/* ===== CSS DESIGN SYSTEM: NANGONG PG ===== */
/* 风格：野兽主义 × 网格解构 × 高饱和流体 */
/* 色彩：暗紫罗兰 + 荧光绿 + 钛白 */
/* 字体：系统黑体 + 极端字重对比 */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;700;900&display=swap');

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

:root {
  --color-bg: #0b0a1a;
  --color-surface: #1a1730;
  --color-accent: #b9ff50;
  --color-accent-dim: #7ab82e;
  --color-text: #f0edff;
  --color-text-muted: #8a84b0;
  --color-border: #2f2a4a;
  --color-card-bg: #1e1b36;
  --color-overlay: rgba(11, 10, 26, 0.85);
  --color-glow: rgba(185, 255, 80, 0.25);
  --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --radius: 4px;
  --transition: 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
  --grid-gap: 2rem;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ===== CONTAINER ===== */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
}

/* ===== SITE HEADER ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-overlay);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  padding: 0 1.5rem;
  max-width: 1280px;
  margin: 0 auto;
}

.logo {
  font-size: 1.6rem;
  font-weight: 900;
  letter-spacing: -0.04em;
  color: var(--color-text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-transform: uppercase;
}

.logo::before {
  content: '';
  display: inline-block;
  width: 12px;
  height: 12px;
  background: var(--color-accent);
  transform: rotate(45deg);
  box-shadow: 0 0 20px var(--color-glow);
}

.main-nav {
  display: flex;
  gap: 2.5rem;
  align-items: center;
}

.main-nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  position: relative;
  transition: color var(--transition);
  padding: 0.25rem 0;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition);
}

.main-nav a:hover {
  color: var(--color-accent);
}

.main-nav a:hover::after {
  width: 100%;
}

.nav-cta {
  background: var(--color-accent);
  color: var(--color-bg) !important;
  padding: 0.5rem 1.2rem !important;
  border-radius: var(--radius);
  font-weight: 900 !important;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav-cta:hover {
  background: white !important;
  color: var(--color-bg) !important;
  transform: scale(1.05);
  box-shadow: 0 0 30px var(--color-glow);
}

.nav-cta::after {
  display: none !important;
}

.menu-toggle {
  display: none;
  background: transparent;
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  width: 44px;
  height: 44px;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  border-radius: var(--radius);
  transition: background var(--transition);
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-accent);
  transition: all var(--transition);
}

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  padding: 8rem 0 4rem;
  overflow: hidden;
  background: radial-gradient(ellipse at 20% 50%, #2a1f4a 0%, transparent 60%),
              radial-gradient(ellipse at 80% 20%, #1a3a2a 0%, transparent 50%);
}

.hero::before {
  content: '';
  position: absolute;
  top: -20%;
  right: -10%;
  width: 60%;
  height: 120%;
  background: repeating-linear-gradient(
    45deg,
    transparent,
    transparent 40px,
    rgba(185, 255, 80, 0.03) 40px,
    rgba(185, 255, 80, 0.03) 41px
  );
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 900;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: rgba(185, 255, 80, 0.1);
  padding: 0.4rem 1rem;
  border: 1px solid rgba(185, 255, 80, 0.2);
  margin-bottom: 1.5rem;
  border-radius: var(--radius);
}

.hero-content h1 {
  font-size: clamp(2.8rem, 8vw, 5.5rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.04em;
  color: var(--color-text);
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}

.hero-content h1 span {
  color: var(--color-accent);
  display: block;
  text-shadow: 0 0 40px var(--color-glow);
}

.hero-content p {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin-bottom: 2.5rem;
  font-weight: 300;
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.hero-image {
  position: absolute;
  right: -5%;
  top: 15%;
  width: 55%;
  height: 70%;
  z-index: 1;
  opacity: 0.6;
  background: radial-gradient(circle at 50% 50%, var(--color-accent-dim) 0%, transparent 70%);
  filter: blur(80px);
  pointer-events: none;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.9rem 2.2rem;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 2px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  position: relative;
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-bg);
  border-color: var(--color-accent);
  box-shadow: 0 0 20px var(--color-glow);
}

.btn-primary:hover {
  background: white;
  border-color: white;
  color: var(--color-bg);
  transform: translateY(-3px);
  box-shadow: 0 0 40px var(--color-glow);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-3px);
  box-shadow: 0 0 20px var(--color-glow);
}

/* ===== SECTION ===== */
.section {
  padding: 6rem 0;
  position: relative;
  border-top: 1px solid var(--color-border);
}

.section-label {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 900;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 1rem;
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: 0.3rem;
}

.section-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text);
  margin-bottom: 1rem;
  text-transform: uppercase;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  max-width: 600px;
  font-weight: 300;
  margin-bottom: 3rem;
}

/* ===== CARDS GRID ===== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--grid-gap);
}

.category-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--color-accent);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform var(--transition);
}

.category-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-accent);
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
}

.category-card:hover::before {
  transform: scaleY(1);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  color: var(--color-accent);
  line-height: 1;
}

.category-card h3 {
  font-size: 1.3rem;
  font-weight: 900;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.category-card p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 300;
  flex: 1;
  margin-bottom: 1.5rem;
}

.card-link {
  color: var(--color-accent);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: gap var(--transition);
}

.card-link:hover {
  gap: 1rem;
}

/* ===== FEATURE BLOCK ===== */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  margin-bottom: 4rem;
}

.feature-image {
  background: var(--color-card-bg);
  aspect-ratio: 4/3;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  color: var(--color-accent);
  opacity: 0.7;
}

.feature-text {
  padding: 1rem 0;
}

.feature-text h3 {
  font-size: 1.8rem;
  font-weight: 900;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
}

