:root {
    --primary-color: #4a90e2;
    --secondary-color: #f5f7fa;
    --text-color: #333;
    --error-color: #e74c3c;
    --success-color: #2ecc71;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 400px;
}

.login-card {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

.brand {
    background-color: var(--primary-color);
    color: #fff;
    padding: 20px;
    text-align: center;
}

.brand i {
    font-size: 48px;
    margin-bottom: 10px;
}

.brand h1 {
    font-size: 24px;
    font-weight: 600;
}

.login-form {
    padding: 40px;
}

.login-form h2 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 5px;
    color: var(--text-color);
}

.login-form > p {
    color: #777;
    margin-bottom: 30px;
}

.input-group {
    position: relative;
    margin-bottom: 25px;
}

.input-group input {
    width: 100%;
    padding: 10px 15px;
    font-size: 16px;
    color: var(--text-color);
    border: 1px solid #ddd;
    border-radius: 5px;
    outline: none;
    transition: border-color 0.3s ease;
}

.input-group input:focus {
    border-color: var(--primary-color);
}

.input-group label {
    position: absolute;
    top: 50%;
    left: 15px;
    transform: translateY(-50%);
    font-size: 16px;
    color: #777;
    pointer-events: none;
    transition: 0.3s ease all;
}

.input-group input:focus ~ label,
.input-group input:valid ~ label {
    top: 0;
    font-size: 12px;
    background-color: #fff;
    padding: 0 5px;
    color: var(--primary-color);
}

.input-group i {
    position: absolute;
    top: 50%;
    right: 15px;
    transform: translateY(-50%);
    color: #777;
}

.toggle-password {
    background: none;
    border: none;
    cursor: pointer;
    position: absolute;
    top: 50%;
    right: 15px;
    transform: translateY(-50%);
    color: #777;
}

.options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

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

.remember-me input {
    display: none;
}

.remember-me .checkmark {
    width: 18px;
    height: 18px;
    border: 2px solid #ddd;
    border-radius: 3px;
    margin-right: 8px;
    display: inline-block;
    position: relative;
}

.remember-me input:checked ~ .checkmark:after {
    content: '\2713';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--primary-color);
    font-size: 14px;
}

.forgot-password {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 14px;
}

.login-btn {
    width: 100%;
    padding: 12px;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.login-btn:hover {
    background-color: #3a7bd5;
}

.error-message {
    color: var(--error-color);
    text-align: center;
    margin-top: 15px;
    font-size: 14px;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-10px); }
    20%, 40%, 60%, 80% { transform: translateX(10px); }
}

.shake {
    animation: shake 0.82s cubic-bezier(.36,.07,.19,.97) both;
}