/* =========================================================
   省心投 BI 官网样式
   设计方向：Editorial Magazine + Refined Minimal
   色彩：暖白纸张底色 + 品牌蓝 #1890ff + 陶土/鼠尾草/暖金点缀
   动效：以 Emil Kowalski 的 design-engineering 原则为准
   ========================================================= */

/* 默认：黑夜模式 */
:root {
  --bg-paper: #0f1419;
  --bg-cream: #161b22;
  --bg-card: #1a2028;

  --text-primary: #ece9e3;
  --text-secondary: #a8a39b;
  --text-tertiary: #6e6a64;

  --brand-blue: #4d9eff;
  --brand-blue-hover: #6bb0ff;
  --brand-blue-soft: rgba(77, 158, 255, 0.12);
  --brand-blue-border: rgba(77, 158, 255, 0.3);

  --accent-terracotta: #d98a6a;
  --accent-sage: #9bc0a0;
  --accent-gold: #d9b947;

  --border-light: rgba(255, 255, 255, 0.08);
  --border-medium: rgba(255, 255, 255, 0.16);

  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-elevated: 0 24px 60px rgba(0, 0, 0, 0.5), 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-float: 0 32px 80px rgba(0, 0, 0, 0.6), 0 12px 32px rgba(0, 0, 0, 0.4);

  --font-serif: "Noto Serif SC", "DM Serif Display", "Songti SC", Georgia, serif;
  --font-sans: "Noto Sans SC", "SF Pro Text", "PingFang SC", system-ui, -apple-system, sans-serif;
  --font-display: "DM Serif Display", "Noto Serif SC", serif;

  /* Emil Kowalski easing curves — built-in CSS easings are too weak */
  --ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-in-out: cubic-bezier(0.77, 0, 0.175, 1);
  --ease-drawer: cubic-bezier(0.32, 0.72, 0, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --stagger: 80ms;

  --blob-blend: screen;
}

/* 白天模式覆盖 */
:root[data-theme="light"] {
  --bg-paper: #f5f2ed;
  --bg-cream: #faf8f5;
  --bg-card: #ffffff;

  --text-primary: #1a1a1a;
  --text-secondary: #525252;
  --text-tertiary: #737373;

  --brand-blue: #1890ff;
  --brand-blue-hover: #40a9ff;
  --brand-blue-soft: rgba(24, 144, 255, 0.08);
  --brand-blue-border: rgba(24, 144, 255, 0.22);

  --accent-terracotta: #c96b4a;
  --accent-sage: #7a9e7e;
  --accent-gold: #c9a227;

  --border-light: rgba(115, 115, 115, 0.12);
  --border-medium: rgba(115, 115, 115, 0.2);

  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-elevated: 0 24px 60px rgba(0, 0, 0, 0.1), 0 8px 24px rgba(0, 0, 0, 0.05);
  --shadow-float: 0 32px 80px rgba(0, 0, 0, 0.12), 0 12px 32px rgba(0, 0, 0, 0.06);

  --blob-blend: multiply;
}

/* 主题切换平滑过渡 */
body,
.screen-card,
.showcase-card,
.feature-item,
.platform-card,
.cta-panel,
.site-header,
.site-footer {
  transition: background-color 0.45s var(--ease-out), color 0.45s var(--ease-out),
    border-color 0.45s var(--ease-out), box-shadow 0.45s var(--ease-out);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-paper);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 纸张纹理（已禁用：让页面背景清晰） */
.grain-overlay {
  display: none;
}

.container {
  width: min(1200px, 92%);
  margin-inline: auto;
}

/* =========================================================
   按钮 —— Emil: 按下 scale(0.97) + 精确 transition
   ========================================================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
  font-weight: 500;
  border-radius: 8px;
  transition:
    transform 160ms var(--ease-out),
    box-shadow 200ms var(--ease-out),
    background-color 200ms var(--ease-out);
  border: 1px solid transparent;
  cursor: pointer;
}

