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

html, body {
  overflow-x: hidden;
}

img,
video,
svg {
  max-width: 100%;
  height: auto;
}

:root {
  --bg-page: #f4f7fb;
  --bg-card: #ffffff;
  --bg-subtle: #f8fbff;
  --line: #dbe5f2;
  --line-soft: #e9eff8;
  --text-main: #1f2a37;
  --text-sub: #5b6b7f;
  --text-muted: #8a96a6;
  --primary: #2468f2;
  --primary-dark: #1e57ca;
  --success: #16a34a;
  --warning: #d97706;
  --danger: #dc2626;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
  --radius: 12px;
  --max-width: 1200px;
}

body.theme-dark {
  --bg-page: #0f172a;
  --bg-card: #111b2d;
  --bg-subtle: #152238;
  --line: #26364f;
  --line-soft: #1f3047;
  --text-main: #e5edf7;
  --text-sub: #b7c5d8;
  --text-muted: #8ea0b9;
  --primary: #3a86ff;
  --primary-dark: #2d6dd1;
  --success: #22c55e;
  --shadow: none;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', Roboto, sans-serif;
  color: var(--text-main);
  background: linear-gradient(180deg, #f6f9ff 0%, #f3f6fb 55%, #eef3fb 100%);
  line-height: 1.5;
  min-height: 100vh;
}

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: min(var(--max-width), calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 30;
}

body.theme-dark .site-header {
  background: rgba(17, 27, 45, 0.92);
}

.site-header-inner {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.2px;
  text-decoration: none;
}

.brand i {
  color: var(--primary);
  font-size: 20px;
}

.top-nav {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  color: var(--text-sub);
  font-size: 14px;
}

.top-nav a {
  color: inherit;
  text-decoration: none;
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
}

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

.top-nav a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 700;
}

.header-actions {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.btn {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 9px 14px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  cursor: pointer;
  transition: .2s ease;
  white-space: nowrap;
}

.btn-primary {
  color: #fff;
  background: var(--primary);
  border-color: var(--primary);
}

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

.btn-secondary {
  color: var(--text-main);
  background: var(--bg-card);
  border-color: var(--line);
}

.btn-secondary:hover {
  border-color: #c2d3ea;
  background: #f7faff;
}

.main {
  flex: 1;
  padding: 24px 0 34px;
}

.hero {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  box-shadow: var(--shadow);
  padding: 26px;
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 22px;
  margin-bottom: 16px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid #cfe0ff;
  border-radius: 999px;
  background: #ecf4ff;
  color: #1f5dd2;
  padding: 6px 12px;
  font-size: 12px;
  font-weight: 600;
  margin-bottom: 14px;
}

body.theme-dark .hero-tag {
  border-color: #31548a;
  background: #1e2f4e;
  color: #b9d6ff;
}

.hero-title {
  font-size: clamp(30px, 4vw, 42px);
  line-height: 1.18;
  margin-bottom: 14px;
  letter-spacing: 0.1px;
}

.hero-desc {
  color: var(--text-sub);
  font-size: 15px;
  max-width: 560px;
  margin-bottom: 18px;
}

.hero-actions {
  display: inline-flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.hero-points {
  display: grid;
  gap: 8px;
  color: var(--text-sub);
  font-size: 13px;
}

.hero-points span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero-points i {
  color: var(--success);
}

.carousel {
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  background: var(--bg-subtle);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  min-height: 340px;
}

.carousel-viewport {
  position: relative;
  flex: 1;
  min-height: 0;
}

.carousel-slide {
  position: absolute;
  inset: 0;
  padding: 18px;
  opacity: 0;
  pointer-events: none;
  transform: translateX(16px);
  transition: opacity .32s ease, transform .32s ease;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.carousel-slide.is-active {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(0);
}

.slide-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.slide-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-main);
}

.slide-tag {
  font-size: 12px;
  color: var(--text-muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 8px;
  background: var(--bg-card);
}

.slide-body {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--bg-card);
  padding: 14px;
  display: grid;
  gap: 10px;
  flex: 1;
}

.slide-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-size: 13px;
  color: var(--text-sub);
}

.slide-row strong {
  color: var(--text-main);
  font-weight: 700;
  min-width: 0;
  max-width: 65%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  text-align: right;
}

.slide-progress {
  height: 10px;
  border-radius: 999px;
  background: #e4ebf7;
  overflow: hidden;
}

.slide-progress span {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, #33c1ff, var(--primary));
}

