/* ===========================
   响应式适配
   =========================== */

/* 大屏 -> 中屏 */
@media (max-width: 1200px) {
  :root {
    --fs-5xl: 2.5rem;
    --fs-6xl: 3rem;
  }

  .footer-main {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
  }

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

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

/* 中屏 -> 小屏 */
@media (max-width: 992px) {
  :root {
    --header-height: 70px;
  }

  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    max-width: 100%;
    margin: 0 auto;
  }

  .hero h1 {
    font-size: 2.25rem;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
    gap: var(--space-8);
  }

  .hero-image {
    max-width: 500px;
    margin: 0 auto;
  }

  .hero-floating-1 {
    left: -10px;
  }

  .hero-floating-2 {
    right: -10px;
  }

  .nav-menu {
    position: fixed;
    top: calc(var(--topbar-height) + var(--header-height));
    right: 0;
    width: 280px;
    height: calc(100vh - var(--topbar-height) - var(--header-height));
    background: var(--color-bg);
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-5);
    box-shadow: var(--shadow-xl);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    overflow-y: auto;
    gap: 0;
  }

  .nav-menu.active {
    transform: translateX(0);
  }

  .nav-link {
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius-md);
  }

  .nav-dropdown {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    box-shadow: none;
    padding-left: var(--space-4);
  }

  .nav-toggle {
    display: block;
  }

  .nav-cta {
    margin: var(--space-3) 0 0;
    text-align: center;
  }

  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .footer-brand {
    grid-column: 1 / -1;
    max-width: 100%;
  }

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

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

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

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-12);
  }

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

  .site-footer .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-6);
  }
}

/* 小屏 */
@media (max-width: 768px) {
  :root {
    --fs-4xl: 1.875rem;
    --fs-5xl: 2rem;
    --fs-6xl: 2.25rem;
    --space-20: 3rem;
    --space-24: 4rem;
  }

  /* 新 header 响应式 */
  .top-company { font-size: 13px; }
  .header-mid-inner { flex-direction: column; align-items: flex-start; }
  .contact-row { flex-direction: column; gap: 18px; align-items: flex-start; }
  .logo-text { font-size: 28px; }
  .nav-toggle { display: inline-block; }
  .nav-slant-inner { flex-direction: column; align-items: stretch; display: none; }
  .nav-slant-inner.open { display: flex; }
  .nav-slant-inner a { padding: 12px 16px; border-top: 1px solid rgba(255,255,255,0.1); }
  .nav-slant { clip-path: none; }
  .top-slant { clip-path: none; }
  .topbar-info {
    gap: var(--space-3);
    font-size: var(--fs-xs);
    flex-wrap: wrap;
  }

  .topbar-info span:nth-child(3) {
    display: none;
  }

  .hero {
    padding: var(--space-16) 0 var(--space-12);
    min-height: auto;
  }

  .hero-image-main svg,
  .hero-image-main img {
    height: 280px;
  }

  .hero-floating {
    display: none;
  }

  .hero-stats {
    flex-direction: column;
    gap: var(--space-4);
    align-items: center;
  }

  .hero-cta {
    flex-direction: column;
    width: 100%;
  }

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

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

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

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

  .stats-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

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

  .section-title h2 {
    font-size: var(--fs-3xl);
  }

  .section-title .subtitle {
    font-size: var(--fs-base);
  }

  .footer-main {
    grid-template-columns: 1fr;
  }

  .site-footer .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

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

  .cta-banner .container {
    flex-direction: column;
    text-align: center;
  }

  .cta-banner h2 {
    font-size: var(--fs-2xl);
  }

  .newsletter-form {
    min-width: 100%;
    flex-direction: column;
    border-radius: var(--radius-lg);
  }

  .newsletter-form input {
    text-align: center;
  }

  .product-categories {
    gap: var(--space-2);
  }

  .category-btn {
    padding: var(--space-2) var(--space-4);
    font-size: var(--fs-xs);
  }

  .process-step {
    padding-left: 70px;
  }

  .process-step::before {
    width: 50px;
    height: 50px;
    font-size: var(--fs-lg);
  }

  .standards-table {
    overflow-x: auto;
  }

  .standards-table table {
    min-width: 600px;
  }

  .about-grid {
    grid-template-columns: 1fr !important;
  }

  .contact-grid {
    grid-template-columns: 1fr !important;
  }
}

/* 超小屏 */
@media (max-width: 480px) {
  .topbar {
    font-size: 0.7rem;
  }

  .topbar-info {
    gap: var(--space-2);
  }

  .topbar-info span:nth-child(2),
  .topbar-info span:nth-child(3) {
    display: none;
  }

