/* ========================================
   响应式策略 - 极简定制空间主题
   ======================================== */

@media (max-width: 1200px) {
  :root {
    --font-size-5xl: 48px;
    --font-size-4xl: 34px;
  }
  
  .container {
    padding: 0 20px;
  }
  
  .grid-4 { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 992px) {
  :root {
    --font-size-5xl: 40px;
    --font-size-4xl: 30px;
    --font-size-3xl: 24px;
  }
  
  .logo-text {
    max-width: 200px;
    font-size: 18px;
    line-height: 1.2;
  }
  
  .navbar .container {
    height: 66px;
  }
  
  .nav-menu {
    position: absolute;
    top: 66px;
    right: 0;
    left: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 12px 20px;
    background: #fff;
    border-bottom: 1px solid var(--color-line);
    display: none;
  }
  
  .nav-menu.active {
    display: flex;
  }
  
  .nav-menu a {
    width: 100%;
    padding: 12px 10px;
    border-radius: var(--radius-md);
  }
  
  .dropdown-menu {
    position: relative;
    top: 0;
    left: 0;
    box-shadow: none;
    border: none;
    width: 100%;
    backdrop-filter: none;
    padding: 0;
    margin-top: 0;
    transform: none;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    display: none;
  }
  
  .dropdown-menu.is-visible {
    display: block;
  }
  
  .cta-panel {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .cta-panel .cta-actions {
    width: 100%;
  }
  
  .cta-panel .cta-actions .btn {
    flex: 1;
    min-width: auto;
  }
  
  .menu-toggle {
    display: inline-flex;
  }
  
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .series-panel, .case-card { grid-template-columns: 1fr; }
  .timeline-item { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  :root {
    --font-size-5xl: 32px;
    --font-size-4xl: 26px;
    --font-size-3xl: 20px;
    --spacing-16: 48px;
  }
  
  .section { padding: var(--spacing-12) 0; }
  .section-heading { flex-direction: column; align-items: flex-start; }
  .hero { padding: 120px 0 96px; }
  .hero-actions { flex-direction: column; width: 100%; }
  .hero-actions .btn { width: 100%; }
  
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .stat-grid { grid-template-columns: repeat(2, 1fr); }
  
  .card { padding: var(--spacing-5); }
  .series-body { padding: var(--spacing-5); }
  .case-card { gap: var(--spacing-4); }
  
  .nav-menu { padding: 12px 16px; }
}