```css
/* ===== 破处合集·学妹巨乳嫩穴开苞内射 | 成人教育网 ===== */
/* ===== 品牌：初夜私语 | egcyorm.cn ===== */
/* ===== 随机风格：深色奢华 + 渐变Banner + 毛玻璃 ===== */

:root{
    --bg:#f5ede4;
    --surface:rgba(255,255,255,0.75);
    --surface-solid:#ffffff;
    --text-main:#2c1e16;
    --text-secondary:#5c4a3e;
    --text-heading:#1a0f0a;
    --text-link:#8a3b2a;
    --text-footer:#d7c8bd;
    --border:rgba(120,80,60,0.25);
    --brand:#b54a35;
    --brand-dark:#8a2e1e;
    --brand-light:#e07a5f;
    --nav-bg:rgba(20,12,8,0.85);
    --nav-text:#f5e9e2;
    --card-bg:rgba(255,255,255,0.7);
    --btn-bg:linear-gradient(135deg,#c25a3f,#9a2e1e);
    --btn-text:#fff8f5;
    --footer-bg:#1a0f0a;
    --code-bg:#f0e4da;
    --shadow:0 8px 32px rgba(80,30,10,0.12);
    --shadow-hover:0 16px 48px rgba(80,30,10,0.2);
    --glass:rgba(255,255,255,0.6);
    --glass-border:rgba(255,255,255,0.8);
    --hero-grad:linear-gradient(145deg,#1a0f0a 0%,#3a1e12 40%,#7a2e1a 100%);
    --card-radius:24px;
    --transition:all 0.3s cubic-bezier(0.25,0.46,0.45,0.94);
}

[data-theme="dark"]{
    --bg:#12100e;
    --surface:rgba(30,24,20,0.85);
    --surface-solid:#1e1815;
    --text-main:#e8ddd6;
    --text-secondary:#c0b0a6;
    --text-heading:#faf3ef;
    --text-link:#e07a5f;
    --text-footer:#8f7a6c;
    --border:rgba(200,160,130,0.2);
    --brand:#e07a5f;
    --brand-dark:#c25a3f;
    --brand-light:#f0a08a;
    --nav-bg:rgba(10,6,4,0.92);
    --nav-text:#efe5df;
    --card-bg:rgba(30,24,20,0.6);
    --btn-bg:linear-gradient(135deg,#e07a5f,#a03a20);
    --btn-text:#fff;
    --footer-bg:#0a0604;
    --code-bg:#2a201a;
    --shadow:0 8px 32px rgba(0,0,0,0.4);
    --shadow-hover:0 16px 48px rgba(0,0,0,0.6);
    --glass:rgba(40,30,25,0.6);
    --glass-border:rgba(255,200,170,0.15);
    --hero-grad:linear-gradient(145deg,#0a0604 0%,#1e0f08 50%,#3a1a0e 100%);
}

*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}

html{
    scroll-behavior:smooth;
    scroll-padding-top:80px;
}

body{
    font-family:'PingFang SC','Microsoft YaHei','Noto Sans SC',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;
    background:var(--bg);
    color:var(--text-main);
    line-height:1.75;
    overflow-x:hidden;
    transition:background 0.4s ease,color 0.3s ease;
    background-image:
        radial-gradient(circle at 15% 20%,rgba(200,120,80,0.06) 0%,transparent 40%),
        radial-gradient(circle at 85% 70%,rgba(150,60,30,0.05) 0%,transparent 50%);
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:linear-gradient(var(--brand),var(--brand-dark));border-radius:20px;border:2px solid var(--bg)}
::-webkit-scrollbar-thumb:hover{background:var(--brand-light)}

/* ===== 通用容器 ===== */
.container{
    max-width:1280px;
    margin:0 auto;
    padding:0 24px;
}

/* ===== 标题 ===== */
h1,h2,h3,h4,h5{
    color:var(--text-heading);
    line-height:1.3;
    font-weight:700;
    letter-spacing:-0.02em;
}

h1{font-size:clamp(2rem,5vw,3.5rem)}
h2{font-size:clamp(1.6rem,3vw,2.4rem)}
h3{font-size:1.25rem}
h4{font-size:1.1rem}

p,li,blockquote,figcaption{color:var(--text-main)}

a{
    color:var(--text-link);
    text-decoration:none;
    position:relative;
    transition:color 0.2s ease;
}

a:hover,a:focus{
    color:var(--brand);
    text-decoration:none;
}

img,svg{
    max-width:100%;
    height:auto;
    display:block;
}

/* ===== 按钮 ===== */
.btn{
    display:inline-flex;
    align-items:center;
    justify-content:center;
    gap:8px;
    padding:0.8rem 2rem;
