:root {
            --primary-color: #007bff; /* A professional blue */
            --secondary-color: #28a745; /* A vibrant green */
            --accent-color: #f7a800; /* A gold/orange for highlights */
            --background-light: #e9f7ef;
            --background-dark: #f0f4f7;
            --card-background: #ffffff;
            --text-dark: #2c3e50;
            --text-medium: #556c7f;
            --text-light: #7f8c8d;
            --border-color: #d1e2ed;
            --error-color: #dc3545;
            --success-color: #28a745;
        }

        body {
            font-family: 'Kanit', sans-serif;
            display: flex;
            flex-direction: column;
            align-items: center;
            min-height: 100vh;
            background: linear-gradient(135deg, var(--background-dark) 0%, var(--background-light) 100%);
            margin: 0;
            line-height: 1.6;
            color: var(--text-dark);
        }

        /* --- Header (Navigation Bar) --- */
        .header {
            width: 100%;
            background-color: var(--card-background);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
            position: sticky;
            top: 0;
            z-index: 1000;
            padding: 15px 0;
            border-bottom: 1px solid var(--border-color);
        }

        .navbar {
            max-width: 1200px;
            margin: 0 auto;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 25px;
        }

        .logo {
            font-size: 1.8em;
            font-weight: 700;
            color: var(--primary-color);
            text-decoration: none;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .logo i {
            color: var(--secondary-color);
            font-size: 1.2em;
        }

        .nav-links {
            list-style: none;
            margin: 0;
            padding: 0;
            display: flex;
            gap: 30px;
        }

        .nav-links li a {
            text-decoration: none;
            color: var(--text-dark);
            font-weight: 600;
            font-size: 1.05em;
            padding: 5px 0;
            position: relative;
            transition: color 0.3s ease;
        }

        .nav-links li a::after {
            content: '';
            position: absolute;
            left: 0;
            bottom: -5px;
            width: 0;
            height: 3px;
            background-color: var(--primary-color);
            transition: width 0.3s ease;
        }

        .nav-links li a:hover {
            color: var(--primary-color);
        }

        .nav-links li a:hover::after,
        .nav-links li a.active::after {
            width: 100%;
        }

        .auth-buttons-nav {
            display: flex;
            gap: 10px;
        }
        .auth-buttons-nav .auth-button {
            padding: 10px 18px;
            font-size: 0.95em;
            border-radius: 8px;
            box-shadow: none;
        }
        .auth-buttons-nav .auth-button.login {
            background-color: var(--primary-color);
            color: white;
        }
        .auth-buttons-nav .auth-button.login:hover {
            background-color: #0056b3;
        }
        .auth-buttons-nav .auth-button.register {
            background-color: var(--accent-color);
            color: white;
        }
        .auth-buttons-nav .auth-button.register:hover {
            background-color: #e69500;
        }

        /* Hamburger menu for mobile */
        .menu-toggle {
            display: none;
            font-size: 1.8em;
            color: var(--text-dark);
            cursor: pointer;
        }

        /* --- Main Content Area --- */
        .main-content {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 25px;
            box-sizing: border-box;
            display: flex;
            flex-direction: column;
            gap: 30px;
        }

        /* --- Image Slider (Hero Section) --- */
        .slider-section {
            width: 100%;
            height: 400px;
            background-color: #ccc;
            border-radius: 15px;
            overflow: hidden;
            position: relative;
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }

        .slider-wrapper {
            display: flex;
            height: 100%;
            transition: transform 0.5s ease-in-out;
        }

        .slide {
            min-width: 100%;
            height: 100%;
            background-size: cover;
            background-position: center;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.6);
            font-size: 2.5em;
            font-weight: 700;
            text-align: center;
            padding: 20px;
            box-sizing: border-box;
            text-decoration: none; /* Remove underline from <a> tag */
        }
        .slide p {
            margin: 0; /* Remove default paragraph margin */
        }
/* ใน css/header.css หรือ css/style.css */
.header .navbar .logo .logo-img {
    height: 40px; /* กำหนดความสูงของโลโก้ */
    width: auto; /* รักษาอัตราส่วนของรูปภาพ */
    /* อาจเพิ่ม margin หรือ padding ถ้าต้องการ */
}

/* หากต้องการปรับโลโก้เมื่ออยู่บนมือถือ */
@media (max-width: 768px) {
    .header .navbar .logo .logo-img {
        height: 30px; /* ลดความสูงลงสำหรับมือถือ */
    }
}
        /* Example slide images - REMOVED, now dynamic from PHP */
        /* .slide:nth-child(1) { background-image: url('...'); } */

