/* ============================================================
   QxBit Studio — 设计系统
   配色：纯黑白 + 单一强调色用于功能性强调
   排版：Inter，高字重对比，紧凑字距
   ============================================================ */

/* ----- 自定义属性 ----- */
:root {
  --black: #0a0a0a;
  --white: #f5f5f5;
  --white-pure: #ffffff;
  --gray-900: #1a1a1a;
  --gray-800: #2a2a2a;
  --gray-200: #e0e0e0;
  --gray-100: #f0f0f0;
  --accent: #ff3300;
  --accent-dim: rgba(255, 51, 0, 0.15);

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --leading: 1.6;
  --leading-tight: 1.15;

  --nav-h: 64px;
  --max-w: 1200px;
  --radius: 2px;

  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
}

/* 西里尔字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic-ext.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* 西里尔字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* 希腊字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-greek-ext.woff2) format('woff2');
  unicode-range: U+1F00-1FFF;
}
/* 希腊字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-greek.woff2) format('woff2');
  unicode-range: U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF;
}
/* 越南文 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* 拉丁字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* 拉丁字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 300;
  font-display: swap;
  src: url(../fonts/Inter-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* 西里尔字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic-ext.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* 西里尔字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* 希腊字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-greek-ext.woff2) format('woff2');
  unicode-range: U+1F00-1FFF;
}
/* 希腊字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-greek.woff2) format('woff2');
  unicode-range: U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF;
}
/* 越南文 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* 拉丁字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* 拉丁字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(../fonts/Inter-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* 西里尔字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic-ext.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* 西里尔字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* 希腊字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-greek-ext.woff2) format('woff2');
  unicode-range: U+1F00-1FFF;
}
/* 希腊字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-greek.woff2) format('woff2');
  unicode-range: U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF;
}
/* 越南文 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* 拉丁字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* 拉丁字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url(../fonts/Inter-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* 西里尔字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic-ext.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* 西里尔字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* 希腊字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-greek-ext.woff2) format('woff2');
  unicode-range: U+1F00-1FFF;
}
/* 希腊字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-greek.woff2) format('woff2');
  unicode-range: U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF;
}
/* 越南文 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* 拉丁字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* 拉丁字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(../fonts/Inter-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* 西里尔字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic-ext.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* 西里尔字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-cyrillic.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* 希腊字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-greek-ext.woff2) format('woff2');
  unicode-range: U+1F00-1FFF;
}
/* 希腊字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-greek.woff2) format('woff2');
  unicode-range: U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF;
}
/* 越南文 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* 拉丁字母扩展 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* 拉丁字母 */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 900;
  font-display: swap;
  src: url(../fonts/Inter-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}


/* ----- 重置与基础 ----- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--gray-800) var(--black);
}

body {
  font-family: var(--font);
  font-weight: 400;
  font-size: 16px;
  line-height: var(--leading);
  color: var(--black);
  background: var(--white-pure);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
  list-style: none;
}

/* ----- 选中 ----- */
::selection {
  background: var(--black);
  color: var(--white);
}

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

/* ============================================================
   导航栏
   ============================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-h);
  background: #000;
  transition: background 0.4s var(--ease-out);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 40px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  color: var(--white);
  transition: opacity 0.25s ease;
}
.nav-logo:hover {
  opacity: 0.7;
}
.logo-symbol {
  color: var(--white);
}
.logo-symbol circle {
  color: var(--accent);
}

/* 菜单 */
.nav-menu {
  display: flex;
  gap: 48px;
}
.nav-link {
  position: relative;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--white-pure);
  padding: 4px 0;
  transition: color 0.25s ease;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s var(--ease-out);
}
.nav-link:hover {
  color: var(--white-pure);
}
.nav-link:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}
.nav-link.nav-link--active {
  color: var(--white-pure);
}
.nav-link.nav-link--active::after {
  transform: scaleX(1);
}
/* 外部链接微妙指示符 */
.nav-link--external::before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 6px;
  background: currentColor;
  opacity: 0.3;
  clip-path: polygon(0 0, 100% 0, 100% 100%);
  vertical-align: middle;
  position: relative;
  top: -1px;
}

