/* ==========================================================================
   几落科技 ZERO TECH（0 科技）— 站点样式
   布局参考行业通用的"全屏纵向分屏 + 弧形能力菜单 + 案例网格"模式
   视觉与代码均为原创，未使用任何原站受版权保护的素材
   ========================================================================== */

/* ---------- 设计变量 ---------- */
:root {
  --ink: #141414;
  --ink-soft: #55565a;
  --ink-faint: #9a9ba0;
  --paper: #ffffff;
  --paper-alt: #f6f7f9;
  --line: #e4e3e3;

  /* 品牌色：取自 logo 的蓝→青渐变，全站强调色 */
  --brand: #0b63f6;         /* 主蓝，与渐变起点一致 */
  --brand-deep: #1440d8;    /* 深蓝：hover / 渐变终点 */
  --brand-soft: #35d6ee;    /* 青，与渐变末端一致 */
  --brand-ink: #0b1220;     /* 深海军蓝：深色屏底色，取自 logo 反白版 */
  --brand-rgb: 11, 99, 246; /* 供 rgba() 使用，改色只需改这一处 */
  --brand-grad: linear-gradient(135deg, #1d4ef5 0%, #1297f5 55%, #35d6ee 100%);

  --radius: 6px;
  --shadow-sm: 0 2px 10px rgba(20, 20, 20, 0.06);
  --shadow-md: 0 14px 40px rgba(20, 20, 20, 0.12);
  --shadow-lg: 0 24px 70px rgba(20, 20, 20, 0.18);

  --header-h: 84px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 基础 ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  /* 全屏分节滚动：滚动容器是 .screens，这里保留锚点平滑 */
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Source Han Sans SC",
    "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow: hidden; /* 由 .screens 承担滚动 */
}

img,
svg {
  display: block;
  max-width: 100%;
}

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

ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 700;
  line-height: 1.2;
}

p {
  margin: 0;
}

button {
  font-family: inherit;
}

.container {
  width: min(1440px, 100% - 120px);
  margin-inline: auto;
}

/* 跳转链接（无障碍） */
.skip-link {
  position: absolute;
  left: 16px;
  top: -60px;
  z-index: 999;
  padding: 10px 18px;
  background: var(--ink);
  color: #fff;
  border-radius: 0 0 var(--radius) var(--radius);
  transition: top 0.25s var(--ease);
}

.skip-link:focus {
  top: 0;
}

/* 统一焦点样式 */
:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 4px;
}

/* 通用间距工具 */
.mb-32 { margin-bottom: 32px; }
.mb-40 { margin-bottom: 40px; }
.mb-48 { margin-bottom: 48px; }
.mb-72 { margin-bottom: 72px; }

/* ---------- 分屏容器（核心） ---------- */
.screens {
  height: 100vh;
  height: 100dvh;
  overflow-y: auto;
  overflow-x: hidden;
  scroll-behavior: smooth;
  scroll-snap-type: y mandatory;
  -webkit-overflow-scrolling: touch;
}

.screen {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  scroll-snap-align: start;
  scroll-snap-stop: always;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
}

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  transition: background 0.35s var(--ease), box-shadow 0.35s var(--ease),
    border-color 0.35s var(--ease);
  border-bottom: 1px solid transparent;
}

/* Hero 屏顶部为红色背景，导航文字用白色 */
.site-header.is-on-hero {
  color: #fff;
}

.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
}

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

.logo {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  transition: color 0.3s var(--ease);
}

/* logo 标记：直接引用品牌 SVG。品牌图形是竖长的「0」（原始比例 371:484），
   故固定竖向高度、宽度按比例自适应，避免被容器拉变形。
   注意：不能用「grid 叠放 + img{height:100%}」——grid 项的百分比高度会
   按行高解析，导致 img 撑到自然高度(371x484)而把 logo 文字顶到几百像素外。
   改用 aspect-ratio 以容器高度反推宽度，img 用 absolute 铺满容器。
   两套标记叠放，由 .is-on-hero 决定显示哪一套：
   Hero 蓝底 → 白色单色版；浅底 → 彩色版。 */
.logo-mark {
  position: relative;
  display: block;
  height: 40px;
  width: auto;
  aspect-ratio: 371 / 484; /* 与原始图形比例一致，宽度随之自动计算 */
  background: transparent;
  flex: none;
}

.logo-mark img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

/* 默认（浅底）：彩色标记 */
.logo-mark .mark-on-dark { display: none; }
.logo-mark .mark-on-light { display: block; }