    border-radius:50px;
    font-weight:600;
    font-size:1rem;
    background:var(--btn-bg);
    color:var(--btn-text);
    border:none;
    cursor:pointer;
    transition:var(--transition);
    box-shadow:0 4px 15px rgba(150,50,20,0.25);
    position:relative;
    overflow:hidden;
    backdrop-filter:blur(4px);
}

.btn::before{
    content:'';
    position:absolute;
    top:0;left:-100%;
    width:100%;height:100%;
    background:linear-gradient(120deg,transparent,rgba(255,255,255,0.2),transparent);
    transition:left 0.5s ease;
}

.btn:hover::before{left:100%}

.btn:hover{
    transform:translateY(-3px);
    box-shadow:0 8px 25px rgba(150,50,20,0.35);
    color:var(--btn-text);
}

.btn:active{
    transform:translateY(-1px);
}

.btn-light{
    background:#fff8f5;
    color:#7a2e1a;
    box-shadow:0 4px 15px rgba(0,0,0,0.15);
}

.btn-light:hover{
    background:#ffffff;
    color:#5a1e0a;
    box-shadow:0 8px 25px rgba(0,0,0,0.2);
}

.btn-outline{
    background:transparent;
    border:2px solid var(--brand);
    color:var(--brand);
    box-shadow:none;
}

.btn-outline:hover{
    background:var(--brand);
    color:#fff;
    box-shadow:0 8px 20px rgba(150,50,20,0.3);
}

/* ===== 卡片 - 毛玻璃效果 ===== */
.card{
    background:var(--glass);
    backdrop-filter:blur(16px) saturate(180%);
    -webkit-backdrop-filter:blur(16px) saturate(180%);
    border:1px solid var(--glass-border);
    border-radius:var(--card-radius);
    padding:2rem;
    box-shadow:var(--shadow);
    transition:var(--transition);
    position:relative;
    overflow:hidden;
}

.card::after{
    content:'';
    position:absolute;
    top:0;left:0;
    right:0;height:1px;
    background:linear-gradient(90deg,transparent,rgba(255,255,255,0.3),transparent);
}

.card:hover{
    transform:translateY(-6px) scale(1.01);
    box-shadow:var(--shadow-hover);
    border-color:rgba(255,255,255,0.6);
}

[data-theme="dark"] .card:hover{
    border-color:rgba(255,180,150,0.25);
}

.card h3,.card h4{
    margin-bottom:1rem;
    position:relative;
    padding-bottom:0.5rem;
}

.card h3::after,.card h4::after{
    content:'';
    position:absolute;
    bottom:0;left:0;
    width:40px;height:3px;
    background:linear-gradient(90deg,var(--brand),var(--brand-light));
    border-radius:4px;
}

/* ===== 网格 ===== */
.grid-2{
    display:grid;
    grid-template-columns:repeat(2,1fr);
    gap:1.8rem;
}

.grid-3{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
    gap:1.8rem;
}

.grid-4{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
    gap:1.2rem;
}

/* ===== Header & 导航 ===== */
.site-header{
    position:fixed;
    top:0;left:0;right:0;
    z-index:1000;
    background:var(--nav-bg);
    backdrop-filter:blur(20px) saturate(200%);
    -webkit-backdrop-filter:blur(20px) saturate(200%);
    border-bottom:1px solid rgba(255,255,255,0.08);
    box-shadow:0 4px 30px rgba(0,0,0,0.15);
    transition:var(--transition);
}

.nav-wrap{
    display:flex;
    justify-content:space-between;
    align-items:center;
    padding:0.8rem 24px;
    gap:1rem;
    flex-wrap:wrap;
    max-width:1280px;
    margin:0 auto;
}

.logo{
    display:flex;
    align-items:center;
    gap:10px;
    font-size:1.4rem;
    font-weight:800;
    color:var(--nav-text);
    letter-spacing:0.02em;
}

.logo .mark{
    width:40px;height:40px;
    border-radius:12px;
    background:linear-gradient(135deg,var(--brand),var(--brand-dark));
    display:flex;
