/* ====================================================================
   仙路湾加速 - 全站核心视觉与动效样式表 (AG Specification 2026 v4.0)
   - 视觉主题：赛博幻想 · 苍穹星门与次元跃迁 (Anime Astral Gate & Ether Flow)
   - 系统原生字体栈 (零网络字体开销，极速秒开)
   - 磨砂晶石质感、呼吸能量脉冲、光泽扫过动效与3D悬停微交互
   - 严格性能优化：GPU加速渲染，全面适配 prefers-reduced-motion
   ==================================================================== */

:root {
  --color-bg: #f8fafc;
  --color-bg-alt: #f1f5f9;
  --color-surface: #ffffff;
  --color-surface-glass: rgba(255, 255, 255, 0.85);
  --color-surface-subtle: #f8fafc;
  --color-text-main: #0f172a;
  --color-text-regular: #334155;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --color-border-glow: rgba(59, 130, 246, 0.35);

  /* 动漫幻想色系：苍穹蓝、晨曦青、幻彩紫、星光金 */
  --anime-blue: #1d4ed8;
  --anime-blue-light: #3b82f6;
  --anime-cyan: #0284c7;
  --anime-teal: #0d9488;
  --anime-purple: #7c3aed;
  --anime-emerald: #059669;
  --anime-gold: #d97706;

  --color-primary: #1d4ed8;
  --color-primary-hover: #1e40af;
  --color-primary-soft: #eff6ff;
  --color-primary-border: #bfdbfe;

  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --max-width: 1160px;
  --header-height: 70px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
}

/* 基础重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text-regular);
  line-height: 1.68;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow-x: hidden;
}

/* 背景动效画布 (轻量级苍穹粒子与浮空星尘) */
.nn-anime-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.55;
}

/* 顶部与主体容器 */
.nn-container {
  width: 100%;
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
  position: relative;
  z-index: 1;
}

/* 头部吸顶导航 */
.nn-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.85);
  height: var(--header-height);
  transition: box-shadow 0.25s ease, background-color 0.25s ease;
}

.nn-header.is-scrolled {
  box-shadow: 0 4px 20px -5px rgba(15, 23, 42, 0.08);
  background-color: rgba(255, 255, 255, 0.96);
}

.nn-header__inner {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nn-header__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--color-text-main);
  letter-spacing: -0.01em;
  min-height: 44px;
}

.nn-header__logo-wrap {
  position: relative;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, #1d4ed8, #0284c7);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(29, 78, 216, 0.3);
}

.nn-header__logo {
  width: 32px;
  height: 32px;
}

.nn-header__nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nn-header__link {
  font-size: 0.9375rem;
  color: var(--color-text-regular);
  font-weight: 600;
  padding: 10px 0;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  position: relative;
  transition: color 0.15s ease;
}

.nn-header__link::after {
  content: "";
  position: absolute;
  bottom: 6px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--anime-blue), var(--anime-cyan));
  border-radius: 2px;
  transition: width 0.25s ease;
}

.nn-header__link:hover {
  color: var(--color-primary);
}

.nn-header__link:hover::after,
.nn-header__link--active::after {
  width: 100%;
}

.nn-header__cta-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nn-menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  padding: 10px 14px;
  min-height: 44px;
  min-width: 44px;
  border-radius: var(--radius-sm);
  color: var(--color-text-main);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
}

/* ====================================================================
   CTA 按钮高转化动效系统 (光泽扫过、能量脉冲、点击波纹与悬停上浮)
   ==================================================================== */
.nn-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9375rem;
  font-weight: 700;
  padding: 11px 24px;
  min-height: 44px;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-align: center;
  border: 1px solid transparent;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s ease, background-color 0.15s ease, border-color 0.15s ease;
  user-select: none;
  z-index: 1;
}

/* 炫彩主按钮 */
.nn-btn--primary {
  background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 50%, #0284c7 100%);
  color: #ffffff;
  box-shadow: 0 4px 14px -2px rgba(29, 78, 216, 0.35);
}

/* 悬停光泽扫过动效 */
.nn-btn--primary::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 60%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transform: skewX(-20deg);
  transition: left 0.6s ease;
  pointer-events: none;
}

.nn-btn--primary:hover::before {
  left: 150%;
}

.nn-btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px -4px rgba(29, 78, 216, 0.45);
  color: #ffffff;
}

.nn-btn--primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px rgba(29, 78, 216, 0.3);
}

