/* ============================================================
   QuickQ 安装包下载页 —— download.css（完整版）
   ------------------------------------------------------------
   包含：
     00  基础重置与设计变量
     01  通用组件（container / btn / 标题）
     02  头部导航（与首页一致）
     03  尾部（与首页一致）
     04  右下悬浮按钮
     05  下载 Hero
     06  数据条
     07  全平台覆盖
     08  系统要求
     09  快速上手
     10  安全与认证 / 哈希校验
     11  版本更新
     12  下载页 FAQ
     13  底部 CTA
     14  哈希复制提示
     15  响应式
   ============================================================ */


/* ============================================================
   00  基础重置与设计变量
   ============================================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #4f7cff;
    --primary-dark: #3a5fd9;
    --primary-glow: rgba(79, 124, 255, .45);
    --accent: #00d4ff;
    --bg-base: #060b18;
    --bg-dark: #0a1122;
    --bg-card: #0f1a30;
    --bg-glass: rgba(15, 26, 48, .55);
    --text: #eaf0ff;
    --text-muted: rgba(255, 255, 255, .65);
    --text-dim: rgba(255, 255, 255, .35);
    --border: rgba(255, 255, 255, .08);
    --border-glow: rgba(79, 124, 255, .25);
    --shadow-card: 0 20px 60px rgba(0, 0, 0, .6);
    --shadow-glow: 0 0 80px rgba(79, 124, 255, .2);
    --radius: 1.25rem;
    --radius-sm: .75rem;
    --radius-full: 9999px;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    background: var(--bg-base);
    color: var(--text);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.7;
    overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { background: none; border: none; cursor: pointer; color: inherit; }
ul, ol, li { list-style: none; }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 10px; }


/* ============================================================
   01  通用组件
   ============================================================ */
.container {
    width: 96%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .6rem;
    padding: .7rem 2rem;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    box-shadow: 0 8px 32px rgba(79, 124, 255, .35);
    color: #fff;
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: .3px;
    position: relative;
    overflow: hidden;
    transition: transform .25s ease, box-shadow .3s ease;
}

.btn-primary::after {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: linear-gradient(135deg, rgba(255, 255, 255, .15), transparent 60%);
    pointer-events: none;
}

.btn-primary:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 14px 44px rgba(79, 124, 255, .5);
}

.btn-primary:active { transform: scale(.97); }

.btn-glow-wrap { position: relative; display: inline-block; }

.btn-glow-wrap::before {
    content: "";
    position: absolute;
    inset: -4px;
    z-index: -1;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--accent), var(--primary));
    background-size: 200% 200%;
    filter: blur(18px);
    opacity: .3;
    animation: glowPulse 3s ease-in-out infinite alternate;
}

@keyframes glowPulse {
    0%   { opacity: .2; transform: scale(.95); }
    100% { opacity: .6; transform: scale(1.05); }
}

.section-title {
    font-size: clamp(1.8rem, 4.5vw, 3.6rem);
    font-weight: 800;
    line-height: 1.15;
    letter-spacing: -.02em;
    text-align: center;
    color: #fff;
}

.section-title .highlight {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-sub {
    max-width: 720px;
    margin: .5rem auto 0;
    color: var(--text-muted);
    font-size: clamp(.95rem, 1.2vw, 1.2rem);
    text-align: center;
}


/* ============================================================
   02  头部导航（与首页一致）
   ============================================================ */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    padding: .4rem 0;
    background: #03050b;
    backdrop-filter: blur(18px) saturate(1.2);
    -webkit-backdrop-filter: blur(18px) saturate(1.2);
    transition: background .3s;
}

.header.scrolled {
    background: rgba(6, 11, 24, .85);
    backdrop-filter: blur(24px) saturate(1.4);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 96%;
    margin: 0 auto;
    padding: 1rem;
}

.logo img { height: 2rem; width: auto; transition: opacity .2s; }
.logo:hover img { opacity: .85; }