.btn svg {
  flex-shrink: 0;
}

.btn-primary {
  background: var(--brand-blue);
  color: #fff;
  box-shadow: 0 4px 14px rgba(24, 144, 255, 0.28);
}

.btn-primary:hover {
  background: var(--brand-blue-hover);
  box-shadow: 0 8px 24px rgba(24, 144, 255, 0.35);
}

/* Emil: 按钮按下必须有缩放反馈，160ms ease-out */
.btn:active {
  transform: scale(0.97);
}

/* hover translateY 仅在支持 hover 的输入设备上生效 */
@media (hover: hover) and (pointer: fine) {
  .btn-primary:hover {
    transform: translateY(-2px);
  }

  .btn-ghost:hover {
    background: #fff;
    border-color: var(--brand-blue-border);
    transform: translateY(-2px);
    box-shadow: var(--shadow-card);
  }
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.6);
  color: var(--text-primary);
  border-color: var(--border-medium);
  backdrop-filter: blur(8px);
}

.btn-large {
  padding: 14px 28px;
  font-size: 16px;
}

.btn-sm {
  padding: 8px 18px;
  font-size: 14px;
}

/* =========================================================
   导航
   ========================================================= */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: background 0.3s var(--ease-out), box-shadow 0.3s var(--ease-out), padding 0.3s var(--ease-out);
}

.site-header.scrolled {
  background: color-mix(in srgb, var(--bg-cream) 86%, transparent);
  backdrop-filter: blur(14px);
  box-shadow: 0 1px 0 var(--border-light);
  padding: 10px 0;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-mark {
  width: 32px;
  height: 32px;
  display: block;
}

.brand-word {
  font-family: var(--font-serif);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.brand-word em {
  font-style: normal;
  color: var(--brand-blue);
  font-family: var(--font-display);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  margin-left: auto;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  position: relative;
  transition: color 180ms var(--ease-out);
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--brand-blue);
  transition: width 220ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .nav-links a:hover {
    color: var(--text-primary);
  }

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

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

/* 右上角下载下拉菜单 */
.nav-download {
  position: relative;
  display: inline-block;
}

.nav-download .caret {
  transition: transform 0.25s var(--ease-out);
  margin-left: 2px;
}

.nav-download.open .caret {
  transform: rotate(180deg);
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background: var(--bg-card);
  border: 1px solid var(--border-medium);
  border-radius: 12px;
  box-shadow: var(--shadow-elevated);
  padding: 6px;
  opacity: 0;
  transform: translateY(-8px) scale(0.96);
  transform-origin: top right;
  transition: opacity 0.22s var(--ease-out), transform 0.22s var(--ease-spring);
  pointer-events: none;
  z-index: 200;
}

.dropdown-menu.open {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  border-radius: 8px;
  cursor: pointer;
  transition:
    background-color 160ms var(--ease-out),
    color 160ms var(--ease-out),
    transform 160ms var(--ease-out);
  text-align: left;
}

.dropdown-item svg {
  flex-shrink: 0;
  color: var(--text-secondary);
  transition: color 160ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .dropdown-item:hover {
    background: var(--brand-blue-soft);
    color: var(--brand-blue);
  }

  .dropdown-item:hover svg {
    color: var(--brand-blue);
  }
}

.dropdown-item:active {
  transform: scale(0.98);
}

/* 下载中状态 */
.btn[data-loading="true"] {
  pointer-events: none;
  opacity: 0.78;
}

/* 主题切换按钮 */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border-medium);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  transition:
    background-color 200ms var(--ease-out),
    color 200ms var(--ease-out),
    border-color 200ms var(--ease-out),
    transform 300ms var(--ease-spring);
}

@media (hover: hover) and (pointer: fine) {
  .theme-toggle:hover {
    color: var(--brand-blue);
    border-color: var(--brand-blue-border);
    background: var(--brand-blue-soft);
    transform: rotate(20deg);
  }
}