/* 次级按钮 */
.nn-btn--secondary {
  background-color: var(--color-surface);
  border-color: var(--color-border);
  color: var(--color-text-main);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.nn-btn--secondary:hover {
  border-color: #93c5fd;
  background-color: #f8fafc;
  color: var(--color-primary);
  transform: translateY(-2px);
  box-shadow: 0 6px 18px -4px rgba(15, 23, 42, 0.08);
}

.nn-btn--large {
  padding: 13px 32px;
  font-size: 1.0625rem;
  min-height: 48px;
  border-radius: var(--radius-md);
}

.nn-btn--block {
  width: 100%;
}

/* 点击波纹涟漪反馈 */
.nn-btn-ripple {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  transform: scale(0);
  animation: nn-ripple-anim 0.55s linear;
  pointer-events: none;
}

@keyframes nn-ripple-anim {
  to {
    transform: scale(3.5);
    opacity: 0;
  }
}

/* ====================================================================
   Hero 首屏区块：苍穹幻境、全景跃迁星门插画与立体视觉
   ==================================================================== */
.nn-hero {
  padding: 70px 0 64px 0;
  position: relative;
  background: radial-gradient(circle at 50% 20%, rgba(219, 234, 254, 0.5) 0%, rgba(248, 250, 252, 0) 70%);
  border-bottom: 1px solid var(--color-border);
  overflow: hidden;
}

.nn-hero__grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 40px;
  align-items: center;
}

.nn-hero__content {
  text-align: left;
}

.nn-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 14px;
  background: linear-gradient(90deg, rgba(239, 246, 255, 0.9), rgba(240, 253, 250, 0.9));
  color: var(--color-primary);
  border: 1px solid #bfdbfe;
  border-radius: 9999px;
  font-size: 0.8125rem;
  font-weight: 700;
  margin-bottom: 22px;
  box-shadow: 0 2px 10px rgba(59, 130, 246, 0.1);
}

.nn-hero__badge-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--anime-cyan);
  box-shadow: 0 0 0 0 rgba(2, 132, 199, 0.7);
  animation: nn-pulse-glow 2s infinite;
}

@keyframes nn-pulse-glow {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(2, 132, 199, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(2, 132, 199, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(2, 132, 199, 0); }
}

.nn-hero__title {
  font-size: 2.85rem;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--color-text-main);
  background: linear-gradient(135deg, #0f172a 30%, #1e40af 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nn-hero__subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 34px;
  max-width: 580px;
}

.nn-hero__actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 36px;
}

.nn-hero__specs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  border-top: 1px solid var(--color-border);
  padding-top: 28px;
}

.nn-hero__spec-item {
  border-left: 2px solid var(--color-primary);
  padding-left: 14px;
}

.nn-hero__spec-label {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.nn-hero__spec-val {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text-main);
}

/* 动漫风全景星门插画 (内联矢量 SVG + 旋转星轨与光晕) */
.nn-hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.nn-astral-gate-wrapper {
  position: relative;
  width: 100%;
  max-width: 440px;
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nn-gate-aura {
  position: absolute;
  width: 80%;
  height: 80%;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, rgba(6, 182, 212, 0.08) 50%, transparent 75%);
  filter: blur(24px);
  animation: nn-aura-breathe 6s ease-in-out infinite alternate;
}

@keyframes nn-aura-breathe {
  0% { transform: scale(0.9); opacity: 0.6; }
  100% { transform: scale(1.15); opacity: 0.95; }
}

.nn-astral-svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 12px 30px rgba(29, 78, 216, 0.18));
}

.nn-rot-clockwise {
  transform-origin: center;
  animation: nn-spin-cw 40s linear infinite;
}

.nn-rot-counter {
  transform-origin: center;
  animation: nn-spin-ccw 55s linear infinite;
}

@keyframes nn-spin-cw {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes nn-spin-ccw {
  from { transform: rotate(0deg); }
  to { transform: rotate(-360deg); }
}

/* ====================================================================
   通用模块与卡片系统 (3D 透视倾斜、磨砂晶莹质感、边框流光)
   ==================================================================== */
.nn-section {
  padding: 80px 0;
  border-bottom: 1px solid var(--color-border);
  position: relative;
}

.nn-section--subtle {
  background-color: var(--color-surface-subtle);
}

.nn-section--white {
  background-color: var(--color-surface);
}

.nn-section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 52px auto;
}

.nn-section-head__title {
  font-size: 2.15rem;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.nn-section-head__desc {
  font-size: 1.025rem;
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* 核心优势/线路分流对比表格 */
.nn-benefits-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  align-items: center;
}