        .slider-dots {
            position: absolute;
            bottom: 20px;
            left: 50%;
            transform: translateX(-50%);
            display: flex;
            gap: 10px;
        }

        .dot {
            width: 12px;
            height: 12px;
            background-color: rgba(255, 255, 255, 0.6);
            border-radius: 50%;
            cursor: pointer;
            transition: background-color 0.3s;
        }

        .dot.active {
            background-color: white;
        }

        /* --- Content Containers --- */
        /* Removed .content-section for simplified grid layout */
        
        .price-card {
            background-color: var(--card-background);
            padding: 40px;
            border-radius: 15px;
            box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
            text-align: center;
            animation: fadeIn 0.8s ease-out;
            border: 1px solid var(--border-color);
            box-sizing: border-box;
            position: relative;
            overflow: hidden;
            margin-bottom: 0; /* Handled by parent gap */
            min-height: 450px; /* Ensure minimum height to prevent squishing */
            display: flex; /* Make it a flex container */
            flex-direction: column; /* Stack content vertically */
            justify-content: space-between; /* Distribute space vertically */
        }
        /* Border pulse for important cards */
        .price-card::before {
            content: '';
            position: absolute;
            top: -2px;
            left: -2px;
            right: -2px;
            bottom: -2px;
            background: linear-gradient(45deg, var(--primary-color), var(--secondary-color), var(--accent-color));
            z-index: -1;
            border-radius: 17px;
            filter: blur(10px);
            opacity: 0.6;
            animation: borderPulse 5s infinite alternate ease-in-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        @keyframes borderPulse {
            0% { transform: scale(1); opacity: 0.6; }
            50% { transform: scale(1.01); opacity: 0.8; }
            100% { transform: scale(1); opacity: 0.6; }
        }

        h1 {
            color: var(--primary-color);
            margin-bottom: 10px;
            font-size: 2.5em;
            font-weight: 700;
            letter-spacing: -0.03em;
        }

        .currency-pair {
            font-size: 1.3em;
            color: var(--text-medium);
            margin-bottom: 25px;
            font-weight: 400;
        }

        .price-display {
            font-size: 5.5em;
            font-weight: bold;
            color: var(--secondary-color);
            margin-bottom: 25px;
            letter-spacing: -0.06em;
            display: block;
            padding: 20px 0;
            background: linear-gradient(to right, #eaf9f0, var(--background-light), #eaf9f0);
            border-radius: 12px;
            box-shadow: inset 0 3px 8px rgba(0, 0, 0, 0.08);
            transition: all 0.4s ease;
        }
        .price-display:hover {
            transform: translateY(-5px) scale(1.01);
            box-shadow: inset 0 3px 10px rgba(0, 0, 0, 0.1), 0 8px 20px rgba(0, 0, 0, 0.1);
        }

        .unit {
            font-size: 0.35em;
            vertical-align: super;
            color: var(--text-medium);
            font-weight: normal;
        }

        .last-updated {
            font-size: 0.95em;
            color: var(--text-light);
            margin-top: 30px;
            padding-top: 20px;
            border-top: 1px dashed var(--border-color);
        }

        .error-message, .success-message {
            font-weight: 600;
            margin-top: 20px;
            padding: 12px;
            border-radius: 8px;
            border: 1px solid;
            background-color: rgba(255, 255, 255, 0.8);
        }
        .error-message {
            color: var(--error-color);
            border-color: var(--error-color);
            background-color: rgba(220, 53, 69, 0.1);
        }
        .success-message {
            color: var(--success-color);
            border-color: var(--success-color);
            background-color: rgba(40, 167, 69, 0.1);
        }

        .note {
            font-size: 0.9em;
            color: var(--text-medium);
            margin-top: 25px;
            padding-top: 20px;
            border-top: 1px solid var(--border-color);
        }

        .exchange-info {
            font-size: 0.95em;
            color: var(--text-light);
            margin-top: 25px;
            border-top: 1px solid var(--border-color);
            padding-top: 25px;
            display: flex;
            flex-direction: column;
            gap: 12px;
            line-height: 1.8;
        }
        .exchange-info p { margin: 0; }
        .exchange-info a {
            color: var(--primary-color);
            text-decoration: none;
            font-weight: 600;
            transition: color 0.2s;
        }
        .exchange-info a:hover {
            color: var(--secondary-color);
            text-decoration: underline;
        }

        /* Login/Register buttons inside the price card (if needed) */
        .auth-buttons {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-top: 30px;
            padding-top: 25px;
            border-top: 1px solid var(--border-color);
        }