.carousel-footer {
  border-top: 1px solid var(--line-soft);
  background: var(--bg-card);
  padding: 10px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.carousel-dots {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.carousel-dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  border: 1px solid #c8d6ea;
  background: #dbe5f3;
  cursor: pointer;
  transition: .2s ease;
}

.carousel-dot.active {
  width: 20px;
  background: var(--primary);
  border-color: var(--primary);
}

.carousel-nav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.carousel-btn {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--bg-card);
  color: var(--text-sub);
  cursor: pointer;
}

.carousel-btn:hover {
  color: var(--primary);
  border-color: #bfd0e8;
}

.page-banner {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  box-shadow: var(--shadow);
  padding: 22px;
  margin-bottom: 14px;
}

.page-banner h1 {
  font-size: clamp(28px, 4vw, 36px);
  margin-bottom: 10px;
  line-height: 1.2;
}

.page-banner p {
  color: var(--text-sub);
  font-size: 15px;
  max-width: 860px;
}

.kpi-row {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.kpi-card {
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--bg-subtle);
  padding: 12px;
}

.kpi-label {
  color: var(--text-muted);
  font-size: 12px;
  margin-bottom: 4px;
}

.kpi-value {
  color: var(--text-main);
  font-size: 18px;
  font-weight: 700;
}

.section {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  box-shadow: var(--shadow);
  padding: 18px;
  margin-bottom: 14px;
}

.section-title {
  font-size: 18px;
  margin-bottom: 12px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.section-title i {
  color: var(--primary);
  font-size: 15px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.feature-card {
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--bg-subtle);
  padding: 14px;
}

.feature-icon {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: #e9f2ff;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
}

.feature-name {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 6px;
}

.feature-desc {
  font-size: 13px;
  color: var(--text-sub);
}

.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.scene {
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--bg-subtle);
  padding: 14px;
  display: grid;
  gap: 8px;
}

.scene h3 {
  font-size: 15px;
}

.scene p {
  font-size: 13px;
  color: var(--text-sub);
}

.list-check {
  list-style: none;
  display: grid;
  gap: 5px;
  font-size: 12px;
  color: var(--text-muted);
}

.list-check li {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.list-check li i {
  color: var(--success);
  font-size: 10px;
}

.matrix {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.matrix-card {
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--bg-subtle);
  padding: 14px;
}

.matrix-card h3 {
  font-size: 15px;
  margin-bottom: 6px;
}

.matrix-card p {
  color: var(--text-sub);
  font-size: 13px;
}

.step-line {
  display: grid;
  gap: 10px;
}

.step-item {
  border: 1px solid var(--line-soft);
  border-radius: 10px;
  background: var(--bg-subtle);
  padding: 12px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.step-num {
  width: 26px;
  height: 26px;
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.step-content p {
  color: var(--text-sub);
  font-size: 13px;
}

.cta-panel {
  border: 1px solid #cfe0ff;
  border-radius: 12px;
  background: #edf4ff;
  padding: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

body.theme-dark .cta-panel {
  border-color: #31548a;
  background: #1e2f4e;
}

.cta-panel p {
  font-size: 14px;
  color: var(--text-sub);
}

.footer {
  border-top: 1px solid var(--line);
  background: var(--bg-card);
  padding: 14px 0;
  color: var(--text-muted);
  font-size: 12px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.footer-tech {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

@media (min-width: 1920px) {
  :root {
    --max-width: 1480px;
  }

  body {
    font-size: 16px;
  }

  .hero {
    padding: 32px;
    gap: 28px;
  }

  .hero-title {
    font-size: clamp(38px, 3vw, 56px);
  }

  .section,
  .page-banner {
    padding: 24px;
  }

  .carousel {
    min-height: 400px;
  }
}

@media (min-width: 2560px) {
  :root {
    --max-width: 1760px;
  }

  body {
    font-size: 17px;
  }

  .hero {
    padding: 36px;
  }

  .carousel {
    min-height: 430px;
  }

  .section,
  .page-banner {
    padding: 28px;
  }
}

@media (max-width: 1060px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .scene-grid,
  .kpi-row,
  .matrix {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 768px) {
  .container {
    width: calc(100% - 20px);
  }

  .site-header-inner {
    min-height: unset;
    padding: 8px 0;
    flex-wrap: wrap;
  }

  .top-nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    white-space: nowrap;
  }

  .header-actions {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .header-actions .btn {
    width: 100%;
  }