.nav-desktop {
    display: none;
    align-items: center;
    gap: .5rem;
    flex: 1;
    margin-left: 2.5rem;
}

@media (min-width: 820px) {
    .nav-desktop { display: flex; }
}

.nav-desktop > a {
    padding: .4rem .9rem;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: .9rem;
    font-weight: 500;
    letter-spacing: .2px;
    white-space: nowrap;
    transition: color .2s, background .2s;
}

.nav-desktop > a:hover {
    color: #fff;
    background: rgba(255, 255, 255, .06);
}

.nav-cta { display: none; align-items: center; gap: .8rem; }

@media (min-width: 820px) {
    .nav-cta { display: flex; }
}

.nav-cta .btn-login {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    padding: .4rem 1.4rem;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    box-shadow: 0 4px 16px rgba(79, 124, 255, .25);
    color: #fff;
    font-size: .85rem;
    font-weight: 600;
    transition: transform .2s, box-shadow .2s;
}

.nav-cta .btn-login:hover {
    transform: scale(1.03);
    box-shadow: 0 8px 28px rgba(79, 124, 255, .4);
}

.hamburger {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: .35rem .7rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, .04);
    color: #fff;
    font-size: 1.1rem;
    transition: background .2s;
}

.hamburger:hover { background: rgba(255, 255, 255, .08); }

@media (min-width: 820px) { .hamburger { display: none; } }

.nav-mobile {
    display: none;
    width: 100%;
    margin: 0 auto;
    padding: .5rem .5rem 1rem;
    border-top: 1px solid var(--border);
    background: rgba(6, 11, 24, .92);
    backdrop-filter: blur(12px);
}

.nav-mobile.open {
    display: block;
    animation: slideDown .25s ease;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.nav-mobile a {
    display: block;
    padding: .5rem .8rem;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: .95rem;
    transition: background .15s, color .15s;
}

.nav-mobile a:hover { background: rgba(255, 255, 255, .05); color: #fff; }

.nav-mobile .btn-login-mobile {
    margin-top: .5rem;
    padding: .6rem;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff !important;
    font-weight: 600;
    text-align: center;
}


/* ============================================================
   03  尾部（与首页一致）
   ============================================================ */
.footer {
    padding: 3.5rem 1rem 1.8rem;
    background: var(--bg-base);
    border-top: 1px solid var(--border);
}

.footer-inner {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: flex-start;
    gap: 2.5rem 4rem;
    margin: 0 auto;
}

.footer-brand { flex: 0 0 auto; min-width: 200px; max-width: 320px; }

.footer-brand .logo-footer img {
    height: 2.6rem;
    width: auto;
    opacity: .9;
    transition: opacity .2s;
}

.footer-brand .logo-footer img:hover { opacity: 1; }

.footer-brand .brand-desc {
    margin-top: .6rem;
    color: var(--text-dim);
    font-size: .82rem;
    line-height: 1.7;
}

.footer-brand .brand-desc strong { color: #fff; }

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem 3rem;
    flex: 1;
    max-width: 560px;
}

.footer-links ul li:first-child {
    display: inline-block;
    position: relative;
    margin-bottom: .6rem;
    color: #fff;
    font-size: .9rem;
    font-weight: 700;
    letter-spacing: .4px;
}

.footer-links ul li:first-child::after {
    content: "";
    display: block;
    width: 24px;
    height: 2px;
    margin-top: .3rem;
    border-radius: 2px;
    background: var(--primary);
    opacity: .5;
}

.footer-links ul li { margin-bottom: .25rem; }

.footer-links ul a {
    display: inline-block;
    padding: .1rem 0;
    color: var(--text-dim);
    font-size: .82rem;
    transition: color .2s, padding-left .2s;
}

.footer-links ul a:hover { color: #fff; padding-left: .3rem; }

.footer-bottom {
    max-width: 1200px;
    margin: 2.8rem auto 0;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border);
    color: var(--text-dim);
    font-size: .7rem;
    letter-spacing: .5px;
    text-align: center;
}