.nn-benefits-lead h3 {
  font-size: 1.6rem;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.nn-benefits-lead p {
  color: var(--color-text-regular);
  margin-bottom: 20px;
  font-size: 0.95rem;
  line-height: 1.7;
}

.nn-status-table {
  width: 100%;
  border-collapse: collapse;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  font-size: 0.875rem;
  box-shadow: 0 4px 18px -4px rgba(15, 23, 42, 0.06);
}

.nn-status-table th,
.nn-status-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

.nn-status-table th {
  background: linear-gradient(180deg, #ffffff, #f8fafc);
  font-weight: 700;
  color: var(--color-text-main);
}

.nn-status-table tr:last-child td {
  border-bottom: none;
}

.nn-status-table tr:hover td {
  background-color: rgba(239, 246, 255, 0.5);
}

.nn-badge-ok {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 3px 9px;
  border-radius: var(--radius-sm);
  background-color: var(--color-success-soft);
  color: var(--color-success);
  font-weight: 700;
  font-size: 0.75rem;
  border: 1px solid rgba(5, 150, 105, 0.2);
}

.nn-badge-ok::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-success);
}

/* 4大特性卡 (3D 悬停透视、晶莹磨砂微边框) */
.nn-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.nn-feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.25s ease, border-color 0.25s ease;
  position: relative;
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

.nn-feature-card:hover {
  transform: translateY(-6px);
  border-color: #93c5fd;
  box-shadow: 0 16px 32px -8px rgba(29, 78, 216, 0.12);
}

.nn-feature-card__icon-box {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(239, 246, 255, 0.9), rgba(240, 253, 250, 0.9));
  border: 1px solid #bfdbfe;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: 18px;
  transition: transform 0.25s ease;
}

.nn-feature-card:hover .nn-feature-card__icon-box {
  transform: scale(1.08) rotate(3deg);
  background: linear-gradient(135deg, #1d4ed8, #0284c7);
  color: #ffffff;
}

.nn-feature-card__tag {
  align-self: flex-start;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
  padding: 3px 9px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.nn-feature-card__title {
  font-size: 1.1875rem;
  margin-bottom: 10px;
}

.nn-feature-card__desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* 流媒体与 AI 支持 */
.nn-media-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.nn-media-box {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: 0 4px 20px -4px rgba(0, 0, 0, 0.04);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.nn-media-box:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px -6px rgba(15, 23, 42, 0.08);
}

.nn-media-box__title {
  font-size: 1.3rem;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nn-media-box__p {
  font-size: 0.9375rem;
  color: var(--color-text-regular);
  margin-bottom: 20px;
  line-height: 1.7;
}

.nn-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.nn-tag-item {
  background: var(--color-surface-subtle);
  border: 1px solid var(--color-border);
  color: var(--color-text-main);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.84rem;
  font-weight: 600;
  transition: all 0.15s ease;
}

.nn-tag-item:hover {
  border-color: #93c5fd;
  color: var(--color-primary);
  background-color: #ffffff;
  transform: translateY(-1px);
}

/* 使用场景卡 (3张) */
.nn-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.nn-scenario-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

.nn-scenario-card:hover {
  transform: translateY(-4px);
  border-color: #93c5fd;
  box-shadow: 0 14px 28px -6px rgba(29, 78, 216, 0.1);
}

.nn-scenario-card__header {
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 14px;
  margin-bottom: 16px;
}

.nn-scenario-card__title {
  font-size: 1.1875rem;
  margin-bottom: 8px;
}

.nn-scenario-card__device {
  font-size: 0.8125rem;
  color: var(--color-primary);
  font-weight: 700;
  background-color: var(--color-primary-soft);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  display: inline-block;
}

.nn-scenario-card__desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.65;
}

/* ====================================================================
   套餐定价区 (动态周期切换器、高亮主力推荐、3D卡片微交互)
   ==================================================================== */
.nn-pricing-switcher {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
}

.nn-switch-btn-group {
  background: var(--color-surface-subtle);
  border: 1px solid var(--color-border);
  padding: 4px;
  border-radius: 9999px;
  display: inline-flex;
}

.nn-switch-btn {
  border: none;
  background: none;
  padding: 8px 20px;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all 0.2s ease;
}

.nn-switch-btn.is-active {
  background: #ffffff;
  color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.nn-switch-badge {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--anime-emerald);
  background-color: var(--color-success-soft);
  padding: 2px 8px;
  border-radius: 9999px;
  border: 1px solid rgba(5, 150, 105, 0.2);
}

.nn-pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.nn-pricing-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.03);
}