  .main {
    padding-top: 16px;
  }

  .hero,
  .section,
  .page-banner {
    padding: 14px;
  }

  .carousel {
    min-height: 320px;
  }

  .feature-grid,
  .scene-grid,
  .kpi-row,
  .matrix {
    grid-template-columns: 1fr;
  }

  .cta-panel {
    flex-direction: column;
    align-items: stretch;
  }

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


/* ===== True Large-Screen Proportional Scaling ===== */
@media (min-width: 1920px) {
  :root {
    --max-width: 1800px;
  }

  body {
    font-size: 17px;
  }

  .container {
    width: min(var(--max-width), calc(100% - 72px));
  }

  .site-header-inner {
    min-height: 82px;
  }

  .brand {
    font-size: 28px;
  }

  .top-nav {
    font-size: 16px;
    gap: 22px;
  }

  .btn {
    font-size: 16px;
    padding: 11px 18px;
  }

  .main {
    padding: 42px 0 58px;
  }

  .hero {
    min-height: 62vh;
    padding: 38px;
    gap: 34px;
    align-items: stretch;
  }

  .hero-title {
    font-size: clamp(50px, 3.6vw, 72px);
    margin-bottom: 18px;
  }

  .hero-desc {
    font-size: 18px;
    max-width: 760px;
    margin-bottom: 22px;
  }

  .hero-points {
    font-size: 15px;
    gap: 10px;
  }

  .carousel {
    min-height: clamp(520px, 58vh, 820px);
  }

  .carousel-slide {
    padding: 26px;
  }

  .slide-title {
    font-size: 24px;
  }

  .slide-row {
    font-size: 15px;
  }

  .section,
  .page-banner {
    padding: 28px;
  }

  .section-title {
    font-size: 24px;
    margin-bottom: 16px;
  }

  .feature-card,
  .scene,
  .matrix-card,
  .step-item,
  .kpi-card {
    padding: 18px;
  }

  .feature-name,
  .scene h3,
  .matrix-card h3,
  .step-content h3 {
    font-size: 18px;
  }

  .feature-desc,
  .scene p,
  .matrix-card p,
  .step-content p {
    font-size: 15px;
  }

  .kpi-value {
    font-size: 26px;
  }

  .footer {
    font-size: 13px;
    padding: 18px 0;
  }
}

@media (min-width: 2560px) {
  :root {
    --max-width: 2200px;
  }

  body {
    font-size: 19px;
  }

  .container {
    width: min(var(--max-width), calc(100% - 96px));
  }

  .site-header-inner {
    min-height: 94px;
  }

  .brand {
    font-size: 32px;
  }

  .top-nav {
    font-size: 18px;
    gap: 26px;
  }

  .btn {
    font-size: 18px;
    padding: 12px 22px;
  }

  .main {
    padding: 52px 0 72px;
  }

  .hero {
    min-height: 66vh;
    padding: 46px;
    gap: 42px;
  }

  .hero-title {
    font-size: clamp(64px, 3.6vw, 92px);
  }

  .hero-desc {
    font-size: 21px;
    max-width: 920px;
  }

  .hero-points {
    font-size: 17px;
    gap: 12px;
  }

  .carousel {
    min-height: clamp(640px, 60vh, 960px);
  }

  .carousel-slide {
    padding: 30px;
  }

  .slide-title {
    font-size: 30px;
  }

  .slide-tag {
    font-size: 14px;
  }

  .slide-row {
    font-size: 18px;
  }

  .section,
  .page-banner {
    padding: 34px;
  }

  .section-title {
    font-size: 30px;
  }

  .feature-name,
  .scene h3,
  .matrix-card h3,
  .step-content h3 {
    font-size: 22px;
  }

  .feature-desc,
  .scene p,
  .matrix-card p,
  .step-content p {
    font-size: 17px;
  }

  .kpi-value {
    font-size: 34px;
  }

  .footer {
    font-size: 15px;
    padding: 22px 0;
  }
}

@media (max-width: 480px) {
  .brand {
    font-size: 19px;
  }

  .hero-title,
  .page-banner h1 {
    font-size: 28px;
  }

  .hero-actions {
    width: 100%;
  }

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

  .carousel-slide {
    padding: 12px;
  }

  .slide-title {
    font-size: 16px;
  }

  .slide-row {
    font-size: 12px;
  }

  .footer-inner,
  .footer-tech {
    justify-content: center;
  }

  .footer {
    text-align: center;
  }
}