.footer-bottom .heart {
    display: inline-block;
    color: var(--accent);
    animation: heartBeat 2s ease-in-out infinite;
}

@keyframes heartBeat {
    0%, 100% { transform: scale(1); }
    50%      { transform: scale(1.15); }
}


/* ============================================================
   04  右下悬浮按钮
   ============================================================ */
.backfab {
    position: fixed;
    right: 20px;
    bottom: 20px;
    z-index: 60;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.backfab button,
.backfab a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .7);
    box-shadow: 0 8px 24px rgba(0, 0, 0, .3);
    color: var(--text-muted);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    transition: transform .2s, background .2s, color .2s, box-shadow .2s;
}

.backfab button:hover,
.backfab a:hover {
    transform: translateY(-2px) scale(1.04);
    border-color: rgba(79, 124, 255, .2);
    background: rgba(79, 124, 255, .15);
    box-shadow: 0 12px 32px rgba(79, 124, 255, .15);
    color: #fff;
}


/* ============================================================
   05  下载 Hero
   ============================================================ */
.main-download { overflow: hidden; }

.main-download .download-hero {
    position: relative;
    display: flex;
    align-items: center;
    min-height: 60vh;
    padding: 2rem 0;
    overflow: hidden;
    background: var(--bg-base);
}

.main-download .download-hero::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background:
        radial-gradient(ellipse at 50% 30%, rgba(79, 124, 255, .08), transparent 70%),
        radial-gradient(ellipse at 80% 80%, rgba(0, 212, 255, .05), transparent 60%);
}

.main-download .download-hero .container {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 2rem;
}

.main-download .hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 4rem;
    padding: 2rem 0;
}

.main-download .hero-left {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
}

.main-download .hero-left .badge {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    margin-bottom: 1rem;
    padding: .2rem 1rem .2rem .6rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(79, 124, 255, .15);
    background: rgba(79, 124, 255, .12);
    color: var(--accent);
    font-size: .75rem;
    font-weight: 500;
    letter-spacing: .5px;
}

.main-download .hero-left .badge i {
    font-size: .5rem;
    color: #4ee6c0;
}

.main-download .hero-left h1 {
    max-width: 720px;
    color: #fff;
    font-size: clamp(2.2rem, 4.5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -.03em;
}

.main-download .hero-left h1 .highlight {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-download .hero-left .sub-headline {
    max-width: 560px;
    margin-top: .8rem;
    color: var(--text-muted);
    font-size: clamp(1rem, 1.1vw, 1.15rem);
    line-height: 1.8;
}

.main-download .hero-left .sub-headline strong { color: #fff; }

.main-download .version-bar {
    display: inline-flex;
    flex-wrap: wrap;
    align-items: center;
    gap: .6rem 1.5rem;
    margin-top: 1.2rem;
    padding: .6rem 1.8rem;
    border-radius: var(--radius-full);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .5);
}

.main-download .version-bar .tag {
    display: inline-flex;
    align-items: center;
    gap: .3rem;
    color: var(--text-dim);
    font-size: .8rem;
}

.main-download .version-bar .tag strong { color: #fff; font-weight: 700; }

.main-download .version-bar .badge-green {
    display: inline-block;
    width: 6px;
    height: 6px;
    margin-right: .2rem;
    border-radius: 50%;
    background: #4ade80;
    box-shadow: 0 0 8px rgba(74, 222, 128, .6);
}

.main-download .hero-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px 20px;
    margin-top: 1.6rem;
}

.main-download .hero-btn-download {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 40px;
    border: none;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    box-shadow: 0 6px 24px rgba(79, 124, 255, .25);
    color: #fff;
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: .3px;
    text-decoration: none;
    cursor: pointer;
    transition: all .3s ease;
}

.main-download .hero-btn-download:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 36px rgba(79, 124, 255, .35);
}

