/* ===================================================================
   贝雪云 BeiXueYun - 雪晶六轴 + 冰晶云端 + 纯净科技
   配色规范：
   - 主背景：#020617 深冰夜
   - 主色：#67E8F9 冰晶青
   - 次色：#E0F2FE 雪光白
   - 文字：#FFFFFF / rgba(255, 255, 255, 0.6)
   - CTA 按钮：冰晶青到雪光白渐变（深色字），12px 圆角，30px 冰晶青辉光，hover 变白辉光
   - 大标题：Space Grotesk 700 字重，冰晶青到雪光白渐变 + 双层文字阴影
   - 正文：Inter / 思源黑体
   =================================================================== */

:root {
  --font-headline: 'Space Grotesk', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --bg-deep: #020617;
  --bg-card: rgba(15, 23, 42, 0.7);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --border-cyan: rgba(103, 232, 249, 0.2);
  --border-cyan-hover: rgba(103, 232, 249, 0.5);
  --primary-cyan: #67E8F9;
  --secondary-snow: #E0F2FE;
  --text-white: #FFFFFF;
  --text-dim: rgba(255, 255, 255, 0.6);
  --text-dark: #020617;
  --gradient-ice: linear-gradient(135deg, #67E8F9 0%, #FFFFFF 50%, #E0F2FE 100%);
  --gradient-btn: linear-gradient(135deg, #67E8F9 0%, #E0F2FE 100%);
  --glow-cyan-btn: 0 0 30px rgba(103, 232, 249, 0.45);
  --glow-white-btn: 0 0 35px rgba(224, 242, 254, 0.75);
  --container-max: 1200px;
  --radius-btn: 12px;
  --radius-card: 18px;
  --radius-pill: 9999px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: var(--font-body);
  background-color: var(--bg-deep);
  color: var(--text-white);
  scroll-behavior: smooth;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  overflow-x: hidden;
  background-color: var(--bg-deep);
  min-height: 100vh;
  position: relative;
}

/* ===================================================================
   无障碍 (a11y) 与键盘焦点与锚点规范
   =================================================================== */
.skip-link {
  position: absolute;
  top: -120px;
  left: 20px;
  background: var(--gradient-btn);
  color: var(--text-dark);
  padding: 12px 24px;
  border-radius: var(--radius-btn);
  font-weight: 700;
  font-size: 0.95rem;
  z-index: 99999;
  transition: top 0.2s ease-in-out;
  box-shadow: var(--glow-cyan-btn);
  text-decoration: none;
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 16px;
  outline: 3px solid #FFFFFF;
  outline-offset: 2px;
}

:focus-visible {
  outline: 2px solid var(--primary-cyan);
  outline-offset: 3px;
  box-shadow: 0 0 12px rgba(103, 232, 249, 0.6);
}

section[id],
div[id],
h1[id],
h2[id],
h3[id],
.pricing-section,
.features-section,
.unlock-section,
.testimonials-section,
.faq-section {
  scroll-margin-top: 86px;
}

/* ===================================================================
   背景动效层 (核心修复：层叠在 body 纯色之上，置于业务组件之下，100% 清晰可见)
   - 全屏径向渐变冰晶青/雪光白辉光
   - 细网格边缘渐隐 (mask-image)
   - 2个大型呼吸缩放 blur 光晕
   - 3条雪花脉络 SVG (4秒 dashoffset 动画)
   - 4个青/白飘落漂移雪花粒子 (12-15秒周期)
   =================================================================== */
.ice-bg-canvas {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1; /* 确保层叠在 body 之上，清晰可见 */
  overflow: hidden;
  background:
    radial-gradient(circle at 45% 15%, rgba(103, 232, 249, 0.26) 0%, rgba(103, 232, 249, 0.08) 40%, transparent 70%),
    radial-gradient(circle at 82% 40%, rgba(224, 242, 254, 0.20) 0%, rgba(103, 232, 249, 0.06) 35%, transparent 65%),
    radial-gradient(circle at 18% 75%, rgba(103, 232, 249, 0.16) 0%, transparent 55%),
    #020617;
}

