/* 万易AI - 企业级AI官网样式系统 */
/* Design System v1.0 */

/* ===== CSS Variables ===== */
:root {
  --bg: #F7F9FC;
  --surface: #FFFFFF;
  --text-primary: #0B1220;
  --text-secondary: #475569;
  --border: #E2E8F0;
  --primary: #2563EB;
  --primary-hover: #1D4ED8;
  --success: #16A34A;

  --font-cn: "HarmonyOS Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-en: "Inter", system-ui, -apple-system, sans-serif;

  --max-width: 1200px;
  --section-spacing: 96px;
  --section-spacing-mobile: 64px;

  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.08);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-cn);
  background-color: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Typography ===== */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 {
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.2;
}

h2 {
  font-size: clamp(24px, 3vw, 30px);
}

h3 {
  font-size: clamp(18px, 2vw, 20px);
}

p {
  color: var(--text-secondary);
  max-width: 760px;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--primary-hover);
}

/* ===== Layout ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

@media (max-width: 768px) {
  .section {
    padding: var(--section-spacing-mobile) 0;
  }

  .container {
    padding: 0 20px;
  }
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(247, 249, 252, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  height: 72px;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo span {
  color: var(--primary);
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 15px;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.15s ease;
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link.active {
  color: var(--text-primary);
}

@media (max-width: 1024px) {
  .nav {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.15s ease;
  border: none;
  font-family: inherit;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--primary);
  border: 1px solid var(--border);
}

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

.btn-sm {
  padding: 8px 16px;
  font-size: 14px;
}

/* ===== Cards ===== */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  transition: box-shadow 0.15s ease, border-color 0.15s ease;
}

.card:hover {
  box-shadow: var(--shadow-hover);
  border-color: #CBD5E1;
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.card-text {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--primary);
}

/* ===== Grid ===== */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {

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

/* ===== Hero Section ===== */
.hero {
  padding-top: 144px;
  padding-bottom: var(--section-spacing);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-content {
  max-width: 600px;
}

.hero-title {
  margin-bottom: 20px;
}

.hero-subtitle {
  font-size: 18px;
  line-height: 1.7;
  margin-bottom: 32px;
}

.hero-trust {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 24px;
}

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

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-grid {
  width: 100%;
  max-width: 480px;
  aspect-ratio: 4/3;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.03) 0%, rgba(37, 99, 235, 0.08) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
}

.hero-grid::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 0.5;
}

.hero-grid::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120px;
  height: 120px;
  border: 2px solid var(--primary);
  border-radius: 50%;
  opacity: 0.2;
}

@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-visual {
    order: -1;
  }

  .hero-grid {
    max-width: 360px;
  }
}

/* ===== Section Header ===== */
.section-header {
  margin-bottom: 48px;
}

.section-title {
  margin-bottom: 16px;
  max-width: 760px;
}

.section-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 760px;
}

/* ===== Feature Cards ===== */
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  height: 100%;
}

.feature-icon {
  width: 48px;
  height: 48px;
  background: rgba(37, 99, 235, 0.08);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary);
}

/* ===== Solution Section ===== */
.solution-block {
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
}

.solution-block:last-child {
  border-bottom: none;
}

.solution-header {
  margin-bottom: 24px;
}

.solution-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  color: var(--primary);
  background: rgba(37, 99, 235, 0.08);
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 12px;
}

.solution-title {
  font-size: 22px;
  margin-bottom: 8px;
}

.solution-desc {
  color: var(--text-secondary);
  font-size: 16px;
}

.solution-list {
  list-style: none;
  margin: 20px 0;
}

.solution-list li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
  color: var(--text-secondary);
}

.solution-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 16px;
  width: 6px;
  height: 6px;
  background: var(--primary);
  border-radius: 50%;
}

.solution-deliverable {
  background: var(--bg);
  padding: 24px;
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--text-secondary);
  border-left: 3px solid var(--primary);
  height: fit-content;
}

/* ===== Use Case Cards ===== */
.usecase-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  height: 100%;
}

.usecase-meta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 24px;
}

.usecase-meta-item {
  padding: 16px;
  background: var(--bg);
  border-radius: 8px;
}

.usecase-meta-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}

.usecase-meta-text {
  font-size: 14px;
  color: var(--text-primary);
  line-height: 1.5;
}