.theme-toggle:active {
  transform: scale(0.92);
}

.theme-toggle .icon-moon,
.theme-toggle .icon-sun {
  position: absolute;
  transition: opacity 250ms var(--ease-out), transform 350ms var(--ease-spring);
}

/* 默认（深色）与 [data-theme="dark"]：显示太阳（提示切到白天） */
:root:not([data-theme="light"]) .theme-toggle .icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}
:root:not([data-theme="light"]) .theme-toggle .icon-moon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.4);
}

/* 白天模式：显示月亮（提示切到黑夜） */
:root[data-theme="light"] .theme-toggle .icon-sun {
  opacity: 0;
  transform: rotate(90deg) scale(0.4);
}
:root[data-theme="light"] .theme-toggle .icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
  position: relative;
  padding: 160px 0 120px;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-geometry {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.geo-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--border-light);
  animation: ring-spin 40s linear infinite;
}

.geo-ring-1 {
  width: 620px;
  height: 620px;
  top: -160px;
  right: -100px;
  opacity: 0.55;
  border-color: rgba(24, 144, 255, 0.18);
  border-style: dashed;
  animation-duration: 50s;
}

.geo-ring-2 {
  width: 380px;
  height: 380px;
  bottom: 60px;
  left: -120px;
  opacity: 0.5;
  border-color: rgba(201, 107, 74, 0.22);
  animation-duration: 35s;
  animation-direction: reverse;
}

.geo-ring-3 {
  width: 220px;
  height: 220px;
  top: 30%;
  left: 40%;
  opacity: 0.4;
  border-color: rgba(201, 162, 39, 0.3);
  border-style: dotted;
  animation-duration: 28s;
}

@keyframes ring-spin {
  to {
    transform: rotate(360deg);
  }
}

/* 多色光斑：缓慢漂浮 + 呼吸缩放 */
.geo-blob {
  position: absolute;
  width: 560px;
  height: 560px;
  border-radius: 50%;
  z-index: 0;
  mix-blend-mode: var(--blob-blend);
  animation: blob-float 14s ease-in-out infinite;
}

.geo-blob-blue {
  top: 8%;
  right: -8%;
  background: radial-gradient(circle at 30% 30%, rgba(24, 144, 255, 0.32), transparent 60%);
  animation-delay: 0s;
}

.geo-blob-terra {
  bottom: 5%;
  left: -10%;
  width: 480px;
  height: 480px;
  background: radial-gradient(circle at 70% 70%, rgba(201, 107, 74, 0.28), transparent 55%);
  animation-delay: -4s;
  animation-duration: 18s;
}

.geo-blob-gold {
  top: 50%;
  left: 35%;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle at 50% 50%, rgba(201, 162, 39, 0.22), transparent 60%);
  animation-delay: -8s;
  animation-duration: 22s;
}

@keyframes blob-float {
  0%, 100% {
    transform: translate(0, 0) scale(1);
    opacity: 0.85;
  }
  33% {
    transform: translate(40px, -30px) scale(1.12);
    opacity: 1;
  }
  66% {
    transform: translate(-30px, 24px) scale(0.94);
    opacity: 0.7;
  }
}

/* 粒子尘埃层：JS 注入小点 */
.dust-field {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.dust-field .dust {
  position: absolute;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--brand-blue);
  opacity: 0;
  box-shadow: 0 0 6px currentColor;
  animation: dust-drift var(--dur, 9s) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
}

@keyframes dust-drift {
  0% {
    transform: translate(0, 0) scale(0);
    opacity: 0;
  }
  20% {
    opacity: 0.8;
    transform: translate(10px, -20px) scale(1);
  }
  60% {
    opacity: 0.9;
  }
  100% {
    transform: translate(var(--tx, 40px), var(--ty, -120px)) scale(0);
    opacity: 0;
  }
}

.hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 64px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 24px;
}