/* 叠加细网格让边缘渐隐 */
.ice-grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(103, 232, 249, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(103, 232, 249, 0.09) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse at 50% 35%, rgba(0, 0, 0, 1) 25%, rgba(0, 0, 0, 0) 80%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 35%, rgba(0, 0, 0, 1) 25%, rgba(0, 0, 0, 0) 80%);
}

/* 2个青/白大型 blur 光晕缓慢呼吸缩放 */
.ice-halo {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
}

.halo-cyan {
  width: 650px;
  height: 650px;
  top: -80px;
  left: 10%;
  background: radial-gradient(circle, rgba(103, 232, 249, 0.38) 0%, rgba(103, 232, 249, 0.15) 45%, transparent 70%);
  filter: blur(80px);
  animation: haloBreath 8s ease-in-out infinite alternate;
}

.halo-white {
  width: 750px;
  height: 750px;
  top: 30%;
  right: -80px;
  background: radial-gradient(circle, rgba(224, 242, 254, 0.28) 0%, rgba(103, 232, 249, 0.10) 45%, transparent 70%);
  filter: blur(90px);
  animation: haloBreath 11s ease-in-out infinite alternate-reverse;
}

@keyframes haloBreath {
  0% { transform: scale(0.88) translate(0, 0); opacity: 0.7; }
  100% { transform: scale(1.18) translate(25px, 35px); opacity: 1; }
}

/* 3 条雪花脉络 SVG (青/白交替，dashoffset 流动动画 4 秒一周期) */
.ice-veins-svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 0 10px rgba(103, 232, 249, 0.65));
}

.vein-path {
  fill: none;
  stroke-linecap: round;
  stroke-dasharray: 220 380;
  vector-effect: non-scaling-stroke;
  animation: veinFlow 4s linear infinite;
}

.vein-1 {
  stroke: url(#veinCyanGrad);
  stroke-width: 2.5;
  animation-duration: 4s;
}

.vein-2 {
  stroke: url(#veinWhiteGrad);
  stroke-width: 2;
  animation-duration: 4.6s;
  animation-delay: -1.8s;
}

.vein-3 {
  stroke: url(#veinCyanGrad);
  stroke-width: 2.2;
  animation-duration: 3.9s;
  animation-delay: -3s;
}

@keyframes veinFlow {
  from { stroke-dashoffset: 600; }
  to { stroke-dashoffset: 0; }
}

/* 4 个青/白雪花粒子从顶部缓慢下落带横向漂移 (12-15 秒一周期) */
.snow-particle {
  position: absolute;
  top: -40px;
  width: 24px;
  height: 24px;
  pointer-events: none;
  filter: drop-shadow(0 0 8px rgba(103, 232, 249, 0.9));
}

.snow-particle svg {
  width: 100%;
  height: 100%;
}

.p1 {
  left: 18%;
  animation: snowDrift1 13s linear infinite;
}

.p2 {
  left: 42%;
  animation: snowDrift2 15s linear infinite;
  animation-delay: -4.5s;
}

.p3 {
  left: 72%;
  animation: snowDrift1 12s linear infinite;
  animation-delay: -8s;
}

.p4 {
  left: 88%;
  animation: snowDrift2 14s linear infinite;
  animation-delay: -2s;
}

@keyframes snowDrift1 {
  0% { transform: translateY(0) translateX(0) rotate(0deg); opacity: 0; }
  10% { opacity: 0.95; }
  50% { transform: translateY(50vh) translateX(55px) rotate(180deg); opacity: 0.9; }
  90% { opacity: 0.85; }
  100% { transform: translateY(105vh) translateX(-25px) rotate(360deg); opacity: 0; }
}

@keyframes snowDrift2 {
  0% { transform: translateY(0) translateX(0) rotate(0deg); opacity: 0; }
  10% { opacity: 0.95; }
  50% { transform: translateY(50vh) translateX(-60px) rotate(-180deg); opacity: 0.9; }
  90% { opacity: 0.8; }
  100% { transform: translateY(105vh) translateX(35px) rotate(-360deg); opacity: 0; }
}

/* ===================================================================
   容器规范与排版工具
   =================================================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