    align-items:center;
    justify-content:center;
    color:#fff;
    font-weight:bold;
    font-size:1.2rem;
    box-shadow:0 4px 12px rgba(150,50,20,0.3);
}

.nav-links{
    display:flex;
    gap:2rem;
    align-items:center;
}

.nav-links a{
    color:var(--nav-text);
    font-weight:500;
    font-size:0.95rem;
    padding:0.4rem 0.2rem;
    position:relative;
    opacity:0.85;
    transition:opacity 0.3s ease;
}

.nav-links a::after{
    content:'';
    position:absolute;
    bottom:0;left:0;
    width:0;height:2px;
    background:var(--brand-light);
    transition:width 0.3s ease;
}

.nav-links a:hover{
    opacity:1;
    color:var(--brand-light);
}

.nav-links a:hover::after{
    width:100%;
}

.search-box{
    display:flex;
    align-items:center;
    background:rgba(255,255,255,0.1);
    border:1px solid rgba(255,255,255,0.1);
    border-radius:50px;
    padding:0.15rem 0.2rem 0.15rem 1rem;
    backdrop-filter:blur(10px);
}

.search-box input{
    border:none;
    background:transparent;
    padding:0.5rem 0.2rem;
    color:var(--nav-text);
    font-size:0.9rem;
    outline:none;
    min-width:140px;
}

.search-box input::placeholder{
    color:rgba(255,255,255,0.5);
}

.search-box button{
    background:linear-gradient(135deg,var(--brand),var(--brand-dark));
    border:none;
    border-radius:50px;
    width:36px;height:36px;
    display:flex;
    align-items:center;
    justify-content:center;
    color:#fff;
    cursor:pointer;
    transition:var(--transition);
    font-size:0.9rem;
}

.search-box button:hover{
    transform:scale(1.1);
    box-shadow:0 0 15px rgba(150,50,20,0.4);
}

.theme-toggle,.mobile-menu{
    background:none;
    border:none;
    color:var(--nav-text);
    font-size:1.4rem;
    cursor:pointer;
    width:40px;height:40px;
    display:flex;
    align-items:center;
    justify-content:center;
    border-radius:50%;
    transition:var(--transition);
    margin-left:0.2rem;
}

.theme-toggle:hover,.mobile-menu:hover{
    background:rgba(255,255,255,0.1);
    transform:rotate(10deg);
}

.mobile-menu{
    display:none;
    font-size:1.6rem;
}

/* ===== Hero 区域 ===== */
.hero{
    background:var(--hero-grad);
    color:#fff;
    padding:8rem 0 5rem;
    position:relative;
    overflow:hidden;
    margin-top:0;
}

.hero::before{
    content:'';
    position:absolute;
    top:-50%;right:-20%;
    width:80%;height:200%;
    background:radial-gradient(circle at center,rgba(255,120,80,0.15) 0%,transparent 70%);
    animation:pulse 8s ease-in-out infinite;
}

.hero::after{
    content:'';
    position:absolute;
    bottom:-30%;left:-10%;
    width:60%;height:150%;
    background:radial-gradient(circle at center,rgba(255,200,150,0.08) 0%,transparent 60%);
    animation:pulse 12s ease-in-out infinite reverse;
}

@keyframes pulse{
    0%,100%{transform:scale(1);opacity:0.8}
    50%{transform:scale(1.2);opacity:1}
}

.hero .container{
    position:relative;
    z-index:2;
    display:flex;
    flex-wrap:wrap;
    gap:3rem;
    align-items:center;
}

.hero-content{
    flex:1 1 50%;
    min-width:300px;
}

.hero h1{
    color:#fff;
    font-size:clamp(2.2rem,5.5vw,3.8rem);
    font-weight:900;
    line-height:1.2;
    margin-bottom:1.5rem;
    text-shadow:0 4px 30px rgba(0,0,0,0.3);
    background:linear-gradient(135deg,#fff 0%,rgba(255,255,255,0.8) 100%);
    -webkit-background-clip:text;
    -webkit-text-fill-color:transparent;
    background-clip:text;
