* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: "Inter", system-ui, -apple-system, sans-serif;
            background: #ffffff;
            color: #102a43;
            line-height: 1.5;
        }
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }
        /* header */
        .navbar {
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            padding: 20px 0;
            border-bottom: 1px solid #e2eaf2;
        }
        .logo {
            font-weight: 700;
            font-size: 1.8rem;
            background: linear-gradient(145deg, #0a2942, #1b3b6b);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            letter-spacing: -0.02em;
        }
        .nav-links {
            display: flex;
            gap: 2rem;
            font-weight: 500;
            color: #2b4a6e;
        }
        .nav-links a {
            text-decoration: none;
            color: inherit;
        }
        .btn-outline {
            border: 1.5px solid #1b3b6b;
            color: #1b3b6b;
            background: transparent;
            padding: 8px 20px;
            border-radius: 30px;
            font-weight: 600;
            font-size: 0.9rem;
            transition: 0.2s;
            text-decoration: none;
        }
        .btn-outline:hover {
            background: #1b3b6b;
            color: white;
        }
        .btn-primary {
            background: #1b3b6b;
            color: white;
            padding: 14px 34px;
            border-radius: 40px;
            font-weight: 600;
            border: none;
            font-size: 1rem;
            cursor: pointer;
            transition: 0.2s;
            box-shadow: 0 10px 18px -8px #1b3b6b40;
            text-decoration: none;
            display: inline-block;
        }
        .btn-primary:hover {
            background: #0f2a4a;
            transform: translateY(-2px);
        }
        .btn-secondary {
            background: white;
            color: #1b3b6b;
            padding: 12px 28px;
            border-radius: 40px;
            font-weight: 600;
            border: 1.5px solid #1b3b6b;
            font-size: 1rem;
            cursor: pointer;
            transition: 0.2s;
            text-decoration: none;
            display: inline-block;
        }
        /* hero */
        .hero {
            padding: 60px 0 40px;
            text-align: center;
        }
        .hero h1 {
            font-size: 3.2rem;
            font-weight: 700;
            letter-spacing: -1.5px;
            background: linear-gradient(135deg, #0a2942, #28548c);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            max-width: 900px;
            margin: 0 auto 20px;
            line-height: 1.2;
        }
        .hero .subhead {
            font-size: 1.25rem;
            color: #3f5a7a;
            max-width: 700px;
            margin: 0 auto 32px;
        }
        .stats {
            display: flex;
            gap: 30px;
            justify-content: center;
            flex-wrap: wrap;
            margin: 30px 0 20px;
        }
        .stat-item {
            background: #f4f9ff;
            padding: 12px 26px;
            border-radius: 60px;
            font-weight: 500;
            border: 1px solid #cddef5;
            color: #1b3b6b;
        }
        .section-title {
            font-size: 2.2rem;
            font-weight: 600;
            margin: 60px 0 20px;
            text-align: center;
            color: #0a2942;
        }
        .section-sub {
            text-align: center;
            color: #4d6a8a;
            max-width: 700px;
            margin: 0 auto 40px;
        }
        .course-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 28px;
            margin: 40px 0;
        }
        .course-card {
            background: #ffffff;
            border: 1px solid #e2ecf9;
            border-radius: 28px;
            padding: 28px 22px;
            box-shadow: 0 8px 18px -8px rgba(0,35,70,0.06);
            transition: 0.2s;
        }
        .course-card:hover {
            border-color: #9cb9da;
            box-shadow: 0 20px 24px -12px #1b3b6b20;
        }
        .course-icon {
            font-size: 2.4rem;
            margin-bottom: 16px;
        }
        .course-card h3 {
            font-size: 1.5rem;
            font-weight: 600;
            margin-bottom: 10px;
            color: #0a2942;
        }
        .course-card p {
            color: #3b5779;
            margin-bottom: 20px;
            font-size: 0.95rem;
        }
        .tag {
            display: inline-block;
            background: #e2ecfc;
            color: #1b3b6b;
            font-size: 0.75rem;
            font-weight: 600;
            padding: 5px 12px;
            border-radius: 40px;
            letter-spacing: 0.3px;
        }
        /* AI tool section (stock diagnosis) */
        .ai-tool {
            background: #f1f7fe;
            border-radius: 48px;
            padding: 50px 40px;
            margin: 70px 0 50px;
            border: 1px solid #c7ddf5;
        }
        .ai-tool h2 {
