* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  width: 100%;
  min-height: 100%;
  overflow-x: hidden;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: #fff;
  background: transparent;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

/* ===== 背景层：整页往上滚动（15秒） ===== */
.bg-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100vh;
  z-index: 0;
  overflow: hidden;
}

.scrolling-images {
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 200%;
  animation: scrollUp 15s linear infinite;
}

.scrolling-image {
  width: 100%;
  height: 50%;
  background-image: url(./changtu.jpg);
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  flex-shrink: 0;
}

@keyframes scrollUp {
  0%   { transform: translateY(0); }
  100% { transform: translateY(-50%); }
}

/* ===== 内容层 ===== */
.content-layer {
  position: relative;
  z-index: 1;
  width: 100%;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 14px 16px 100px;
  background: transparent;
}

/* ===== 左上角：自定义图标 + prvo ===== */
.top-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
}

.app-icon {
  width: 46px;
  height: 46px;
  border-radius: 10px;
  flex-shrink: 0;
  object-fit: cover;
  display: block;
  box-shadow: 0 4px 12px rgba(255, 51, 102, 0.5);
}

.app-name {
  font-size: 24px;
  font-weight: bold;
  color: #fff;
  letter-spacing: 1px;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
}

/* ===== 中部：加粗白色文字 ===== */
.main-content {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 20px;
}

.hero-text {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.6;
  color: #ffffff;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.75);
  padding: 0 2px;
}

/* ===== 底部缩略图 ===== */
.thumbnails {
  width: 100%;
  overflow: hidden;
  padding: 22px 0;
  margin-top: auto;
  background: transparent;
}

.thumbnails-container {
  display: flex;
  gap: 12px;
  width: max-content;
  animation: thumbScroll 26s linear infinite;
}

.thumbnail {
  width: 100px;
  height: 135px;
  object-fit: cover;
  border-radius: 12px;
  border: 2px solid #ff3366;
  flex-shrink: 0;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
}

@keyframes thumbScroll {
  0%   { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ===== 下载按钮：固定底部 ===== */
.download-button {
  position: fixed;
  left: 50%;
  bottom: 20px;
  transform: translateX(-50%);
  z-index: 999;
  display: block;
  width: 90%;
  max-width: 340px;
  padding: 16px 0;
  background: #ff3366;
  color: #fff;
  text-align: center;
  text-decoration: none;
  font-size: 18px;
  font-weight: bold;
  border-radius: 50px;
  box-shadow: 0 6px 18px rgba(255, 51, 102, 0.6);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  animation: pulseBtn 1.8s ease-in-out infinite;
}

.download-button:active {
  transform: translateX(-50%) scale(0.97);
}

.download-button span {
  display: inline-block;
}

@keyframes pulseBtn {
  0%, 100% { box-shadow: 0 6px 18px rgba(255, 51, 102, 0.5); }
  50%      { box-shadow: 0 6px 28px rgba(255, 51, 102, 0.9); }
}

/* ===== 手机小屏 ===== */
@media (max-width: 360px) {
  .app-icon { width: 42px; height: 42px; }
  .app-name { font-size: 22px; }
  .hero-text { font-size: 14px; }
  .thumbnail { width: 90px; height: 120px; }
  .download-button { font-size: 17px; padding: 14px 0; bottom: 14px; }
}

/* ===== 电脑上居中限宽 ===== */
@media (min-width: 768px) {
  .content-layer {
    max-width: 480px;
    margin: 0 auto;
  }
}