@import url('https://fonts.googleapis.com/css2?family=Kanit:wght@300;400;500;700&display=swap');

/* --- การตั้งค่าพื้นฐานและตัวแปรสี --- */
:root {
    --primary-blue: #0D2F4B; /* สีน้ำเงินเข้ม (Navy) */
    --accent-gold: #D4AF37;   /* สีทอง */
    --light-gray: #f4f7f6;    /* สีเทาอ่อนสำหรับพื้นหลัง */
    --dark-gray: #333333;     /* สีเทาเข้มสำหรับตัวอักษร */
    --white: #ffffff;
}

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

body {
    font-family: 'Kanit', sans-serif;
    line-height: 1.6;
    color: var(--dark-gray);
    background-color: var(--white);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* --- ส่วนของ Navigation Bar --- */
.navbar {
    background-color: var(--white);
    padding: 1rem 0;
    border-bottom: 1px solid #e0e0e0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar .logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-blue);
}

.navbar .nav-links a {
    color: var(--primary-blue);
    text-decoration: none;
    margin: 0 15px;
    font-weight: 500;
    transition: color 0.3s ease;
}

.navbar .nav-links a:hover {
    color: var(--accent-gold);
}

.btn {
    padding: 10px 25px;
    border: none;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn-primary {
    background-color: var(--accent-gold);
    color: var(--primary-blue);
}

.btn-primary:hover {
    background-color: #c8a02b;
}

/* --- ส่วน Hero Section --- */
.hero {
    background-color: var(--light-gray);
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    color: var(--primary-blue);
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto 2rem auto;
    color: #555;
}

/* --- ส่วนจุดเด่น (Features) --- */
.features {
    padding: 60px 0;
}

.features .section-title {
    text-align: center;
    font-size: 2.2rem;
    color: var(--primary-blue);
    margin-bottom: 40px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-item {
    background-color: var(--white);
    padding: 30px;
    text-align: center;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.07);
}

.feature-item .icon {
    font-size: 3rem;
    color: var(--accent-gold);
    margin-bottom: 15px;
}

.feature-item h3 {
    font-size: 1.3rem;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

/* --- ส่วนขั้นตอนการทำงาน (How it works) --- */
.how-it-works {
    padding: 60px 0;
    background-color: var(--light-gray);
}

.how-it-works .section-title {
    text-align: center;
    font-size: 2.2rem;
    color: var(--primary-blue);
    margin-bottom: 40px;
}

.steps-container {
    display: flex;
    justify-content: space-around;
    text-align: center;
}

.step {
    max-width: 280px;
}

.step .step-number {
    width: 60px;
    height: 60px;
    background-color: var(--primary-blue);
    color: var(--white);
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 15px;
    border: 3px solid var(--accent-gold);
}

.step h3 {
    font-size: 1.3rem;
    color: var(--primary-blue);
    margin-bottom: 10px;
}

/* --- ส่วนแผนการออม (Saving Plan) --- */
.saving-plan {
    padding: 60px 0;
    background-color: var(--light-gray);
}

.saving-plan .section-title {
    text-align: center;
    font-size: 2.2rem;
    color: var(--primary-blue);
    margin-bottom: 40px;
}

.plan-card {
    background: var(--white);
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 30px 40px;
    max-width: 800px;
    margin: 0 auto;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.07);
}

.plan-header {
    text-align: center;
    margin-bottom: 30px;
}

.plan-header h3 {
    font-size: 1.8rem;
    color: var(--primary-blue);
    margin-bottom: 5px;
}

.plan-header p {
    font-size: 1.1rem;
    color: #666;
}

.plan-details-list {
    list-style: none;
    padding: 0;
    margin-bottom: 30px;
}

.plan-details-list li {
    padding: 15px 0;
    border-bottom: 1px solid #f0f0f0;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
}

.plan-details-list li:last-child {
    border-bottom: none;
}

.plan-details-list li::before {
    content: '✔';
    color: var(--accent-gold);
    font-weight: bold;
    font-size: 1.2rem;
    margin-right: 15px;
}

/* --- ส่วนท้าย (Footer) --- */
.footer {
    background-color: var(--primary-blue);
    color: var(--light-gray);
    padding: 40px 0;
    text-align: center;
}

.footer .container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer p {
    margin-top: 1rem;
}

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

.faq-section .section-title {
    text-align: center;
    font-size: 2.2rem;
    color: var(--primary-blue);
    margin-bottom: 40px;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid #e0e0e0;
    padding: 15px 0;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-item summary {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--primary-blue);
    cursor: pointer;
    list-style: none; /* Remove default marker */
    position: relative;
    padding-right: 30px; /* Space for the icon */
}

.faq-item summary::-webkit-details-marker {
    display: none; /* For Chrome/Safari */
}

.faq-item summary::after {
    content: '+';
    font-size: 1.5rem;
    color: var(--accent-gold);
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    transition: transform 0.2s ease-in-out;
}

.faq-item[open] summary::after {
    content: '−'; /* A minus sign */
    transform: translateY(-50%);
}

.faq-content {
    padding: 15px 0 5px 0;
    color: var(--dark-gray);
    line-height: 1.7;
}

/* --- Responsive Design for Mobile --- */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
    }
    .navbar .nav-links {
        margin-top: 1rem;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .steps-container {
        flex-direction: column;
        align-items: center;
        gap: 40px;
    }
    .plan-card {
        padding: 25px 20px;
    }
}