            font-size: 2rem;
            font-weight: 600;
            color: #0a2942;
            margin-bottom: 16px;
        }
        .ai-tool p {
            color: #335577;
            max-width: 700px;
            margin-bottom: 30px;
        }
        .tool-box {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 16px;
            background: white;
            padding: 18px 28px;
            border-radius: 60px;
            box-shadow: 0 8px 18px -8px rgba(0,0,0,0.1);
            max-width: 700px;
            margin: 0 auto;
        }
        .tool-box input {
            flex: 3 1 250px;
            padding: 16px 24px;
            border: 1px solid #bdd1e8;
            border-radius: 60px;
            font-size: 1rem;
            outline: none;
            font-weight: 500;
        }
        .tool-box input:focus {
            border-color: #1b3b6b;
            box-shadow: 0 0 0 3px #a3c0e4;
        }
        .tool-box button {
            flex: 1 1 auto;
            background: #1b3b6b;
            color: white;
            border: none;
            padding: 16px 32px;
            border-radius: 60px;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: 0.15s;
            white-space: nowrap;
        }
        .tool-box button:hover {
            background: #0f2e52;
        }
        .tool-disclaimer {
            font-size: 0.8rem;
            color: #5b779b;
            margin-top: 20px;
            text-align: center;
        }
        /* custom popup (modal) */
        .popup-overlay {
            display: none;
            position: fixed;
            top: 0; left: 0; width: 100%; height: 100%;
            background: rgba(0,0,0,0.3);
            align-items: center;
            justify-content: center;
            z-index: 999;
        }
        .popup-card {
            background: white;
            max-width: 400px;
            width: 90%;
            padding: 32px 28px;
            border-radius: 40px;
            box-shadow: 0 30px 50px rgba(0,20,50,0.3);
            text-align: center;
            border: 1px solid #c1d8f0;
            position: relative;
        }
        .popup-card h4 {
            font-size: 1.6rem;
            font-weight: 600;
            color: #0a2942;
            margin-bottom: 10px;
        }
        .popup-card .stock-code {
            background: #eaf2fc;
            padding: 10px;
            border-radius: 40px;
            font-weight: 700;
            font-size: 1.3rem;
            margin: 15px 0;
            color: #1b3b6b;
        }
        .popup-card .popup-message {
            color: #2c4b74;
            margin-bottom: 20px;
        }
        .popup-card .disclaimer-small {
            font-size: 0.75rem;
            color: #889fc5;
            margin: 20px 0 10px;
        }
        .close-popup {
            background: #e2eaf5;
            border: none;
            padding: 12px 28px;
            border-radius: 40px;
            font-weight: 600;
            cursor: pointer;
            margin-top: 10px;
        }
        .close-popup:hover {
            background: #cbd8ea;
        }
        /* instructor / trust */
        .trust-row {
            display: flex;
            flex-wrap: wrap;
            background: #f3f8ff;
            border-radius: 40px;
            padding: 40px 36px;
            margin: 60px 0;
            align-items: center;
            gap: 30px;
            border: 1px solid #d2e3fa;
        }
        .trust-text {
            flex: 2;
        }
        .trust-text h2 {
            font-size: 1.9rem;
            font-weight: 600;
            margin-bottom: 16px;
            color: #0a2942;
        }
        .trust-text p {
            color: #38567a;
            max-width: 500px;
        }
        .trust-avatars {
            flex: 1;
            display: flex;
            justify-content: center;
            gap: 20px;
        }
        .avatar {
            background: #1b3b6b;
            width: 60px;
            height: 60px;
            border-radius: 60px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-weight: 600;
            font-size: 1.5rem;
            border: 3px solid white;
            box-shadow: 0 4px 10px rgba(0,0,0,0.05);
        }
        /* risk disclaimer */
        .risk {
            background: #fef7ec;
            border-left: 4px solid #dba958;
            padding: 20px 24px;
            border-radius: 20px;
            color: #5b4a2a;
            font-size: 0.9rem;
            margin: 40px 0 20px;
        }
        footer {
            border-top: 1px solid #d4e1f0;
            padding: 32px 0;
            margin-top: 40px;
            font-size: 0.8rem;
            color: #5e7c9f;
            text-align: center;
        }
        .flex-center {
            display: flex;
            justify-content: center;
            gap: 20px;
            flex-wrap: wrap;
        }
        @media (max-width: 600px) {
            .hero h1 { font-size: 2.4rem; }
            .navbar { flex-direction: column; gap: 15px; }
        }