.main-download .hero-btn-download i { font-size: 1.1rem; }

.main-download .hero-btn-outline {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    background: transparent;
    color: var(--text-muted);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all .3s ease;
}

.main-download .hero-btn-outline:hover {
    transform: translateY(-2px);
    border-color: var(--primary);
    background: rgba(79, 124, 255, .08);
    color: #fff;
}

.main-download .hero-right {
    display: flex;
    align-items: center;
    justify-content: center;
}

.main-download .hero-right .hero-image {
    width: 100%;
    max-width: 560px;
    height: auto;
    border-radius: var(--radius);
    transition: transform .4s ease;
}

.main-download .hero-right .hero-image:hover { transform: scale(1.01); }


/* ============================================================
   06  下载数据条
   ============================================================ */
.main-download .download-stats {
    padding: 1.2rem 0;
    background: var(--bg-dark);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.main-download .download-stats .stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
    max-width: 900px;
    margin: 0 auto;
    padding: 0 1rem;
    text-align: center;
}

.main-download .download-stats .stats-item .number {
    display: block;
    color: #fff;
    font-size: clamp(1.6rem, 2.5vw, 2.4rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -.02em;
}

.main-download .download-stats .stats-item .label {
    display: block;
    margin-top: .05rem;
    color: var(--text-dim);
    font-size: clamp(.7rem, .85vw, .9rem);
}


/* ============================================================
   07  全平台覆盖 —— 下载卡片
   ============================================================ */
.main-download .download-platforms {
    padding: 3.5rem 1rem 4rem;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.main-download .section-header {
    margin-bottom: 2rem;
    text-align: center;
}

.main-download .section-badge {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    margin-bottom: .5rem;
    padding: .2rem 1rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(79, 124, 255, .15);
    background: rgba(79, 124, 255, .12);
    color: var(--accent);
    font-size: .7rem;
    font-weight: 500;
    letter-spacing: .5px;
}

.main-download .section-badge i { font-size: .7rem; }

.main-download .section-title {
    color: #fff;
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -.02em;
}

.main-download .section-title .highlight {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-download .section-sub {
    max-width: 720px;
    margin: .4rem auto 0;
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1.7;
}

.main-download .download-flex {
    display: flex;
    flex-wrap: wrap;
    gap: 1.2rem;
    justify-content: center;
    max-width: 1200px;
    margin: 1.5rem auto 0;
    padding: 0 1rem;
}

.main-download .download-card {
    display: flex;
    flex: 0 0 calc(20% - 1.2rem);
    flex-direction: column;
    align-items: center;
    min-width: 190px;
    max-width: 240px;
    padding: 1.6rem 1rem 1.3rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .5);
    backdrop-filter: blur(4px);
    text-align: center;
    transition: all .35s ease;
}

.main-download .download-card:hover {
    border-color: rgba(79, 124, 255, .3);
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, .35), 0 0 0 1px rgba(79, 124, 255, .1);
}

.main-download .download-card .os-icon {
    display: block;
    margin-bottom: .35rem;
    color: var(--accent);
    font-size: 2.6rem;
    line-height: 1.2;
    text-align: center;
    transition: transform .3s ease;
}

.main-download .download-card:hover .os-icon { transform: scale(1.1); }

.main-download .download-card .os-icon i {
    display: inline-block;
    vertical-align: middle;
}

.main-download .download-card .badge-hot {
    display: inline-block;
    margin-bottom: .35rem;
    padding: .1rem .7rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(79, 124, 255, .1);
    background: rgba(79, 124, 255, .12);
    color: var(--accent);
    font-size: .6rem;
    font-weight: 600;
    letter-spacing: .3px;
}

.main-download .download-card .os-name {
    color: #fff;
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: -.01em;
}

.main-download .download-card .os-version {
    margin-top: .15rem;
    color: var(--text-muted);
    font-size: .75rem;
}

.main-download .download-card .os-size {
    margin-top: .1rem;
    color: var(--text-dim);
    font-size: .7rem;
    line-height: 1.5;
}

