/* ============================================================
   Puchuan — base.css
   设计令牌 + 全局重置 + 通用工具类（手写替代 Tailwind 产物）
   科技蓝设计系统：primary #2563eb / secondary #0ea5e9
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root {
  /* 品牌色（Dawn color scheme 变量由 theme.liquid 输出覆盖） */
  --color-primary: #2563eb;
  --color-primary-50: #eff6ff;
  --color-primary-100: #dbeafe;
  --color-primary-200: #bfdbfe;
  --color-primary-300: #93c5fd;
  --color-primary-400: #60a5fa;
  --color-primary-500: #3b82f6;
  --color-primary-600: #2563eb;
  --color-primary-700: #1d4ed8;
  --color-primary-800: #1e40af;
  --color-primary-900: #1e3a8a;
  --color-secondary: #0ea5e9;
  --color-secondary-50: #f0f9ff;
  --color-secondary-100: #e0f2fe;
  --color-secondary-200: #bae6fd;
  --color-secondary-300: #7dd3fc;
  --color-secondary-400: #38bdf8;
  --color-secondary-500: #0ea5e9;
  --color-secondary-600: #0284c7;
  --color-secondary-700: #0369a1;
  --color-background: #f8fafc;
  --color-background-subtle: #f1f5f9;
  --color-surface: #ffffff;
  --color-surface-elevated: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;
  --color-text-muted-light: #94a3b8;
  --color-on-primary: #ffffff;
  --color-on-secondary: #ffffff;
  --color-sky-200: #bae6fd;
  --color-sky-300: #7dd3fc;
  --color-sky-400: #38bdf8;
  --color-cyan-300: #67e8f9;
  --color-cyan-600: #0891b2;
  --color-slate-500: #64748b;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;

  /* 字体（系统字体栈，零外部依赖） */
  --font-body-family:
    "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system,
    "Segoe UI", Roboto, sans-serif;
  --font-heading-family:
    "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system,
    "Segoe UI", Roboto, sans-serif;

  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-card:
    0 1px 2px rgba(15, 23, 42, 0.04), 0 8px 24px rgba(15, 23, 42, 0.06);
  --shadow-card-hover:
    0 1px 2px rgba(15, 23, 42, 0.04), 0 16px 40px rgba(15, 23, 42, 0.1);
  --shadow-lg:
    0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.08);
  --shadow-xl:
    0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --shadow-glow-primary:
    0 0 20px rgba(37, 99, 235, 0.3), 0 0 40px rgba(37, 99, 235, 0.1);
  --shadow-glow-primary-lg:
    0 0 30px rgba(37, 99, 235, 0.4), 0 0 60px rgba(37, 99, 235, 0.2);

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #2563eb 0%, #0ea5e9 100%);
  --gradient-text-primary: linear-gradient(90deg, #2563eb, #0ea5e9);

  /* 布局 */
  --page-width: 1600px;
  --page-padding: 1.5rem;
  --spacing-scale: 100%;

  /* 断点 */
  --breakpoint-tablet: 768px;
  --breakpoint-desktop: 1024px;

  /* 颜色淡色/半透明变体（底色 tint、边框 tint、状态弱化） */
  --color-primary-tint-8: rgba(37, 99, 235, 0.08);
  --color-primary-tint-10: rgba(37, 99, 235, 0.1);
  --color-primary-border-soft: rgba(37, 99, 235, 0.18);
  --color-primary-border-hover: rgba(37, 99, 235, 0.25);
  --color-primary-border-strong: rgba(37, 99, 235, 0.4);
  --color-border-dark: rgba(148, 163, 184, 0.15);
  --color-border-muted: rgba(148, 163, 184, 0.5);
  --color-border-70: rgba(226, 232, 240, 0.7);
  --color-error-soft-bg: rgba(239, 68, 68, 0.08);
  --color-error-soft-border: rgba(239, 68, 68, 0.3);