        .auth-button {
            display: inline-block;
            padding: 15px 30px;
            border-radius: 10px;
            text-decoration: none;
            font-weight: 700;
            font-size: 1.1em;
            transition: all 0.3s ease;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
            min-width: 150px;
        }

        .auth-button.login {
            background-color: var(--primary-color);
            color: #ffffff;
        }
        .auth-button.login:hover {
            background-color: #0056b3;
            transform: translateY(-3px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
        }

        .auth-button.register {
            background-color: var(--accent-color);
            color: #ffffff;
        }
        .auth-button.register:hover {
            background-color: #e69500;
            transform: translateY(-3px);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
        }

        /* Why Us Section Styles */
        .section-header {
            color: var(--primary-color);
            margin-bottom: 30px;
            font-size: 2.2em;
            font-weight: 700;
            position: relative;
            padding-top: 10px;
            text-align: center; /* Default to center */
        }
        .section-header i {
            font-size: 1em;
            margin-right: 10px;
            color: var(--secondary-color);
        }
        .section-header::after {
            content: '';
            display: block;
            width: 70px;
            height: 4px;
            background-color: var(--secondary-color);
            margin: 15px auto 0; /* Center the line */
            border-radius: 5px;
        }

        .features-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 25px;
            text-align: left;
        }
        @media (min-width: 480px) {
            .features-grid { grid-template-columns: 1fr 1fr; }
        }

        .feature-item {
            display: flex;
            align-items: flex-start;
            gap: 15px;
            background-color: var(--background-dark);
            padding: 20px;
            border-radius: 10px;
            border: 1px solid var(--border-color);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
            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, 0.1);
        }

        .feature-item .icon {
            font-size: 2em;
            color: var(--secondary-color);
            flex-shrink: 0;
            margin-top: 5px;
        }

        .feature-item .text h3 {
            margin-top: 0;
            color: var(--primary-color);
            font-size: 1.15em;
            font-weight: 600;
            margin-bottom: 8px;
        }

        .feature-item .text p {
            font-size: 0.9em;
            color: var(--text-medium);
            margin: 0;
        }

        /* Review Section Styles */
        .review-section h2 {
            color: var(--secondary-color);
        }
        .review-section h2::after {
            background-color: var(--primary-color);
        }

        .review-item {
            background-color: var(--background-dark);
            border-radius: 10px;
            padding: 25px;
            margin-bottom: 20px;
            text-align: left;
            border: 1px solid var(--border-color);
            box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.05);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .review-item:hover {
            transform: translateY(-3px);
            box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.1), 0 5px 15px rgba(0, 0, 0, 0.08);
        }

        .review-author {
            font-weight: 700;
            color: var(--primary-color);
            margin-bottom: 8px;
            font-size: 1.2em;
        }

        .review-stars {
            color: var(--accent-color);
            margin-bottom: 12px;
            font-size: 1.3em;
        }

        .review-text {
            color: var(--text-dark);
            font-size: 0.98em;
            line-height: 1.7;
        }

        /* Exchange Form Styling */
        .exchange-form {
            text-align: left;
            /* Removed padding and margin as it's now inside .price-card */
        }
        .exchange-form .section-header {
            text-align: center; /* Center header for form card */
            margin-bottom: 25px;
        }
        .exchange-form .section-header::after {
            margin: 15px auto 0; /* Center line for form card header */
        }
        .form-group { margin-bottom: 18px; }
        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: var(--text-dark);
            font-size: 0.95em;
        }
        .form-group input[type="text"],
        .form-group input[type="email"],
        .form-group input[type="tel"],
        .form-group input[type="number"],
        .form-group select {
            width: calc(100% - 24px);
            padding: 12px;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            font-size: 1em;
            color: var(--text-dark);
            box-sizing: border-box;
            transition: border-color 0.3s ease, box-shadow 0.3s ease;
        }
        .form-group input:focus, .form-group select:focus {
            border-color: var(--secondary-color);
            box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.25);
            outline: none;
        }
        .form-group select {
            background-color: var(--card-background);
            appearance: none;
            background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23000%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13%205.4l-118%20118.2L18.4%2074.9a17.6%2017.6%200%200%0A0-25.3%2024.9l130.4%20130.6c2.8%202.8%206.7%204.3%2010.6%204.3s7.8-1.5%2010.6-4.3l130.4-130.6a17.6%2017.6%200%200%200%200-24.9z%22%2F%3E%3C%2Fsvg%3E');
            background-repeat: no-repeat;
            background-position: right 10px center;
            background-size: 12px;
        }
        .submit-button {
            background-color: var(--secondary-color);
            color: #fff;
            padding: 14px 25px;
            border: none;
            border-radius: 8px;
            font-size: 1.1em;
            font-weight: 600;
            cursor: pointer;
            transition: background-color 0.3s ease, transform 0.2s ease, box-shadow 0.3s ease;
            width: 100%;
            margin-top: 10px;
        }
        .submit-button:hover {
            background-color: #218838;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
        }