.nn-pricing-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 16px 36px -8px rgba(15, 23, 42, 0.1);
}

.nn-pricing-card--popular {
  border: 2px solid var(--color-primary);
  background: linear-gradient(180deg, #ffffff 0%, rgba(239, 246, 255, 0.3) 100%);
  box-shadow: 0 8px 28px -4px rgba(29, 78, 216, 0.18);
}

.nn-pricing-card__badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, #1d4ed8, #0284c7);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 16px;
  border-radius: 9999px;
  letter-spacing: 0.05em;
  box-shadow: 0 4px 12px rgba(29, 78, 216, 0.35);
}

.nn-pricing-card__tier {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 6px;
  color: var(--color-text-main);
}

.nn-pricing-card__target {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-bottom: 22px;
}

.nn-pricing-card__price-row {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 20px;
}

.nn-pricing-card__amount {
  font-size: 2.45rem;
  font-weight: 800;
  color: var(--color-text-main);
  line-height: 1;
}

.nn-pricing-card__unit {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.nn-pricing-card__features {
  list-style: none;
  margin-bottom: 30px;
  flex-grow: 1;
}

.nn-pricing-card__feature-item {
  font-size: 0.875rem;
  padding: 7px 0;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--color-text-regular);
}

.nn-pricing-card__feature-item::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 800;
  font-size: 0.875rem;
}

/* FAQ 常见问题 (原生 details/summary 无障碍手风琴) */
.nn-faq-list {
  max-width: 820px;
  margin: 0 auto;
}

.nn-faq-item {
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  border-radius: var(--radius-md);
  margin-bottom: 14px;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.nn-faq-item:hover,
.nn-faq-item[open] {
  border-color: #93c5fd;
  box-shadow: 0 4px 14px -2px rgba(29, 78, 216, 0.08);
}

.nn-faq-summary {
  width: 100%;
  padding: 18px 22px;
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--color-text-main);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  list-style: none;
  user-select: none;
  min-height: 44px;
}

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

.nn-faq-icon {
  font-size: 1.35rem;
  font-weight: 400;
  color: var(--color-text-muted);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), color 0.2s ease;
  line-height: 1;
}

details[open] .nn-faq-icon {
  transform: rotate(45deg);
  color: var(--color-primary);
}

.nn-faq-answer {
  padding: 0 22px 22px 22px;
  font-size: 0.9375rem;
  color: var(--color-text-regular);
  line-height: 1.7;
  border-top: 1px dashed var(--color-border);
  padding-top: 16px;
}

/* Final CTA 区块 (动感弥散光晕背景) */
.nn-final-cta {
  padding: 86px 0;
  background: radial-gradient(circle at 50% 50%, rgba(219, 234, 254, 0.6) 0%, rgba(255, 255, 255, 0.95) 70%);
  border-bottom: 1px solid var(--color-border);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.nn-final-cta__inner {
  max-width: 640px;
  margin: 0 auto;
}

.nn-final-cta__title {
  font-size: 2.35rem;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.nn-final-cta__desc {
  font-size: 1.025rem;
  color: var(--color-text-muted);
  margin-bottom: 30px;
}

/* 规范页脚 */
.nn-footer {
  background-color: #ffffff;
  padding: 48px 0 36px 0;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-top: auto;
  border-top: 1px solid var(--color-border);
}

.nn-footer__nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 28px;
  margin-bottom: 24px;
}

.nn-footer__nav a {
  color: var(--color-text-regular);
  font-weight: 600;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  transition: color 0.15s ease;
}

.nn-footer__nav a:hover {
  color: var(--color-primary);
}

.nn-footer__disclosure {
  text-align: center;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  max-width: 680px;
  margin: 0 auto 16px auto;
  line-height: 1.6;
}

.nn-footer__copyright {
  text-align: center;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

/* 移动端吸底 CTA */
.nn-mobile-sticky-cta {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-top: 1px solid rgba(226, 232, 240, 0.9);
  padding: 10px 18px;
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transform: translateY(100%);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.06);
}

.nn-mobile-sticky-cta.is-visible {
  transform: translateY(0);
}

.nn-mobile-sticky-cta__info {
  display: flex;
  flex-direction: column;
}

.nn-mobile-sticky-cta__title {
  font-size: 0.875rem;
  font-weight: 800;
  color: var(--color-text-main);
}

.nn-mobile-sticky-cta__desc {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

/* 文章页及标准内容页排版 */
.nn-article-page {
  padding: 48px 0 72px 0;
  background-color: #ffffff;
  flex-grow: 1;
}