.eyebrow-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--brand-blue);
  box-shadow: 0 0 0 4px var(--brand-blue-soft);
  animation: pulse-dot 1.6s var(--ease-out) infinite;
}

@keyframes pulse-dot {
  0%, 100% {
    box-shadow: 0 0 0 4px var(--brand-blue-soft), 0 0 0 0 color-mix(in srgb, var(--brand-blue) 50%, transparent);
  }
  50% {
    box-shadow: 0 0 0 4px var(--brand-blue-soft), 0 0 0 10px transparent;
  }
}

.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(42px, 5.5vw, 68px);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 28px;
}

/* 两行容器 */
.hero-line {
  display: block;
}

/* 拆字字符：Emil BlurText 思路 —— opacity + translateY + filter
   默认隐藏，hero-title.split-started 后逐字进场。
   注意：不要给 .hero-word 加 overflow:hidden，否则 transform: translateY
   会把字符下半部分裁切，视觉上"少字"。 */
.hero-word {
  display: inline-block;
  white-space: pre;
}

/* 同一行内多个 hero-word 之间需要视觉间距
   （「变成」+「开户增长」两段 inline-block 紧贴会看起来重叠） */
.hero-line .hero-word + .hero-word {
  margin-left: 0.4em;
}

.hero-word .char {
  display: inline-block;
  opacity: 0;
  transform: translateY(0.4em);
  filter: blur(6px);
  transition:
    opacity 720ms var(--ease-out),
    transform 720ms var(--ease-out),
    filter 720ms var(--ease-out);
  transition-delay: var(--char-delay, 0ms);
}

.hero-title.split-started .hero-word .char {
  opacity: 1;
  transform: translateY(0);
  filter: blur(0);
}

/* 空格字符：不参与动画，立即显示，保持视觉间距 */
.hero-word .char-space {
  opacity: 1;
  transform: none;
  filter: none;
  transition: none;
}

.title-italic {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  /* 拆字后用单色，避免 background-clip:text 与 inline-block 子元素的渲染冲突。
     高亮通过 brand-blue + accent-terracotta 的两个 span 共同呈现。 */
  color: var(--brand-blue);
  /* 斜体字符右下"成"字的视觉溢出：直接给 inline-block 容器加 margin-right，
     让后面的"开户增长" word 离斜体字符更远，padding-right 在 inline-block
     上不会撑出 box 实际渲染宽度（与 block 不同），margin 才是 inline-block
     之间的有效外间距。 */
  margin-right: 0.22em;
}

/* 斜体"成"字字形溢出补偿（合成层裁切修复）：
   .char 带 transform+filter 被提升为合成层，Chromium 按盒子边界裁切
   字形溢出，导致斜体"成"字捺笔末端（实测溢出约 10px）被切。
   给最后一个 .char 加 padding-right 把溢出收进盒子，再用负 margin 抵消
   布局偏移，后续词位置不变。仅作用于 .title-italic 内末字。 */
.title-italic .char:last-child {
  padding-right: 0.2em;
  margin-right: -0.2em;
}

/* 拆字字符的渐变变体（保留原 title-flow 流光动效）
   注意：background-clip:text 是元素级，inline-block 子元素拿不到；
   这里每个 .char 单独应用并同步动画，让整体仍然呈现流光效果。 */
.char-gradient {
  background: linear-gradient(
    100deg,
    var(--brand-blue) 0%,
    var(--brand-blue-hover) 30%,
    var(--accent-terracotta) 60%,
    var(--accent-gold) 90%,
    var(--brand-blue) 100%
  );
  background-size: 220% 100%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  animation: title-flow 6s linear infinite;
}

@keyframes title-flow {
  to {
    background-position: 220% 0;
  }
}

.hero-lead {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 480px;
  margin-bottom: 36px;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.meta-separator {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border-medium);
}

/* 截图舞台 */
.hero-visual {
  position: relative;
  perspective: 1400px;
  --mx: 0;
  --my: 0;
  --enter: 0;
}

