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

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: #ffffff;
  color: #011925;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

img { display: block; }

/* ============================================================
   导航（1920 基准：图标 44，字 28/600/#193261，左边距 200）
   ============================================================ */
.nav {
  display: flex;
  align-items: center;
  height: 4.583vw;              /* 88 */
  padding: 0 10.417vw;          /* 200 */
}
.nav-icon { width: 2.292vw; height: 2.292vw; border-radius: 0.625vw; }  /* 44 / r12 */
.nav-brand {
  margin-left: 0.417vw;          /* 8 */
  font-size: clamp(17px, 1.458vw, 28px);
  font-weight: 600;
  color: #193261;
  line-height: 1;
  letter-spacing: 0;
}

/* ============================================================
   主视觉（1920 基准的按比例缩放布局）
   ============================================================ */
.hero { position: relative; height: 44.375vw; }   /* 852 */

/* 左侧装饰椭圆 886x404 #E2FDF0 @ (160,212) hero-rel */
.deco-desktop {
  position: absolute;
  left: 8.333vw;                /* 160 */
  top: 11.042vw;                /* 212 */
  width: 46.146vw;              /* 886 */
  height: 21.875vw;             /* 420（设计稿视觉高度 ≈420） */
}
.deco-mobile { display: none; }

/* App 图标 160x160 r28 @ (200,120) hero-rel */
.app-icon {
  position: absolute;
  left: 10.417vw;               /* 200 */
  top: 6.25vw;                 /* 120 */
  width: 8.333vw;
  height: 8.333vw;
  border-radius: 1.458vw;       /* 28 */
}

/* 标题「云小言APP」48/600 */
.title {
  position: absolute;
  left: 10.417vw;               /* 200 */
  top: 17.708vw;                /* 340 (ink 429.5 → 块顶约 426) */
  margin: 0;
  font-size: clamp(28px, 2.5vw, 48px);
  font-weight: 600;
  color: #011925;
  line-height: 1;
  letter-spacing: 0;
}

/* 正文 24/400 行高 40 字距 2.4，宽 880 @ (200,436) hero-rel */
.body-wrap { position: static; }
.desc {
  position: absolute;
  left: 10.417vw;               /* 200 */
  top: 22.708vw;                /* 436 (ink 534 → 块顶约 524) */
  margin: 0;
  width: 45.833vw;              /* 880 */
  font-size: clamp(15px, 1.25vw, 24px);
  font-weight: 400;
  line-height: clamp(26px, 2.083vw, 40px);
  letter-spacing: clamp(1.4px, 0.125vw, 2.4px);
  color: #102A13;
}

/* 右侧艺术字 560x370 @ (1219,120) hero-rel */
.art { position: absolute; left: 63.49vw; top: 6.25vw; }
.art img { width: 29.167vw; height: auto; }

/* ============================================================
   Footer 140 高纯黑（24.5 / 20 / 31 / 14 / 19 / 14 / 17.5）
   ============================================================ */
.footer {
  background: #000000;
  color: #ffffff;
  text-align: center;
  padding: 1.276vw 0 0.911vw;   /* 24.5 / 17.5 */
}
.footer p { margin: 0; line-height: 1; }
.footer .contact {
  font-size: clamp(14px, 1.042vw, 20px);
  font-weight: 500;
  margin-bottom: 1.615vw;       /* 31 */
}
.footer .copyright,
.footer .copyright-en {
  font-size: clamp(11px, 0.729vw, 14px);
  font-weight: 400;
}
.footer .copyright { margin-bottom: 0.99vw; }   /* 19 */

/* ============================================================
   手机端（<1024px，375 基准）
   ============================================================ */
@media (max-width: 1023px) {
  .deco-desktop { display: none; }

  /* 导航 9/20/9 padding，图标 40，字 18 */
  .nav {
    height: auto;
    padding: 9px 20px 9px 20px;
  }
  .nav-icon { width: 40px; height: 40px; border-radius: 12px; }
  .nav-brand { margin-left: 8px; font-size: 18px; }

  /* 主视觉改为流式居中列 */
  .hero { height: auto; padding-bottom: 81px; position: relative; }

  .app-icon {
    position: static;
    width: 88px;
    height: 88px;
    border-radius: 16px;
    margin: 40px auto 0;
  }

  .title {
    position: static;
    margin: 26px auto 0;
    text-align: center;
    font-size: 24px;
    font-weight: 500;
    line-height: 1;
  }

  /* 装饰椭圆贴住正文块，随正文行数变化 */
  .body-wrap {
    position: relative;
    margin-top: 20px;
  }
  .deco-mobile {
    display: block;
    position: absolute;
    left: 50%;
    top: 0;
    transform: translateX(-50%);
    width: min(94.67vw, 440px);   /* 375-10-10 = 355 */
    height: min(47.47vw, 220px);  /* 178 */
  }
  .desc {
    position: relative;
    left: auto; top: auto;        /* 清掉桌面端的绝对定位偏移 */
    margin: 0 auto;
    width: auto;
    padding: 0 24px;              /* (375-327)/2 */
    max-width: 420px;
    font-size: 14px;
    letter-spacing: 1.4px;
    line-height: 24px;
    text-align: center;
  }

  .art {
    position: static;
    display: block;
    margin: 68px auto 0;
  }
  .art img { width: min(92.27vw, 346px); height: auto; margin: 0 auto; }

  /* Footer 172 高纯黑（34 / 16 / 37 / 12 / 23 / 12 / 38） */
  .footer { padding: 34px 0 38px; }
  .footer .contact { font-size: 16px; margin-bottom: 37px; }
  .footer .copyright,
  .footer .copyright-en { font-size: 12px; }
  .footer .copyright { margin-bottom: 23px; }
}