  /* 交互反馈（焦点环 / 选区高亮） */
  --focus-ring-color: rgba(59, 130, 246, 0.8);
  --focus-ring-primary-soft: rgba(37, 99, 235, 0.12);
  --selection-background: rgba(59, 130, 246, 0.2);

  /* 玻璃拟态与白/深色底半透明文字 */
  --color-glass-background: rgba(255, 255, 255, 0.72);
  --color-glass-tag: rgba(255, 255, 255, 0.2);
  --color-on-primary-85: rgba(255, 255, 255, 0.85);
  --color-text-on-dark-muted: rgba(186, 230, 253, 0.85);

  /* 阴影补充（md 通用档 / 发光特效 / 头部） */
  --shadow-md:
    0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-glow-logo: 0 4px 12px rgba(37, 99, 235, 0.35);
  --shadow-glow-cta: 0 4px 14px rgba(6, 182, 212, 0.35);
  --shadow-glow-cta-lg: 0 6px 18px rgba(6, 182, 212, 0.45);
  --shadow-glow-icon: 0 6px 16px rgba(37, 99, 235, 0.28);
  --shadow-glow-timeline:
    0 0 0 4px rgba(37, 99, 235, 0.14), 0 0 12px rgba(37, 99, 235, 0.35);
  --shadow-art:
    0 1px 2px rgba(15, 23, 42, 0.04), 0 8px 24px rgba(37, 99, 235, 0.08);
  --shadow-header: 0 1px 12px rgba(15, 23, 42, 0.06);
}

/* ---------- 全局重置（对齐 Tailwind preflight 核心） ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
  border: 0 solid var(--color-border);
}

html {
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  -moz-tab-size: 4;
  tab-size: 4;
  font-family: var(--font-body-family);
  -webkit-tap-highlight-color: transparent;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body-family);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: inherit;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-size: inherit;
  font-weight: inherit;
  margin: 0;
}

p {
  margin: 0;
}

a {
  color: inherit;
  text-decoration: inherit;
}

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

button,
input,
select,
textarea {
  font-family: inherit;
  font-size: 100%;
  font-weight: inherit;
  line-height: inherit;
  letter-spacing: inherit;
  color: inherit;
  margin: 0;
  padding: 0;
}

button {
  background-color: transparent;
  background-image: none;
  cursor: pointer;
}

img,
svg,
video {
  display: block;
  vertical-align: middle;
}

img,
video {
  max-width: 100%;
  height: auto;
}

::selection {
  background-color: var(--selection-background);
  color: var(--color-text-primary);
}

:focus-visible {
  outline: 2px solid var(--focus-ring-color);
  outline-offset: 2px;
}

/* ---------- 排版工具 ---------- */
.text-center {
  text-align: center;
}
.text-primary {
  color: var(--color-primary);
}
.text-primary-500 {
  color: var(--color-primary-500);
}
.text-primary-600 {
  color: var(--color-primary-600);
}
.text-primary-700 {
  color: var(--color-primary-700);
}
.text-secondary-600 {
  color: var(--color-secondary-600);
}
.text-cyan-600 {
  color: var(--color-cyan-600);
}
.text-sky-200 {
  color: var(--color-sky-200);
}
.text-sky-300 {
  color: var(--color-sky-300);
}
.text-slate-500 {
  color: var(--color-slate-500);
}
.text-text-primary {
  color: var(--color-text-primary);
}
.text-text-secondary {
  color: var(--color-text-secondary);
}
.text-text-muted {
  color: var(--color-text-muted);
}
.text-white {
  color: var(--color-on-primary);
}
.text-sky-200\/85 {
  color: var(--color-text-on-dark-muted);
}
.text-white\/85 {
  color: var(--color-on-primary-85);
}

.font-medium {
  font-weight: 500;
}
.font-semibold {
  font-weight: 600;
}
.font-bold {
  font-weight: 700;
}