}

.hero p{
    color:rgba(255,255,255,0.9);
    font-size:1.15rem;
    max-width:560px;
    margin-bottom:2rem;
    line-height:1.8;
}

.hero-actions{
    display:flex;
    gap:1rem;
    flex-wrap:wrap;
}

.hero-visual{
    flex:1 1 35%;
    min-width:280px;
    display:flex;
    justify-content:center;
    align-items:center;
}

.hero-visual svg{
    width:100%;
    max-width:400px;
    height:auto;
    filter:drop-shadow(0 20px 40px rgba(0,0,0,0.3));
    border-radius:24px;
    background:rgba(255,255,255,0.05);
    backdrop-filter:blur(10px);
    border:1px solid rgba(255,255,255,0.1);
}

/* ===== 通用区块 ===== */
.section{
    padding:5rem 0;
    position:relative;
}

.section:nth-child(even){
    background:rgba(0,0,0,0.02);
}

[data-theme="dark"] .section:nth-child(even){
    background:rgba(255,255,255,0.02);
}

.section-title{
    font-size:clamp(1.8rem,3.5vw,2.6rem);
    margin-bottom:3rem;
    position:relative;
    display:inline-block;
    padding-bottom:1rem;
}

.section-title::after{
    content:'';
    position:absolute;
    bottom:0;left:0;
    width:80px;height:4px;
    background:linear-gradient(90deg,var(--brand),var(--brand-light));
    border-radius:4px;
}

.section-title::before{
    content:'';
    position:absolute;
    bottom:0;left:80px;
    width:20px;height:4px;
    background:linear-gradient(90deg,var(--brand-light),transparent);
    border-radius:4px;
}

/* ===== 品牌区块 ===== */
.brand-cards{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
    gap:2rem;
    margin-bottom:2rem;
}

.brand-info{
    display:flex;
    flex-wrap:wrap;
    gap:1rem;
    margin-top:2rem;
}

.tag{
    background:var(--code-bg);
    color:var(--text-main);
    padding:0.4rem 1rem;
    border-radius:50px;
    font-size:0.85rem;
    display:inline-flex;
    align-items:center;
    gap:0.4rem;
    border:1px solid var(--border);
    backdrop-filter:blur(4px);
    transition:var(--transition);
}

.tag:hover{
    transform:translateY(-2px);
    box-shadow:0 4px 12px rgba(0,0,0,0.1);
}

/* ===== 文章卡片 ===== */
article.card{
    display:flex;
    flex-direction:column;
    height:100%;
}

article.card p{
    flex-grow:1;
}

article.card .btn{
    align-self:flex-start;
    margin-top:auto;
}

article.card .meta{
    font-size:0.85rem;
    color:var(--text-secondary);
    margin-bottom:0.8rem;
    display:flex;
    gap:1rem;
    align-items:center;
}

article.card .meta span{
    background:var(--code-bg);
    padding:0.2rem 0.6rem;
    border-radius:20px;
    font-size:0.8rem;
}

/* ===== FAQ ===== */
.faq-item{
    background:var(--glass);
    backdrop-filter:blur(12px);
    border:1px solid var(--glass-border);
    border-radius:16px;
    margin-bottom:1rem;
    overflow:hidden;
    transition:var(--transition);
}

.faq-item:hover{
    border-color:var(--brand-light);
    box-shadow:0 4px 20px rgba(150,50,20,0.1);
}

.faq-q{
    padding:1.2rem 1.8rem;
    cursor:pointer;
    font-weight:600;
    color:var(--text-heading);
    display:flex;
    justify-content:space-between;
    align-items:center;
    gap:1rem;
    transition:var(--transition);
    font-size:1.05rem;
}

.faq-q:hover{
    color:var(--brand);
}

.faq-q::after{
    content:'＋';
    font-size:1.4rem;
    color:var(--brand);
    transition:transform 0.3s ease,color 0.3s ease;
    flex-shrink:0;
}

.faq-item.open .faq-q::after{
    content:'－';
    transform:rotate(180deg);
}

.faq-a{
    padding:0 1.8rem 1.2rem;