/* Hero 与深色底：切到白色单色标记 */
.site-header.is-on-hero .logo-mark .mark-on-dark,
.footer-brand .logo-mark .mark-on-dark { display: block; }
.site-header.is-on-hero .logo-mark .mark-on-light,
.footer-brand .logo-mark .mark-on-light { display: none; }

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.logo-text small {
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.26em;
  opacity: 0.7;
}

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

.main-nav ul {
  display: flex;
  gap: 32px;
}

.main-nav a:not(.nav-cta) {
  position: relative;
  font-size: 15px;
  font-weight: 500;
  padding: 6px 2px;
  transition: color 0.25s var(--ease);
}

.main-nav a:not(.nav-cta)::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s var(--ease);
}

.main-nav a:not(.nav-cta):hover::after,
.main-nav a:not(.nav-cta)[aria-current="true"]::after {
  transform: scaleX(1);
}

/* 非 Hero 屏（白色导航背景）的链接色 */
.site-header:not(.is-on-hero) .main-nav a:not(.nav-cta) {
  color: var(--ink-soft);
}

.site-header:not(.is-on-hero) .main-nav a:not(.nav-cta):hover,
.site-header:not(.is-on-hero) .main-nav a:not(.nav-cta)[aria-current="true"] {
  color: var(--ink);
}

/* Hero 屏的链接色 */
.site-header.is-on-hero .main-nav a:not(.nav-cta) {
  color: rgba(255, 255, 255, 0.88);
}

.site-header.is-on-hero .main-nav a:not(.nav-cta):hover,
.site-header.is-on-hero .main-nav a:not(.nav-cta)[aria-current="true"] {
  color: #fff;
}

.site-header.is-on-hero .nav-cta {
  background: #fff;
  color: var(--brand);
}

.nav-cta {
  background: var(--brand);
  color: #fff;
  padding: 10px 24px;
  font-size: 14px;
}

.nav-cta:hover {
  background: var(--brand-deep);
  color: #fff;
}

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 0;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--ink);
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease),
    background 0.3s var(--ease);
}

.site-header.is-on-hero .nav-toggle span {
  background: #fff;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 30px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease),
    background 0.25s var(--ease), color 0.25s var(--ease),
    border-color 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--brand);
  color: #fff;
}

.btn-primary:hover {
  background: var(--brand-deep);
  box-shadow: 0 10px 26px rgba(var(--brand-rgb), 0.32);
}

/* ---------- 右侧分页圆点 ---------- */
.pager {
  position: fixed;
  right: 34px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 90;
}

.pager ul {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.pager button {
  position: relative;
  display: block;
  width: 22px;
  height: 22px;
  padding: 0;
  background: transparent;
  border: 0;
  cursor: pointer;
}

/* 圆点本体：用 background-clip 做出"空心圆环"效果 */
.pager button::before {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 50%;
  border: 2px solid transparent;
  background: #8c8c8c;
  background-clip: content-box;
  opacity: 0.5;
  box-sizing: border-box;
  transition: opacity 0.3s var(--ease), background 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.pager button:hover::before {
  opacity: 1;
}

/* 当前屏：空心品牌色圆环（深色屏上用 logo 的青，浅色屏上用主蓝） */
.pager button[aria-current="true"]::before {
  border-color: var(--brand);
  background: transparent;
  opacity: 1;
}

/* 深色背景屏（Hero / 联系）上的圆点反白 */
.pager.is-on-dark button::before {
  background: #fff;
  background-clip: content-box;
  opacity: 0.55;
}

.pager.is-on-dark button[aria-current="true"]::before {
  border-color: var(--brand-soft);
}

.pager.is-on-dark button[aria-current="true"]::before {
  border-color: #fff;
  background: transparent;
  opacity: 1;
}

/* ---------- 滚动进度条 ---------- */
.scroll-progress {
  position: fixed;
  left: 0;
  top: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--brand), #1297f5, var(--brand-soft));
  z-index: 110;
  transition: width 0.1s linear;
}

/* ---------- 标题与描述（跨屏复用） ---------- */
.slide-title {
  font-size: clamp(32px, 3.4vw, 48px);
  letter-spacing: 5px;
  line-height: 1.22;
  font-weight: 700;
}

.title-line {
  display: block;
}

/* 带横线的那一行：文字 + 横线 */
.title-line--with-rule {
  display: flex;
  align-items: center;
  gap: 30px;
}

.title-rule {
  display: block;
  width: 100px;
  height: 1px;
  background: var(--ink);
  flex: none;
}