.text-xs {
  font-size: 0.75rem;
  line-height: 1rem;
}
.text-sm {
  font-size: 0.875rem;
  line-height: 1.25rem;
}
.text-base {
  font-size: 1rem;
  line-height: 1.5rem;
}
.text-lg {
  font-size: 1.125rem;
  line-height: 1.75rem;
}
.text-xl {
  font-size: 1.25rem;
  line-height: 1.75rem;
}
.text-2xl {
  font-size: 1.5rem;
  line-height: 2rem;
}
.text-3xl {
  font-size: 1.875rem;
  line-height: 2.25rem;
}
.text-4xl {
  font-size: 2.25rem;
  line-height: 2.5rem;
}
.text-\[11px\] {
  font-size: 0.6875rem;
  line-height: 1rem;
}

.leading-relaxed {
  line-height: 1.625;
}
.leading-snug {
  line-height: 1.375;
}
.leading-\[1\.12\] {
  line-height: 1.12;
}
.tabular-nums {
  font-variant-numeric: tabular-nums;
}
.tracking-tight {
  letter-spacing: -0.025em;
}
.tracking-widest {
  letter-spacing: 0.1em;
}
.uppercase {
  text-transform: uppercase;
}
.antialiased {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 渐变文字 */
.text-gradient-primary {
  background-image: var(--gradient-text-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- 布局工具 ---------- */
.mx-auto {
  margin-left: auto;
  margin-right: auto;
}
.mt-0 {
  margin-top: 0;
}
.mt-0\.5 {
  margin-top: 0.125rem;
}
.mt-2 {
  margin-top: 0.5rem;
}
.mt-2\.5 {
  margin-top: 0.625rem;
}
.mt-3 {
  margin-top: 0.75rem;
}
.mt-4 {
  margin-top: 1rem;
}
.mt-5 {
  margin-top: 1.25rem;
}
.mt-6 {
  margin-top: 1.5rem;
}
.mt-8 {
  margin-top: 2rem;
}
.mt-9 {
  margin-top: 2.25rem;
}
.mt-14 {
  margin-top: 3.5rem;
}
.mt-auto {
  margin-top: auto;
}
.mb-0 {
  margin-bottom: 0;
}
.mb-4 {
  margin-bottom: 1rem;
}
.mb-5 {
  margin-bottom: 1.25rem;
}
.mb-6 {
  margin-bottom: 1.5rem;
}
.mb-8 {
  margin-bottom: 2rem;
}
.mb-10 {
  margin-bottom: 2.5rem;
}
.mb-12 {
  margin-bottom: 3rem;
}

.flex {
  display: flex;
}
.inline-flex {
  display: inline-flex;
}
.grid {
  display: grid;
}
.grid-cols-2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.block {
  display: block;
}
.hidden {
  display: none;
}

.flex-col {
  flex-direction: column;
}
.flex-wrap {
  flex-wrap: wrap;
}
.flex-1 {
  flex: 1 1 0%;
}
.flex-none {
  flex: none;
}
.content-start {
  align-content: flex-start;
}
.items-start {
  align-items: flex-start;
}
.items-end {
  align-items: flex-end;
}
.items-center {
  align-items: center;
}
.items-baseline {
  align-items: baseline;
}
.justify-center {
  justify-content: center;
}
.justify-between {
  justify-content: space-between;
}

.gap-1 {
  gap: 0.25rem;
}
.gap-1\.5 {
  gap: 0.375rem;
}
.gap-2 {
  gap: 0.5rem;
}
.gap-2\.5 {
  gap: 0.625rem;
}
.gap-3 {
  gap: 0.75rem;
}
.gap-4 {
  gap: 1rem;
}
.gap-6 {
  gap: 1.5rem;
}
.gap-8 {
  gap: 2rem;
}
.gap-10 {
  gap: 2.5rem;
}
.gap-12 {
  gap: 3rem;
}
.space-y-2\.5 > * + * {
  margin-top: 0.625rem;
}

.relative {
  position: relative;
}
.absolute {
  position: absolute;
}
.static {
  position: static;
}
.sticky {
  position: sticky;
}
.inset-0 {
  inset: 0;
}
.pointer-events-none {
  pointer-events: none;
}
.overflow-hidden {
  overflow: hidden;
}