  .logo-text small {
    display: none;
  }

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

  .hero h1 {
    font-size: 1.875rem;
  }
}

/* ===========================
   特殊页面布局
   =========================== */

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.about-image {
  position: relative;
}

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

.about-image-frame::before {
  content: "";
  position: absolute;
  top: var(--space-5);
  left: var(--space-5);
  right: -20px;
  bottom: -20px;
  border: 3px solid var(--color-accent);
  border-radius: var(--radius-lg);
  z-index: -1;
}

.about-image-frame svg {
  width: 100%;
  height: 400px;
}

.about-features {
  margin-top: var(--space-6);
  display: grid;
  gap: var(--space-4);
}

.about-feature-item {
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
}

.about-feature-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(243, 156, 18, 0.15);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.about-feature-icon svg {
  width: 18px;
  height: 18px;
}

.about-feature-item h5 {
  color: var(--color-text);
  margin-bottom: var(--space-1);
  font-size: var(--fs-base);
}

.about-feature-item p {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

/* ===========================
   Contact Page
   =========================== */

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: var(--space-12);
}

.contact-info-card {
  background: var(--color-primary);
  color: var(--color-text-white);
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  position: relative;
  overflow: hidden;
}

.contact-info-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 80% 20%, rgba(243, 156, 18, 0.15) 0%, transparent 50%);
}

.contact-info-card > * {
  position: relative;
}

.contact-info-card h3 {
  color: var(--color-text-white);
  margin-bottom: var(--space-3);
}

.contact-info-card > p {
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-6);
}

.contact-info-list {
  display: grid;
  gap: var(--space-5);
}

.contact-info-item {
  display: flex;
  gap: var(--space-3);
}

.contact-info-icon {
  width: 44px;
  height: 44px;
  background: rgba(243, 156, 18, 0.15);
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent);
  flex-shrink: 0;
}

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

.contact-info-item strong {
  display: block;
  color: var(--color-text-white);
  margin-bottom: var(--space-1);
  font-size: var(--fs-base);
}

.contact-info-item span {
  color: rgba(255, 255, 255, 0.75);
  font-size: var(--fs-sm);
}

.contact-form {
  background: var(--color-bg);
  padding: var(--space-8);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.contact-form h3 {
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.contact-form > p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-6);
  font-size: var(--fs-sm);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.form-group {
  margin-bottom: var(--space-4);
}

.form-group label {
  display: block;
  margin-bottom: var(--space-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
}

.form-group label .required {
  color: var(--color-danger);
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--fs-base);
  font-family: inherit;
  background: var(--color-bg);
  color: var(--color-text);
  transition: var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(26, 58, 108, 0.1);
}

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

/* ===========================
   Map / Location
   =========================== */

.map-container {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  height: 400px;
  background: var(--color-bg-gray);
  display: flex;
  align-items: center;
  justify-content: center;
}

.map-container svg {
  width: 100%;
  height: 100%;
}

/* ===========================
   FAQ
   =========================== */

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-bg);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-3);
  border: 1px solid var(--color-border-light);
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-item.active {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  padding: var(--space-5);
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--fs-base);
  font-weight: 600;
  color: var(--color-text);
  text-align: left;
  font-family: inherit;
}

.faq-question::after {
  content: "+";
  font-size: var(--fs-2xl);
  color: var(--color-accent);
  font-weight: 300;
  transition: var(--transition-fast);
}

.faq-item.active .faq-question::after {
  content: "−";
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-inner {
  padding: 0 var(--space-5) var(--space-5);
  color: var(--color-text-secondary);
  font-size: var(--fs-sm);
  line-height: 1.7;
}

/* ===========================
   Installation Training Page
   =========================== */

.training-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
}

.training-tab {
  padding: var(--space-3) var(--space-5);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-weight: 600;
  font-size: var(--fs-sm);
  color: var(--color-text);
  transition: var(--transition-fast);
}

.training-tab:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.training-tab.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-white);
}

.training-panel {
  display: none;
}

.training-panel.active {
  display: block;
  animation: fadeInUp 0.4s ease-out;
}

.training-panel h3 {
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.training-panel ul {
  padding-left: var(--space-5);
}

.training-panel ul li {
  list-style: disc;
  margin-bottom: var(--space-2);
  color: var(--color-text-secondary);
}