.text-gradient {
  background: var(--gradient-ice);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.section-title-wrap {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 50px auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 18px;
  border-radius: var(--radius-pill);
  background: rgba(103, 232, 249, 0.08);
  border: 1px solid rgba(103, 232, 249, 0.28);
  color: var(--primary-cyan);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  line-height: 1.25;
  color: #ffffff;
}

.section-subtitle {
  color: var(--text-dim);
  font-size: clamp(0.95rem, 1.8vw, 1.1rem);
}

/* ===================================================================
   CTA 按钮规范：
   冰晶青到雪光白渐变（文字深色），圆角 12px，带 30px 冰晶青辉光，hover 变白辉光
   =================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 30px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-btn); /* 严格 12px 圆角 */
  cursor: pointer;
  transition: var(--transition);
  border: none;
  min-height: 48px;
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-btn);
  color: var(--text-dark); /* 深色文字 */
  box-shadow: var(--glow-cyan-btn); /* 30px 冰晶青辉光 */
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--glow-white-btn); /* hover 时辉光变白 */
  filter: brightness(1.05);
  color: #020617;
}

.btn-outline {
  background: rgba(255, 255, 255, 0.04);
  color: var(--secondary-snow);
  border: 1px solid rgba(103, 232, 249, 0.3);
  border-radius: var(--radius-btn);
}

.btn-outline:hover {
  background: rgba(103, 232, 249, 0.12);
  border-color: var(--primary-cyan);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 0 20px rgba(103, 232, 249, 0.25);
}

.btn-block {
  width: 100%;
}

/* ===================================================================
   顶部导航栏
   =================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(2, 6, 23, 0.85);
  border-bottom: 1px solid rgba(103, 232, 249, 0.12);
  height: 72px;
  display: flex;
  align-items: center;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'Space Grotesk', -apple-system, sans-serif;
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.01em;
}

.brand-icon {
  width: 32px;
  height: 32px;
  fill: none;
  stroke: url(#logoGradient);
  filter: drop-shadow(0 0 6px rgba(103, 232, 249, 0.6));
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  color: var(--text-dim);
  font-size: 0.95rem;
  font-weight: 500;
}

.nav-link:hover {
  color: var(--secondary-snow);
  text-shadow: 0 0 10px rgba(103, 232, 249, 0.5);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ===================================================================
   主视觉区 (Hero Section)
   左侧：H1「贝雪云」使用 Space Grotesk，标题文字带冰晶青到雪光白的渐变 + 双层文字阴影
   右侧：340×340px 的六轴雪晶 SVG (6主臂+3对分支+6顶点发光节点+双层反向虚线圆轨道+50px中心呼吸核心)
   =================================================================== */
.hero-section {
  padding: 60px 0 60px 0;
  position: relative;
}

.hero-layout-split {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  margin-bottom: 40px;
}

.hero-left-col {
  flex: 1;
  max-width: 680px;
  text-align: left;
}

.hero-right-col {
  flex-shrink: 0;
  width: 340px;
  height: 340px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

/* H1 严格配置：Space Grotesk 700，冰晶青到雪光白渐变 + 双层文字阴影 */
.hero-headline {
  font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  font-weight: 700;
  font-size: clamp(2.4rem, 4.8vw, 3.8rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #67E8F9 0%, #FFFFFF 50%, #E0F2FE 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 25px rgba(103, 232, 249, 0.45), 0 0 50px rgba(224, 242, 254, 0.25);
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 18px;
  border-radius: var(--radius-pill);
  background: rgba(103, 232, 249, 0.08);
  border: 1px solid rgba(103, 232, 249, 0.25);
  font-size: 0.88rem;
  color: var(--secondary-snow);
  margin-bottom: 20px;
}

.hero-pill-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #67E8F9;
  box-shadow: 0 0 10px #67E8F9;
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.8); }
}

.hero-subheadline {
  font-size: clamp(1.05rem, 1.8vw, 1.2rem);
  color: var(--text-dim);
  margin-bottom: 24px;
  line-height: 1.65;
}

.hero-intro-box {
  background: rgba(15, 23, 42, 0.65);
  border: 1px solid rgba(103, 232, 249, 0.18);
  border-radius: var(--radius-btn);
  padding: 16px 22px;
  margin-bottom: 30px;
  backdrop-filter: blur(8px);
}