.main-download .download-card .btn-download {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    max-width: 205px;
    margin-top: .8rem;
    padding: .55rem 1.2rem;
    border: none;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    box-shadow: 0 4px 16px rgba(79, 124, 255, .2);
    color: #fff;
    font-size: .82rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all .3s ease;
}

.main-download .download-card .btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(79, 124, 255, .35);
}

.main-download .download-card .btn-download i { display: inline-block; vertical-align: middle; }

.main-download .download-card .security-badge {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: .65rem;
    color: var(--text-dim);
    font-size: .6rem;
    line-height: 1.4;
    text-align: center;
}

.main-download .download-card .security-badge i {
    flex-shrink: 0;
    color: #4ade80;
    font-size: .5rem;
}

.main-download .download-footnote {
    max-width: 760px;
    margin: 1.8rem auto 0;
    padding: 0 1rem;
    color: var(--text-dim);
    font-size: .85rem;
    line-height: 1.7;
    text-align: center;
}

.main-download .download-footnote i {
    color: #4ade80;
    margin-right: .2rem;
    vertical-align: middle;
}

.main-download .download-footnote a {
    color: var(--accent);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 1px dashed rgba(0, 212, 255, .4);
    transition: color .2s;
}

.main-download .download-footnote a:hover { color: #fff; }


/* ============================================================
   08  系统要求
   ============================================================ */
.main-download .system-section {
    padding: 3rem 1rem 3.5rem;
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border);
}

.main-download .system-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 1rem;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 1rem;
}

.main-download .system-item {
    padding: 1.2rem .8rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .4);
    text-align: center;
    transition: .3s;
}

.main-download .system-item:hover {
    border-color: rgba(79, 124, 255, .25);
    transform: translateY(-2px);
    background: rgba(15, 26, 48, .6);
}

.main-download .system-item .sys-icon {
    display: block;
    margin-bottom: .3rem;
    color: var(--accent);
    font-size: 1.7rem;
    line-height: 1.2;
    text-align: center;
}

.main-download .system-item .sys-icon i { display: inline-block; vertical-align: middle; }

.main-download .system-item h4 {
    color: #fff;
    font-size: .9rem;
    font-weight: 700;
}

.main-download .system-item p {
    margin-top: .25rem;
    color: var(--text-muted);
    font-size: .72rem;
    line-height: 1.6;
}

.main-download .system-footnote {
    max-width: 820px;
    margin: 1.4rem auto 0;
    padding: 0 1rem;
    color: var(--text-dim);
    font-size: .82rem;
    line-height: 1.75;
    text-align: center;
}

.main-download .system-footnote strong {
    color: var(--text-muted);
    font-weight: 600;
}


/* ============================================================
   09  快速上手
   ============================================================ */
.main-download .steps-section {
    padding: 3rem 1rem 4rem;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.main-download .steps-flex {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.8rem;
    max-width: 1080px;
    margin: .5rem auto 0;
    padding: 0 1rem;
}

.main-download .step-card {
    position: relative;
    flex: 0 0 calc(33.33% - 1.8rem);
    min-width: 240px;
    max-width: 340px;
    padding: 1.8rem 1.4rem 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .35);
    text-align: center;
    transition: .3s;
}

.main-download .step-card:hover {
    border-color: rgba(79, 124, 255, .25);
    transform: translateY(-4px);
    background: rgba(15, 26, 48, .55);
}

.main-download .step-card .step-num {
    display: inline-block;
    width: 44px;
    height: 44px;
    margin-bottom: .8rem;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    box-shadow: 0 6px 18px rgba(79, 124, 255, .3);
    color: #fff;
    font-size: 1.2rem;
    font-weight: 800;
    line-height: 44px;
    text-align: center;
}

.main-download .step-card h3 {
    margin-bottom: .4rem;
    color: #fff;
    font-size: 1.05rem;
    font-weight: 700;
}

