:root{--primary-color:#06f;--primary-gradient:linear-gradient(135deg,#06f 0,#08f 100%)}body{font-family:"Microsoft YaHei",sans-serif;min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px;position:relative;overflow-x:hidden}body::before{content:'';position:fixed;top:0;left:0;width:100%;height:100%;background-image:url('../images/pexels-photo-36745921.png');background-size:cover;background-position:center;background-repeat:no-repeat;z-index:-2}body::after{content:'';position:fixed;top:0;left:0;width:100%;height:100%;background-color:rgba(0,0,0,0.8);z-index:-1}.login-wrapper{width:100%;max-width:500px;position:relative;z-index:10}.card{border-radius:16px;box-shadow:0 8px 24px rgba(0,102,255,0.15);border:0;overflow:hidden;background:rgba(255,255,255,0.95);backdrop-filter:blur(4px)}.card-header{background:var(--primary-gradient);color:white;text-align:center;padding:24px 20px}.card-header h4{margin:0;font-weight:bold}.card-body{padding:30px}.form-label{font-weight:600;color:#333}.form-control{height:46px;border-radius:8px;border:1px solid #ddd}.form-control:focus{border-color:var(--primary-color);box-shadow:0 0 0 .25rem rgba(0,102,255,0.15)}.btn-primary{height:48px;border-radius:8px;background:var(--primary-color);border:0;font-weight:600}.btn-primary:hover{background:#0052cc}.toggle-box{text-align:center;margin-top:20px;color:#666}.toggle-box a{color:var(--primary-color);text-decoration:none;font-weight:600}.toggle-box a:hover{text-decoration:underline}.invalid-feedback{font-size:12px}.input-group-text{cursor:pointer;background:white;border-left:none}.input-group .form-control{border-right:0}.logo{text-align:center;margin-bottom:24px}.logo img{width:60px;height:60px;border-radius:50%;object-fit:cover;margin-bottom:12px}.logo h5{color:#fff;font-weight:bold;text-shadow:0 1px 3px rgba(0,0,0,0.3)}.form-text{font-size:12px;color:#666}