/* ============================================================
   首屏
   ============================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--white-pure);
  position: relative;
  overflow: hidden;
  padding: 120px 40px 80px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}
/* 微妙点阵纹理 */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: radial-gradient(circle, rgba(0, 0, 0, 0.06) 1px, transparent 1px);
  background-size: 20px 20px;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 20%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black 20%, transparent 100%);
}
/* 角落几何标记 */
.hero::after {
  content: '';
  position: absolute;
  pointer-events: none;
  top: 48px;
  right: 48px;
  width: 40px;
  height: 40px;
  border-top: 2px solid var(--accent);
  border-right: 2px solid var(--accent);
  opacity: 0.12;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
  max-width: var(--max-w);
  width: 100%;
}

/* 几何装饰 */
.hero-geo {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}
/* 左下角呼应标记 */
.hero-geo::after {
  content: '';
  position: absolute;
  pointer-events: none;
  bottom: -12px;
  left: -12px;
  width: 40px;
  height: 40px;
  border-bottom: 2px solid var(--accent);
  border-left: 2px solid var(--accent);
  opacity: 0.12;
}
.hero-geo-svg {
  width: min(440px, 58vw);
  height: auto;
  color: var(--black);
  opacity: 1;
}

/* ----- SVG 绘制动画 ----- */
/* 初始状态：所有动画元素在动画开始前不可见 */
.hero-geo-svg .draw-stroke {
  stroke-dasharray: var(--plen);
  stroke-dashoffset: var(--plen);
  animation: geoDrawStroke 1.6s var(--ease-out) forwards;
  animation-delay: var(--d, 0s);
}
@keyframes geoDrawStroke {
  to { stroke-dashoffset: 0; }
}

.hero-geo-svg .draw-fade {
  opacity: 0;
  animation: geoDrawFade 1.0s var(--ease-out) forwards;
  animation-delay: var(--d, 0s);
}
@keyframes geoDrawFade {
  to { opacity: var(--to, 1); }
}

.hero-geo-svg .draw-dot {
  opacity: 0;
  transform-origin: var(--ox, center);
  transform-box: fill-box;
  animation: geoDrawDot 0.8s var(--ease-out) forwards;
  animation-delay: var(--d, 0s);
}
@keyframes geoDrawDot {
  0%   { opacity: 0; transform: scale(0); }
  60%  { opacity: 1; transform: scale(1.3); }
  100% { opacity: var(--to, 1); transform: scale(1); }
}

/* 文字 */
.hero-text {
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: relative;
}
/* 文字区背景装饰 — 大圆环 */
.hero-text::before {
  content: '';
  position: absolute;
  right: -60px;
  top: -40px;
  width: 200px;
  height: 200px;
  border: 1px solid rgba(0, 0, 0, 0.04);
  border-radius: 50%;
  pointer-events: none;
}
.hero-text::after {
  content: '';
  position: absolute;
  right: 20px;
  top: 20px;
  width: 80px;
  height: 80px;
  border: 1px solid rgba(0, 0, 0, 0.05);
  border-radius: 50%;
  pointer-events: none;
}

.hero-kicker {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.35em;
  color: var(--accent);
  text-transform: uppercase;
  position: relative;
  padding-left: 28px;
}
/* kicker 左侧装饰线 */
.hero-kicker::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 1px;
  background: var(--accent);
  opacity: 0.5;
}

.hero-title {
  font-size: clamp(48px, 8vw, 96px);
  font-weight: 900;
  line-height: 0.92;
  letter-spacing: -0.03em;
  color: var(--black);
  position: relative;
  padding-bottom: 0.12em;
}
/* 标题下方强调色装饰线 */
.hero-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0.35em;
  height: 3px;
  background: var(--accent);
  opacity: 0.45;
}