.main-download .step-card p {
    color: var(--text-muted);
    font-size: .85rem;
    line-height: 1.75;
}

.main-download .step-card p strong {
    color: var(--accent);
    font-weight: 600;
}


/* ============================================================
   10  安全与认证
   ============================================================ */
.main-download .security-section {
    padding: 3rem 1rem 4rem;
    background: var(--bg-dark);
    border-bottom: 1px solid var(--border);
}

.main-download .security-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 1rem;
}

.main-download .security-item {
    padding: 1.8rem 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .4);
    text-align: center;
    transition: .3s;
}

.main-download .security-item:hover {
    border-color: rgba(79, 124, 255, .25);
    transform: translateY(-4px);
    background: rgba(15, 26, 48, .6);
}

.main-download .security-item .sec-icon {
    display: block;
    margin-bottom: .6rem;
    color: var(--accent);
    font-size: 2.2rem;
    line-height: 1.2;
    text-align: center;
}

.main-download .security-item .sec-icon i { display: inline-block; vertical-align: middle; }

.main-download .security-item h4 {
    margin-bottom: .3rem;
    color: #fff;
    font-size: 1.05rem;
    font-weight: 700;
}

.main-download .security-item p {
    color: var(--text-muted);
    font-size: .85rem;
    line-height: 1.75;
}

.main-download .security-item p strong { color: var(--accent); font-weight: 600; }

/* 哈希 / 版本日志框 */
.main-download .changelog-box {
    max-width: 820px;
    margin: 0 auto;
    padding: 1.6rem 1.8rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .4);
    backdrop-filter: blur(4px);
}

.main-download .changelog-box .version-row {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    margin-bottom: .9rem;
    padding-bottom: .8rem;
    border-bottom: 1px solid var(--border);
}

.main-download .changelog-box .version-row .ver {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    color: var(--accent);
    font-size: 1.05rem;
    font-weight: 700;
}

.main-download .changelog-box .version-row .ver .tag {
    padding: .1rem .7rem;
    border-radius: var(--radius-full);
    background: rgba(74, 222, 128, .12);
    border: 1px solid rgba(74, 222, 128, .2);
    color: #4ade80;
    font-size: .6rem;
    font-weight: 600;
}

.main-download .changelog-box .version-row .date {
    color: var(--text-dim);
    font-size: .8rem;
}

.main-download .changelog-box ul { margin: 0; padding: 0; list-style: none; }

.main-download .changelog-box ul li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: .45rem 0;
    color: var(--text-muted);
    font-size: .88rem;
    line-height: 1.75;
}

.main-download .changelog-box ul li i {
    flex-shrink: 0;
    margin-top: 4px;
    color: #4ade80;
    font-size: .75rem;
}

.main-download .changelog-box ul li strong { color: #fff; font-weight: 600; }

.main-download .changelog-box ul li code {
    display: inline-block;
    margin-left: .2rem;
    padding: .05rem .4rem;
    border-radius: 4px;
    border: 1px solid hsla(0, 0%, 100%, .08);
    background: hsla(0, 0%, 100%, .05);
    color: #4ee6c0;
    font-family: "JetBrains Mono", "Fira Code", Menlo, monospace;
    font-size: .78rem;
    letter-spacing: -.01em;
    vertical-align: middle;
}


/* ============================================================
   11  版本更新
   ============================================================ */
.main-download .changelog-section {
    padding: 3rem 1rem 4rem;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.main-download .changelog-section .changelog-box {
    background: rgba(15, 26, 48, .35);
    border: 1px solid var(--border);
}


/* ============================================================
   12  下载页 FAQ
   ============================================================ */
.main-download .faq-section {
    padding: 3rem 1rem 4rem;
    background: var(--bg-dark);
}

.main-download .faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.2rem;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 1rem;
}

.main-download .faq-card {
    padding: 1.3rem 1.5rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(10, 17, 34, .5);
    backdrop-filter: blur(6px);
    transition: .3s;
}

