Animated embossed login animation | HTML, CSS & JavaScript

:root {
            --bg-color: #e0e5ec;
            --text-color: #4a5568;
            --light-shadow: #ffffff;
            --dark-shadow: #a3b1c6;
            --accent-color: #4299e1;
            
            /* Error colors */
            --error-color: #e53e3e;
            --error-dark: #d09a9a;
            --error-light: #fff5f5;
        }

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

body {
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background-color: var(--bg-color);
        }

.login-circle {
            position: relative;
            width: 380px;
            height: 380px;
            border-radius: 50%;
            background-color: var(--bg-color);
            box-shadow: 15px 15px 30px var(--dark-shadow), 
                       -15px -15px 30px var(--light-shadow);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            padding: 40px;
            transition: all 0.3s ease;
            overflow: hidden; /* Keeps animations inside */
        }

h2 {
            color: var(--text-color);
            margin-bottom: 5px;
            font-size: 1.5rem;
            font-weight: 600;
            letter-spacing: 1px;
            text-align: center;
        }

.hint {
            font-size: 0.75rem;
            color: #8fa0b5;
            margin-bottom: 20px;
            text-align: center;
        }

.input-group {
            position: relative;
            margin-bottom: 20px;
            width: 80%;
            perspective: 1000px;
        }

.input-group input {
            width: 100%;
            padding: 12px 20px;
            border: none;
            outline: none;
            background: var(--bg-color);
            border-radius: 25px;
            color: var(--text-color);
            font-size: 0.9rem;
            box-shadow: inset 5px 5px 10px var(--dark-shadow), 
                        inset -5px -5px 10px var(--light-shadow);
            transition: box-shadow 0.3s ease, color 0.3s ease;
        }

.input-group input:focus {
            box-shadow: inset 7px 7px 14px var(--dark-shadow), 
                        inset -7px -7px 14px var(--light-shadow);
        }

/* --- ERROR ANIMATION STYLES --- */
        .input-group input.error {
            color: var(--error-color);
            box-shadow: inset 5px 5px 10px var(--error-dark), 
                        inset -5px -5px 10px var(--error-light);
            animation: rotate-error 0.5s ease-in-out;
        }

@keyframes rotate-error {
            0% { transform: rotate(0deg); }
            20% { transform: rotate(-8deg); }
            40% { transform: rotate(8deg); }
            60% { transform: rotate(-8deg); }
            80% { transform: rotate(8deg); }
            100% { transform: rotate(0deg); }
        }

/* --- SUCCESS ANIMATION STYLES --- */
        .input-group input.success {
            animation: rotate-success 0.6s ease-in-out forwards;
        }

@keyframes rotate-success {
            0% { transform: rotate(0deg) scale(1); opacity: 1; }
            100% { transform: rotate(360deg) scale(0); opacity: 0; }
        }

.btn-submit {
            width: 80%;
            padding: 12px;
            border: none;
            outline: none;
            border-radius: 25px;
            background: var(--bg-color);
            color: var(--accent-color);
            font-weight: bold;
            font-size: 1rem;
            cursor: pointer;
            margin-top: 10px;
            box-shadow: 5px 5px 10px var(--dark-shadow), 
                       -5px -5px 10px var(--light-shadow);
            transition: all 0.2s ease;
        }

.btn-submit:active {
            box-shadow: inset 5px 5px 10px var(--dark-shadow), 
                        inset -5px -5px 10px var(--light-shadow);
            transform: scale(0.98);
        }

.form-content {
            display: flex;
            flex-direction: column;
            align-items: center;
            width: 100%;
            transition: opacity 0.4s ease;
        }
        
        .form-content.hide {
            opacity: 0;
            pointer-events: none;
        }

/* SUCCESS MESSAGE STYLES */
        .success-msg {
            position: absolute;
            opacity: 0;
            transform: scale(0.5); /* Start small for bounce effect */
            color: #48bb78;
            font-weight: bold;
            text-align: center;
            pointer-events: none;
            display: flex;
            flex-direction: column;
            align-items: center;
        }
        
        .success-msg.show {
            opacity: 1;
            /* Bouncy pop-in animation */
            animation: pop-in 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
        }

.success-msg .check-circle {
            width: 60px;
            height: 60px;
            border-radius: 50%;
            background: var(--bg-color);
            box-shadow: 5px 5px 10px var(--dark-shadow), 
                       -5px -5px 10px var(--light-shadow);
            display: flex;
            justify-content: center;
            align-items: center;
            font-size: 2rem;
            margin-bottom: 15px;
            color: #48bb78;
        }

@keyframes pop-in {
            0% { transform: scale(0.5); opacity: 0; }
            100% { transform: scale(1); opacity: 1; }
        }

function handleLogin() {
            const userInp = document.getElementById('username');
            const passInp = document.getElementById('password');
            const formContent = document.getElementById('formContent');
            const successMsg = document.getElementById('successMsg');
            
            // Mock credentials for testing
            const correctUser = "admin";
            const correctPass = "1234";

// Remove previous animation classes if they exist
            userInp.classList.remove('error', 'success');
            passInp.classList.remove('error', 'success');

// Trigger reflow so animations can restart if clicked multiple times
            void userInp.offsetWidth;
            void passInp.offsetWidth;

if (userInp.value === correctUser && passInp.value === correctPass) {
                // --- SUCCESS STATE ---
                // Add rotate-out success animation to inputs
                userInp.classList.add('success');
                passInp.classList.add('success');

// Wait for input rotation to finish (600ms), then fade out form & pop in success message
                setTimeout(() => {
                    formContent.classList.add('hide');
                    successMsg.classList.add('show');
                }, 600);

// Optional: Reset form automatically after 4 seconds to test again
                setTimeout(() => {
                    successMsg.classList.remove('show');
                    
                    setTimeout(() => {
                        formContent.classList.remove('hide');
                        userInp.value = '';
                        passInp.value = '';
                        userInp.classList.remove('success');
                        passInp.classList.remove('success');
                    }, 400);
                }, 4000);

} else {
                // --- ERROR STATE ---
                // Add rotation wobble and red colors
                userInp.classList.add('error');
                passInp.classList.add('error');

// Automatically remove the error class after the animation ends (500ms) 
                // so it returns back to the original design
                setTimeout(() => {
                    userInp.classList.remove('error');
                    passInp.classList.remove('error');
                }, 500);
            }
        }

- Animated embossed login animation

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