* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}
/* 关键：锚点全局偏移，导航54px，预留70px安全距离 */
html {
    scroll-behavior: smooth;
    scroll-padding-top: 70px;
}
img {
    max-width: 100%;
    height: auto;
}
body {
    background: linear-gradient(180deg, #f0f7ff 0%, #ffffff 48%, #f7fafc 100%);
    color: #1f2937;
    font-family: system-ui, -apple-system, Helvetica, sans-serif;
    line-height: 1.65;
    padding-top: 54px;
    padding-bottom: 50px;
}
/* 顶部固定导航 */
.top-navbar{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 54px;
    background:#ffffff;
    box-shadow:0 2px 10px rgba(37, 99, 235, 0.08);
    z-index:9998;
}
.nav-inner{
    max-width:620px;
    margin:0 auto;
    height:100%;
    display:flex;
    align-items:center;
    justify-content: space-around;
    padding:0 12px;
}
.nav-item{
    font-size:14px;
    color:#475569;
    text-decoration:none;
    padding:4px 6px;
    border-radius:6px;
}
.nav-item.active{
    color:#2563eb;
    font-weight:600;
    background:#f0f7ff;
}
.app-container {
    max-width: 620px;
    margin: 0 auto;
    padding: 14px;
}
.card {
    border-radius: 16px;
    padding: 20px 16px;
    margin-bottom: 16px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    box-shadow: 0 6px 20px rgba(30, 64, 175, 0.06);
}
.hero-section {
    position: relative;
    text-align: center;
    padding: 28px 16px 22px;
    background: linear-gradient(180deg, #eaf4ff 0%, #ffffff 100%);
    border-radius: 18px;
    margin-bottom: 16px;
    overflow: hidden;
}
.hero-section::before {
    content: "";
    position: absolute;
    left: -20%;
    top: -10%;
    width: 140%;
    height: 140%;
    background: radial-gradient(circle at 10% 10%, rgba37, 99, 235, 0.08), transparent 24%),
                radial-gradient(circle at 90% 20%, rgba(59, 130, 246, 0.06), transparent 28%);
    pointer-events: none;
}
.security-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    background: #dbeafe;
    color: #1d4ed8;
    font-size: 12px;
    padding: 3px 10px;
    border-radius: 16px;
    font-weight: 500;
    z-index: 2;
}
.logo-area {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 6px;
}
.app-logo-img {
    border-radius: 12px;
    width: 70px;
    height: 70px;
    object-fit: cover;
    box-shadow: 0 6px 18px rgba(30, 64, 175, 0.14);
    background: #f3f4f6;
}
.app-title h1 {
    font-size: 24px;
    font-weight: 700;
    color: #1e40af;
    letter-spacing: 0.6px;
}
.app-subtitle {
    position: relative;
    z-index: 2;
    font-size: 14px;
    color: #64748b;
    margin-top: 4px;
}
.hero-downloads {
    position: relative;
    z-index: 2;
    margin-top: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.dl-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    background: linear-gradient(90deg, #2563eb, #3b82f6);
    color: #fff;
    text-decoration: none;
    border-radius: 12px;
    padding: 12px;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.22s ease;
    min-height: 46px;
}
.dl-btn:active {
    transform: scale(0.97);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.dl-btn.secondary {
    background: #ffffff;
    color: #2563eb;
    border: 1px solid #bfdbfe;
}
.dl-icon {
    width: 19px;
    height: 19px;
}
.dl-icon svg {
    width: 100%;
    height: 100%;
    fill: currentColor;
}
.invite-section {
    padding: 20px 16px;
    background: linear-gradient(135deg, #ffffff 0%, #f0f7ff 100%);
    border: 1px solid #bfdbfe;
}
.invite-header {
    font-size: 16px;
    color: #1e40af;
    margin-bottom: 14px;
    font-weight: 700;
    text-align: center;
}
.invite-box {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    flex-wrap: wrap;
    padding: 14px 16px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
}
.invite-left {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
    min-width: 0;
}
.invite-label {
    font-size: 15px;
    color: #374151;
}
.invite-code {
    color: #2563eb;
    font-weight: 700;
    font-size: 19px;
    letter-spacing: 1.4px;
}
.copy-btn {
    background: linear-gradient(90deg, #2563eb, #3b82f6);
    color: #fff;
    border: none;
    padding: 6px 14px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.22s ease;
    min-height: 38px;
}
.copy-btn:active {
    transform: scale(0.95);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}
.invite-tip {
    margin-top: 10px;
    font-size: 13px;
    color: #64748b;
    text-align: center;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 16px;
}
.feature-item {
    padding: 14px 10px;
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    text-align: center;
}
.feature-icon {
    width: 26px;
    height: 26px;
    margin: 0 auto 8px;
    color: #2563eb;
}
.feature-icon svg {
    width: 100%;
    height: 100%;
    fill: currentColor;
}
.feature-title {
    font-size: 14px;
    font-weight: 600;
    color: #1f2937;
}
.feature-desc {
    font-size: 12px;
    color: #64748b;
    margin-top: 3px;
}
.seo-content {
    padding: 18px 16px;
    line-height: 1.75;
    font-size: 14.5px;
    color: #475569;
    margin-bottom: 16px;
}
.seo-content h2 {
    margin: 16px 0 8px;
    color: #1e40af;
    font-size: 18px;
}
.seo-content h3 {
    margin:14px 0 7px;
    color:#254b9c;
    font-size:16px;
}
.seo-content ul {
    padding-left: 22px;
}
.seo-content p {
    margin-bottom: 9px;
}
.friend-link {
    padding: 18px 16px;
}
.friend-link-title {
    font-size: 16px;
    color: #1e40af;
    margin-bottom: 12px;
    font-weight: 700;
}
.friend-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.friend-list a {
    padding: 5px 12px;
    border: 1px solid #bfdbfe;
    color: #2563eb;
    text-decoration: none;
    border-radius: 8px;
    font-size: 13px;
    transition: 0.2s;
    background: #f0f7ff;
}
.friend-list a:hover {
    background: #dbeafe;
}
.main-footer {
    text-align: center;
    font-size: 12.5px;
    color: #64748b;
    padding: 10px 0;
}
#weixin-tip {
    position: fixed;
    left: 0;
    top: 0;
    background: rgba(15, 23, 42, 0.92);
    width: 100%;
    height: 100%;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.weixin-box {
    text-align: center;
}
.weixin-box p {
    color: #e2e8f0;
    font-size: 15px;
    margin-top: 20px;
    line-height: 1.7;
}
.toast {
    position: fixed;
    left: 50%;
    top: 42%;
    transform: translate(-50%, -50%);
    background: rgba(15, 23, 42, 0.88);
    border: 1px solid #3b82f6;
    color: #fff;
    padding: 10px 20px;
    border-radius: 10px;
    font-size: 14px;
    z-index: 99999;
    display: none;
}
/* 返回顶部悬浮按钮 */
#backTop {
    position: fixed;
    right: 14px;
    bottom: 22px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: #ffffff;
    border: 1px solid #bfdbfe;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 998;
    opacity: 0;
    visibility: hidden;
    transition: 0.24s ease;
    box-shadow: 0 3px 10px rgba(37, 99, 235, 0.12);
}
#backTop.show {
    opacity: 1;
    visibility: visible;
}
#backTop svg {
    width: 20px;
    height: 20px;
    fill: #2563eb;
}
#backTop:active {
    transform: scale(0.92);
}
/* 底部安全留白，避免悬浮按钮遮挡内容 */
.safe-bottom {
    height:60px;
}