:root {
  --bg: #070a0f;
  --bg-1: #090d13;
  --bg-2: #0c1119;
  --surface: #0f1620;
  --surface-2: #121b27;
  --surface-3: #162130;
  --line: rgba(76, 52, 52, 0.13);
  --line-strong: rgba(76, 52, 52, 0.24);
  --text: #eef3f9;
  --text-soft: #c7d1df;
  --muted: #8592a6;
  --muted-2: #5e6b7d;
  --accent: #a33036;
  --accent-soft: #d07872;
  --accent-dim: rgba(163, 48, 54, 0.1);
  --gold: #d9b678;
  --danger: #ff8b9b;
  --paper: #eef1f5;
  --paper-ink: #111820;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --font-mono: 'SFMono-Regular', 'Cascadia Code', 'Roboto Mono', Consolas, 'Liberation Mono', monospace;
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --container: 1240px;
  --header-h: 76px;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);

  /* 顶部导航与 LOGO 统一尺寸：只改这里，全站页头同步生效 */
  --fs-nav: 16px;          /* 顶部菜单字号 */
  --brand-mark: 48px;      /* LOGO 图形尺寸（盒子与图形同尺寸，避免留白） */
  --brand-mark-icon: 48px; /* LOGO 图形本体尺寸 */
  --brand-gap: 10px;       /* LOGO 与品牌文字的间距 */
  --brand-name-fs: 22px;   /* 品牌中文名 */
  --brand-sub-fs: 12px;    /* 品牌英文副标 */
  --brand-name-ls: 0.08em; /* 品牌中文名字距 */
  --brand-sub-ls: 0.2em;   /* 品牌英文副标字距 */
  --brand-stroke: 2.1;     /* LOGO 线条粗细 */

  /* 全站区块标题（H2）唯一字号来源：改这一处即全局生效 */
  --fs-section-title: clamp(29px, 3.4vw + 12px, 48px);
  --lh-section-title: 1.18;

  /* 全站正文字号阶梯（UI 标准）——详见 ui-standard.html */
  --fs-body-lg: 16px; /* 正文·大：首屏导语、表单输入 */
  --fs-body: 15px;    /* 正文：段落、列表、卡片描述 */
  --fs-sm: 14px;      /* 次要正文：卡片说明、表格内容、导航 */
  --fs-xs: 13px;      /* 辅助说明：注释、脚注、表单提示 */
  --fs-micro: 12px;   /* 最小字号：眉标、编号、图注、标签 */
  --lh-body: 1.85;    /* 正文行高 */
  --lh-sm: 1.75;      /* 次要正文行高 */
  --lh-tight: 1.5;    /* 单行标签行高 */
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 112px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

body.menu-open {
  overflow: hidden;
}

::selection {
  background: var(--accent);
  color: #fff8f5;
}

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

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

img,
svg {
  display: block;
}

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

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.03em;
}

p {
  text-wrap: pretty;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 1000;
  transform: translateY(-150%);
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff8f5;
  font-size: var(--fs-body);
  font-weight: 700;
}

.skip-link:focus {
  transform: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.page-grain {
  position: fixed;
  inset: 0;
  z-index: 999;
  pointer-events: none;
  opacity: 0.028;
  background-image: url('data:image/svg+xml,%3Csvg viewBox=%220 0 180 180%22 xmlns=%22http://www.w3.org/2000/svg%22%3E%3Cfilter id=%22n%22%3E%3CfeTurbulence type=%22fractalNoise%22 baseFrequency=%22.85%22 numOctaves=%223%22 stitchTiles=%22stitch%22/%3E%3C/filter%3E%3Crect width=%22100%25%22 height=%22100%25%22 filter=%22url(%23n)%22 opacity=%22.45%22/%3E%3C/svg%3E');
}

.container {
  width: min(calc(100% - 48px), var(--container));
  margin-inline: auto;
}

.section {
  position: relative;
  padding: 128px 0;
}

.section-heading {
  margin-bottom: 64px;
}

.section-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 26px;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.section-kicker span {
  color: var(--accent);
}

.section-kicker::after {
  content: '';
  width: 56px;
  height: 1px;
  background: var(--line-strong);
}

.section-heading__row {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(280px, 0.7fr);
  gap: 56px;
  align-items: end;
}

.section-heading h2 {
  max-width: 760px;
  font-size: var(--fs-section-title);
  line-height: var(--lh-section-title);
  letter-spacing: -0.045em;
}

.section-heading__row > p {
  max-width: 430px;
  padding-bottom: 6px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 26px;
  color: var(--text-soft);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.eyebrow__dot {
  position: relative;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 5px rgba(163, 48, 54, 0.08);
}

.eyebrow__dot::after {
  content: '';
  position: absolute;
  inset: -5px;
  border: 1px solid rgba(163, 48, 54, 0.24);
  border-radius: inherit;
  animation: pulse 3s ease-out infinite;
}

@keyframes pulse {
  0% { transform: scale(0.7); opacity: 0.8; }
  70% { transform: scale(1.7); opacity: 0; }
  100% { transform: scale(1.7); opacity: 0; }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 50px;
  padding: 0 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: var(--fs-body);
  font-weight: 650;
  line-height: 1;
  letter-spacing: 0.01em;
  transition: background 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn svg {
  width: 16px;
  height: 16px;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn--primary {
  background: var(--accent);
  color: #fff8f5;
  box-shadow: 0 8px 32px rgba(163, 48, 54, 0.18);
}