.main-download .faq-card:hover {
    border-color: rgba(79, 124, 255, .3);
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, .4);
}

.main-download .faq-card .faq-q {
    display: flex;
    align-items: center;
    gap: .6rem;
    margin-bottom: .5rem;
    color: #fff;
    font-size: clamp(.98rem, 1.05vw, 1.08rem);
    font-weight: 700;
    line-height: 1.4;
}

.main-download .faq-card .faq-q i {
    flex-shrink: 0;
    width: 18px;
    color: var(--accent);
    font-size: .9rem;
    text-align: center;
}

.main-download .faq-card .faq-a {
    padding-left: 1.75rem;
    color: var(--text-muted);
    font-size: .88rem;
    line-height: 1.8;
}

.main-download .faq-card .faq-a p { margin: 0; }

.main-download .faq-card .faq-a strong { color: #eaf0ff; font-weight: 600; }


/* ============================================================
   13  底部 CTA
   ============================================================ */
.main-download .cta-section {
    padding: 3rem 1rem 4rem;
    background: var(--bg-dark);
    border-top: 1px solid var(--border);
}

.main-download .cta-section .cta-box {
    max-width: 680px;
    margin: 0 auto;
    padding: 2rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: rgba(15, 26, 48, .4);
    text-align: center;
}

.main-download .cta-section .cta-box h3 {
    margin-bottom: .4rem;
    color: #fff;
    font-size: 1.4rem;
    font-weight: 700;
}

.main-download .cta-section .cta-box p {
    margin-bottom: 1.2rem;
    color: var(--text-muted);
    font-size: .95rem;
    line-height: 1.7;
}

.main-download .cta-section .cta-box .hero-btn-outline {
    padding: 10px 22px;
    font-size: .9rem;
}


/* ============================================================
   14  哈希复制提示
   ============================================================ */
.main-download .changelog-box ul li code {
    position: relative;
    cursor: pointer;
    transition: background .2s, border-color .2s;
}

.main-download .changelog-box ul li code:hover {
    background: rgba(79, 124, 255, .12);
    border-color: rgba(79, 124, 255, .3);
}

.main-download .changelog-box ul li code .copy-tip {
    position: absolute;
    left: 50%;
    bottom: calc(100% + 6px);
    transform: translateX(-50%) translateY(4px);
    padding: .15rem .5rem;
    border-radius: 6px;
    background: rgba(6, 11, 24, .95);
    border: 1px solid rgba(79, 124, 255, .35);
    color: #4ee6c0;
    font-size: .65rem;
    font-weight: 600;
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity .2s ease, transform .2s ease, visibility .2s;
    z-index: 10;
}

.main-download .changelog-box ul li code .copy-tip.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* fa-spin 兜底 */
@keyframes fa-spin {
    0%   { transform: rotate(0deg); }
    100% { transform: rotate(1turn); }
}

.fa-spin { animation: fa-spin 1s linear infinite; }


/* ============================================================
   15  响应式
   ============================================================ */

/* ---- 平板 ---- */
@media (max-width: 1024px) {
    .main-download .hero-grid { gap: 2.5rem; }
    .main-download .system-grid { grid-template-columns: repeat(3, 1fr); }
    .main-download .security-grid { grid-template-columns: repeat(2, 1fr); }
    .main-download .download-card { flex: 0 0 calc(33.33% - 1.2rem); }
}

/* ---- 中小屏 ---- */
@media (max-width: 820px) {
    .container { width: 100%; }
    .logo img { height: 1.2rem; }

    .main-download .download-hero {
        min-height: auto;
        padding: 2rem 0 3rem;
    }

    .main-download .hero-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
        padding: 1rem 0;
    }

    .main-download .hero-left {
        align-items: center;
        text-align: center;
    }

    .main-download .hero-left h1 { font-size: clamp(1.8rem, 4vw, 2.4rem); }
    .main-download .hero-left .sub-headline { max-width: 100%; }