.hero-visual.entered {
  --enter: 1;
}

.screen-stage {
  position: relative;
  width: 100%;
  height: 560px;
}

.screen-card {
  position: absolute;
  border-radius: 16px;
  overflow: hidden;
  background: var(--bg-card);
  box-shadow: var(--shadow-elevated);
  border: 1px solid var(--border-light);
  opacity: var(--enter);
  transition:
    transform 0.8s var(--ease-spring),
    box-shadow 0.5s var(--ease-out),
    opacity 0.8s var(--ease-out);
}

/* 卡片描边发光：默认就有微弱蓝光，悬停时变强 */
.screen-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 16px;
  pointer-events: none;
  box-shadow:
    0 0 0 1px rgba(24, 144, 255, 0.0),
    0 0 28px rgba(24, 144, 255, 0.0);
  transition: box-shadow 0.4s var(--ease-out);
}

.hero-visual:hover .screen-main::after {
  box-shadow:
    0 0 0 1px rgba(24, 144, 255, 0.4),
    0 0 32px rgba(24, 144, 255, 0.45);
}

.hero-visual:hover .screen-float-1::after {
  box-shadow:
    0 0 0 1px rgba(201, 107, 74, 0.4),
    0 0 28px rgba(201, 107, 74, 0.4);
}

.hero-visual:hover .screen-float-2::after {
  box-shadow:
    0 0 0 1px rgba(201, 162, 39, 0.4),
    0 0 30px rgba(201, 162, 39, 0.4);
}

.screen-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.screen-main {
  width: 640px;
  height: 420px;
  top: 40px;
  left: 0;
  z-index: 3;
  transform:
    rotateY(calc(-8deg + var(--mx) * 4deg))
    rotateX(calc(4deg + var(--my) * -3deg))
    translateY(calc((1 - var(--enter)) * 120px))
    translateZ(calc((1 - var(--enter)) * -120px))
    scale(calc(0.82 + var(--enter) * 0.18));
  transition-delay: 0.15s;
}

.screen-float-1 {
  width: 320px;
  height: 220px;
  top: 0;
  right: 20px;
  z-index: 2;
  transform:
    rotateY(calc(8deg + var(--mx) * -5deg))
    rotateX(calc(-3deg + var(--my) * 4deg))
    translateZ(-40px)
    translateY(calc((1 - var(--enter)) * 180px))
    translateX(calc((1 - var(--enter)) * 60px))
    scale(calc(0.78 + var(--enter) * 0.22));
  box-shadow: var(--shadow-float);
  transition-delay: 0.36s;
}

.screen-float-2 {
  width: 340px;
  height: 230px;
  bottom: 20px;
  right: 60px;
  z-index: 4;
  transform:
    rotateY(calc(6deg + var(--mx) * -6deg))
    rotateX(calc(2deg + var(--my) * 3deg))
    translateZ(20px)
    translateY(calc((1 - var(--enter)) * 160px))
    translateX(calc((1 - var(--enter)) * -50px))
    scale(calc(0.8 + var(--enter) * 0.2));
  box-shadow: var(--shadow-float);
  transition-delay: 0.56s;
}

/* Hover：聚焦主图 + 浮动卡片错落退后 */
.hero-visual:hover .screen-main {
  transform:
    rotateY(calc(-4deg + var(--mx) * 4deg))
    rotateX(calc(2deg + var(--my) * -3deg))
    translateY(-10px)
    scale(1.02);
}

.hero-visual:hover .screen-float-1 {
  transform:
    rotateY(calc(10deg + var(--mx) * -5deg))
    rotateX(calc(-4deg + var(--my) * 4deg))
    translateZ(-20px)
    translateY(-16px)
    translateX(8px)
    scale(0.96);
}

.hero-visual:hover .screen-float-2 {
  transform:
    rotateY(calc(8deg + var(--mx) * -6deg))
    rotateX(calc(3deg + var(--my) * 3deg))
    translateZ(40px)
    translateY(-14px)
    translateX(-6px)
    scale(1.04);
}

