:root {
    --primary-red: #C80430; /* Accent color */
    --primary-blue: #004083; /* Main action color */
    --text-dark: #333; /* Dark text for readability */
    --text-light: #666; /* Lighter text for tips/footer */
    --background-white: #fff;
    --border-light: #eee;
    --border-medium: #ddd;
}

/* Base Styles */
body {
    font-family: 'Open Sans', 'Roboto', Arial, sans-serif; /* Modern sans-serif stack */
    background-color: var(--background-white);
    color: var(--text-dark);
    margin: 0;
    padding: 0;
    line-height: 1.6;
    font-size: 16px;
}

.container {
    max-width: 960px; /* Wider container for a modern feel */
    margin: 40px auto; /* More vertical space */
    padding: 30px;
    background-color: var(--background-white);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08); /* Subtle shadow for depth */
    border-radius: 8px; /* Slightly rounded corners */
}

/* Header */
header {
    text-align: center;
    margin-bottom: 50px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-light); /* Clean separator */
}

header h1 {
    font-size: 2.8em; /* Larger welcome message */
    color: var(--primary-blue); /* Use blue for main heading */
    margin: 0 0 10px;
    font-weight: 700;
}

.company-legal-name {
    font-size: 1.8em; /* Legal name prominent but secondary */
    color: var(--text-dark);
    margin: 0;
    font-weight: 600;
    line-height: 1.3;
}

/* Company Details Section */
.company-details {
    margin-bottom: 50px;
}

.data-group {
    margin-bottom: 30px; /* Space between data sections */
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-light);
}

.data-group:last-child {
    border-bottom: none; /* No border for the last section */
}

.data-group h3 {
    font-size: 1.5em;
    color: var(--primary-red); /* Red accent for sub-headings */
    margin-top: 0;
    margin-bottom: 15px;
    font-weight: 600;
}

/* Definition List Styling (dl, dt, dd) for professional data display */
dl {
    display: grid;
    grid-template-columns: 200px 1fr; /* Fixed width for labels, rest for values */
    gap: 10px 20px; /* More space between items */
    margin: 0;
    padding: 0;
}

dt {
    font-weight: 600; /* Labels are slightly bold */
    color: var(--text-dark);
    text-align: right; /* Align labels to the right */
    padding-right: 10px; /* Space between label and value */
}

dd {
    margin: 0;
    padding: 0;
    color: var(--text-dark);
}

/* Unsubscribe Section */
.unsubscribe-section {
    margin-top: 50px;
    padding-top: 30px;
    border-top: 1px solid var(--border-light);
}

.unsubscribe-section h2 {
    font-size: 1.8em;
    color: var(--primary-blue);
    margin-top: 0;
    margin-bottom: 20px;
    font-weight: 600;
}

.unsubscribe-section p {
    margin-bottom: 15px;
    color: var(--text-dark);
}

.input-group {
    display: flex; /* Aligns input and button horizontally */
    gap: 10px; /* Space between input and button */
    margin-bottom: 10px;
}

#emailInput {
    flex-grow: 1; /* Input takes available space */
    padding: 12px 15px;
    border: 1px solid var(--border-medium);
    border-radius: 5px;
    font-size: 1em;
    box-sizing: border-box; /* Ensures padding doesn't increase total width */
    max-width: 500px; /* Prevents input from becoming too wide */
}

#emailInput::placeholder {
    color: #aaa;
}

#submitEmails {
    padding: 12px 25px;
    background-color: var(--primary-blue);
    color: var(--background-white);
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.05em;
    font-weight: 600;
    transition: background-color 0.2s ease; /* Smooth hover effect */
}

#submitEmails:hover {
    background-color: var(--primary-red); /* Red on hover for contrast */
}

.tip {
    font-size: 0.85em;
    color: var(--text-light);
    margin-top: 5px;
    text-align: left;
}

.feedback-message {
    margin-top: 15px;
    padding: 10px 15px;
    border-radius: 5px;
    font-weight: 500;
    color: var(--primary-blue); /* Default feedback color */
}

/* Footer */
footer {
    text-align: center;
    margin-top: 50px;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
    font-size: 0.9em;
    color: var(--text-light);
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .container {
        margin: 20px auto;
        padding: 20px;
    }

    header h1 {
        font-size: 2em;
    }

    .company-legal-name {
        font-size: 1.5em;
    }

    dl {
        grid-template-columns: 1fr; /* Stack dt and dd on smaller screens */
        gap: 5px 0;
    }

    dt {
        text-align: left; /* Align labels to the left when stacked */
        padding-right: 0;
        margin-bottom: 5px; /* Add space below label when stacked */
    }
    
    .input-group {
        flex-direction: column; /* Stack input and button */
    }

    #emailInput {
        max-width: 100%;
    }

    #submitEmails {
        width: 100%; /* Make button full width when stacked */
    }
}