: 22px;
}

.hero h1 {
  font-size: 52px;
  line-height: 1.15;
  font-weight: 800;
  margin-bottom: 22px;
  color: var(--white);
}

.hero h1 span {
  background: linear-gradient(90deg, #38bdf8, #67e8f9);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 19px;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 36px;
}

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

/* ============ 通用 section ============ */
.section {
  padding: 88px 0;
}

.section-alt {
  background: var(--gray-50);
}

.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-head .eyebrow {
  color: var(--primary);
  font-weight: 700;
  letter-spacing: 1.5px;
  font-size: 14px;
  text-transform: uppercase;
}

.section-head h2 {
  font-size: 38px;
  color: var(--dark);
  margin: 12px 0 16px;
  font-weight: 800;
}

.section-head p {
  font-size: 17px;
  color: var(--gray-500);
}

/* ============ 数据条 ============ */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: -60px;
  position: relative;
  z-index: 2;
}

.stat-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.stat-card .num {
  font-size: 40px;
  font-weight: 800;
  color: var(--primary);
}

.stat-card .label {
  color: var(--gray-500);
  font-size: 15px;
  margin-top: 4px;
}

/* ============ 服务卡片 ============ */
.grid {
  display: grid;
  gap: 28px;
}

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

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

.card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius);
  padding: 34px 28px;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.card .icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}

.card h3 {
  font-size: 20px;
  color: var(--dark);
  margin-bottom: 10px;
}

.card p {
  color: var(--gray-500);
  font-size: 15px;
}

.card ul {
  margin-top: 14px;
  padding-left: 18px;
  color: var(--gray-500);
  font-size: 14.5px;
}

.card ul li {
  margin-bottom: 6px;
}

/* ============ 流程步骤 ============ */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
  counter-reset: step;
}

.step {
  position: relative;
  padding-top: 16px;
}

.step .step-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
  margin-bottom: 16px;
}

.step h4 {
  color: var(--dark);
  font-size: 18px;
  margin-bottom: 8px;
}

.step p {
  color: var(--gray-500);
  font-size: 14.5px;
}

/* ============ CTA 区块 ============ */
.cta {
  background: linear-gradient(135deg, var(--primary-dark), var(--accent));
  border-radius: 20px;
  padding: 60px;
  text-align: center;
  color: var(--white);
}

.cta h2 {
  font-size: 32px;
  margin-bottom: 14px;
  color: var(--white);
}

.cta p {
  font-size: 17px;
  opacity: 0.9;
  margin-bottom: 28px;
}

/* ============ 页内通用 banner ============ */
.page-hero {
  background: linear-gradient(135deg, #0f172a, #1e3a8a);
  color: var(--white);
  padding: 72px 0;
  text-align: center;
}

.page-hero h1 {
  font-size: 42px;
  font-weight: 800;
  color: var(--white);
}

.page-hero p {
  margin-top: 12px;
  font-size: 17px;
  color: rgba(255, 255, 255, 0.8);
}

.breadcrumb {
  margin-top: 16px;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
}

/* ============ 关于我们 ============ */
.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 56px;
  align-items: center;
}

.about-grid h2 {
  font-size: 34px;
  color: var(--dark);
  margin-bottom: 18px;
}

.about-grid p {
  color: var(--gray-500);
  margin-bottom: 16px;
}

.about-visual {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 20px;
  min-height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 80px;
  box-shadow: var(--shadow-lg);
}

.value-list {
  list-style: none;
  margin-top: 10px;
}

.value-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin-bottom: 14px;
}

.value-list .check {
  color: var(--primary);
  font-weight: 800;
  font-size: 18px;
}

/* ============ 联系表单 ============ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 48px;
}

.contact-info .info-item {
  display: flex;
  gap: 16px;
  margin-bottom: 28px;
}

.contact-info .info-item .icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}

.contact-info h4 {
  color: var(--dark);
  font-size: 16px;
}

.contact-info p {
  color: var(--gray-500);
  font-size: 15px;
}

.form {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 8px;
  font-size: 14.5px;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--gray-300);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* ============ 页脚 ============ */
.footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.75);
  padding: 64px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 44px;
}

.footer .logo {
  color: var(--white);
  margin-bottom: 16px;
}

.footer-col h4 {
  color: var(--white);
  font-size: 16px;
  margin-bottom: 18px;
}

.footer-col ul {
  list-style: none;
}

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

.footer-col a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.5);
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.65);
  transition: color 0.2s ease;
}

.footer-bottom a:hover {
  color: var(--white);
  text-decoration: underline;
}

/* ============ 响应式 ============ */
@media (max-width: 960px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .about-grid,
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 40px; }
}

@media (max-width: 640px) {
  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    gap: 4px;
    box-shadow: var(--shadow-lg);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 16px; }
  .nav-toggle { display: flex; }
  .stats,
  .grid-3,
  .grid-2,
  .steps { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 90px; }
  .hero h1 { font-size: 32px; }
  .hero p { font-size: 17px; }
  .section { padding: 60px 0; }
  .section-head h2 { font-size: 30px; }
  .cta { padding: 40px 24px; }
}