/* =========================================================
   通用区块
   ========================================================= */
.section {
  padding: 120px 0;
  position: relative;
}

.section-header {
  max-width: 640px;
  margin-bottom: 72px;
}

.section-eyebrow {
  display: block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--brand-blue);
  margin-bottom: 16px;
}

.section-title {
  font-family: var(--font-serif);
  font-size: clamp(34px, 4vw, 48px);
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-lead {
  margin-top: 18px;
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 560px;
}

/* =========================================================
   核心能力 —— 编辑式分隔网格，无卡片
   ========================================================= */
.section-features {
  background: linear-gradient(180deg, var(--bg-paper) 0%, var(--bg-cream) 100%);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid var(--border-light);
}

.feature-item {
  padding: 48px 40px 56px;
  border-bottom: 1px solid var(--border-light);
  border-right: 1px solid var(--border-light);
  position: relative;
  transition: background-color 320ms var(--ease-out);
}

/* 偶数列去掉右边线，最后一行去掉底边线 */
.feature-item:nth-child(2n) {
  border-right: none;
}
.feature-item:nth-last-child(-n + 2) {
  border-bottom: none;
}

/* 顶部细线锚点：hover 时延伸并染色 */
.feature-item::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--brand-blue);
  transition: width 360ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .feature-item:hover {
    background: color-mix(in srgb, var(--brand-blue) 8%, transparent);
  }

  .feature-item:hover::before {
    width: 120px;
  }

  .feature-item:hover .feature-icon {
    opacity: 1;
  }
}

.feature-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
}

.feature-num {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--brand-blue);
  line-height: 1;
}

.feature-icon {
  width: 44px;
  height: 44px;
  display: block;
  opacity: 0.85;
  transition: opacity 320ms var(--ease-out);
}

.feature-item h3 {
  font-family: var(--font-serif);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.feature-item p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.75;
  max-width: 38ch;
}

/* =========================================================
   界面展示
   ========================================================= */
.section-showcase {
  background: var(--bg-cream);
}

.showcase-header {
  text-align: center;
  margin-inline: auto;
  margin-bottom: 72px;
  max-width: 760px;
}

.showcase-header .section-title {
  margin-inline: auto;
}

.showcase-header .section-lead {
  margin-inline: auto;
  max-width: none;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.showcase-card {
  margin: 0;
  background: var(--bg-card);
  border-radius: 20px;
  padding: 14px;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-card);
  transition:
    transform 400ms var(--ease-out),
    box-shadow 400ms var(--ease-out);
  position: relative;
}

@media (hover: hover) and (pointer: fine) {
  .showcase-card:hover {
    transform: translateY(-10px);
    box-shadow:
      var(--shadow-elevated),
      0 0 0 1px rgba(24, 144, 255, 0.28),
      0 24px 50px rgba(24, 144, 255, 0.18);
  }
}

.showcase-frame {
  border-radius: 12px;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: var(--bg-paper);
  position: relative;
}

.showcase-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition:
    transform 600ms var(--ease-out),
    filter 320ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .showcase-card:hover .showcase-frame img {
    transform: scale(1.06);
    filter: saturate(1.1) brightness(1.02);
  }
}

/* 聚光灯斜光扫过：CSS transition 取代 keyframe，可中断。
   触发用 :hover 时扫一次，鼠标移开反向收回。 */
.frame-sheen {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(
      115deg,
      transparent 38%,
      rgba(24, 144, 255, 0.5) 47%,
      rgba(255, 255, 255, 0.7) 50%,
      rgba(201, 107, 74, 0.5) 53%,
      transparent 62%
    );
  transform: translateX(-130%) skewX(-8deg);
  opacity: 0;
  mix-blend-mode: screen;
  transition:
    transform 900ms var(--ease-out),
    opacity 360ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .showcase-card:hover .frame-sheen {
    transform: translateX(130%) skewX(-8deg);
    opacity: 1;
  }
}