.h-0\.5 {
  height: 0.125rem;
}
.h-4 {
  height: 1rem;
}
.h-5 {
  height: 1.25rem;
}
.h-6 {
  height: 1.5rem;
}
.h-11 {
  height: 2.75rem;
}
.h-12 {
  height: 3rem;
}
.h-40 {
  height: 10rem;
}
.h-64 {
  height: 16rem;
}
.h-72 {
  height: 18rem;
}
.h-full {
  height: 100%;
}
.w-4 {
  width: 1rem;
}
.w-5 {
  width: 1.25rem;
}
.w-6 {
  width: 1.5rem;
}
.w-11 {
  width: 2.75rem;
}
.w-12 {
  width: 3rem;
}
.w-64 {
  width: 16rem;
}
.w-72 {
  width: 18rem;
}
.w-full {
  width: 100%;
}

.max-w-xl {
  max-width: 36rem;
}
.max-w-2xl {
  max-width: 42rem;
}
.max-w-3xl {
  max-width: 48rem;
}
.max-w-6xl {
  max-width: 72rem;
}
.max-w-7xl {
  max-width: 80rem;
}

.p-0 {
  padding: 0;
}
.p-5 {
  padding: 1.25rem;
}
.p-6 {
  padding: 1.5rem;
}
.px-3 {
  padding-left: 0.75rem;
  padding-right: 0.75rem;
}
.px-4 {
  padding-left: 1rem;
  padding-right: 1rem;
}
.px-5 {
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}
.px-6 {
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}
.px-8 {
  padding-left: 2rem;
  padding-right: 2rem;
}
.px-10 {
  padding-left: 2.5rem;
  padding-right: 2.5rem;
}
.py-1 {
  padding-top: 0.25rem;
  padding-bottom: 0.25rem;
}
.py-1\.5 {
  padding-top: 0.375rem;
  padding-bottom: 0.375rem;
}
.py-3 {
  padding-top: 0.75rem;
  padding-bottom: 0.75rem;
}
.py-3\.5 {
  padding-top: 0.875rem;
  padding-bottom: 0.875rem;
}
.py-4 {
  padding-top: 1rem;
  padding-bottom: 1rem;
}
.py-12 {
  padding-top: 3rem;
  padding-bottom: 3rem;
}
.py-14 {
  padding-top: 3.5rem;
  padding-bottom: 3.5rem;
}
.py-16 {
  padding-top: 4rem;
  padding-bottom: 4rem;
}
.py-20 {
  padding-top: 5rem;
  padding-bottom: 5rem;
}
.pt-3 {
  padding-top: 0.75rem;
}
.pt-4 {
  padding-top: 1rem;
}
.pt-6 {
  padding-top: 1.5rem;
}
.pt-10 {
  padding-top: 2.5rem;
}
.pt-12 {
  padding-top: 3rem;
}
.pb-8 {
  padding-bottom: 2rem;
}
.pb-24 {
  padding-bottom: 6rem;
}

/* ---------- 圆角/边框 ---------- */
.rounded-xl {
  border-radius: 0.75rem;
}
.rounded-2xl {
  border-radius: 1rem;
}
.rounded-3xl {
  border-radius: 1.5rem;
}
.rounded-full {
  border-radius: 999px;
}
.border {
  border-width: 1px;
}
.border-b {
  border-bottom-width: 1px;
}
.border-t {
  border-top-width: 1px;
}
.border-slate-200 {
  border-color: var(--color-border);
}
.border-slate-200\/70 {
  border-color: var(--color-border-70);
}
.border-primary-200 {
  border-color: var(--color-primary-200);
}
.border-primary-300 {
  border-color: var(--color-primary-300);
}
.border-primary\/40 {
  border-color: var(--color-primary-border-strong);
}
.border-gray-divider {
  border-color: var(--color-border);
}

