/* FAQ / 帮助中心 —— 视觉与 AppDownload 下载页、ApkLanding 落地页一致(浅蓝渐变 + 白卡),无广告位 */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { width: 100%; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: linear-gradient(to bottom, #E4EEF6 0%, #C9DDF4 100%);
    background-attachment: fixed;
    min-height: 100vh;
    color: #2B3A4A;
    -webkit-font-smoothing: antialiased;
    padding-bottom: calc(40px + env(safe-area-inset-bottom));
}

/* 顶部背景线稿:与落地页同一张图、同一处理方式 */
.top_image {
    position: absolute; top: 0; left: 0; z-index: 0;
    width: 70%; pointer-events: none;
    mix-blend-mode: multiply;
    -webkit-mask-image: radial-gradient(150% 150% at 0 0, #000 30%, transparent 78%);
            mask-image: radial-gradient(150% 150% at 0 0, #000 30%, transparent 78%);
}

/* 顶部标题栏(毛玻璃,照 landing.css) */
.nav-bar {
    width: 100%; height: 52px;
    background: rgba(228, 238, 246, .5);
    backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    display: flex; align-items: center; padding: 0 16px; gap: 10px;
    position: sticky; top: 0; z-index: 100;
}
.nav-back {
    font-size: 26px; color: #2B3A4A; line-height: 1; text-decoration: none;
    padding: 2px 8px 4px 0; flex-shrink: 0;
}
.nav-title {
    position: absolute; left: 50%; transform: translateX(-50%);
    font-size: 16px; font-weight: 600; color: #2B3A4A; white-space: nowrap;
}

.page {
    position: relative; z-index: 1;
    width: 100%; max-width: 560px; margin: 0 auto;
    padding: 0 16px;
}

/* 单 App 抬头(锁定模式) */
.app-head {
    display: flex; align-items: center; justify-content: center; gap: 12px;
    margin: 30px 0 6px;
}
.app-logo {
    width: 46px; height: 46px; border-radius: 12px; flex-shrink: 0;
    box-shadow: 0 4px 14px rgba(0,0,0,.15);
}
.app-name { font-size: 24px; font-weight: 600; letter-spacing: .5px; }

/* 三款 App 选项卡 */
.apps { display: flex; gap: 10px; margin: 22px 0 10px; }
.app-tab {
    flex: 1; min-width: 0; display: flex; flex-direction: column; align-items: center; gap: 6px;
    padding: 12px 6px 10px; border-radius: 14px; cursor: pointer; font: inherit; color: #2B3A4A;
    background: rgba(255,255,255,.6); border: 1px solid rgba(58,126,228,.18);
    transition: background .15s, border-color .15s, box-shadow .15s, transform .15s;
    -webkit-tap-highlight-color: transparent;
}
.app-tab img { width: 46px; height: 46px; border-radius: 12px; box-shadow: 0 4px 14px rgba(0,0,0,.15); }
.app-tab span { font-size: 14px; font-weight: 700; line-height: 1.2; text-align: center; }
.app-tab small { font-size: 11px; color: #8a97a8; line-height: 1.2; text-align: center; }
.app-tab.on {
    background: #fff; border-color: #3a7ee4; box-shadow: 0 8px 22px rgba(58,126,228,.22);
    transform: translateY(-2px);
}
.app-tab.on span { color: #2c6fe0; }
.app-sub  { text-align: center; font-size: 13px; color: #5a6b7b; }

