* {
    padding: 0;
    margin: 0;
    -webkit-user-drag: none;
    user-select: none;
    box-sizing: border-box;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    width: 100%;
    height: 100%;
}

.desktop {
    position: relative;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

/* ============ 背景轮播 ============ */
.bg-carousel {
    position: absolute;
    inset: 0;
    z-index: 0;
    overflow: hidden;
}

.bg-track {
    display: flex;
    width: 400%;
    height: 100%;
    transition: transform 0.7s ease;
    will-change: transform;
}

.bg-track.no-transition {
    transition: none;
}

.bg-track[data-idx="0"] {
    transform: translateX(0);
}

.bg-track[data-idx="1"] {
    transform: translateX(-25%);
}

.bg-track[data-idx="2"] {
    transform: translateX(-50%);
}

.bg-track[data-idx="3"] {
    transform: translateX(-75%);
}

.bg-img {
    position: relative;
    width: 25%;
    height: 100%;
    flex-shrink: 0;
    background-repeat: no-repeat;
    background-position: top center;
    background-size: cover;
}

.title-img {
    position: absolute;
    left: 50%;
    bottom: 5vw;
    transform: translateX(-50%);
    width: 32vw;
    max-width: 600px;
    height: auto;
    object-fit: contain;
    pointer-events: none;
    filter: drop-shadow(0 6px 18px rgba(0, 0, 0, 0.35));
}

/* ============ 覆盖层 ============ */
.overlay {
    position: absolute;
    inset: 0;
    z-index: 2;
    pointer-events: none;
}

.overlay>* {
    pointer-events: auto;
}

/* 顶部 logo + 按钮 */
.header {
    position: absolute;
    top: 2vw;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5vw 7.5vw;
    gap: 2vw;
}

.logo {
    height: 4.5vw;
    width: auto;
    object-fit: contain;
    flex-shrink: 0;
}

.contact {
    display: flex;
    align-items: center;
    gap: 1vw;
}

.nav-btn {
    width: 7vw;
    height: auto;
    object-fit: contain;
    cursor: pointer;
    transition: transform 0.2s, opacity 0.2s;
}

.nav-btn:active {
    transform: scale(0.97);
    opacity: 0.85;
}

/* 右下角：灰底 + 左右布局（左二维码 / 右安装提示） */
.qr-block {
    position: absolute;
    right: 14vw;
    bottom: 2vw;
    display: flex;
    align-items: center;
    gap: 0.8vw;
    padding: 0.8vw 1vw;
    background: rgba(112, 111, 111, 0.55);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    border: 1px solid #fff;
    border-radius: 0.4vw;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.25);
}

.qrcode-box {
    width: 6vw;
    aspect-ratio: 1;
    background: #fff;
    padding: 0.3vw;
    border-radius: 0.3vw;
    flex-shrink: 0;
}

.qrcode-box #qrcode {
    width: 100%;
    height: 100%;
}

.qrcode-box #qrcode img,
.qrcode-box #qrcode canvas {
    width: 100% !important;
    height: 100% !important;
    display: block;
}

.tip-img {
    width: 9vw;
    height: auto;
    object-fit: contain;
    display: block;
}