    color:var(--text-main);
    display:none;
    line-height:1.8;
    border-top:1px dashed var(--border);
    margin-top:0.2rem;
}

.faq-item.open .faq-a{
    display:block;
    animation:fadeIn 0.3s ease;
}

@keyframes fadeIn{
    from{opacity:0;transform:translateY(-10px)}
    to{opacity:1;transform:translateY(0)}
}

/* ===== 教程区块 ===== */
.howto-steps{
    counter-reset:step;
}

.howto-steps ol{
    list-style:none;
    padding:0;
}

.howto-steps li{
    counter-increment:step;
    padding:1.2rem 1.2rem 1.2rem 4rem;
    position:relative;
    margin-bottom:1rem;
    background:var(--glass);
    border-radius:16px;
    border-left:4px solid var(--brand);
    transition:var(--transition);
}

.howto-steps li::before{
    content:counter(step);
    position:absolute;
    left:1.2rem;top:1.2rem;
    width:2rem;height:2rem;
    background:linear-gradient(135deg,var(--brand),var(--brand-dark));
    color:#fff;
    border-radius:50%;
    display:flex;
    align-items:center;
    justify-content:center;
    font-weight:bold;
    font-size:0.9rem;
    box-shadow:0 2px 8px rgba(150,50,20,0.3);
}

.howto-steps li:hover{
    transform:translateX(8px);
    border-left-color:var(--brand-light);
}

.howto-steps h3{
    margin-bottom:1rem;
    color:var(--brand);
    font-size:1.2rem;
}

.howto-steps ul{
    margin-top:1rem;
    padding-left:1.5rem;
}

.howto-steps ul li{
    padding:0.4rem 0;
    background:none;
    border:none;
    margin:0;
    list-style:disc;
}

.howto-steps ul li::before{
    display:none;
}

/* ===== 案例卡片 ===== */
.case-card{
    background:var(--glass);
    border-radius:20px;
    padding:2rem;
    position:relative;
    overflow:hidden;
    transition:var(--transition);
    border:1px solid var(--glass-border);
}

.case-card::before{
    content:'“';
    position:absolute;
    top:-20px;right:10px;
    font-size:8rem;
    color:var(--brand);
    opacity:0.1;
    font-family:Georgia,serif;
}

.case-card:hover{
    transform:translateY(-5px);
    box-shadow:var(--shadow-hover);
}

.case-card .avatar{
    width:60px;height:60px;
    border-radius:50%;
    background:linear-gradient(135deg,var(--brand),var(--brand-light));
    display:flex;
    align-items:center;
    justify-content:center;
    font-weight:bold;
    color:#fff;
    font-size:1.5rem;
    margin-bottom:1rem;
    box-shadow:0 4px 12px rgba(150,50,20,0.3);
}

.case-card .quote{
    font-style:italic;
    line-height:1.8;
    color:var(--text-main);
    position:relative;
    z-index:1;
}

.case-card .author{
    margin-top:1rem;
    font-weight:600;
    color:var(--brand);
}

/* ===== Footer ===== */
.footer{
    background:var(--footer-bg);
    color:var(--text-footer);
    padding:4rem 0 2rem;
    position:relative;
    overflow:hidden;
}

.footer::before{
    content:'';
    position:absolute;
    top:0;left:0;right:0;
    height:1px;
    background:linear-gradient(90deg,transparent,var(--brand),transparent);
}

.footer-grid{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(180px,1fr));
    gap:2.5rem;
    margin-bottom:2rem;
}

.footer h4{
    color:#fff;
    margin-bottom:1.2rem;
    font-size:1.1rem;
    position:relative;
    padding-bottom:0.5rem;
}

.footer h4::after{
    content:'';
    position:absolute;
    bottom:0;left:0;
    width:30px;height:2px;
    background:var(--brand);
}

.footer ul{
    list-style:none;
}

.footer ul li{
    margin-bottom:0.6rem;
}