.hero-intro-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary-cyan);
  background: rgba(103, 232, 249, 0.12);
  padding: 2px 8px;
  border-radius: 4px;
  margin-bottom: 6px;
  letter-spacing: 0.05em;
}

.hero-intro-text {
  font-size: 0.93rem;
  color: #cbd5e1;
  line-height: 1.6;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

/* ===================================================================
   340×340px 六轴雪晶 SVG 动画核心规范
   - 整体 360° 缓慢旋转 (30秒一周期)
   - 50×50px 白→青径向渐变冰晶核心 (脉冲呼吸 3秒一周期)
   - 2层虚线圆轨道 (反向旋转 20秒 / 14秒)
   - 6主臂 + 3对分支 + 6顶点发光节点
   =================================================================== */
.snow-crystal-container {
  width: 340px;
  height: 340px;
  position: relative;
  filter: drop-shadow(0 0 24px rgba(103, 232, 249, 0.35));
}

.snowflake-svg {
  width: 340px;
  height: 340px;
  overflow: visible;
}

/* 整体 360° 缓慢旋转 (30 秒一周期) */
.snow-rotator-main {
  transform-origin: 170px 170px;
  animation: snowSpin30s 30s linear infinite;
}

@keyframes snowSpin30s {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* 2 层虚线圆轨道反向旋转 (内层 20秒逆时针，外层 14秒顺时针) */
.orbit-inner-dashed {
  transform-origin: 170px 170px;
  animation: orbitReverse 20s linear infinite;
}

.orbit-outer-dashed {
  transform-origin: 170px 170px;
  animation: orbitForward 14s linear infinite;
}

@keyframes orbitReverse {
  from { transform: rotate(360deg); }
  to { transform: rotate(0deg); }
}

@keyframes orbitForward {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* 50×50px 白→青径向渐变冰晶核心 (脉冲呼吸 3 秒一周期) */
.snow-core-pulse {
  transform-origin: 170px 170px;
  animation: corePulse3s 3s ease-in-out infinite alternate;
}

@keyframes corePulse3s {
  0% { transform: scale(0.88); opacity: 0.75; filter: drop-shadow(0 0 8px #67E8F9); }
  100% { transform: scale(1.15); opacity: 1; filter: drop-shadow(0 0 22px #E0F2FE); }
}

/* 顶点发光节点光晕 */
.vertex-glow-node {
  animation: vertexGlow 3s ease-in-out infinite alternate;
}

@keyframes vertexGlow {
  0% { r: 3.5; opacity: 0.7; }
  100% { r: 5; opacity: 1; }
}

/* 核心指标卡片 */
.hero-badges-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 36px;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-btn);
  padding: 18px 12px;
  text-align: center;
  backdrop-filter: blur(8px);
}

.metric-value {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.6rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 4px;
}

.metric-label {
  font-size: 0.82rem;
  color: var(--text-dim);
}

/* ===================================================================
   核心优势 (3个图文卡片)
   =================================================================== */
.features-section {
  padding: 80px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-card);
  padding: 36px 28px;
  position: relative;
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-ice);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-cyan-hover);
  background: var(--bg-card-hover);
  box-shadow: 0 16px 36px rgba(2, 6, 23, 0.8), 0 0 20px rgba(103, 232, 249, 0.15);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-btn);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 22px;
  background: rgba(103, 232, 249, 0.1);
  border: 1px solid rgba(103, 232, 249, 0.3);
  color: var(--primary-cyan);
}

.feature-icon-box svg {
  width: 28px;
  height: 28px;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.feature-desc {
  color: var(--text-dim);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-list {
  list-style: none;
  border-top: 1px solid rgba(103, 232, 249, 0.1);
  padding-top: 16px;
}

.feature-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: #cbd5e1;
  margin-bottom: 8px;
}

.feature-list li svg {
  width: 16px;
  height: 16px;
  stroke: var(--primary-cyan);
  flex-shrink: 0;
}

/* ===================================================================
   流媒体与 AI 支持图卡
   =================================================================== */
.unlock-section {
  padding: 80px 0;
  background: linear-gradient(180deg, rgba(2,6,23,0) 0%, rgba(103,232,249,0.03) 50%, rgba(2,6,23,0) 100%);
}

