:root{
  --bs-dark:#0d1117;
  --bs-success:#00ff89;
  --hack-glow:0 0 8px var(--bs-success);
}
body.hack-dark{
  background-color:var(--bs-dark);
  color:#e6edf3;
  font-family:"Segoe UI",Roboto,"Helvetica Neue",Arial;
}
a{color:var(--bs-success);}
a:hover{color:#00ff89;filter:brightness(1.2);}
/* 头部 */
.hack-header{background:#000;border-bottom:1px solid var(--bs-success);}
.logo{font-size:1.25rem;font-weight:700;letter-spacing:1px;}
.nav-link{position:relative;padding:.5rem 1rem;}
.nav-link.active,.nav-link:hover{color:var(--bs-success)!important;text-shadow:var(--hack-glow);}
/* 轮播 */
.carousel-mask{position:absolute;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.55);}
.hack-hero{min-height:100vh;display:flex;align-items:center;}
.carousel-item{min-height:100vh;}
/* 卡片 */
.card{border:1px solid #333;}
.card.bg-dark{background:#161b22!important;}
/* 城市 */
.city-tag{display:block;padding:.25rem .5rem;background:#161b22;border:1px solid #00ff89;color:var(--bs-success);text-align:center;border-radius:3px;font-size:.8125rem;transition:.3s;}
.city-tag:hover{background:var(--bs-success);color:#000;}
/* 步骤 */
.step-box{background:#161b22;border:1px solid #00ff89;border-radius:6px;padding:1.5rem 1rem;text-align:center;}
.step-number{display:inline-flex;width:40px;height:40px;align-items:center;justify-content:center;background:var(--bs-success);color:#000;border-radius:50%;font-weight:700;}
/* 技术徽章 */
.tech-badge{background:#161b22;border:1px solid #00ff89;padding:.4rem .8rem;border-radius:20px;font-size:.875rem;}
/* 固定图片 */
.fixed-img{height:180px;object-fit:cover;width:100%;}
/* 表单 */
.form-control,.form-control:focus{background:#161b22;border:1px solid #444;color:#fff;}
.form-control:focus{border-color:var(--bs-success);box-shadow:var(--hack-glow);}
/* 页脚 */
.hack-footer{background:#000;}
.ultra-small{font-size:.75rem;}
/* 响应式 */
@media (max-width:576px){
  .carousel-caption h1{font-size:1.6rem;}
  .section-title{font-size:1.4rem;}
}
#cs_box {
    width: 90%;
    max-width: 240px;
    height: auto;
    min-height: 230px;
    color: #fff;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 16px;
    z-index: 1000;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    overflow: hidden;
}

.cs_close {
    color: #fff;
    position: absolute;
    right: 10px;
    top: 10px;
    cursor: pointer;
    font-size: 20px;
    font-family: Verdana, Geneva, sans-serif;
    z-index: 2;
}

.cs_title {
    font-size: 14px;
    margin: 10px;
    font-weight: bold;
    text-align: center;
}

.cs_img {
    width: 120px;
    height: 120px;
    background: #fff;
    margin: 10px auto;
    border-radius: 8px;
    background-image: url(/kf-tuya.jpg);
    background-size: cover;
    background-position: center;
}

.cs_info {
    font-size: 20px;
    margin: 10px auto;
    text-align: center;
    color: #fff;
    display: block;
    width: fit-content;
    max-width: 90%;
    font-weight: bold;
}

.cs_btn {
    width: calc(100% - 20px);
    height: 44px;
    background: rgba(0, 0, 0, 0.3);
    margin: 8px auto;
    border-radius: 8px;
    font-size: 25px;
    line-height: 44px;
    color: red;
    text-align: center;
    cursor: pointer;
    transition: background 0.3s ease;
}

.cs_btn:hover {
    background: rgba(0, 0, 0, 0.5);
}

/* 手机端微调 */
@media (max-width: 480px) {
    #cs_box {
        max-width: 240px;
        min-height: 220px;
    }

    .cs_img {
        width: 100px;
        height: 100px;
    }

    .cs_btn {
        height: 40px;
        line-height: 40px;
        font-size: 25px;
    }
}