.footer ul li a{
    color:var(--text-footer);
    transition:var(--transition);
    opacity:0.8;
}

.footer ul li a:hover{
    color:var(--brand-light);
    opacity:1;
    padding-left:5px;
}

.footer-contact p{
    color:var(--text-footer);
    margin-bottom:0.4rem;
}

.footer-bottom{
    border-top:1px solid rgba(255,255,255,0.1);
    padding-top:1.5rem;
    display:flex;
    justify-content:space-between;
    align-items:center;
    flex-wrap:wrap;
    gap:1rem;
    font-size:0.85rem;
}

.footer-bottom p{
    color:var(--text-footer);
    opacity:0.7;
}

/* ===== 返回顶部 ===== */
#backTop{
    position:fixed;
    bottom:30px;right:30px;
    width:52px;height:52px;
    background:linear-gradient(135deg,var(--brand),var(--brand-dark));
    color:#fff;
    border:none;
    border-radius:50%;
    font-size:1.5rem;
    cursor:pointer;
    display:none;
    align-items:center;
    justify-content:center;
    box-shadow:0 8px 25px rgba(150,50,20,0.4);
    transition:var(--transition);
    z-index:999;
    backdrop-filter:blur(10px);
}

#backTop:hover{
    transform:translateY(-5px) scale(1.05);
    box-shadow:0 12px 35px rgba(150,50,20,0.5);
}

#backTop.show{
    display:flex;
    animation:fadeInUp 0.3s ease;
}

@keyframes fadeInUp{
    from{opacity:0;transform:translateY(20px)}
    to{opacity:1;transform:translateY(0)}
}

/* ===== 滚动动画 Reveal ===== */
.reveal{
    opacity:0;
    transform:translateY(40px);
    transition:opacity 0.8s cubic-bezier(0.25,0.46,0.45,0.94),
               transform 0.8s cubic-bezier(0.25,0.46,0.45,0.94);
    will-change:transform,opacity;
}

.reveal.visible{
    opacity:1;
    transform:none;
}

.reveal-delay-1{transition-delay:0.1s}
.reveal-delay-2{transition-delay:0.2s}
.reveal-delay-3{transition-delay:0.3s}
.reveal-delay-4{transition-delay:0.4s}
.reveal-delay-5{transition-delay:0.5s}

/* ===== 图表/表格 ===== */
table{
    width:100%;
    border-collapse:collapse;
    margin:1.5rem 0;
    border-radius:12px;
    overflow:hidden;
    box-shadow:0 4px 15px rgba(0,0,0,0.05);
}

th,td{
    padding:1rem 1.2rem;
    text-align:left;
    border-bottom:1px solid var(--border);
}

th{
    background:linear-gradient(135deg,var(--brand),var(--brand-dark));
    color:#fff;
    font-weight:600;
    letter-spacing:0.02em;
}

tr:nth-child(even){
    background:rgba(0,0,0,0.02);
}

[data-theme="dark"] tr:nth-child(even){
    background:rgba(255,255,255,0.03);
}

tr:hover{
    background:rgba(150,50,20,0.05);
}

/* ===== 列表样式 ===== */
ul,ol{
    padding-left:1.5rem;
}

li{
    margin-bottom:0.5rem;
}

/* ===== 引用块 ===== */
blockquote{
    border-left:4px solid var(--brand);
    padding:1rem 1.5rem;
    background:var(--glass);
    border-radius:0 12px 12px 0;
    font-style:italic;
    margin:1.5rem 0;
}

/* ===== 代码块 ===== */
code{
    background:var(--code-bg);
    padding:0.2rem 0.5rem;
    border-radius:6px;
    font-size:0.9em;
    color:var(--brand);
}

pre{
    background:var(--code-bg);
    padding:1.5rem;
    border-radius:12px;
    overflow-x:auto;
    margin:1.5rem 0;
}

pre code{
    background:none;
    padding:0;
    color:var(--text-main);
}

/* ===== 分隔线 ===== */
hr{
    border:none;
    height:1px;
    background:linear-gradient(90deg,transparent,var(--border),transparent);
    margin:2rem 0;
}

/* ===== 响应式断点 ===== */
@media (max-width: 1024px){
    .nav-links{
        gap:1.2rem;
    }
    
    .hero{
        padding:7rem 0 4rem;
    }
    
    .section{
