body{margin:0;font-family:Segoe UI,Roboto,sans-serif;background:linear-gradient(135deg,#4d8eff,#6a5acd,#2a3a5e);background-size:200% 200%;animation:gradientShift 18s ease infinite;min-height:100vh;display:flex;flex-direction:column;color:#fff}@keyframes gradientShift{0%{background-position:0% 50%}50%{background-position:100% 50%}to{background-position:0% 50%}}header{background:#1b243bcc;-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);padding:16px 32px;display:flex;align-items:center;justify-content:space-between;color:#fff;box-shadow:0 2px 6px #0000004d}header .logo{display:flex;align-items:center;gap:14px}header .logo img{height:36px}header .logo a{color:#fff;text-decoration:none;font-size:22px;font-weight:600;transition:color .3s}header .logo a:hover{color:#4d8eff}.nav-links{display:flex;align-items:center;gap:24px;font-size:16px}.nav-link{color:#cbd5e0;text-decoration:none;font-weight:500;position:relative;transition:color .3s}.nav-link:hover{color:#fff}.nav-link.active{color:#4d8eff}.nav-link.active:after{content:"";position:absolute;bottom:-6px;left:0;right:0;height:2px;background:linear-gradient(90deg,#4d8eff,#6a5acd);border-radius:2px}.main-content{flex:1;display:flex;justify-content:center;align-items:center}.card-signin{background:#1b243bcc;border:1px solid #2a3a5e;border-radius:16px;box-shadow:0 10px 30px #0006;color:#fff}.form-control{background:#ffffff1a;border:1px solid rgba(255,255,255,.3);color:#fff}.form-control::placeholder{color:#fff9}label{color:#cbd5e0}.btn-primary{background:linear-gradient(90deg,#4d8eff,#6a5acd);border:none;transition:opacity .3s}.btn-primary:hover{opacity:.9}