/* 1. Base Reset and Variables */
:root {
    --primary-color: #2563eb;    /* Clean blue for links/buttons */
    --primary-hover: #1d4ed8;    /* Darker blue for hover states */
    --text-color: #1f2937;       /* Dark charcoal for high contrast text */
    --bg-color: #f9fafb;         /* Soft off-white background */
    --card-bg: #ffffff;          /* Pure white for the content box */
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 2. Layout Container (Desktop Default) */
.container {
    max-width: 650px;
    width: 100%;
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    text-align: center;
}

/* 3. Typography & Spacing */
.header h1 {
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 12px;
    color: #111827;
}

.subtitle {
    font-size: 1.15rem;
    color: #4b5563;
    margin-bottom: 30px;
}

.content p {
    font-size: 1rem;
    margin-bottom: 30px;
    text-align: left; /* Keeps body text readable */
}

.cta-section h2 {
    font-size: 1.5rem;
    margin-bottom: 8px;
}

.cta-section p {
    color: #4b5563;
    margin-bottom: 20px;
    font-size: 0.95rem;
}

/* 4. Responsive Button Layout */
.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    padding: 14px 32px;
    font-weight: 600;
    border-radius: 8px;
    transition: background-color 0.2s ease, transform 0.1s ease;
    width: auto; /* Fits text on desktop */
}

.btn:hover {
    background-color: var(--primary-hover);
}

.btn:active {
    transform: scale(0.98);
}

/* 5. Mobile Responsive Adjustments (Screens smaller than 480px) */
@media (max-width: 480px) {
    body {
        padding: 12px; /* Less border padding on small mobile screens */
    }

    .container {
        padding: 24px 16px; /* Tighter padding inside the card */
    }

    .header h1 {
        font-size: 1.75rem; /* Shrinks large titles so they don't awkwardly wrap */
    }

    .btn {
        display: block; /* Stacks the button to fill the screen width */
        width: 100%;
        padding: 16px; /* Slightly larger tap target for thumbs */
    }
}