/* 背景为 1080p 设计稿，视口内自适应；Logo 居中且相对位置随缩放保持 */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  min-height: 100dvh;
}

body {
  overflow: hidden;
}

/* 页面层：铺满视口，背景图按 1080p 比例自适应 */
.page {
  position: relative;
  width: 100vw;
  min-height: 100vh;
  min-height: 100dvh;
  background-image: url("../images/background.png");
  background-repeat: no-repeat;
  background-position: center;
  background-size: cover;
}

/* 品牌区：以 1920px 宽为基准，Logo 宽 1012px，随窗口宽度同比例缩放 */
.brand {
  position: absolute;
  left: 50%;
  top: 32%;
  transform: translate(-50%, 0);
  width: min(1012px, calc(1012 * 100vw / 1920));
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.logo {
  width: 100%;
  height: auto;
  display: block;
  object-fit: contain;
}

.slogan {
  margin: 0;
  margin-top: 15px;
  font-family: "PingFang SC";
  font-size: min(32px, calc(32 * 100vw / 1920));
  font-weight: 400;
  color: rgba(255, 255, 255, 1);
  text-align: center;
  white-space: nowrap;
}

@media (max-width: 480px) {
  .slogan {
    white-space: normal;
  }
}

.copyright {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 20px;
  z-index: 10;
  text-align: center;
  font-size: 12px;
  color: rgba(255, 255, 255, 0.9);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.45);
}

.copyright a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.55);
  padding-bottom: 1px;
  transition: color 0.2s ease, border-color 0.2s ease, opacity 0.2s ease;
  opacity: 0.92;
}

.copyright a:hover {
  color: #ffffff;
  border-bottom-color: rgba(255, 255, 255, 0.9);
  opacity: 1;
}