Animated Glassmorphism Login | HTML, CSS & JavaScript

<div class="login-container">
        <form class="login-form" onsubmit="event.preventDefault();">
            <h2>Login</h2>
            <p class="subtitle">Please enter your credentials to connect.</p>
            
            <div class="input-group">
                <input type="email" required placeholder=" ">
                <label>Email Address</label>
            </div>
            
            <div class="input-group">
                <input type="password" required placeholder=" ">
                <label>Password</label>
            </div>
            
            <div class="form-actions">
                <label class="remember-me">
                    <input type="checkbox"> Remember device
                </label>
                <a href="#" class="forgot-pass">Forgot details?</a>
            </div>
            
            <button type="submit" class="submit-btn">Sign In</button>
            
            <p class="signup-text">New around here? <a href="#">Create account</a></p>
        </form>
    </div>

* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

body {
            position: relative;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background: #0f111a;
            overflow: hidden;
        }

/* ----------------------------------------------------
           ANIMATED BACKGROUND LAYER (Fixed Stack Order)
        ---------------------------------------------------- */
        .background-glow {
            position: absolute;
            width: 100%;
            height: 100%;
            top: 0;
            left: 0;
            z-index: 1; /* Explicitly beneath the login card */
            pointer-events: none; /* Prevents background elements from blocking clicks */
        }

.sphere {
            position: absolute;
            border-radius: 50%;
            filter: blur(60px);
            -webkit-filter: blur(60px);
            
            /* Performance fixes to prevent animation stuttering */
            will-change: transform;
            transform: translate3d(0, 0, 0); 
        }

.sphere-1 {
            width: 350px;
            height: 350px;
            background: linear-gradient(135px, #ff007f, #7928ca);
            top: 15%;
            left: 20%;
            animation: driftFirst 14s infinite alternate ease-in-out;
        }

.sphere-2 {
            width: 450px;
            height: 450px;
            background: linear-gradient(135px, #00dfd8, #007cf0);
            bottom: 10%;
            right: 15%;
            animation: driftSecond 18s infinite alternate ease-in-out;
        }

/* Smooth floating keyframes */
        @keyframes driftFirst {
            0% { transform: translate(0, 0) scale(1); }
            50% { transform: translate(80px, -40px) scale(1.1); }
            100% { transform: translate(140px, 60px) scale(1); }
        }

@keyframes driftSecond {
            0% { transform: translate(0, 0) scale(1); }
            50% { transform: translate(-100px, 40px) scale(0.9); }
            100% { transform: translate(-160px, -60px) scale(1.1); }
        }

/* ----------------------------------------------------
           GLASSMORPHISM LOGIN CARD
        ---------------------------------------------------- */
        .login-container {
            position: relative;
            z-index: 2; /* Sits completely above the spheres layer */
            width: 420px;
            padding: 40px;
            border-radius: 24px;
            background: rgba(18, 88, 200, 0.3);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border: 1px solid rgba(255, 255, 255, 0.12);
            box-shadow: 0 25px 45px rgba(0, 0, 0, 0.4);
            
            /* Pop-in entry animation */
            animation: cardAppear 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
            opacity: 0;
            transform: translateY(30px);
        }

@keyframes cardAppear {
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

/* Typography */
        h2 {
            color: #fff;
            font-size: 2rem;
            font-weight: 600;
            margin-bottom: 6px;
            text-align: center;
            letter-spacing: -0.5px;
        }

.subtitle {
            color: rgba(255, 255, 255, 0.5);
            font-size: 0.9rem;
            margin-bottom: 35px;
            text-align: center;
        }

/* Smooth Interactive Form Controls */
        .input-group {
            position: relative;
            margin-bottom: 25px;
        }

.input-group input {
            width: 100%;
            padding: 15px 16px;
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid rgba(255, 255, 255, 0.08);
            border-radius: 12px;
            outline: none;
            color: #fff;
            font-size: 1rem;
            transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
        }

.input-group input:focus {
            border-color: rgba(0, 223, 216, 0.6);
            background: rgba(255, 255, 255, 0.1);
            box-shadow: 0 0 20px rgba(0, 223, 216, 0.15);
        }

.input-group label {
            position: absolute;
            left: 16px;
            top: 50%;
            transform: translateY(-50%);
            color: rgba(255, 255, 255, 0.4);
            transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
            pointer-events: none;
        }

/* Float animation rules when input is populated or focused */
        .input-group input:focus ~ label,
        .input-group input:not(:placeholder-shown) ~ label {
            top: -10px;
            left: 10px;
            font-size: 0.8rem;
            padding: 0 6px;
            color: #00dfd8;
        }

/* Inline Action Elements */
        .form-actions {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 0.85rem;
            margin-bottom: 30px;
            color: rgba(255, 255, 255, 0.6);
        }

.remember-me {
            display: flex;
            align-items: center;
            gap: 8px;
            cursor: pointer;
        }

.remember-me input {
            accent-color: #00dfd8;
            cursor: pointer;
        }

.forgot-pass, .signup-text a {
            color: #00dfd8;
            text-decoration: none;
            transition: color 0.2s ease;
        }

.forgot-pass:hover, .signup-text a:hover {
            color: #007cf0;
            text-decoration: underline;
        }

/* High Vibrancy Submit Button */
        .submit-btn {
            width: 100%;
            padding: 15px;
            background: #fff;
            border: none;
            border-radius: 12px;
            color: #0f111a;
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
        }

.submit-btn:hover {
            background: #00dfd8;
            color: #fff;
            box-shadow: 0 10px 25px rgba(0, 223, 216, 0.4);
            transform: translateY(-2px);
        }

.submit-btn:active {
            transform: translateY(0);
        }

.signup-text {
            text-align: center;
            font-size: 0.85rem;
            color: rgba(255, 255, 255, 0.5);
            margin-top: 30px;
        }

- Animated Glassmorphism Login

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