.unlock-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 28px;
}

.unlock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-card);
  padding: 36px 32px;
  transition: var(--transition);
}

.unlock-card:hover {
  border-color: var(--border-cyan-hover);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4), 0 0 20px rgba(103, 232, 249, 0.12);
}

.unlock-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.unlock-badge-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-btn);
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(103, 232, 249, 0.12);
  border: 1px solid rgba(103, 232, 249, 0.3);
  color: var(--primary-cyan);
}

.unlock-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
}

.unlock-subtitle {
  color: var(--text-dim);
  font-size: 0.9rem;
}

.unlock-desc {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

.unlock-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.unlock-tag-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: var(--radius-btn);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(103, 232, 249, 0.15);
  font-size: 0.88rem;
  font-weight: 500;
  color: #e2e8f0;
}

/* ===================================================================
   套餐价格对比表
   =================================================================== */
.pricing-section {
  padding: 80px 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-card);
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-cyan-hover);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.6), 0 0 25px rgba(103, 232, 249, 0.18);
}

.pricing-card.popular {
  border-color: rgba(103, 232, 249, 0.6);
  background: linear-gradient(180deg, rgba(103, 232, 249, 0.1) 0%, rgba(15, 23, 42, 0.9) 100%);
  box-shadow: 0 8px 30px rgba(103, 232, 249, 0.2);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-btn);
  color: var(--text-dark);
  padding: 4px 18px;
  border-radius: var(--radius-pill);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  box-shadow: 0 0 15px rgba(103, 232, 249, 0.5);
}

.pricing-plan-name {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #fff;
}

.pricing-plan-desc {
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-bottom: 20px;
  min-height: 42px;
}

.pricing-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 8px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(103, 232, 249, 0.12);
}

.currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-cyan);
}

.price-number {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  color: #ffffff;
}

.price-period {
  color: var(--text-dim);
  font-size: 0.95rem;
}

.pricing-cycle-tag {
  display: inline-block;
  font-size: 0.78rem;
  color: var(--primary-cyan);
  background: rgba(103, 232, 249, 0.1);
  border: 1px solid rgba(103, 232, 249, 0.25);
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  font-weight: 500;
}

.pricing-features {
  list-style: none;
  margin: 20px 0 32px 0;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: #cbd5e1;
  margin-bottom: 14px;
}

.pricing-features li svg {
  width: 18px;
  height: 18px;
  stroke: var(--primary-cyan);
  flex-shrink: 0;
}

/* ===================================================================
   用户评价 (Testimonials)
   =================================================================== */
.testimonials-section {
  padding: 80px 0;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-btn);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-cyan-hover);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.35);
}

.testimonial-stars {
  display: flex;
  gap: 4px;
  margin-bottom: 14px;
  color: #38bdf8;
}

.testimonial-text {
  font-size: 0.9rem;
  color: #cbd5e1;
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid rgba(103, 232, 249, 0.1);
  padding-top: 12px;
}

.author-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, #67E8F9, #0284c7);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: #020617;
}

.author-info h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: #ffffff;
}

.author-info p {
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* ===================================================================
   常见问题解答 (FAQ)
   =================================================================== */
.faq-section {
  padding: 80px 0;
}

.faq-grid {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

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

.faq-question {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-arrow {
  width: 20px;
  height: 20px;
  stroke: var(--primary-cyan);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

details[open] .faq-arrow {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 24px 20px 24px;
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.65;
  border-top: 1px solid rgba(103, 232, 249, 0.08);
  padding-top: 14px;
}

/* ===================================================================
   底栏转化横幅
   =================================================================== */
.bottom-banner-section {
  padding: 60px 0 80px 0;
}

.bottom-banner {
  background: linear-gradient(135deg, rgba(103, 232, 249, 0.12) 0%, rgba(224, 242, 254, 0.08) 100%);
  border: 1px solid rgba(103, 232, 249, 0.35);
  border-radius: var(--radius-card);
  padding: 50px 30px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 0 30px rgba(103, 232, 249, 0.1);
}

.bottom-banner h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 14px;
  color: #ffffff;
}

