/* --- CSS Reset & Variables --- */
:root {
    --primary-blue: #007bff;
    --dark-blue: #0056b3;
    --sky-blue: #e3f2fd;
    --text-dark: #333333;
    --text-light: #666666;
    --white: #ffffff;
    --gradient-bg: linear-gradient(135deg, #007bff 0%, #00c6ff 100%);
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

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

body {
    font-family: 'Kanit', sans-serif;
    background-color: #f9f9f9;
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; height: auto; display: block; }

/* --- Components --- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    font-weight: 700;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-size: 1.1rem;
}

.btn-primary {
    background: var(--gradient-bg);
    color: var(--white);
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 123, 255, 0.6);
}

.btn-download {
    background: var(--white);
    color: var(--primary-blue);
    border: 2px solid var(--primary-blue);
    padding: 8px 20px;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

/* --- Header --- */
header {
    background-color: var(--white);
    height: 70px;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo img {
    height: 50px;
    width: auto;
}

/* --- Hero Section --- */
.hero {
    background: linear-gradient(180deg, #ffffff 0%, #eef7ff 100%);
    padding: 40px 0 60px;
    text-align: center;
}

.hero-banner {
    max-width: 800px;
    margin: 0 auto 30px;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.cta-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.main-cta {
    font-size: 1.5rem;
    padding: 15px 50px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(0, 123, 255, 0.7); }
    70% { box-shadow: 0 0 0 20px rgba(0, 123, 255, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 123, 255, 0); }
}

/* --- Image Grid (Extra Images) --- */
.intro-images {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 40px;
    flex-wrap: wrap;
}
.intro-images img {
    border-radius: 10px;
    max-height: 150px;
    object-fit: contain;
}

/* --- Content Sections (SEO) --- */
.content-section {
    padding: 60px 0;
    border-bottom: 1px solid #eee;
}

.content-section:nth-child(even) {
    background-color: var(--white);
}

.content-section:nth-child(odd) {
    background-color: #f4faff;
}

.row {
    display: flex;
    align-items: center;
    gap: 40px;
}

.row.reverse {
    flex-direction: row-reverse;
}

.text-col {
    flex: 1;
}

.img-col {
    flex: 1;
    display: flex;
    justify-content: center;
}

.img-col img {
    border-radius: 15px;
    box-shadow: var(--shadow);
    max-height: 400px;
    object-fit: cover;
    width: 100%;
}

h2 {
    color: var(--primary-blue);
    font-size: 2rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

h2::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 60px;
    height: 4px;
    background: var(--gradient-bg);
    border-radius: 2px;
}

p {
    margin-bottom: 15px;
    color: var(--text-light);
    text-align: justify;
}

/* --- FAQ Section --- */
.faq-section {
    padding: 60px 0;
    background-color: var(--white);
}

.faq-title {
    text-align: center;
    margin-bottom: 40px;
}

.faq-item {
    background: #f8f9fa;
    margin-bottom: 15px;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid #e9ecef;
}

.faq-summary {
    padding: 20px;
    cursor: pointer;
    font-weight: 600;
    color: var(--dark-blue);
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* ซ่อนเครื่องหมายเริ่มต้นของ details/summary */
summary::-webkit-details-marker {
    display: none;
}
summary::marker {
    display: none;
}

/* สร้างเครื่องหมาย +/ - ด้วย CSS */
.faq-summary:after {
    content: '+';
    font-size: 1.5rem;
    color: var(--primary-blue);
    transition: transform 0.3s;
}

details[open] .faq-summary:after {
    content: '-';
    transform: rotate(0deg);
}

.faq-content {
    padding: 0 20px 20px;
    color: var(--text-light);
    border-top: 1px solid #eee;
}

/* --- Footer --- */
footer {
    background-color: #1a1a1a;
    color: #ccc;
    padding: 40px 0 20px;
    text-align: center;
}

.footer-logo img {
    height: 60px;
    margin: 0 auto 20px;
}

.copyright {
    margin-top: 20px;
    font-size: 0.9rem;
    border-top: 1px solid #333;
    padding-top: 20px;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .header-content {
        padding: 0 10px;
    }
    
    .row, .row.reverse {
        flex-direction: column;
    }

    h2 {
        font-size: 1.6rem;
        text-align: center;
    }

    h2::after {
        left: 50%;
        transform: translateX(-50%);
    }

    .main-cta {
        width: 90%;
    }

    .intro-images img {
        max-width: 45%;
    }
}