/* ---------- 背景/渐变 ---------- */
.bg-white {
  background-color: var(--color-surface);
}
.bg-white\/20 {
  background-color: rgba(255, 255, 255, 0.2);
}
.bg-surface {
  background-color: var(--color-surface);
}
.bg-background {
  background-color: var(--color-background);
}
.bg-primary-50 {
  background-color: var(--color-primary-50);
}
.bg-primary-100 {
  background-color: var(--color-primary-100);
}
.bg-primary-200 {
  background-color: var(--color-primary-200);
}
.bg-primary-100\/40 {
  background-color: rgba(219, 234, 254, 0.4);
}
.bg-primary-200\/50 {
  background-color: rgba(191, 219, 254, 0.5);
}
.bg-primary\/10 {
  background-color: var(--color-primary-tint-10);
}
.bg-secondary-200\/50 {
  background-color: rgba(186, 230, 253, 0.5);
}
.bg-gradient-primary {
  background-image: var(--gradient-primary);
}
/* 渐变端点（from-/to- 覆盖起止色） */
.from-sky-400 {
  --tw-gradient-from: var(--color-sky-400);
}
.to-cyan-300 {
  --tw-gradient-to: var(--color-cyan-300);
}
.bg-gradient-to-br {
  background-image: linear-gradient(
    to bottom right,
    var(--tw-gradient-from, var(--color-primary)),
    var(--tw-gradient-to, var(--color-secondary))
  );
}
.bg-gradient-to-r {
  background-image: linear-gradient(
    to right,
    var(--tw-gradient-from, var(--color-primary)),
    var(--tw-gradient-to, var(--color-secondary))
  );
}

/* 案例卡渐变（select 值映射） */
.pc-gradient-blue-cyan {
  background-image: linear-gradient(135deg, #3b82f6, #2563eb, #06b6d4);
}
.pc-gradient-sky-blue {
  background-image: linear-gradient(135deg, #0ea5e9, #0284c7, #2563eb);
}
.pc-gradient-cyan-blue {
  background-image: linear-gradient(135deg, #06b6d4, #3b82f6, #1d4ed8);
}
.pc-gradient-light {
  background-image: linear-gradient(135deg, #60a5fa, #06b6d4, #0ea5e9);
}

/* ---------- 阴影 ---------- */
.shadow-sm {
  box-shadow: var(--shadow-sm);
}
.shadow-lg {
  box-shadow: var(--shadow-lg);
}
.shadow-xl {
  box-shadow: var(--shadow-xl);
}
.shadow-glow-primary {
  box-shadow: var(--shadow-glow-primary);
}
.shadow-glow-primary-lg {
  box-shadow: var(--shadow-glow-primary-lg);
}

/* ---------- 模糊/背景特效 ---------- */
.blur-3xl {
  filter: blur(64px);
}
.backdrop-blur-sm {
  backdrop-filter: blur(4px);
}

/* ---------- 过渡/动画 ---------- */
.transition {
  transition:
    color 0.15s,
    background-color 0.15s,
    border-color 0.15s,
    box-shadow 0.15s,
    transform 0.15s,
    opacity 0.15s;
}
.transition-all {
  transition:
    transform 0.3s,
    box-shadow 0.3s,
    border-color 0.3s,
    color 0.3s,
    background-color 0.3s,
    opacity 0.3s;
}
.transition-colors {
  transition:
    color 0.15s,
    background-color 0.15s,
    border-color 0.15s;
}
.transition-transform {
  transition: transform 0.15s;
}
.duration-300 {
  transition-duration: 0.3s;
}
.ease-in-out {
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Hover / Group-hover 变体 ---------- */
.hover\:-translate-y-0\.5:hover {
  transform: translateY(-2px);
}
.hover\:-translate-y-1:hover {
  transform: translateY(-4px);
}
.hover\:-translate-y-1\.5:hover {
  transform: translateY(-6px);
}
.hover\:-translate-y-2:hover {
  transform: translateY(-8px);
}
.hover\:shadow-md:hover {
  box-shadow: var(--shadow-md);
}
.hover\:shadow-lg:hover {
  box-shadow: var(--shadow-lg);
}
.hover\:shadow-xl:hover {
  box-shadow: var(--shadow-xl);
}
.hover\:shadow-card-hover:hover {
  box-shadow: var(--shadow-card-hover);
}
.hover\:shadow-glow-primary-lg:hover {
  box-shadow: var(--shadow-glow-primary-lg);
}
.hover\:border-primary-300:hover {
  border-color: var(--color-primary-300);
}
.hover\:border-primary\/40:hover {
  border-color: var(--color-primary-border-strong);
}