.slide-title--light {
  color: #fff;
}

.slide-title--light .title-rule {
  background: #fff;
}

.slide-desc {
  max-width: 420px;
  font-size: 16px;
  letter-spacing: 1px;
  line-height: 1.75;
  color: var(--ink-soft);
}

.slide-desc--dark {
  color: var(--ink-soft);
  opacity: 0.75;
}

.slide-desc--light {
  color: rgba(255, 255, 255, 0.82);
}

/* ==========================================================================
   第 1 屏：Hero
   ========================================================================== */
/* Hero 底色：取 logo 的蓝→青渐变，右下转向深海军蓝，避免大面积高饱和刺眼 */
.screen--hero {
  background:
    radial-gradient(120% 110% at 78% 20%, #35d6ee 0%, #1297f5 34%, #1d4ef5 62%, #1030c8 100%),
    var(--brand-deep);
  color: #fff;
}

.hero-bg {
  position: absolute;
  inset: 0;
}

#heroCanvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(1440px, 100% - 120px);
  padding-top: var(--header-h);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 60px;
}

.hero-copy {
  max-width: 520px;
}

.hero-more {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.06em;
  padding-bottom: 6px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.5);
  transition: border-color 0.3s var(--ease), gap 0.3s var(--ease);
}

.hero-more:hover {
  border-bottom-color: #fff;
  gap: 18px;
}

.hero-more-icon {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.6);
  transition: background 0.3s var(--ease), color 0.3s var(--ease);
}

.hero-more:hover .hero-more-icon {
  background: #fff;
  color: var(--brand);
}

/* Hero 右侧抽象图形组合 */
.hero-figure {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-stage {
  position: relative;
  width: min(460px, 42vw);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
}

.hero-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.32);
}

.ring-outer {
  inset: 0;
  animation: spin 34s linear infinite;
  border-style: dashed;
}

.ring-mid {
  inset: 16%;
  border-color: rgba(255, 255, 255, 0.5);
  animation: spin 22s linear infinite reverse;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.18);
}

.orb-a {
  width: 120px;
  height: 120px;
  left: 6%;
  top: 16%;
  animation: float 7s ease-in-out infinite;
}

.orb-b {
  width: 74px;
  height: 74px;
  right: 12%;
  top: 30%;
  animation: float 9s ease-in-out infinite reverse;
}

.orb-c {
  width: 46px;
  height: 46px;
  right: 26%;
  bottom: 18%;
  animation: float 6s ease-in-out infinite;
}

.hero-badge {
  position: relative;
  z-index: 2;
  display: grid;
  place-items: center;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: #fff;
  color: var(--brand);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.22);
}

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

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-16px); }
}

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%);
  z-index: 3;
  opacity: 0.8;
  transition: opacity 0.3s var(--ease);
}

.scroll-hint:hover {
  opacity: 1;
}

.mouse {
  display: block;
  width: 24px;
  height: 40px;
  border: 2px solid #fff;
  border-radius: 13px;
  position: relative;
  background: rgba(112, 112, 112, 0.24);
}

.wheel {
  position: absolute;
  left: 50%;
  top: 7px;
  width: 3px;
  height: 7px;
  margin-left: -1.5px;
  border-radius: 3px;
  background: #fff;
  animation: wheel 1.8s infinite;
}

@keyframes wheel {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(13px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ==========================================================================
   第 2 屏：一站式解决方案能力（弧形菜单）
   版式：左栏文案 + 右侧弧线菜单，内容面板浮在弧线右侧空白处
   ========================================================================== */
.screen--ability {
  background: var(--paper);
}

.ability-inner {
  position: relative;
  padding-top: var(--header-h);
}

.ability-left {
  max-width: 460px;
}

/* 弧形区域：整体绝对定位到右侧，避免参与栅格导致宽度被动 */
.arc-wrap {
  position: absolute;
  top: 50%;
  /* 弧线整体落在容器右半边，左侧留给文案，两者不重叠 */
  left: 50%;
  right: 0;
  height: var(--arc-h, 620px);
  transform: translateY(-50%);
  --arc-h: 620px;
  --arc-r: 265px;      /* 半径 */
  --arc-ring: 140px;   /* 圆环厚度 */
  --arc-cx: 50px;      /* 圆心相对 wrap 左边界的水平偏移，须 > 半径，圆钮才不会掉出左边界 */
  --arc-cy: 310px;     /* 圆心相对 wrap 上边界的垂直偏移 = arc-h / 2 */
  --arc-gutter: 72px;  /* 右侧预留带：给固定定位的分页点让位，内容面板不得越入 */
}

