/* ===== Variables ===== */
:root {
  --color-primary: #f97316;
  --color-primary-dark: #ea580c;
  --color-primary-light: #fb923c;
  --color-accent: #ff8c42;
  --color-bg: #fafafa;
  --color-bg-alt: #fff7ed;
  --color-text: #1c1917;
  --color-text-muted: #57534e;
  --color-border: #e7e5e4;
  --color-white: #ffffff;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 20px rgba(249, 115, 22, 0.12);
  --shadow-lg: 0 12px 40px rgba(249, 115, 22, 0.18);
  --radius: 12px;
  --radius-lg: 20px;
  --header-height: 72px;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --transition: 0.25s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.header.scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  object-fit: cover;
}

.logo-text {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 36px;
}

.nav a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
  position: relative;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
  transition: width var(--transition);
}

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

.nav a:hover::after,
.nav a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-height) + 48px) 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #fff7ed 0%, #ffedd5 40%, #fed7aa 100%);
  z-index: 0;
}

.hero-bg::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 60%;
  height: 80%;
  background: radial-gradient(ellipse, rgba(249, 115, 22, 0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-bg::after {
  content: "";
  position: absolute;
  bottom: -10%;
  left: -5%;
  width: 40%;
  height: 50%;
  background: radial-gradient(ellipse, rgba(251, 146, 60, 0.12) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 680px;
}

.hero-tag {
  display: inline-block;
  padding: 6px 16px;
  margin-bottom: 24px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary-dark);
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid rgba(249, 115, 22, 0.25);
  border-radius: 100px;
  letter-spacing: 0.05em;
}

.hero h1 {
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.25;
  color: var(--color-text);
  margin-bottom: 24px;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  margin-bottom: 40px;
  max-width: 540px;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 100px;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}

.btn-primary {
  color: var(--color-white);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  box-shadow: var(--shadow-md);
}

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

.btn-outline {
  color: var(--color-primary-dark);
  background: var(--color-white);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-bg-alt);
  transform: translateY(-2px);
}

/* ===== Stats ===== */
.stats {
  position: relative;
  z-index: 2;
  margin-top: -48px;
  padding-bottom: 48px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 28px 16px;
  background: var(--color-white);
  text-align: center;
}

.stat-item strong {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.2;
}

.stat-item span {
  margin-top: 6px;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* ===== Sections ===== */
.section {
  padding: 96px 0;
}

.section-alt {
  background: var(--color-bg-alt);
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}

.section-label {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.section-header h2 {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.section-header p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

/* ===== Cards ===== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.card {
  padding: 36px 28px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md);
  border-color: rgba(249, 115, 22, 0.3);
}

.card-featured {
  background: linear-gradient(160deg, #fff7ed 0%, #ffffff 100%);
  border-color: rgba(249, 115, 22, 0.35);
  box-shadow: var(--shadow-md);
}

.card-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--color-primary);
  background: var(--color-bg-alt);
  border-radius: 14px;
}

.card-icon svg {
  width: 32px;
  height: 32px;
}

.card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.card > p {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.card-list li {
  position: relative;
  padding-left: 18px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.card-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  background: var(--color-primary);
  border-radius: 50%;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 56px;
  align-items: start;
}

.about-text h2 {
  font-size: clamp(1.5rem, 2.5vw, 2rem);
  font-weight: 800;
  margin-bottom: 24px;
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.about-text strong {
  color: var(--color-text);
}

.scope-details {
  margin-top: 24px;
  padding: 16px 20px;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.scope-details summary {
  font-weight: 600;
  color: var(--color-primary-dark);
  cursor: pointer;
  user-select: none;
}

.scope-details summary:hover {
  color: var(--color-primary);
}

.scope-full {
  margin-top: 16px;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--color-text-muted);
}

.about-visual {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.about-logo {
  width: 100%;
  max-width: 280px;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.about-info-card {
  padding: 28px;
  background: var(--color-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.about-info-card dl div {
  margin-bottom: 20px;
}

.about-info-card dl div:last-child {
  margin-bottom: 0;
}

.about-info-card dt {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}

.about-info-card dd {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.5;
}

/* ===== Contact ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.contact-card {
  padding: 32px 28px;
  text-align: center;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: box-shadow var(--transition);
}

.contact-card:hover {
  box-shadow: var(--shadow-md);
}

.contact-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.contact-card p {
  font-size: 0.95rem;
  color: var(--color-text-muted);
}

/* ===== Footer ===== */
.footer {
  padding: 48px 0 32px;
  background: #1c1917;
  color: #a8a29e;
}

.footer-inner {
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 1rem;
  font-weight: 600;
  color: #fafaf9;
}

.footer-logo {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: cover;
}

.footer-address {
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.footer-beian {
  font-size: 0.85rem;
  line-height: 1.8;
}

.footer-beian a {
  color: #d6d3d1;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

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

/* ===== Responsive ===== */
@media (max-width: 992px) {
  .cards-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }

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

  .about-visual {
    order: -1;
  }

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

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    padding: 16px 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition), opacity var(--transition), visibility var(--transition);
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav a {
    display: block;
    padding: 14px 24px;
    width: 100%;
  }

  .nav a::after {
    display: none;
  }

  .hero {
    min-height: auto;
    padding-bottom: 64px;
  }

  .stats {
    margin-top: 0;
  }

  .section {
    padding: 64px 0;
  }

  .logo-text {
    font-size: 0.9rem;
  }
}

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

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

  .btn {
    width: 100%;
  }
}