@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&family=Prompt:wght@300;400;600&display=swap');

:root {
            --tsu-blue: #003366;
            --tsu-red: #95081b;
            --tsu-white: #ffffff;
            --tsu-light: #f8f9fa;
        }

        body {
            font-family: 'Prompt', sans-serif;
            color: #333;
            scroll-behavior: smooth;
        }

        h1, h2, h3, h4, h5, .nav-link {
            font-family: 'Montserrat', sans-serif;
            font-weight: 700;
        }

        /* Navbar */
        .navbar {
            background-color: var(--tsu-blue);
            border-bottom: 4px solid var(--tsu-red);
        }
        .navbar-brand, .nav-link {
            color: white !important;
        }
        .nav-link:hover {
            color: #ccc !important;
        }

        /* Hero Section with New bg.jpg */
        .hero {
            position: relative;
            /* background: linear-gradient(rgba(0, 31, 63, 0.4), rgba(0, 31, 63, 0.4)), url('header_bg.webp'); */
            background-size: cover;
            background-position: center;
            background-repeat: no-repeat;
            background-attachment: scroll;
            color: white;
            padding: 70px 0;
            overflow: hidden;
            display: flex;
            align-items: center; /* จัดกึ่งกลางแนวตั้ง */
            min-height: 420px; /* ความสูงหน้าจอ */
            text-align: left; /* วางข้อความชิดซ้าย */
            width: 100vw;
            margin-left: calc(50% - 50vw);
            margin-right: calc(50% - 50vw);
        }
        
        /* จำกัดพื้นที่ข้อความ 75% */
        .hero-content {
            display: flex;
            align-items: center;
            width: 100%;
        }

        .hero-text-container {
            flex: 0 0 70%;
            max-width: 70%;
            animation: fadeInContent 1.5s ease-out;
        }

        .hero-icon-container {
            flex: 0 0 30%;
            max-width: 30%;
            text-align: center;
            animation: fadeInContent 1.5s ease-out;
        }

        .hero-icon {
            width: 100%;
            max-width: 280px;
            height: auto;
            filter: drop-shadow(0 10px 20px rgba(0, 0, 0, 0.35));
        }

        .hero h1 {
            font-size: 2.5rem;
            line-height: 1.2;
            margin-bottom: 25px;
            /* text-transform: uppercase; */
            text-shadow: 2px 2px 15px rgba(0,0,0,0.6);
        }
        .hero-date-location {
            background: var(--tsu-red);
            display: inline-block;
            padding: 12px 24px;
            border-radius: 5px;
            font-size: 1.1rem;
            box-shadow: 0 4px 15px rgba(0,0,0,0.4);
            margin-bottom: 30px;
        }
        
        @keyframes fadeInContent {
            from { opacity: 0; transform: translateX(-30px); }
            to { opacity: 1; transform: translateX(0); }
        }

        /* Sections */
        .section-padding {
            padding: 80px 0;
        }
        .section-title {
            color: var(--tsu-blue);
            margin-bottom: 50px;
            position: relative;
            padding-bottom: 15px;
            text-align: center;
        }
        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--tsu-red);
        }
        /* Sidebar Info Box */
        .info-sidebar-card {
            background: white;
            padding: 25px;
            border-radius: 10px;
            box-shadow: 0 5px 20px rgba(0,0,0,0.05);
            border-top: 5px solid var(--tsu-blue);
        }
        /* Topics */
        .topic-card {
            border: none;
            border-top: 4px solid var(--tsu-blue);
            transition: 0.3s;
            height: 100%;
            background: var(--tsu-white);
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        .topic-card p {
            margin-bottom: 5px;
        }
        .topic-card h5 {
            font-size: 1rem;
            line-height: 1.35;
            margin-bottom: 0.35rem;
        }
        .topic-card:hover {
            transform: translateY(-3px);
            border-top-color: var(--tsu-red);
            box-shadow: 0 8px 15px rgba(0,0,0,0.1);
        }
        .topic-icon {
            font-size: 3rem;
            color: var(--tsu-red);
            margin-bottom: 2px;
        }

        /* Login Box */
        .login-box {
            background: white;
            padding: 20px;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
            border-top: 5px solid var(--tsu-red);
            /* position: sticky; */
            top: 100px;
        }

        /* Keynote Speakers */
        .speaker-card {
            border: none;
            background: white;
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0,0,0,0.08);
            transition: 0.4s;
            height: 100%;
            margin-bottom: 30px;
        }
        .speaker-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        .speaker-img-box {
            position: relative;
            padding-top: 20px;
        }
        .speaker-img-circle {
            width: 160px;
            height: 160px;
            margin: 0 auto;
            border-radius: 50%;
            border: 6px solid var(--tsu-light);
            overflow: hidden;
        }
        .speaker-img-circle img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        .speaker-badge {
            position: absolute;
            top: 10px;
            right: 20px;
            background: var(--tsu-red);
            color: white;
            font-size: 0.7rem;
            padding: 4px 12px;
            border-radius: 20px;
            font-weight: bold;
        }

        /* Download List */
        .download-item {
            background: white;
            border: 1px solid #ddd;
            border-radius: 8px;
            padding: 12px 18px;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        .btn-download {
            background-color: var(--tsu-blue);
            color: white !important;
            border-radius: 5px;
            font-weight: 600;
            font-size: 0.8rem;
            padding: 6px 12px;
        }

        /* Payment info */
        .payment-box {
            border: 2px dashed var(--tsu-blue);
            border-radius: 10px;
            background-color: white;
            height: 80%;
        }

        /* Venue Map */
        .map-container {
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 4px 10px rgba(0,0,0,0.1);
        }

        /* Contact Section */
        .contact-icon {
            width: 40px;
            height: 40px;
            background-color: var(--tsu-blue);
            color: white;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1rem;
            margin-right: 15px;
        }

        /* Footer */
        footer {
            background-color: var(--tsu-blue);
            color: white;
            padding: 40px 0;
        }

        .btn-tsu {
            background-color: var(--tsu-red);
            color: white;
            padding: 10px 25px;
            font-weight: bold;
            border: none;
            border-radius: 50px;
            transition: 0.3s;
        }

        @media (max-width: 992px) {
            .hero-content { flex-direction: column; }
            .hero-text-container { flex: 0 0 100%; max-width: 100%; }
            .hero-icon-container { flex: 0 0 100%; max-width: 100%; margin-top: 25px; }
            .hero-icon { max-width: 200px; }
            .hero h1 { font-size: 2.2rem; }
            .login-box { position: static; margin-top: 40px; }
        }
        
        @media (max-width: 768px) {
            .hero { text-align: center; }
            .hero-text-container { max-width: 100%; margin: 0 auto; }
            .hero-icon-container { display: none; }
        }