@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&display=swap');

*,
*::before,
*::after {
    box-sizing: border-box;
}

:root {
    --primary-color: #2a5298;
    --secondary-color: #2ab31d;
    --accent-color: #2a7ad2;
    --background-gradient: linear-gradient(135deg, #f4f7f6 0%, #e9efee 100%);
    --form-bg: #ffffff;
    --text-color: #333;
    --input-border: #ccc;
    --input-focus-border: var(--accent-color);
    --btn-bg: linear-gradient(135deg, var(--secondary-color), #239a17);
    --btn-hover-bg: linear-gradient(135deg, #32c724, #239a17);
    --shadow-md: 0 8px 20px rgba(0, 0, 0, 0.08);
}

body {
    margin: 0;
    height: 100vh;
    font-family: 'Poppins', sans-serif;
    background: var(--background-gradient);
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--text-color);
}

form {
    background: var(--form-bg);
    padding: 40px 30px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    width: 350px;
    box-sizing: border-box;
}

h2 {
    margin: 0 0 25px;
    text-align: center;
    font-weight: 600;
    color: var(--primary-color);
    font-size: 28px;
    position: relative;
    padding-bottom: 12px;
}

h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    border-radius: 2px;
    margin: 12px auto 0;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #555;
}

input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 14px 18px;
    margin-bottom: 25px;
    border: 2px solid var(--input-border);
    border-radius: 12px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

input[type="text"]:focus,
input[type="password"]:focus {
    outline: none;
    border-color: var(--input-focus-border);
    box-shadow: 0 0 8px rgba(42, 122, 210, 0.25);
}

button {
    width: 100%;
    padding: 14px 0;
    border: none;
    border-radius: 12px;
    background: var(--btn-bg);
    color: white;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 6px 15px rgba(42, 179, 29, 0.4);
    transition: background 0.3s ease, transform 0.2s ease;
}

button:hover {
    background: var(--btn-hover-bg);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(50, 199, 36, 0.6);
}

button:active {
    transform: translateY(1px);
    box-shadow: 0 4px 10px rgba(34, 144, 26, 0.5);
}

.error {
    color: #ff3333;
    font-size: 14px;
    text-align: center;
    margin-bottom: 15px;
    font-weight: 600;
}