.hero-tagline {
  font-size: clamp(18px, 2.5vw, 26px);
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--black);
  margin-top: 4px;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'JetBrains Mono', 'Consolas', monospace;
}
.tagline-prompt {
  color: var(--accent);
  font-weight: 400;
  margin-right: 0.15em;
}
.tagline-cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--accent);
  margin-left: 2px;
  vertical-align: text-bottom;
  animation: cursorBlink 0.8s step-end infinite;
}
@keyframes cursorBlink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.hero-sub {
  font-size: 15px;
  font-weight: 400;
  color: rgba(0, 0, 0, 0.6);
  max-width: 360px;
  line-height: 1.7;
}

/* 滚动提示 */
.scroll-hint {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.scroll-line {
  display: block;
  width: 1px;
  height: 48px;
  background: rgba(0, 0, 0, 0.22);
  position: relative;
  overflow: hidden;
}
.scroll-line::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--black);
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%   { transform: translateY(-100%); }
  50%  { transform: translateY(100%); }
  100% { transform: translateY(100%); }
}

/* ============================================================
   章节标题（共享）
   ============================================================ */
.section-head {
  max-width: var(--max-w);
  margin: 0 auto 64px;
  padding: 0 40px;
}
.section-index {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.3em;
  color: var(--accent);
  text-transform: uppercase;
}
.section-title {
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 900;
  letter-spacing: -0.025em;
  line-height: 1.05;
  margin-top: 8px;
  color: var(--black);
}

/* ============================================================
   作品 / 作品集
   ============================================================ */
.works {
  padding: 120px 40px;
  background: var(--white-pure);
}

.works-grid {
  max-width: var(--max-w);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.work-card--wide {
  grid-column: 1 / -1;
}

.work-card {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}
.work-card.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 缩略图 */
.work-thumb {
  display: grid;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: var(--gray-100);
}
.work-img {
  grid-row: 1;
  grid-column: 1;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(100%) contrast(1.15) brightness(0.95);
  transition: filter 0.5s ease, transform 0.6s var(--ease-out);
  aspect-ratio: 2 / 1;
}
.work-card--wide .work-img {
  aspect-ratio: 3 / 1;
}
.work-card:hover .work-img {
  filter: grayscale(100%) contrast(1.25) brightness(0.85);
  transform: scale(1.03);
}

/* 叠加层 — 与图片共享同一 grid cell，内容自然撑开高度 */
.work-overlay {
  grid-row: 1;
  grid-column: 1;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 32px;
  background: linear-gradient(to top, rgba(0,0,0,0.55) 0%, transparent 60%);
  color: var(--white);
  pointer-events: none;
}
.work-overlay > * {
  pointer-events: auto;
}
.work-overlay--frost {
  background: rgba(0, 0, 0, 0.35);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  justify-content: center;
  align-items: flex-start;
  padding: 48px;
  overflow: hidden;
}

/* 标签 */
.work-tag {
  display: inline-block;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 4px 10px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: var(--white);
  margin-bottom: 12px;
  width: fit-content;
}
.work-tag--light {
  border-color: rgba(255, 255, 255, 0.6);
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.work-name {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}
.work-desc {
  font-size: 13px;
  font-weight: 400;
  opacity: 0.75;
  max-width: 420px;
  line-height: 1.5;
}

/* 缩略图下方信息（卡片2）*/
.work-info {
  padding: 20px 0 0;
}
.work-info .work-tag {
  color: var(--accent);
  border-color: rgba(0, 0, 0, 0.12);
  background: transparent;
  margin-bottom: 8px;
}
.work-info .work-name {
  color: var(--black);
  font-size: 22px;
}
.work-info .work-desc {
  color: rgba(0, 0, 0, 0.5);
  font-size: 13px;
}

/* ============================================================
   服务
   ============================================================ */
.services {
  padding: 120px 40px;
  background: var(--white-pure);
}