/* Showcase 入场时整体辉光扩散 */
.showcase-card::before {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: 22px;
  background: radial-gradient(circle at 50% 0%, rgba(24, 144, 255, 0.18), transparent 70%);
  opacity: 0;
  transition: opacity 400ms var(--ease-out);
  pointer-events: none;
  z-index: -1;
}

@media (hover: hover) and (pointer: fine) {
  .showcase-card:hover::before {
    opacity: 1;
  }
}

.showcase-card figcaption {
  padding: 18px 8px 10px;
}

.showcase-card figcaption strong {
  display: block;
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 4px;
}

.showcase-card figcaption span {
  font-size: 14px;
  color: var(--text-tertiary);
}

/* =========================================================
   三端支持
   ========================================================= */
.section-platforms {
  background: var(--bg-paper);
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.platform-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 20px;
  padding: 40px 32px;
  position: relative;
  overflow: hidden;
  transition:
    transform 280ms var(--ease-out),
    box-shadow 280ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .platform-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-elevated);
  }
}

.platform-number {
  font-family: var(--font-display);
  font-size: 64px;
  line-height: 1;
  color: rgba(24, 144, 255, 0.1);
  position: absolute;
  top: 20px;
  right: 24px;
  font-style: italic;
}

.platform-card h3 {
  font-family: var(--font-serif);
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.platform-card p {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.7;
  position: relative;
  z-index: 1;
}

/* =========================================================
   CTA
   ========================================================= */
.section-cta {
  padding-bottom: 140px;
}

.cta-panel {
  position: relative;
  background:
    linear-gradient(135deg, var(--bg-card) 0%, color-mix(in srgb, var(--bg-card) 80%, var(--brand-blue)) 100%);
  border: 1px solid var(--border-medium);
  border-radius: 28px;
  padding: 80px;
  color: var(--text-primary);
  overflow: hidden;
}

.cta-ornament {
  position: absolute;
  top: -80px;
  right: -80px;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background:
    radial-gradient(circle, rgba(24, 144, 255, 0.42), transparent 60%),
    radial-gradient(circle at 60% 40%, rgba(201, 107, 74, 0.3), transparent 55%);
  animation: cta-glow 5s ease-in-out infinite;
}

.cta-ornament::before,
.cta-ornament::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid rgba(24, 144, 255, 0.4);
  animation: cta-ring 4s ease-out infinite;
}

.cta-ornament::after {
  animation-delay: 2s;
  border-color: rgba(201, 162, 39, 0.35);
}

@keyframes cta-glow {
  0%, 100% {
    transform: scale(1) translate(0, 0) rotate(0deg);
    opacity: 0.85;
  }
  50% {
    transform: scale(1.2) translate(-16px, 10px) rotate(180deg);
    opacity: 1;
  }
}

@keyframes cta-ring {
  0% {
    transform: scale(0.6);
    opacity: 0.9;
  }
  100% {
    transform: scale(1.6);
    opacity: 0;
  }
}

.cta-content {
  position: relative;
  z-index: 1;
  max-width: 600px;
}

.cta-title {
  font-family: var(--font-serif);
  font-size: clamp(32px, 4vw, 44px);
  font-weight: 700;
  margin-bottom: 18px;
}

.cta-lead {
  color: var(--text-secondary);
  font-size: 17px;
  line-height: 1.7;
  margin-bottom: 36px;
}

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

.cta-actions .btn-primary {
  background: var(--brand-blue);
  color: #fff;
  box-shadow: 0 4px 18px color-mix(in srgb, var(--brand-blue) 40%, transparent);
}

.cta-actions .btn-primary:hover {
  background: var(--brand-blue-hover);
  box-shadow: 0 8px 28px color-mix(in srgb, var(--brand-blue) 50%, transparent);
}