/* 搜索框 + 分类跳转条 */
.search {
    display: flex; align-items: center; gap: 8px;
    margin: 18px 0 12px; padding: 0 14px; height: 44px;
    background: #fff; border-radius: 12px; border: 1px solid rgba(58,126,228,.18);
    box-shadow: 0 4px 16px rgba(43,58,74,.06); color: #8a97a8;
}
.search svg { width: 18px; height: 18px; flex-shrink: 0; }
.search input {
    flex: 1; min-width: 0; height: 100%; border: 0; outline: 0; background: transparent;
    font: inherit; font-size: 15px; color: #2B3A4A;
}
.search input::placeholder { color: #a3aebc; }
.search input::-webkit-search-cancel-button { -webkit-appearance: none; }
.chips {
    display: flex; flex-wrap: wrap; gap: 8px; padding: 2px 0 6px;   /* 全部展示,自动换行,不横向滑动 */
}
.chips a {
    padding: 7px 12px; border-radius: 999px; text-decoration: none;
    font-size: 13px; font-weight: 600; color: #2c6fe0;
    background: rgba(255,255,255,.72); border: 1px solid rgba(58,126,228,.22);
}
.chips a:active { background: #fff; }
.hidden { display: none !important; }

/* 分区标题(左侧渐变竖条,呼应落地页标题的蓝紫渐变) */
.sec { scroll-margin-top: 64px; }                 /* 锚点跳转时让开吸顶导航 */
.sec-title {
    display: flex; align-items: center; gap: 8px;
    font-size: 17px; font-weight: 700; margin: 28px 2px 10px;
}
.sec-count {
    font-size: 12px; font-weight: 600; color: #8a97a8;
    background: rgba(43,58,74,.06); border-radius: 999px; padding: 2px 8px;
}
.sec-title::before {
    content: ''; width: 4px; height: 18px; border-radius: 2px; flex-shrink: 0;
    background: linear-gradient(180deg, #3a7ee4, #9333ea);
}

/* 问题分组卡片 */
.group {
    background: #F7FBFF; border-radius: 12px; padding: 2px 14px;
    box-shadow: 0 4px 16px rgba(43,58,74,.08);
}
.group-title {
    font-size: 12px; color: #8a97a8; letter-spacing: .04em;
    padding: 14px 0 2px;
}

.item { border-bottom: 1px solid rgba(43,58,74,.08); }
.item:last-child { border-bottom: none; }
.item-head {
    display: flex; align-items: center; gap: 10px;
    padding: 14px 0; cursor: pointer;
    -webkit-tap-highlight-color: transparent; user-select: none;
}
.item-q { flex: 1; font-size: 15px; line-height: 1.5; }
.item-arrow {
    width: 18px; height: 18px; flex-shrink: 0; color: #8a97a8;
    transition: transform .25s ease;
}
.item.open .item-arrow { transform: rotate(180deg); }
.item-body { display: none; padding: 0 0 16px; }
.item.open .item-body { display: block; }
.item-a {
    font-size: 14px; line-height: 1.9; color: #4a5a6a;
    background: #fff; border-radius: 10px; padding: 12px 14px;
}
.item-a p { margin: 0 0 8px; }
.item-a p:last-child { margin: 0; }
:root { --faq-fig-h: 250px; }             /* 配图高度 = 原信息流广告卡(300×250)的高度 */
.item-fig {
    margin: 0 0 16px; height: var(--faq-fig-h);          /* 常显,不随答案折叠 */
    border-radius: 12px; overflow-x: auto; overflow-y: hidden;
    -webkit-overflow-scrolling: touch; scrollbar-width: none;
    display: flex; justify-content: safe center;   /* 图比容器窄时居中,比容器宽时从左开始可横滑 */
    background: #eef4ff;
}
.item-fig::-webkit-scrollbar { display: none; }
.item-img {
    display: block; height: 100%; width: auto; max-width: none;   /* 定高、按原比例出宽,不裁切 */
    border-radius: 12px; cursor: zoom-in; flex-shrink: 0;
}

.status { text-align: center; color: #8a97a8; padding: 40px 0; font-size: 14px; }
.foot {
    margin-top: 32px; text-align: center;
    font-size: 12px; color: #8a97a8; line-height: 1.8;
}
.foot a { color: #2eab6e; text-decoration: none; font-weight: 600; }