/* 弧线轨道：与 JS 计算的圆心、半径保持同一套参数
   只做视觉引导，不加白色实心填充，避免遮挡左侧文案 */
.arc-track {
  position: absolute;
  left: calc(var(--arc-cx) - var(--arc-r) - var(--arc-ring));
  top: calc(var(--arc-cy) - var(--arc-r) - var(--arc-ring));
  width: calc((var(--arc-r) + var(--arc-ring)) * 2);
  height: calc((var(--arc-r) + var(--arc-ring)) * 2);
  border-radius: 50%;
  border: var(--arc-ring) solid rgba(0, 0, 0, 0.022);
  pointer-events: none;
}

/* 圆钮容器 */
.arc-menu {
  position: absolute;
  inset: 0;
}

/* 单个圆钮：绝对定位，left/top 由 JS 按弧线计算 */
.arc-item {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 118px;
  height: 118px;
  padding: 0;
  background: transparent;
  border: 0;
  cursor: pointer;
  transform: translate(-50%, -50%);
}

.arc-item-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background-image: linear-gradient(229deg, #fff 0%, var(--paper-alt) 97%);
  border: 0.5px solid #e3e3e3;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: 1px;
  color: var(--ink-soft);
  text-align: center;
  transition: width 0.35s var(--ease), height 0.35s var(--ease),
    border-color 0.3s var(--ease), color 0.3s var(--ease),
    box-shadow 0.35s var(--ease), background 0.3s var(--ease);
}

.arc-item:hover .arc-item-inner {
  border-color: var(--brand);
  color: var(--brand);
}

/* 当前项：放大 + 品牌渐变底白字 */
.arc-item[aria-selected="true"] .arc-item-inner {
  width: 100px;
  height: 100px;
  background: var(--brand-grad);
  border-color: transparent;
  color: #fff;
  font-size: 16px;
  box-shadow: 0 14px 34px rgba(var(--brand-rgb), 0.34);
}

/* 内容展示区：left / width 由 JS 按弧线最右端计算，落在弧线右侧 */
.ability-show {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 3;
  /* 宽度由 main.js 的 layoutArc() 按「弧线右边界 + 间隙、右侧再让出分页点」
     实算后以内联 style 写入。这里只给一个软下限，且必须与 JS 里的 minW 一致，
     否则 min-width 会顶掉内联 width，面板就会在窄屏越过右侧分页点。 */
  min-width: 260px;
}

.ability-panel {
  animation: panelIn 0.5s var(--ease);
}

@keyframes panelIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 代表项目标签 */
.ability-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 14px;
  margin-bottom: 26px;
}

.ability-tag {
  position: relative;
  padding-left: 18px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--ink);
  transition: color 0.25s var(--ease);
}

.ability-tag::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 6px;
  height: 6px;
  margin-top: -3px;
  border-radius: 50%;
  background: var(--brand);
  transition: transform 0.25s var(--ease);
}

.ability-tag:hover {
  color: var(--brand);
}

.ability-tag:hover::before {
  transform: scale(1.5);
}

.ability-desc {
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: 1px;
  color: var(--ink-soft);
  opacity: 0.78;
  max-width: 460px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

/* ==========================================================================
   第 3 屏：行业服务案例
   ========================================================================== */
.screen--cases {
  background: var(--paper-alt);
}

.cases-inner {
  padding-top: var(--header-h);
  display: grid;
  grid-template-columns: 320px 1fr;
  align-items: center;
  gap: 70px;
}

.cases-head {
  max-width: 320px;
}

.cases-head .slide-title {
  font-size: clamp(28px, 2.6vw, 38px);
}

.cases-head .title-rule {
  width: 64px;
}

.case-more {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  font-size: 18px;
  font-weight: 600;
  color: var(--ink);
  padding-bottom: 5px;
  border-bottom: 1px solid var(--ink);
  transition: gap 0.3s var(--ease), color 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.case-more:hover {
  gap: 22px;
  color: var(--brand);
  border-color: var(--brand);
}

.case-more-arrow {
  font-size: 18px;
  line-height: 1;
}

/* 3 × 3 卡片网格 */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.case-card {
  position: relative;
  display: block;
  min-height: 172px;
  padding: 26px 24px;
  background: var(--paper-alt);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.35s var(--ease), box-shadow 0.35s var(--ease),
    transform 0.35s var(--ease);
}