@media (max-width: 640px) {
  .usecase-meta {
    grid-template-columns: 1fr;
  }
}

/* ===== Process Steps ===== */
.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin: 48px 0;
}

.process-step {
  position: relative;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.process-step::after {
  content: '';
  position: absolute;
  top: 50%;
  right: -24px;
  width: 24px;
  height: 2px;
  background: var(--border);
  transform: translateY(-50%);
}

.process-step:last-child::after {
  display: none;
}

.process-number {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  opacity: 0.3;
  margin-bottom: 12px;
}

.process-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.process-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.5;
}

@media (max-width: 1024px) {
  .process-steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .process-step::after {
    display: none;
  }
}

@media (max-width: 640px) {
  .process-steps {
    grid-template-columns: 1fr;
  }
}

/* ===== FAQ ===== */
.faq-item {
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
}

.faq-question {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-answer {
  margin-top: 12px;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== CTA Section ===== */
.cta-section {
  background: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 80px 0;
  text-align: center;
}

.cta-title {
  margin-bottom: 16px;
}

.cta-text {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Contact Page ===== */
.contact-section {
  padding-top: 144px;
  padding-bottom: var(--section-spacing);
}

.contact-header {
  text-align: center;
  margin-bottom: 64px;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.contact-qr {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 48px;
  text-align: center;
}

.qr-placeholder {
  width: 200px;
  height: 200px;
  background: var(--bg);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  margin: 0 auto 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 14px;
}

.contact-trust {
  margin-top: 48px;
}

.trust-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 14px;
  color: var(--text-secondary);
}

.trust-icon {
  width: 20px;
  height: 20px;
  color: var(--success);
  flex-shrink: 0;
}

@media (max-width: 768px) {
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }
}

/* ===== Article Page ===== */
.article-section {
  padding-top: 144px;
  padding-bottom: var(--section-spacing);
}

.article-container {
  max-width: 760px;
  margin: 0 auto;
}

.article-header {
  margin-bottom: 48px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border);
}

.article-title {
  font-size: 32px;
  margin-bottom: 16px;
}

.article-meta {
  font-size: 14px;
  color: var(--text-secondary);
}

.article-content {
  font-size: 17px;
  line-height: 1.8;
}

.article-content h2 {
  margin-top: 48px;
  margin-bottom: 20px;
  font-size: 24px;
}

.article-content h3 {
  margin-top: 32px;
  margin-bottom: 16px;
  font-size: 20px;
}

.article-content p {
  margin-bottom: 20px;
  color: var(--text-secondary);
}

.article-content ul,
.article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 8px;
  color: var(--text-secondary);
}

/* ===== Insights List ===== */
.insight-item {
  padding: 32px 0;
  border-bottom: 1px solid var(--border);
}

.insight-title {
  font-size: 20px;
  margin-bottom: 12px;
}

.insight-title a {
  color: var(--text-primary);
}

.insight-title a:hover {
  color: var(--primary);
}

.insight-excerpt {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.insight-tag {
  display: inline-block;
  font-size: 12px;
  color: var(--primary);
  background: rgba(37, 99, 235, 0.08);
  padding: 4px 10px;
  border-radius: 4px;
}

/* ===== Footer ===== */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-title {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-links {
  list-style: none;
}

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

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
}

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

.footer-bottom {
  display: flex;
  flex-direction: column;
  /* 改为垂直排列 */
  align-items: center;
  /* 水平居中，可选 */
  gap: 8px;
  /* 添加间距，可选 */
}

.footer-copyright {
  font-size: 13px;
  color: var(--text-secondary);
}

.footer-icp {
  font-size: 13px;
  color: var(--text-secondary);
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

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

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== Page Header ===== */
.page-header {
  padding-top: 144px;
  padding-bottom: 64px;
  border-bottom: 1px solid var(--border);
}

.page-title {
  margin-bottom: 16px;
}

.page-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 760px;
}

/* ===== Utility ===== */
.text-center {
  text-align: center;
}

.mt-4 {
  margin-top: 16px;
}

.mt-8 {
  margin-top: 32px;
}

.mb-4 {
  margin-bottom: 16px;
}

.mb-8 {
  margin-bottom: 32px;
}