:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --bg-light: #f8fafc;
    --white: #ffffff;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-main);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 650px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding-top: 20px;
}

.logo {
    color: var(--primary);
    font-weight: 800;
    font-size: 1.2rem;
    margin-bottom: 15px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -1px;
    line-height: 1.1;
    margin-bottom: 15px;
}

header h1 span { color: var(--primary); }
.subtitle { color: var(--text-muted); font-size: 1.1rem; }

/* --- Added Banner Styling for SEO & Trust --- */
.banner-container {
    margin-top: 25px;
    text-align: center;
}

.retailer-banner {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    border: 1px solid #e2e8f0;
}
/* -------------------------------------------- */

.calculator-card {
    background: var(--white);
    padding: 30px;
    border-radius: 24px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    border: 1px solid #f1f5f9;
}

.input-group { margin-bottom: 20px; }

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

select, input {
    width: 100%;
    display: block;
    padding: 14px;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    font-size: 1rem;
    background-color: #ffffff;
}

button {
    width: 100%;
    padding: 16px;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: background-color 0.2s;
}

button:hover {
    background-color: var(--primary-dark);
}

.result-box {
    margin-top: 20px;
}

.info-section {
    margin-top: 40px;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 20px;
}

.guide-grid { 
    display: grid; 
    grid-template-columns: 1fr 1fr; 
    gap: 15px; 
    margin-top: 20px; 
}

.guide-card { 
    background: var(--white); 
    padding: 20px; 
    border-radius: 16px; 
    text-decoration: none; 
    color: inherit; 
    border: 1px solid #f1f5f9; 
    transition: transform 0.2s, box-shadow 0.2s;
}

.guide-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.guide-card i {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 10px;
}

.guide-card h3 {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.guide-card p {
    font-size: 0.9rem;
    color: var(--text-muted);
}

footer { 
    margin-top: 50px; 
    text-align: center; 
    padding: 30px 0; 
    border-top: 1px solid #e2e8f0; 
}

.footer-links {
    margin-bottom: 10px;
}

.footer-links a {
    text-decoration: none;
    color: var(--text-muted);
    margin: 0 10px;
    font-size: 0.9rem;
}

footer p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

@media (max-width: 600px) {
    .guide-grid { grid-template-columns: 1fr; }
    header h1 { font-size: 2rem; }
    .container { padding: 0 10px; }
}