        padding:4rem 0;
    }
}

@media (max-width: 768px){
    .nav-wrap{
        padding:0.6rem 16px;
    }
    
    .nav-links{
        display:none;
        position:absolute;
        top:100%;left:0;right:0;
        background:var(--nav-bg);
        backdrop-filter:blur(20px);
        flex-direction:column;
        padding:1rem 2rem;
        gap:0.5rem;
        border-bottom:1px solid rgba(255,255,255,0.1);
        box-shadow:0 10px 30px rgba(0,0,0,0.2);
    }
    
    .nav-links.show{
        display:flex;
        animation:fadeIn 0.3s ease;
    }
    
    .nav-links a{
        padding:0.8rem 0;
        width:100%;
        text-align:center;
        font-size:1.1rem;
    }
    
    .mobile-menu{
        display:flex;
    }
    
    .search-box{
        display:none;
    }
    
    .hero .container{
        flex-direction:column-reverse;
        text-align:center;
        gap:2rem;
    }
    
    .hero p{
        margin-left:auto;
        margin-right:auto;
    }
    
    .hero-actions{
        justify-content:center;
    }
    
    .grid-2{
        grid-template-columns:1fr;
        gap:1.2rem;
    }
    
    .grid-3{
        grid-template-columns:1fr;
        gap:1.2rem;
    }
    
    .grid-4{
        grid-template-columns:repeat(2,1fr);
        gap:1rem;
    }
    
    .section-title{
        font-size:1.6rem;
    }
    
    .footer-grid{
        grid-template-columns:repeat(2,1fr);
        gap:1.5rem;
    }
    
    .footer-bottom{
        flex-direction:column;
        text-align:center;
    }
    
    #backTop{
        bottom:20px;right:20px;
        width:44px;height:44px;
        font-size:1.2rem;
    }
}

@media (max-width: 480px){
    .container{
        padding:0 16px;
    }
    
    .grid-4{
        grid-template-columns:1fr;
    }
    
    .footer-grid{
        grid-template-columns:1fr;
        gap:2rem;
    }
    
    .hero h1{
        font-size:1.8rem;
    }
    
    .card{
        padding:1.5rem;
    }
    
    .btn{
        padding:0.7rem 1.5rem;
        font-size:0.9rem;
    }
    
    .faq-q{
        padding:1rem 1.2rem;
        font-size:0.95rem;
    }
    
    .faq-a{
        padding:0 1.2rem 1rem;
    }
    
    .tag{
        font-size:0.75rem;
        padding:0.3rem 0.8rem;
    }
}

/* ===== 暗色模式过渡 ===== */
body, .site-header, .card, .btn, .footer{
    transition:background 0.4s ease,color 0.3s ease,border-color 0.3s ease,box-shadow 0.3s ease;
}

/* ===== 无障碍 ===== */
:focus-visible{
    outline:3px solid var(--brand-light);
    outline-offset:3px;
    border-radius:4px;
}

::selection{
    background:var(--brand);
    color:#fff;
}

/* ===== 懒加载图片占位 ===== */
.lazy-img{
    background:linear-gradient(110deg,var(--code-bg) 8%,var(--surface) 18%,var(--code-bg) 33%);
    background-size:200% 100%;
    animation:shimmer 1.5s linear infinite;
    border-radius:12px;
    min-height:100px;
}

@keyframes shimmer{
    0%{background-position:200% 0}
    100%{background-position:-200% 0}
}

/* ===== 打印样式 ===== */
@media print{
    .site-header,.footer,#backTop,.search-box,.theme-toggle,.mobile-menu{
        display:none !important;
    }
    
    body{
        background:#fff;
        color:#000;
    }
    
    .card{
        box-shadow:none;
        border:1px solid #ddd;
        background:#fff;
    }
    
    .hero{
        background:#fff;
        color:#000;
        padding:2rem 0;
    }
    
    .hero h1,.hero p{
        color:#000;
    }
}
```