    .main-download .version-bar {
        flex-wrap: wrap;
        justify-content: center;
        padding: .5rem 1rem;
    }

    .main-download .hero-actions { justify-content: center; }
    .main-download .hero-right .hero-image { max-width: 90%; }

    .main-download .download-stats .stats-grid { gap: 1rem; }
    .main-download .download-card { flex: 0 0 calc(50% - 1.2rem); }
    .main-download .system-grid { grid-template-columns: repeat(3, 1fr); }
    .main-download .security-grid { grid-template-columns: 1fr; }

    .main-download .step-card { flex: 0 0 calc(50% - 1.8rem); }
    .main-download .faq-grid { grid-template-columns: 1fr; }

    .main-download .changelog-box { padding: 1.3rem 1.2rem; }

    /* 尾部响应式 */
    .footer-inner {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
        text-align: center;
    }
    .footer-brand { max-width: 100%; text-align: center; }
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem 2rem;
        max-width: 100%;
        width: 100%;
    }
    .footer-links ul li:first-child::after {
        margin-left: auto;
        margin-right: auto;
    }
}

/* ---- 手机 ---- */
@media (max-width: 600px) {
    .main-download .download-hero .container { padding: 0 1rem; }

    .main-download .download-stats .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: .8rem 1rem;
    }

    .main-download .download-card {
        flex: 0 0 100%;
        max-width: 320px;
    }

    .main-download .step-card {
        flex: 0 0 100%;
        max-width: 340px;
    }

    .main-download .system-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: .8rem;
    }
}

/* ---- 极小屏 ---- */
@media (max-width: 480px) {
    .main-download .hero-left h1 { font-size: 1.6rem; }

    .main-download .hero-btn-download,
    .main-download .hero-btn-outline {
        justify-content: center;
        width: 100%;
        max-width: 280px;
        font-size: .9rem;
        padding: 12px 20px;
    }

    .main-download .hero-actions { flex-direction: column; align-items: center; }

    .main-download .download-platforms,
    .main-download .system-section,
    .main-download .steps-section,
    .main-download .security-section,
    .main-download .changelog-section,
    .main-download .faq-section,
    .main-download .cta-section {
        padding-left: .5rem;
        padding-right: .5rem;
    }

    .main-download .download-card {
        flex: 0 0 100%;
        max-width: 300px;
    }

    .main-download .system-grid {
        grid-template-columns: 1fr 1fr;
        gap: .7rem;
    }

    .main-download .system-item { padding: 1rem .6rem; }
    .main-download .system-item h4 { font-size: .82rem; }
    .main-download .system-item p { font-size: .68rem; }

    .main-download .security-item { padding: 1.4rem 1rem; }
    .main-download .security-item h4 { font-size: .95rem; }
    .main-download .security-item p { font-size: .8rem; }

    .main-download .changelog-box { padding: 1rem; }
    .main-download .changelog-box .version-row .ver { font-size: .95rem; }
    .main-download .changelog-box ul li { font-size: .8rem; }
    .main-download .changelog-box ul li code { font-size: .7rem; }

    .main-download .faq-card { padding: 1rem 1.1rem; }
    .main-download .faq-card .faq-q { font-size: .9rem; }
    .main-download .faq-card .faq-a {
        padding-left: 0;
        font-size: .82rem;
    }

    .main-download .cta-section .cta-box { padding: 1.5rem 1rem; }
    .main-download .cta-section .cta-box h3 { font-size: 1.1rem; }

    /* 尾部响应式 */
    .footer { padding: 2.5rem .5rem 1.2rem; }
    .footer-links { grid-template-columns: 1fr 1fr; gap: 1.2rem; }
    .footer-links ul li:first-child { font-size: .8rem; }
    .footer-links ul a { font-size: .75rem; }
    .footer-brand .logo-footer img { height: 2rem; }
    .footer-brand .brand-desc { font-size: .75rem; }
    .footer-bottom { margin-top: 2rem; padding-top: 1rem; font-size: .6rem; }
}