.group:hover .group-hover\:gap-2\.5 {
  gap: 0.625rem;
}
.group:hover .group-hover\:text-primary-700 {
  color: var(--color-primary-700);
}
.group:hover .group-hover\:translate-x-1 {
  transform: translateX(4px);
}

/* ---------- 组件 ---------- */

/* 亮色卡片 */
.section-card {
  position: relative;
  border-radius: 1.5rem;
  background-color: var(--color-card-background, var(--color-surface));
  border: 1px solid var(--color-card-border, var(--color-border));
  box-shadow: var(--shadow-card);
  padding: 2rem;
  margin-bottom: 2rem;
  transition:
    box-shadow 0.3s ease,
    transform 0.3s ease;
}

.section-card:hover {
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-2px);
}

/* 主按钮（与 section-hero.css 同值：客户页仅加载 base.css，需在此全局定义） */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border-radius: 999px;
  background-image: var(--gradient-primary);
  color: #ffffff;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow-glow-primary);
  transition:
    transform 0.3s,
    box-shadow 0.3s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow-primary-lg);
}

/* 次按钮（与 section-hero.css 同值：客户页仅加载 base.css，需在此全局定义） */
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 2rem;
  border-radius: 999px;
  border: 1px solid var(--color-primary-200);
  background-color: #ffffff;
  color: var(--color-primary-700);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow-sm);
  transition:
    transform 0.3s,
    border-color 0.3s,
    box-shadow 0.3s;
}

.btn-secondary:hover {
  transform: translateY(-2px);
  border-color: var(--color-primary-300);
  box-shadow: var(--shadow-lg);
}

/* 居中渐变分割线 */
.section-divider {
  position: relative;
  padding-top: 3rem;
  padding-bottom: 3rem;
}

.section-divider::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  max-width: 600px;
  height: 1px;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(59, 130, 246, 0.35) 20%,
    rgba(34, 211, 238, 0.35) 50%,
    rgba(59, 130, 246, 0.35) 80%,
    transparent 100%
  );
}

/* 滚动渐入系统（animations.js 驱动） */
.section-fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition:
    opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity, transform;
}

.section-fade-in.section-visible {
  opacity: 1;
  transform: translateY(0);
}

.section-fade-in .stagger-item {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.section-fade-in.section-visible .stagger-item {
  opacity: 1;
  transform: translateY(0);
}

.section-fade-in.section-visible .stagger-item:nth-child(1) {
  transition-delay: 0.1s;
}
.section-fade-in.section-visible .stagger-item:nth-child(2) {
  transition-delay: 0.15s;
}
.section-fade-in.section-visible .stagger-item:nth-child(3) {
  transition-delay: 0.2s;
}
.section-fade-in.section-visible .stagger-item:nth-child(4) {
  transition-delay: 0.25s;
}
.section-fade-in.section-visible .stagger-item:nth-child(5) {
  transition-delay: 0.3s;
}
.section-fade-in.section-visible .stagger-item:nth-child(6) {
  transition-delay: 0.35s;
}
.section-fade-in.section-visible .stagger-item:nth-child(7) {
  transition-delay: 0.4s;
}
.section-fade-in.section-visible .stagger-item:nth-child(8) {
  transition-delay: 0.45s;
}

/* 缩放渐入 */
.section-fade-in .scale-item {
  opacity: 0;
  transform: scale(0.95);
  transition:
    opacity 0.5s ease-out,
    transform 0.5s ease-out;
}