.services-list {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
}

/* 服务项 */
.service-item {
  padding: 72px 56px;
  transition: background 0.3s ease;
}
.service-item--dark {
  background: var(--black);
  color: var(--white);
}
.service-item--light {
  background: var(--white-pure);
  color: var(--black);
}

.service-inner {
  max-width: 720px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 24px 40px;
}

.service-num {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.25em;
  opacity: 0.35;
  padding-top: 2px;
}

.service-name {
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 900;
  letter-spacing: -0.025em;
  line-height: 1.1;
}

.service-desc {
  grid-column: 2;
  font-size: 15px;
  line-height: 1.7;
  opacity: 0.65;
  max-width: 520px;
}

.service-details {
  grid-column: 2;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.service-details li {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.08em;
  padding: 6px 14px;
  border: 1px solid currentColor;
  opacity: 0.4;
  transition: opacity 0.25s ease, border-color 0.25s ease;
}

/* 深色背景毛玻璃标签 */
.service-item--dark .service-details li {
  background: rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  border-color: rgba(255, 255, 255, 0.15);
}
.service-item--light .service-details li {
  background: rgba(0, 0, 0, 0.02);
  border-color: rgba(0, 0, 0, 0.1);
}

.service-item:hover .service-details li {
  opacity: 0.75;
}

/* ============================================================
   页脚
   ============================================================ */
.footer {
  background: var(--black);
  color: var(--white);
  padding: 80px 40px 32px;
}

.footer-grid {
  max-width: var(--max-w);
  margin: 0 auto 48px;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 48px;
  align-items: start;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.footer-line {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
}
.footer-line--dim {
  opacity: 0.4;
  font-weight: 400;
  font-size: 12px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-link {
  font-size: 13px;
  font-weight: 400;
  opacity: 0.5;
  transition: opacity 0.25s ease;
  width: fit-content;
}
.footer-link:hover {
  opacity: 1;
  color: var(--accent);
}

.footer-social {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-end;
}
.footer-social-label {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.35;
}
.footer-social-icons {
  display: flex;
  gap: 16px;
}
.social-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: rgba(255, 255, 255, 0.4);
  transition: color 0.25s ease, border-color 0.25s ease, background 0.25s ease;
}
.social-icon:hover {
  color: var(--white-pure);
  border-color: var(--white);
  background: rgba(255, 255, 255, 0.06);
}

.footer-bottom {
  max-width: var(--max-w);
  margin: 0 auto;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  display: flex;
  gap: 8px;
  font-size: 11px;
  font-weight: 400;
  opacity: 0.3;
  letter-spacing: 0.06em;
}
.footer-dot {
  opacity: 0.4;
}

/* ============================================================
   动画
   ============================================================ */
.fade-up {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 服务项同样获得淡入效果 */
.service-item {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out), background 0.3s ease;
}
.service-item.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
    text-align: center;
  }
  .hero-geo {
    order: -1;
  }
  .hero-geo-svg {
    width: min(260px, 50vw);
  }
  .hero-geo::after,
  .hero-kicker::before,
  .hero-title::after {
    display: none;
  }
  .hero-sub {
    margin: 0 auto;
  }

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

  .service-item {
    padding: 48px 24px;
  }
  .service-inner {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .service-desc,
  .service-details {
    grid-column: 1;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .footer-social {
    align-items: flex-start;
  }

  .nav-menu {
    gap: 28px;
  }
  .nav-inner {
    padding: 0 24px;
  }
  .section-head {
    padding: 0 24px;
  }
  .hero {
    padding: 100px 24px 60px;
  }
  .works,
  .services {
    padding: 80px 24px;
  }
  .footer {
    padding: 60px 24px 24px;
  }

  .work-overlay--frost {
    padding: 24px;
  }
  .work-overlay {
    padding: 24px;
  }

}

@media (max-width: 480px) {
  .nav-menu {
    gap: 18px;
  }
  .nav-link {
    font-size: 11px;
    letter-spacing: 0.08em;
  }
  .hero-title {
    font-size: clamp(36px, 12vw, 56px);
  }
}