.nn-breadcrumbs {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.nn-breadcrumbs a {
  color: var(--color-text-muted);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.nn-breadcrumbs a:hover {
  color: var(--color-primary);
}

.nn-article-header {
  margin-bottom: 36px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 28px;
}

.nn-article-header__title {
  font-size: 2.25rem;
  line-height: 1.25;
  margin-bottom: 16px;
}

.nn-article-header__meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.nn-article-body {
  max-width: 820px;
  line-height: 1.8;
  font-size: 1rem;
  color: var(--color-text-regular);
}

.nn-article-body h2 {
  font-size: 1.5rem;
  margin-top: 40px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.nn-article-body h3 {
  font-size: 1.2rem;
  margin-top: 28px;
  margin-bottom: 12px;
}

.nn-article-body p {
  margin-bottom: 20px;
}

.nn-article-body ul,
.nn-article-body ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.nn-article-body li {
  margin-bottom: 8px;
}

.nn-article-body blockquote {
  border-left: 3px solid var(--color-primary);
  background-color: var(--color-primary-soft);
  padding: 14px 18px;
  margin: 24px 0;
  border-radius: var(--radius-sm);
  color: var(--color-text-main);
  font-size: 0.9375rem;
}

.nn-article-cta {
  background: linear-gradient(135deg, rgba(239, 246, 255, 0.7), rgba(240, 253, 250, 0.7));
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  text-align: center;
  margin: 48px 0;
}

.nn-article-cta__title {
  font-size: 1.375rem;
  margin-bottom: 10px;
}

.nn-article-cta__desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin-bottom: 20px;
}

.nn-related-articles {
  border-top: 1px solid var(--color-border);
  padding-top: 32px;
  margin-top: 48px;
}

.nn-related-articles__title {
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.nn-related-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.nn-related-list li a {
  display: block;
  padding: 12px 16px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--color-text-main);
  min-height: 44px;
  transition: all 0.15s ease;
}

.nn-related-list li a:hover {
  border-color: #93c5fd;
  color: var(--color-primary);
  background-color: #ffffff;
  transform: translateX(4px);
}

/* 指南列表页 */
.nn-guides-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  margin-top: 32px;
}

.nn-guide-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.nn-guide-item:hover {
  transform: translateY(-4px);
  border-color: #93c5fd;
  box-shadow: 0 14px 28px -6px rgba(29, 78, 216, 0.1);
}

.nn-guide-item__thumb {
  width: 100%;
  height: 140px;
  background: linear-gradient(135deg, rgba(239, 246, 255, 0.8), rgba(240, 253, 250, 0.8));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}

.nn-guide-item__title {
  font-size: 1.1875rem;
  margin-bottom: 10px;
}

.nn-guide-item__desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: 18px;
  flex-grow: 1;
}

.nn-guide-item__meta {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  padding-top: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nn-guide-item__link {
  font-weight: 700;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

/* 网站地图样式 */
.nn-sitemap-group {
  margin-bottom: 36px;
}

.nn-sitemap-group__title {
  font-size: 1.25rem;
  margin-bottom: 16px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--color-border);
}

.nn-sitemap-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.nn-sitemap-list a {
  color: var(--color-text-regular);
  font-size: 0.9375rem;
  padding: 8px 0;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.nn-sitemap-list a:hover {
  color: var(--color-primary);
}

/* 响应式断点 */
@media (max-width: 992px) {
  .nn-hero__grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .nn-hero__content {
    text-align: center;
  }
  .nn-hero__subtitle {
    margin-left: auto;
    margin-right: auto;
  }
  .nn-hero__actions {
    justify-content: center;
  }
  .nn-hero__specs {
    text-align: left;
  }
  .nn-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .nn-pricing-grid {
    grid-template-columns: 1fr;
    max-width: 440px;
    margin: 0 auto;
  }
}

@media (max-width: 768px) {
  .nn-header__nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: #ffffff;
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
  }
  .nn-header__nav.is-open {
    display: flex;
  }
  .nn-menu-toggle {
    display: block;
  }
  .nn-hero__title {
    font-size: 2.15rem;
  }
  .nn-hero__specs {
    grid-template-columns: 1fr;
    gap: 14px;
  }
  .nn-grid-3,
  .nn-media-grid,
  .nn-benefits-row,
  .nn-guides-grid,
  .nn-related-list,
  .nn-sitemap-list {
    grid-template-columns: 1fr;
  }
  .nn-mobile-sticky-cta {
    display: flex;
  }
}