        /* --- Footer --- */
        .footer {
            width: 100%;
            background-color: var(--text-dark);
            color: white;
            padding: 30px 25px;
            text-align: center;
            font-size: 0.9em;
            margin-top: 40px;
        }
        .footer p {
            margin: 0;
            margin-bottom: 10px;
        }
        .footer a {
            color: var(--primary-color);
            text-decoration: none;
            transition: color 0.2s;
        }
        .footer a:hover {
            color: var(--accent-color);
        }

        /* Responsive adjustments */
        @media (max-width: 900px) {
            .navbar {
                flex-wrap: wrap;
                justify-content: center;
                gap: 15px;
            }
            .logo, .nav-links, .auth-buttons-nav {
                width: 100%;
                justify-content: center;
            }
            .nav-links {
                flex-direction: column;
                display: none;
                width: 100%;
                text-align: center;
                gap: 15px;
                padding-top: 15px;
                border-top: 1px solid var(--border-color);
            }
            .nav-links.active {
                display: flex;
            }
            .menu-toggle {
                display: block;
                position: absolute;
                right: 25px;
                top: 20px;
            }
            .auth-buttons-nav {
                margin-top: 15px;
            }
        }

        @media (max-width: 767px) {
            .main-content {
                padding: 15px;
            }
            .price-card { /* Adjust padding for mobile */
                padding: 30px 20px;
                min-height: unset; /* Remove min-height on mobile */
            }
            h1 { font-size: 2em; }
            .currency-pair { font-size: 1.1em; }
            .price-display { font-size: 4em; }
            .auth-buttons {
                flex-direction: column;
                gap: 15px;
            }
            .auth-button { width: 100%; }
            .why-us-section h2, .review-section h2, .exchange-form .section-header { font-size: 2em; }
            .feature-item {
                flex-direction: column;
                align-items: center;
                text-align: center;
            }
            .feature-item .icon { margin-bottom: 10px; margin-top: 0; }
            .slider-section { height: 250px; }
            .slide { font-size: 1.8em; }
        }

        @media (min-width: 768px) {
            /* Adjust main-content to use grid for two columns */
            .main-content {
                display: grid;
                grid-template-columns: 1fr 1fr; /* Two equal columns */
                gap: 30px;
                align-items: flex-start; /* Align items to the top of the grid cell */
            }

            /* Place the price card and the exchange form directly as grid items */
            .price-card-container, .exchange-form-container {
                display: flex; /* Use flexbox to make the card fill the container */
                flex-direction: column;
                flex: 1; /* Allow them to grow and fill available space */
            }
            /* Set a min-height for the containers of the price card and form */
            /* This helps keep them visually balanced even if content length differs slightly */
            .price-card-container {
                min-height: 550px; /* Example min-height for price card column */
            }
            .exchange-form-container {
                min-height: 550px; /* Example min-height for form column */
            }

            /* Why Us and Reviews sections span both columns */
            .why-us-section, .review-section {
                grid-column: 1 / 3; /* Span both columns */
            }

            /* Adjust price card specific to its container */
            .price-card {
                height: 100%; /* Make price-card fill its parent container */
            }
            /* Adjust form within its container */
            .exchange-form {
                height: 100%; /* Make exchange-form fill its parent container */
                display: flex;
                flex-direction: column;
                justify-content: space-between; /* Distribute content vertically */
            }
        }
        .form-group input[type="text"],
.form-group input[type="number"],
.form-group input[type="email"],
.form-group input[type="tel"],
.form-group input[type="password"], /* ตรวจสอบให้แน่ใจว่ามีอันนี้อยู่ */
.form-group select,
.form-group textarea {
    width: calc(100% - 24px); /* Full width minus padding (12px on each side) */
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1em;
    color: var(--text-dark);
    box-sizing: border-box; /* สำคัญมาก: ทำให้ padding นับรวมใน width */
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    font-family: 'Kanit', sans-serif;
    /* เพิ่ม: กำหนด appearance เป็น none สำหรับบาง browser ที่อาจมี style เฉพาะ */
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(40, 167, 69, 0.25);
    outline: none;
}