.container1 {
            margin-top: 2rem;
            margin-bottom: 2rem;
            max-width: 920px;
            margin-inline: auto;
            padding: clamp(1rem, 3vw, 1.5rem);
            border-radius: 20px;
            border: 1px solid transparent;
            transition: background .2s ease, color .2s ease, border-color .2s ease, box-shadow .2s ease;
        }

        .logo { height: 50px; }
    
        /* Light mode */
        body.theme-light .container1 {
            background: #ffffff;
            color: #0f172a;
            border-color: rgba(203, 213, 225, 0.6);
            box-shadow: 0 24px 48px rgba(15, 23, 42, 0.06);
        }

        /* Dark mode */
        body.theme-dark .container1 {
            background: rgba(15, 23, 42, 0.9);
            color: #e2e8f0;
            border-color: rgba(148, 163, 184, 0.18);
            box-shadow: 0 24px 48px rgba(2, 6, 23, 0.4);
        }

        .container1 h2 {
            margin: 0 0 0.75rem;
            font-weight: 800;
            letter-spacing: 0.2px;
            text-align: center;
        }

        .container1 a { text-decoration: underline; }
        body.theme-light .container1 a { color: #1d4ed8; }
        body.theme-dark .container1 a { color: #93c5fd; }