/* ==================================================================
   爱思助手官方下载页 —— 暖橙社区风（v3 皮肤）
   单页落地：平台下载卡 + 安装步骤 + 下载前必看 + 相关帖子
   ================================================================== */
:root {
    --tone: #e0522d;
    --tone-deep: #ab3e1e;
    --tx0: #1d1d1f;
    --tx1: #5b6270;
    --tx2: #9aa0ab;
    --edge: #eae4d6;
    --floor: #f7f4ee;
    --panel: #fff;
    --round: 16px;
    --lift1: 0 1px 2px rgba(16,24,40,.04), 0 8px 24px rgba(16,24,40,.06);
    --lift2: 0 8px 16px rgba(16,24,40,.08), 0 20px 48px rgba(16,24,40,.12);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, "Microsoft Yahei", "Helvetica Neue", Arial, sans-serif;
    font-size: 14px; color: var(--tx0); background: var(--floor);
    -webkit-font-smoothing: antialiased;
}
a { color: var(--tone); text-decoration: none; }
a:hover { color: var(--tone-deep); }
img { border: 0; max-width: 100%; display: block; }
ul, ol { list-style: none; }
.shell { width: 1080px; max-width: 100%; margin: 0 auto; padding: 0 24px; }

/* ---------------- 顶栏 ---------------- */
.mast {
    position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.86);
    -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--edge);
}
.mast-in { height: 62px; display: flex; align-items: center; }
.mast-logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 16px; color: var(--tx0); }
.mast-logo img { width: 30px; height: 30px; }
.mast-links { margin-left: auto; display: flex; gap: 26px; }
.mast-links a { color: var(--tx1); font-size: 14px; }
.mast-links a:hover, .mast-links a.now2 { color: var(--tone); }

/* ---------------- Hero ---------------- */
.intro {
    background: radial-gradient(1200px 400px at 50% -120px, rgba(224, 82, 45,.14), transparent 70%), #fff;
    border-bottom: 1px solid var(--edge); text-align: center; padding: 56px 0 48px;
}
.intro-tag { display: inline-block; font-size: 12.5px; color: var(--tone); background: #fdf1e8; border: 1px solid #f5cdb8; border-radius: 20px; padding: 4px 14px; margin-bottom: 16px; font-weight: 600; }
.intro h1 { font-size: 34px; letter-spacing: -.5px; }
.intro h1 em { font-style: normal; color: var(--tone); }
.intro p { color: var(--tx1); font-size: 15px; margin-top: 14px; line-height: 1.8; }
.intro-meta { margin-top: 14px; color: var(--tx2); font-size: 13px; }
.intro-meta b { color: var(--tx1); font-weight: 600; }

.dlmain { padding: 40px 0 64px; }
.part-cap { font-size: 18px; font-weight: 700; margin: 0 0 18px; display: flex; align-items: baseline; gap: 10px; }
.part-cap em { font-style: normal; font-size: 13px; color: var(--tx2); font-weight: 400; }

/* ---------------- 平台下载卡 ---------------- */
.plats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-bottom: 44px; }
.plat {
    background: var(--panel); border: 1px solid var(--edge); border-radius: var(--round);
    padding: 24px 22px; transition: transform .16s, box-shadow .16s, border-color .16s;
}
.plat:hover { transform: translateY(-3px); box-shadow: var(--lift2); border-color: transparent; }
.plat-os { display: flex; align-items: center; gap: 10px; font-size: 16px; font-weight: 700; }
.plat-os img { width: 28px; height: 28px; }
.plat-os span { font-size: 12px; color: var(--tx2); font-weight: 400; margin-left: auto; }
.plat-tx { color: var(--tx1); font-size: 13px; line-height: 1.7; margin: 12px 0 16px; min-height: 44px; }
.plat-btn {
    display: flex; align-items: center; justify-content: center; gap: 8px;
    height: 46px; border-radius: 12px; background: var(--tone); color: #fff;
    font-size: 15px; font-weight: 700; letter-spacing: 1px;
}
.plat-btn:hover { background: var(--tone-deep); color: #fff; }
.plat-note { text-align: center; font-size: 12px; color: var(--tx2); margin-top: 10px; }

/* ---------------- 安装步骤 ---------------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 44px; }
.step { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--round); padding: 22px 20px; position: relative; }
.step-no { width: 30px; height: 30px; border-radius: 50%; background: var(--tone); color: #fff; font-weight: 700; font-size: 15px; display: flex; align-items: center; justify-content: center; margin-bottom: 12px; }
.step b { display: block; font-size: 15px; margin-bottom: 6px; }
.step p { color: var(--tx1); font-size: 13px; line-height: 1.7; }

/* ---------------- 必看 + 相关帖 ---------------- */
.duo { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 44px; }
.duo-box { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--round); padding: 24px 26px; }
.duo-box h2 { font-size: 16px; margin-bottom: 14px; padding-left: 12px; border-left: 4px solid var(--tone); }
.duo-box li { position: relative; padding-left: 20px; margin: 10px 0; color: var(--tx1); font-size: 13.5px; line-height: 1.7; }
.duo-box li::before { content: ""; position: absolute; left: 4px; top: 8px; width: 7px; height: 7px; border-radius: 50%; background: var(--tone); }
.duo-box li a { color: var(--tx0); font-weight: 600; }
.duo-box li a:hover { color: var(--tone); }
.duo-box li i { font-style: normal; color: var(--tx2); font-size: 12px; display: block; margin-top: 2px; }

/* ---------------- FAQ ---------------- */
.faqz { background: var(--panel); border: 1px solid var(--edge); border-radius: var(--round); padding: 28px 30px; margin-bottom: 44px; }
.faqz h2 { font-size: 16px; margin-bottom: 16px; padding-left: 12px; border-left: 4px solid var(--tone); }
.fq { border-top: 1px solid var(--edge); padding: 16px 0; }
.fq:first-of-type { border-top: 0; }
.fq-q { font-size: 15px; font-weight: 700; margin-bottom: 8px; }
.fq-a { color: var(--tx1); font-size: 13.5px; line-height: 1.8; }

.btm { border-top: 1px solid var(--edge); background: #fff; padding: 26px 0; color: var(--tx2); font-size: 12.5px; line-height: 1.8; }
.btm a { color: var(--tx1); }

@media (max-width: 980px) {
    .plats { grid-template-columns: repeat(2, 1fr); }
    .steps { grid-template-columns: repeat(2, 1fr); }
    .duo { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
    .shell { padding: 0 16px; }
    .plats { grid-template-columns: 1fr; }
    .steps { grid-template-columns: 1fr; }
    .intro h1 { font-size: 26px; }
    .mast-links { gap: 16px; }
}