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

:root {
    --bg-color: #f4f7f6;
    --text-color: #333;
    --button-text: white;
    --button-hover-bg: #004d7a;
    --label-color: #004d7a;
    --error-color: red;
    --details-bg: #ffffff;
    --details-border: #ddd;
    --details-text: #333;
    --shadow-color: rgba(0, 0, 0, 0.5);
}

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    flex-direction: column;
    transition: background-color 0.3s, color 0.3s;
}

h1, h2 {
    color: var(--label-color);
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    font-size: 2rem;
}

h2 {
    font-size: 1.5rem;
}

body.dark-mode {
    --bg-color: #1c1c1c;
    --text-color: #f4f4f4;
    --button-text: #fff;
    --button-hover-bg: #005f75;
    --label-color: #4db8ff;
    --error-color: #ff4d4d;
    --details-bg: #2d2d2d;
    --details-border: #555;
    --details-text: #f4f4f4;
    --shadow-color: rgba(255, 255, 255, 0.1);
}

div {
    display: flex;
    flex-direction: column;
    gap: 3em;
}

button {
    padding: 30px 60px;
    font-size: 2rem;
    font-weight: bold;
    background-image: linear-gradient(120deg, #005f75,#1e90ff);
    color: var(--button-text);
    border: none;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 4px 4px 8px var(--shadow-color);
    transition: background-color 0.3s, transform 0.2s;
}

button:hover {
    background-color: var(--button-hover-bg);
    transform: scale(1.05);
}

button:focus {
    outline: none;
}

button:active {
    transform: scale(1);
}