.case-card:hover {
  border-color: transparent;
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

/* 卡片正面：标题 + 图标 */
.case-card-face {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  transition: opacity 0.32s var(--ease), transform 0.32s var(--ease);
}

.case-card-title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 1px;
  color: rgba(0, 0, 0, 0.68);
  transition: color 0.3s var(--ease);
}

.case-card-title::after {
  content: "";
  display: block;
  width: 26px;
  height: 2px;
  margin-top: 12px;
  background: var(--brand);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s var(--ease);
}

.case-card:hover .case-card-title::after {
  transform: scaleX(1);
}

/* 图标块：用 CSS 图形代替位图图标 */
.case-card-icon {
  position: relative;
  flex: none;
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: linear-gradient(140deg, var(--brand-soft), var(--brand));
  opacity: 0.85;
  transition: transform 0.35s var(--ease), opacity 0.35s var(--ease);
}

.case-card-icon::after {
  content: "";
  position: absolute;
  inset: 9px;
  border: 1.5px solid rgba(255, 255, 255, 0.92);
  border-radius: 3px;
}

/* 每个行业用不同旋转角，形成图标差异 */
.grid-icon0 { background: var(--brand-grad); }
.grid-icon1 { background: linear-gradient(140deg, #ffb26b, #e86a00); }
.grid-icon2 { background: linear-gradient(140deg, #6ee7b7, #0d9488); }
.grid-icon3 { background: linear-gradient(140deg, #7dd3fc, #0369a1); }
.grid-icon4 { background: linear-gradient(140deg, #c4b5fd, #6d28d9); }
.grid-icon5 { background: linear-gradient(140deg, #fca5a5, #b91c1c); }
.grid-icon6 { background: linear-gradient(140deg, #fde68a, #d97706); }
.grid-icon7 { background: linear-gradient(140deg, #a5b4fc, #4338ca); }
.grid-icon8 { background: linear-gradient(140deg, #f9a8d4, #be185d); }

.case-card:hover .case-card-icon {
  transform: rotate(-8deg) scale(1.08);
  opacity: 1;
}

/* 卡片背面：hover 时覆盖上来 */
.case-card-hover {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  padding: 24px;
  background: var(--brand-grad);
  color: #fff;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.32s var(--ease), visibility 0.32s,
    transform 0.32s var(--ease);
}

.case-card:hover .case-card-hover,
.case-card:focus-visible .case-card-hover {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.case-card-hover li {
  font-size: 14px;
  line-height: 1.5;
  opacity: 0.94;
  padding-left: 14px;
  position: relative;
}

.case-card-hover li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.8);
}

.case-card-hover-more {
  margin-top: 6px;
  padding-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.34);
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

/* ==========================================================================
   第 4 屏：团队动态
   ========================================================================== */
.screen--news {
  background: var(--paper);
}

.news-inner {
  padding-top: var(--header-h);
}

.news-title .title-rule {
  width: 300px;
  opacity: 0.16;
}

/* 不规则网格：3 列 × 3 行，第一格跨两行 */
.news-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr 1fr;
  grid-template-rows: repeat(3, 176px);
  gap: 14px;
}

.news-card {
  position: relative;
  display: block;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--paper-alt);
}

.news-card.is-featured {
  grid-row: span 2;
}

/* 封面：多种渐变构图 */
.news-cover {
  position: absolute;
  inset: 0;
  transition: transform 0.6s var(--ease);
}

.news-card:hover .news-cover {
  transform: scale(1.06);
}

.cover-a {
  background:
    radial-gradient(120px 120px at 76% 22%, rgba(255, 255, 255, 0.4) 0 26%, transparent 27%),
    linear-gradient(135deg, #1030c8, var(--brand) 52%, var(--brand-soft));
}

.cover-b {
  background:
    radial-gradient(150px 150px at 20% 78%, rgba(255, 255, 255, 0.28) 0 30%, transparent 31%),
    linear-gradient(200deg, #0f4f46, #16a085 58%, #8ee3c8);
}

.cover-c {
  background: conic-gradient(from 210deg at 72% 28%, #ffd166, #ef8354 42%, #a8311c 78%, #6d1d10);
}

.cover-d {
  background:
    repeating-linear-gradient(45deg, rgba(255, 255, 255, 0.14) 0 14px, transparent 14px 28px),
    linear-gradient(120deg, #23222b, #514a66 70%, #8d7bb0);
}