.bottom-banner p {
  color: var(--text-dim);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto 30px auto;
}

/* ===================================================================
   页脚 (Footer)
   =================================================================== */
main {
  position: relative;
  z-index: 2;
}

.site-footer {
  position: relative;
  z-index: 2;
  background: rgba(1, 4, 15, 0.88);
  border-top: 1px solid rgba(103, 232, 249, 0.12);
  padding: 48px 0 36px 0;
  text-align: center;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  list-style: none;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-link {
  color: var(--text-dim);
  font-size: 0.98rem;
  font-weight: 500;
  padding: 8px 12px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.footer-link:hover {
  color: var(--secondary-snow);
  text-decoration: underline;
  text-shadow: 0 0 8px rgba(103, 232, 249, 0.6);
}

.footer-copy {
  color: rgba(255, 255, 255, 0.65); /* 提升对比度至 >7:1，满足 WCAG 4.5:1 要求 */
  font-size: 0.85rem;
  margin-top: 16px;
}

/* ===================================================================
   独立子页面通用容器
   =================================================================== */
.subpage-container {
  max-width: 860px;
  margin: 40px auto 80px auto;
  padding: 40px 30px;
  background: var(--bg-card);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-card);
}

.subpage-header {
  margin-bottom: 36px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(103, 232, 249, 0.12);
}

.subpage-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #ffffff;
}

.subpage-date {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.subpage-body h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin: 32px 0 14px 0;
  color: var(--primary-cyan);
}

.subpage-body p {
  color: #cbd5e1;
  font-size: 0.98rem;
  line-height: 1.75;
  margin-bottom: 16px;
}

.subpage-body ul {
  list-style: disc;
  padding-left: 24px;
  color: #cbd5e1;
  margin-bottom: 20px;
}

.subpage-body li {
  margin-bottom: 8px;
  line-height: 1.6;
}

.back-home-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 24px;
  color: var(--primary-cyan);
  font-size: 0.9rem;
  font-weight: 600;
}

.back-home-btn:hover {
  color: #ffffff;
}

/* ===================================================================
   响应式媒体查询 (@media) - 确保手机端单栏自适应
   =================================================================== */
@media (max-width: 1024px) {
  .hero-badges-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

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

@media (max-width: 860px) {
  .hero-layout-split {
    flex-direction: column;
    text-align: center;
    gap: 30px;
  }

  .hero-left-col {
    max-width: 100%;
    text-align: center;
  }

  .hero-intro-box {
    text-align: left;
  }

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

  .hero-right-col {
    margin: 0 auto;
  }
}

@media (max-width: 768px) {
  .site-header {
    height: auto;
    padding: 14px 0;
  }

  .nav-container {
    flex-wrap: wrap;
    gap: 12px;
  }

  .nav-menu {
    display: none;
  }

  .nav-actions {
    margin-left: auto;
  }

  .hero-section {
    padding: 40px 0 30px 0;
  }

  .hero-headline {
    font-size: 2.1rem;
  }

  .hero-subheadline {
    font-size: 1rem;
    margin-bottom: 24px;
  }

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

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

  .hero-right-col {
    width: 280px;
    height: 280px;
  }

  .snow-crystal-container {
    width: 280px;
    height: 280px;
  }

  .snowflake-svg {
    width: 280px;
    height: 280px;
  }

  .hero-badges-grid {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }

  .metric-card {
    padding: 12px 8px;
  }

  .metric-value {
    font-size: 1.35rem;
  }

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

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

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

  .pricing-card.popular {
    transform: none;
  }

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

  .footer-nav {
    flex-direction: column;
    gap: 14px;
  }

  .bottom-banner {
    padding: 36px 18px;
  }

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

  .subpage-container {
    padding: 24px 16px;
    margin: 20px auto 60px auto;
  }
}

/* ===================================================================
   动画偏好 (prefers-reduced-motion) 适配
   =================================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
    scroll-behavior: auto !important;
  }
  .snow-crystal-svg,
  .vein-path,
  .snow-particle,
  .halo-cyan,
  .halo-white,
  .crystal-orbit-outer,
  .crystal-orbit-inner,
  .crystal-core {
    animation: none !important;
  }
}