.feature-text p {
  color: var(--color-text-muted);
  font-weight: 300;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.feature-list li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 300;
  font-size: 0.95rem;
}

.feature-list li::before {
  content: '▶';
  color: var(--color-accent);
  font-size: 0.7rem;
}

/* ===== STATS BAR ===== */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  padding: 4rem 0;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  margin: 4rem 0;
}

.stat-item {
  text-align: center;
  padding: 1.5rem;
  border-right: 1px solid var(--color-border);
}

.stat-item:last-child {
  border-right: none;
}

.stat-number {
  font-size: 3rem;
  font-weight: 900;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 0.5rem;
  letter-spacing: -0.04em;
}

.stat-label {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
}

/* ===== CONTENT WALL ===== */
.content-wall {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--grid-gap);
}

.content-wall-item {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all var(--transition);
  position: relative;
}

.content-wall-item:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.3);
}

.content-wall-item h4 {
  font-size: 1.1rem;
  font-weight: 900;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.content-wall-body {
  color: var(--color-text-muted);
  font-weight: 300;
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ===== FAQ ===== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 800px;
}

.faq-item {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition);
}

.faq-item:hover {
  border-color: var(--color-accent-dim);
}

.faq-item summary {
  padding: 1.25rem 1.5rem;
  font-weight: 700;
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  transition: color var(--transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--color-accent);
  transition: transform var(--transition);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item[open] summary {
  color: var(--color-accent);
}

.faq-answer {
  padding: 0 1.5rem 1.25rem;
  color: var(--color-text-muted);
  font-weight: 300;
  font-size: 0.95rem;
  line-height: 1.6;
}

/* ===== CTA BANNER ===== */
.cta-banner {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 4rem 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin: 4rem 0;
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(185,255,80,0.05) 0%, transparent 60%);
  pointer-events: none;
}

.cta-banner h2 {
  font-size: 2.2rem;
  font-weight: 900;
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
  position: relative;
}

.cta-banner p {
  color: var(--color-text-muted);
  max-width: 500px;
  margin: 0 auto 2rem;
  font-weight: 300;
  position: relative;
}

.cta-banner .btn {
  position: relative;
}

/* ===== SITE FOOTER ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 4rem 0 2rem;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--color-border);
}

.footer-brand .logo {
  margin-bottom: 1rem;
}

.footer-brand p {
  color: var(--color-text-muted);
  font-weight: 300;
  font-size: 0.9rem;
  max-width: 300px;
}

.footer-col h4 {
  font-size: 0.8rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: 1.5rem;
}

.footer-col a {
  display: block;
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 300;
  font-size: 0.9rem;
  padding: 0.3rem 0;
  transition: color var(--transition);
}

.footer-col a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 2rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  font-weight: 300;
}

/* ===== UTILITY ===== */
.text-accent {
  color: var(--color-accent);
}

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

.seo-description {
  padding: 3rem 0;
  color: var(--color-text-muted);
  font-weight: 300;
  font-size: 0.85rem;
  line-height: 1.7;
  border-top: 1px solid var(--color-border);
  margin-top: 3rem;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .feature-block {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  .stats-bar {
    grid-template-columns: repeat(2, 1fr);
  }
  .stats-bar .stat-item:nth-child(2) {
    border-right: none;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .content-wall {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .header-inner {
    height: 64px;
  }

  .main-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-overlay);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 2rem 1.5rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--color-border);
  }

  .main-nav.active {
    display: flex;
  }

  .menu-toggle {
    display: flex;
  }

  .hero {
    padding: 6rem 0 3rem;
  }

  .hero-content h1 {
    font-size: clamp(2rem, 10vw, 3.5rem);
  }

  .hero-image {
    display: none;
  }

  .section {
    padding: 4rem 0;
  }

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

  .content-wall {
    grid-template-columns: 1fr;
  }

  .stats-bar {
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    padding: 2rem 0;
  }

  .stat-item {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    padding: 1rem;
  }

  .stat-item:nth-child(odd) {
    border-right: 1px solid var(--color-border);
  }

  .stat-number {
    font-size: 2.2rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 0.5rem;
    text-align: center;
  }

  .cta-banner {
    padding: 3rem 1.5rem;
  }

  .cta-banner h2 {
    font-size: 1.6rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .hero-content h1 {
    font-size: 2rem;
  }

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

  .btn {
    width: 100%;
    justify-content: center;
  }

  .stats-bar {
    grid-template-columns: 1fr;
  }

  .stat-item {
    border-right: none !important;
    border-bottom: 1px solid var(--color-border);
  }

  .feature-block {
    gap: 1.5rem;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .logo {
    font-size: 1.3rem;
  }

  .faq-item summary {
    font-size: 0.9rem;
    padding: 1rem 1.2rem;
  }

  .faq-answer {
    padding: 0 1.2rem 1rem;
  }
}

/* ===== ANIMATIONS ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-content {
  animation: fadeInUp 0.8s ease-out;
}

.section {
  animation: fadeInUp 0.6s ease-out;
  animation-fill-mode: both;
  animation-timeline: view();
  animation-range: entry 0% entry 20%;
}

.category-card {
  transition: all var(--transition);
}

.category-card:hover {
  animation: pulse 0.6s ease-in-out;
}

@keyframes pulse {
  0%, 100% { transform: translateY(-8px); }
  50% { transform: translateY(-12px); }
}

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar {
  width: 6px;
  background: var(--color-bg);
}

::-webkit-scrollbar-track {
  background: var(--color-surface);
}

::-webkit-scrollbar-thumb {
  background: var(--color-accent-dim);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-accent);
}

/* ===== SELECTION ===== */
::selection {
  background: var(--color-accent);
  color: var(--color-bg);
}