.cover-e {
  background:
    radial-gradient(70px 70px at 32% 28%, rgba(255, 255, 255, 0.85) 0 22%, transparent 23%),
    radial-gradient(100px 100px at 76% 72%, rgba(255, 255, 255, 0.3) 0 26%, transparent 27%),
    linear-gradient(160deg, #12324f, #3f7cac);
}

.cover-f {
  background:
    conic-gradient(from 40deg at 30% 70%, #1f2937, #4a4e69 36%, #9a8c98 66%, #c9ada7 86%, #1f2937);
}

.news-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(0, 0, 0, 0.05) 0%, rgba(0, 0, 0, 0.62) 100%);
}

/* 文字覆盖层 */
.news-overlay {
  position: absolute;
  inset: auto 0 0 0;
  padding: 22px 24px;
  color: #fff;
  z-index: 2;
  transition: transform 0.4s var(--ease);
}

.news-card.is-featured .news-overlay {
  padding: 30px;
}

.news-date {
  display: inline-block;
  font-size: 12.5px;
  letter-spacing: 0.08em;
  opacity: 0.78;
  margin-bottom: 8px;
}

.news-card h3 {
  font-size: 17px;
  line-height: 1.4;
  letter-spacing: 0.02em;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.news-card.is-featured h3 {
  font-size: 23px;
  -webkit-line-clamp: 3;
}

/* 摘要默认收起，hover 时展开 */
.news-summary {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  font-size: 13.5px;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.84);
  transition: max-height 0.45s var(--ease), opacity 0.35s var(--ease),
    margin-top 0.35s var(--ease);
}

.news-card:hover .news-summary,
.news-card:focus-visible .news-summary {
  max-height: 120px;
  opacity: 1;
  margin-top: 10px;
}

/* ==========================================================================
   第 5 屏：联系我们 + 页脚
   ========================================================================== */
/* 深色屏底色：取自 logo 反白版的深海军蓝 */
.screen--contact {
  background: var(--brand-ink);
  color: #fff;
  justify-content: space-between;
}

.contact-inner {
  padding-top: calc(var(--header-h) + 40px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 100vh;
  min-height: 100dvh;
}

.contact-top {
  padding-bottom: 70px;
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: 24px;
  align-items: flex-start;
}

/* 一行 = 文案 + 动效箭头 + 邮箱明文，三者同为一个视觉整体。
   悬停任意位置（含邮箱）箭头都会向右滑动，但【只走 transform，不占布局】，
   所以右侧的邮箱纹丝不动。 */
.contact-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 30px;
  font-size: clamp(19px, 1.7vw, 24px);
  font-weight: 600;
  letter-spacing: 0.03em;
  color: rgba(255, 255, 255, 0.9);
}

.contact-main {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  color: inherit;
  transition: color 0.3s var(--ease);
}

/* 鼠标落在整行任意处（文案 / 箭头 / 邮箱）都让箭头拉开 */
.contact-line:hover {
  color: #fff;
}

.contact-line:hover .contact-mail {
  color: inherit;
}

.contact-main:focus-visible,
.contact-mail:focus-visible {
  outline: 2px solid rgba(255, 255, 255, 0.7);
  outline-offset: 3px;
  border-radius: 3px;
}

/* 箭头：用 transform 右移来表达「拉开」，不改变任何盒模型尺寸，
   因此不会把右侧的邮箱推走（这是关键，勿改回 gap 动画）。 */
.contact-arrow {
  line-height: 1;
  transform: translateX(0);
  transition: transform 0.3s var(--ease);
}

.contact-line:hover .contact-arrow {
  transform: translateX(10px);
}

@media (prefers-reduced-motion: reduce) {
  .contact-arrow {
    transition: none;
  }
  .contact-line:hover .contact-arrow {
    transform: none;
  }
}

/* 邮箱明文：与主文案同字号同色，只是可点击复制，没有任何容器/底色 */
.contact-mail {
  display: inline-flex;
  align-items: baseline;
  gap: 9px;
  padding: 0;
  margin: 0;
  font-family: inherit;
  font-size: inherit;
  font-weight: inherit;
  letter-spacing: inherit;
  color: inherit;
  background: none;
  border: 0;
  border-radius: 0;
  cursor: pointer;
  transition: color 0.3s var(--ease);
}

.contact-mail-hint {
  font-size: 0.7em;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.42);
  transition: color 0.25s var(--ease);
}

.contact-line:hover .contact-mail-hint {
  color: rgba(255, 255, 255, 0.72);
}

/* 复制成功：仅提示文字变绿并显示「已复制」，2 秒后由 JS 复位。
   邮箱本体不加背景/描边，保持静态文字观感。 */
.contact-mail.is-copied .contact-mail-hint {
  color: #5fe08f;
}