.cta-actions .btn-ghost {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border-medium);
}

.cta-actions .btn-ghost:hover {
  background: var(--brand-blue-soft);
  border-color: var(--brand-blue-border);
  color: var(--brand-blue);
}

/* =========================================================
   Footer
   ========================================================= */
.site-footer {
  border-top: 1px solid var(--border-light);
  padding: 40px 0;
  background: var(--bg-cream);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 16px;
}

.footer-mark {
  width: 24px;
  height: 24px;
}

.footer-copy {
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 180ms var(--ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .footer-links a:hover {
    color: var(--brand-blue);
  }
}

/* =========================================================
   动效：Reveal —— Emil: 滚动入场 320ms ease-out（<300ms 内）
   ========================================================= */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 320ms var(--ease-out),
    transform 320ms var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal[data-reveal="1"] { transition-delay: calc(var(--stagger) * 0); }
.reveal[data-reveal="2"] { transition-delay: calc(var(--stagger) * 1); }
.reveal[data-reveal="3"] { transition-delay: calc(var(--stagger) * 2); }
.reveal[data-reveal="4"] { transition-delay: calc(var(--stagger) * 3); }
.reveal[data-reveal="5"] { transition-delay: calc(var(--stagger) * 4); }

/* Hero reveal: marketing 区，可稍长（≈600ms），符合 Emil marketing/explanatory 规则 */
.hero .reveal {
  opacity: 0;
  transition: opacity 600ms var(--ease-out);
}

.hero .reveal.visible {
  opacity: 1;
}

/* hero-title 自己承担拆字动画，不再叠加 translateY */
.hero .hero-title.reveal {
  transform: none;
}

/* 截图卡片的加载动画 */
.screen-card {
  opacity: 0;
  transform: translateY(40px) rotateY(-8deg) rotateX(4deg);
  animation: screenIn 1.2s var(--ease-out) forwards;
}

.screen-float-1 { animation-delay: 0.25s; }
.screen-float-2 { animation-delay: 0.45s; }

@keyframes screenIn {
  to {
    opacity: 1;
    transform: translateY(0) rotateY(-8deg) rotateX(4deg);
  }
}

.screen-float-1 {
  transform: rotateY(8deg) rotateX(-3deg) translateZ(-40px);
  animation-name: screenInFloat1;
}

@keyframes screenInFloat1 {
  to {
    opacity: 1;
    transform: rotateY(8deg) rotateX(-3deg) translateZ(-40px);
  }
}

.screen-float-2 {
  transform: rotateY(6deg) rotateX(2deg) translateZ(20px);
  animation-name: screenInFloat2;
}

@keyframes screenInFloat2 {
  to {
    opacity: 1;
    transform: rotateY(6deg) rotateX(2deg) translateZ(20px);
  }
}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 64px;
  }

  .hero-visual {
    order: -1;
  }

  .screen-stage {
    height: 420px;
  }

  .screen-main {
    width: 100%;
    max-width: 560px;
    height: 340px;
    top: 50px;
    left: 50%;
    transform: translateX(-50%) rotateY(-6deg) rotateX(3deg);
  }

  .screen-float-1,
  .screen-float-2 {
    display: none;
  }

  .feature-grid,
  .showcase-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 640px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding: 120px 0 80px;
  }

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

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

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

  .cta-panel {
    padding: 48px 28px;
  }

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

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* =========================================================
   无障碍：prefers-reduced-motion
   Emil: 尊重系统级偏好，保留 opacity/color，去掉 transform 动效
   ========================================================= */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .geo-ring,
  .geo-blob,
  .dust-field .dust,
  .cta-ornament,
  .cta-ornament::before,
  .cta-ornament::after,
  .title-italic {
    animation: none !important;
  }

  .screen-card,
  .screen-float-1,
  .screen-float-2 {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }

  /* 拆字字符：直接显示，跳过入场 */
  .hero-word .char {
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
    transition: none !important;
  }
}