.btn--primary:hover {
  background: var(--accent-soft);
  box-shadow: 0 12px 40px rgba(163, 48, 54, 0.26);
}

.btn--ghost {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.02);
  color: var(--text);
}

.btn--ghost:hover {
  border-color: rgba(76, 52, 52, 0.42);
  background: rgba(255, 255, 255, 0.045);
}

.btn--sm {
  min-height: 40px;
  padding: 0 17px;
  font-size: var(--fs-sm);
}

.btn--wide {
  width: 100%;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-size: var(--fs-body);
  font-weight: 600;
  border-bottom: 1px solid var(--line-strong);
  padding-bottom: 4px;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.text-link span {
  color: var(--accent);
  transition: transform 0.2s ease;
}

.text-link:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.text-link:hover span {
  transform: translate(2px, -2px);
}

.reveal {
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}

.js .reveal {
  opacity: 0;
  transform: translateY(26px);
}

.js .reveal.is-visible {
  opacity: 1;
  transform: none;
}

.js .reveal[data-reveal-delay='1'] {
  transition-delay: 0.12s;
}

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  border-bottom: 1px solid transparent;
  transition: background 0.3s ease, border-color 0.3s ease, backdrop-filter 0.3s ease;
}

.site-header.is-scrolled {
  background: rgba(7, 10, 15, 0.84);
  border-color: var(--line);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--brand-gap);
  flex: 0 0 auto;
  min-height: 44px;
}

/* LOGO：纯图形，无底色、无描边、无投影 */
.brand__mark {
  display: grid;
  place-items: center;
  width: var(--brand-mark);
  height: var(--brand-mark);
  border: 0;
  border-radius: 0;
  background: none;
  box-shadow: none;
  color: var(--accent);
}

.brand__mark svg {
  width: var(--brand-mark-icon);
  height: var(--brand-mark-icon);
}

/* 覆盖 HTML 里的 stroke-width 呈现属性，统一加粗线条 */
.brand__mark svg path {
  stroke-width: var(--brand-stroke);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand__text strong {
  font-size: var(--brand-name-fs);
  font-weight: 650;
  letter-spacing: var(--brand-name-ls);
}

.brand__text small {
  color: var(--muted-2);
  font-family: var(--font-mono);
  font-size: var(--brand-sub-fs);
  letter-spacing: var(--brand-sub-ls);
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 30px;
  margin-left: auto;
  color: var(--muted);
  font-size: var(--fs-nav);
}

.desktop-nav a {
  position: relative;
  padding: 6px 0;
  transition: color 0.2s ease;
}

.desktop-nav a::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.desktop-nav a:hover,
.desktop-nav a.is-active {
  color: var(--text);
}

.desktop-nav a:hover::after,
.desktop-nav a.is-active::after {
  transform: scaleX(1);
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.menu-button {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: transparent;
  color: var(--text);
}

.menu-button span {
  width: 16px;
  height: 1px;
  background: currentColor;
  transition: transform 0.25s ease;
}

body.menu-open .menu-button span:first-child {
  transform: translateY(3px) rotate(45deg);
}

body.menu-open .menu-button span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 90;
  padding-top: var(--header-h);
  background: rgba(7, 10, 15, 0.98);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s var(--ease);
}

.mobile-menu.is-open {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.mobile-menu__inner {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  width: min(calc(100% - 48px), 700px);
  height: 100%;
  margin-inline: auto;
  padding: 22px 0 40px;
  overflow-y: auto;
}

.mobile-menu__nav {
  display: flex;
  flex-direction: column;
}

.mobile-menu__nav a {
  display: flex;
  align-items: flex-start;
  gap: 22px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
  font-size: clamp(24px, 6vw, 34px);
  font-weight: 600;
  letter-spacing: -0.035em;
}

.mobile-menu__nav a span {
  padding-top: 8px;
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.12em;
}

.mobile-menu__foot {
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding-top: 40px;
}

.mobile-menu__foot p {
  color: var(--muted);
  font-size: var(--fs-body);
}

.mobile-menu__foot .btn {
  width: 100%;
}

.site-footer {
  position: relative;
  padding: 76px 0 30px;
  border-top: 1px solid var(--line);
  background: var(--bg-1);
}

.footer__main {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.3fr);
  gap: 80px;
  padding-bottom: 68px;
}

.footer__brand p {
  max-width: 300px;
  margin-top: 24px;
  color: var(--muted);
  font-size: var(--fs-body);
  line-height: 1.8;
}

.footer__nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 32px;
}

.footer__nav div {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer__nav div > span:first-child {
  margin-bottom: 4px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.footer__nav a,
.footer__nav div > span:not(:first-child) {
  color: var(--muted);
  font-size: var(--fs-body);
}

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

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 34px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  color: var(--muted-2);
  font-size: var(--fs-xs);
  line-height: 1.7;
}

.footer__risk {
  flex-basis: 100%;
  max-width: 820px;
}

.mobile-cta {
  display: none;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

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

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

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