/* 复制失败（极少数环境不支持 Clipboard API）时的提示 */
.contact-mail.is-failed .contact-mail-hint {
  color: #f2c94c;
}

/* 页脚 */
.site-footer {
  padding-bottom: 30px;
}

.footer-divider {
  height: 1px;
  background: rgba(255, 255, 255, 0.14);
  margin-bottom: 42px;
}

.footer-cols {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 60px;
  padding-bottom: 40px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.footer-col h3 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #fff;
  margin-bottom: 18px;
}

.footer-col a {
  display: inline-block;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.58);
  padding: 5px 0;
  transition: color 0.22s var(--ease), transform 0.22s var(--ease);
}

.footer-col a:hover {
  color: #fff;
  transform: translateX(4px);
}

.footer-brand {
  text-align: right;
}

.footer-brand .logo {
  justify-content: flex-end;
  color: #fff;
}

.footer-brand .logo-mark {
  height: 48px;
  background: transparent;
}

.footer-brand > p {
  margin-top: 16px;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.52);
}

.footer-qr {
  margin-top: 22px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
}

/* 二维码占位：用 CSS 棋盘格模拟，替换为真实二维码图片 */
.qr-box {
  display: block;
  width: 104px;
  height: 104px;
  border-radius: 6px;
  background-color: #fff;
  background-image:
    linear-gradient(45deg, #141414 25%, transparent 25%, transparent 75%, #141414 75%),
    linear-gradient(45deg, #141414 25%, transparent 25%, transparent 75%, #141414 75%);
  background-size: 14px 14px;
  background-position: 0 0, 7px 7px;
  opacity: 0.92;
}

.footer-qr p {
  font-size: 12.5px;
  color: rgba(255, 255, 255, 0.5);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.42);
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.62);
  transition: color 0.22s var(--ease);
}

.footer-bottom a:hover {
  color: #fff;
}

/* 页脚右下角的域名标识（本站无备案号，用域名占住右侧，视觉更平衡） */
.footer-domain {
  letter-spacing: 0.02em;
}

.footer-domain a {
  color: rgba(255, 255, 255, 0.62);
}

.footer-domain a:hover {
  color: #fff;
}

/* ---------- 滚动淡入 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}

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

/* ==========================================================================
   响应式
   ========================================================================== */

/* --- 平板 --- */
/* 能力屏的并排布局需要：弧线右边界 + 36px 间隙 + 260px 面板最小宽 + 72px 分页点预留带。
   1366 起才排得下；更窄时并排会让面板越过右边界（实测 1280 仍溢出 22px），
   故从 1320px 起就退回上下堆叠。 */
@media (max-width: 1320px) {
  .container,
  .hero-inner {
    width: min(1440px, 100% - 72px);
  }

  /* 能力屏：此宽度下「弧线 + 面板」并排放不下——弧线右边界之后
     再留 36px 间隙与 72px 分页点预留带，已不足面板最小宽度 260px，
     继续并排只会让正文溢出视口。故提前改为上下堆叠。 */
  .arc-wrap {
    position: static;
    transform: none;
    height: auto;
    margin-top: 32px;
  }

  .arc-track {
    display: none;
  }

  .arc-menu {
    position: static;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  /* 关键：只把容器改成网格还不够——圆钮自身仍是 absolute，
     会继续沿用 JS 写入的 left/top，全部叠在一点上。
     必须同时把 .arc-item 复位为 static 才能进网格流。 */
  .arc-item {
    position: static;
    transform: none;
    width: 100%;
    height: auto;
  }

  .arc-item-inner,
  .arc-item[aria-selected="true"] .arc-item-inner {
    width: 100%;
    height: 84px;
    border-radius: var(--radius);
    font-size: 15px;
  }

  .ability-show {
    position: static;
    transform: none;
    width: 100%;
    min-width: 0;
    margin-top: 32px;
  }

  .cases-inner {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .cases-head {
    max-width: 100%;
  }

  .news-grid {
    grid-template-rows: repeat(3, 150px);
  }
}

/* --- 小屏 / 竖屏：放弃全屏吸附，改为普通滚动 --- */
@media (max-width: 1024px), (max-height: 680px) {
  body {
    overflow: auto;
  }

  .screens {
    height: auto;
    overflow: visible;
    scroll-snap-type: none;
  }

  .screen {
    min-height: auto;
    padding: 96px 0 72px;
    scroll-snap-align: none;
  }