.section-fade-in.section-visible .scale-item {
  opacity: 1;
  transform: scale(1);
}

/* 顶部小标签 */
.eyebrow {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary-600);
}

/* 焦点环 */
.focus-visible-ring:focus-visible {
  outline: 2px solid var(--focus-ring-color);
  outline-offset: 2px;
}

/* 文本截断 */
.line-clamp-2 {
  overflow: hidden;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.line-clamp-3 {
  overflow: hidden;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}

/* 无障碍跳过链接 */
.skip-to-content-link {
  position: absolute;
  left: 1rem;
  top: 1rem;
  z-index: 100;
  padding: 0.625rem 1rem;
  border-radius: 0.75rem;
  background-color: var(--color-primary);
  color: var(--color-button-label);
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  transform: translateY(-300%);
  transition: transform 0.2s;
}

.skip-to-content-link:focus {
  transform: translateY(0);
}

/* 锚点滚动偏移补偿（配合 JS scrollToAnchor） */
#contact,
#book-demo,
.solutions-anchor,
section[id^="block-"] {
  scroll-margin-top: 80px;
}

/* ---------- 响应式工具类（对齐 Tailwind sm/md/lg/xl 断点） ---------- */
@media (min-width: 640px) {
  .sm\:grid-cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .sm\:px-6 {
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
  .sm\:py-16 {
    padding-top: 4rem;
    padding-bottom: 4rem;
  }
  .sm\:py-24 {
    padding-top: 6rem;
    padding-bottom: 6rem;
  }
  .sm\:text-2xl {
    font-size: 1.5rem;
    line-height: 2rem;
  }
  .sm\:text-3xl {
    font-size: 1.875rem;
    line-height: 2.25rem;
  }
  .sm\:text-5xl {
    font-size: 3rem;
    line-height: 1;
  }
}

@media (min-width: 768px) {
  :root {
    --page-padding: 2rem;
  }

  .md\:col-span-2 {
    grid-column: span 2 / span 2;
  }
  .md\:col-span-3 {
    grid-column: span 3 / span 3;
  }
  .md\:grid-cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .md\:grid-cols-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .md\:grid-cols-5 {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
  .md\:p-7 {
    padding: 1.75rem;
  }
  .md\:px-6 {
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
  .md\:py-16 {
    padding-top: 4rem;
    padding-bottom: 4rem;
  }
  .md\:text-4xl {
    font-size: 2.25rem;
    line-height: 2.5rem;
  }
  .md\:text-5xl {
    font-size: 3rem;
    line-height: 1;
  }
  .md\:text-lg {
    font-size: 1.125rem;
    line-height: 1.75rem;
  }
  .md\:text-xl {
    font-size: 1.25rem;
    line-height: 1.75rem;
  }
}

@media (min-width: 1024px) {
  .lg\:block {
    display: block;
  }
  .lg\:grid-cols-2 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .lg\:grid-cols-3 {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .lg\:grid-cols-4 {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .lg\:grid-cols-5 {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
  .lg\:gap-6 {
    gap: 1.5rem;
  }
  .lg\:gap-16 {
    gap: 4rem;
  }
  .lg\:px-8 {
    padding-left: 2rem;
    padding-right: 2rem;
  }
  .lg\:px-16 {
    padding-left: 4rem;
    padding-right: 4rem;
  }
  .lg\:py-20 {
    padding-top: 5rem;
    padding-bottom: 5rem;
  }
  .lg\:py-28 {
    padding-top: 7rem;
    padding-bottom: 7rem;
  }
}

@media (min-width: 1280px) {
  .xl\:px-12 {
    padding-left: 3rem;
    padding-right: 3rem;
  }
  .xl\:text-6xl {
    font-size: 3.75rem;
    line-height: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .section-card,
  .btn-primary,
  .btn-secondary,
  .section-fade-in,
  .section-fade-in .scale-item,
  .section-fade-in .stagger-item {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .transition,
  .transition-all,
  .transition-colors,
  .transition-transform {
    transition: none;
  }
}