  .pager {
    display: none;
  }

  /* 导航变白底，文字转深色 */
  .site-header,
  .site-header.is-on-hero {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(14px);
    border-bottom-color: var(--line);
    color: var(--ink);
  }

  .site-header.is-on-hero .main-nav a:not(.nav-cta),
  .site-header:not(.is-on-hero) .main-nav a:not(.nav-cta) {
    color: var(--ink-soft);
  }

  .site-header.is-on-hero .main-nav a:not(.nav-cta):hover,
  .site-header:not(.is-on-hero) .main-nav a:not(.nav-cta):hover {
    color: var(--ink);
  }

  .nav-toggle span,
  .site-header.is-on-hero .nav-toggle span {
    background: var(--ink);
  }

  .site-header.is-on-hero .nav-cta,
  .nav-cta {
    background: var(--brand);
    color: #fff;
  }

  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding: 18px 24px 26px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-md);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.3s var(--ease), opacity 0.3s var(--ease),
      visibility 0.3s;
  }

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

  .main-nav ul {
    flex-direction: column;
    gap: 4px;
    width: 100%;
  }

  .main-nav a:not(.nav-cta) {
    font-size: 16px;
    padding: 11px 2px;
  }

  .nav-cta {
    margin-top: 12px;
  }

  .nav-toggle {
    display: flex;
  }

  /* Hero */
  .hero-inner,
  .ability-inner,
  .cases-inner,
  .news-inner,
  .contact-inner {
    padding-top: 0;
    min-height: auto;
  }

  /* 窄屏：邮箱换到下一行，左对齐，避免和主文案挤在一行 */
  .contact-line {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    font-size: 20px;
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .hero-copy {
    max-width: 100%;
  }

  .hero-stage {
    width: min(300px, 68vw);
    margin-inline: auto;
  }

  .hero-badge {
    width: 110px;
    height: 110px;
    font-size: 13px;
  }

  .orb-a { width: 84px; height: 84px; }
  .orb-b { width: 54px; height: 54px; }
  .orb-c { width: 34px; height: 34px; }

  .scroll-hint {
    display: none;
  }

  /* 能力：弧形菜单回退为普通网格 */
  .ability-left {
    max-width: 100%;
  }

  .arc-wrap {
    position: static;
    transform: none;
    height: auto;
    margin-top: 36px;
  }

  .arc-track {
    display: none;
  }

  .arc-menu {
    position: static;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .arc-item {
    position: static;
    transform: none;
    width: 100%;
    height: auto;
  }

  .arc-item-inner,
  .arc-item[aria-selected="true"] .arc-item-inner {
    width: 100%;
    height: 84px;
    border-radius: var(--radius);
    font-size: 15px;
  }

  .ability-show {
    position: static;
    transform: none;
    width: 100%;
    margin-top: 32px;
  }

  .ability-desc {
    max-width: 100%;
  }

  /* 案例网格 */
  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* 动态网格：取消跨行 */
  .news-grid {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: auto;
    grid-auto-rows: 190px;
  }

  .news-card.is-featured {
    grid-row: auto;
    grid-column: span 2;
  }

  .news-card.is-featured h3 {
    font-size: 19px;
  }

  /* 页脚 */
  .footer-cols {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .footer-brand {
    text-align: left;
  }

  .footer-brand .logo {
    justify-content: flex-start;
  }

  .footer-qr {
    align-items: flex-start;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* --- 手机 --- */
@media (max-width: 640px) {
  .container,
  .hero-inner {
    width: min(1440px, 100% - 40px);
  }

  .screen {
    padding: 88px 0 56px;
  }

  .slide-title {
    letter-spacing: 3px;
  }

  .title-line--with-rule {
    gap: 16px;
  }

  .title-rule {
    width: 54px;
  }

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

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

  .case-card {
    min-height: 148px;
  }

  .news-grid {
    grid-template-columns: 1fr;
    grid-auto-rows: 178px;
  }

  .news-card.is-featured {
    grid-column: auto;
  }

  .news-title .title-rule {
    width: 120px;
  }

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

/* ---------- 减少动态偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .screens {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 打印 ---------- */
@media print {
  body {
    overflow: visible;
  }

  .screens {
    height: auto;
    overflow: visible;
  }

  .screen {
    min-height: auto;
    page-break-after: always;
  }

  .site-header,
  .pager,
  .scroll-progress,
  .scroll-hint,
  #heroCanvas {
    display: none;
  }
}