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

        body {
            background: linear-gradient(165deg, #f8f9ff 0%, #edf0fa 100%);
            font-family: 'Inter', sans-serif;
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1.5rem;
            position: relative;
        }

        /* Professional abstract background */
        body::before {
            content: '';
            position: fixed;
            width: 60vw;
            height: 60vw;
            max-width: 800px;
            max-height: 800px;
            background: radial-gradient(circle at 30% 30%, rgba(98, 0, 234, 0.03), rgba(0, 113, 227, 0.02) 70%);
            top: -20%;
            right: -10%;
            border-radius: 50%;
            z-index: 0;
        }

        body::after {
            content: '';
            position: fixed;
            width: 70vw;
            height: 70vw;
            max-width: 900px;
            max-height: 900px;
            background: radial-gradient(circle at 70% 70%, rgba( 0, 180, 216, 0.03), rgba(106, 17, 203, 0.02) 70%);
            bottom: -25%;
            left: -10%;
            border-radius: 50%;
            z-index: 0;
        }

        /* Main card - elevated professional */
        .signup-card {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-radius: 2rem;
            box-shadow: 
                0 25px 50px -12px rgba(0, 0, 0, 0.15),
                0 0 0 1px rgba(255, 255, 255, 0.8) inset,
                0 0 0 1px rgba(98, 0, 234, 0.1);
            width: 100%;
            max-width: 560px;
            padding: 2.8rem 2.8rem;
            z-index: 10;
            position: relative;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .signup-card:hover {
            box-shadow: 
                0 30px 60px -15px rgba(55, 0, 130, 0.2),
                0 0 0 1px rgba(255, 255, 255, 0.9) inset;
        }

        /* Header - RID Research Library */
        .card-header {
            margin-bottom: 2.2rem;
            text-align: left;
            position: relative;
        }

        .library-badge {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            margin-bottom: 0.75rem;
        }

        .rid-logo {
            width: 48px;
            height: 48px;
            background: linear-gradient(145deg, #2a1b5e, #1a2b6b);
            border-radius: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 10px 18px -6px #2a1b5e;
        }

        .rid-logo i {
            font-size: 1.8rem;
            color: white;
        }

        .rid-text {
            font-size: 1.8rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            background: linear-gradient(145deg, #1e293b, #0f1a3a);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }

        .rid-text span {
            background: linear-gradient(145deg, #6200ea, #0071e3);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            font-weight: 800;
        }

        .header-sub {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
            gap: 0.5rem;
            margin-top: 0.5rem;
        }

        .header-sub h2 {
            font-size: 1.5rem;
            font-weight: 600;
            color: #1e293b;
            line-height: 1.3;
        }

        .header-sub .badge {
            background: rgba(98, 0, 234, 0.08);
            padding: 0.3rem 1rem;
            border-radius: 40px;
            font-size: 0.75rem;
            font-weight: 600;
            color: #6200ea;
            letter-spacing: 0.3px;
            border: 1px solid rgba(98, 0, 234, 0.2);
            white-space: nowrap;
        }

        /* Input groups - refined professional */
        .input-group {
            position: relative;
            margin-bottom: 1.25rem;
        }

        .input-group i {
            position: absolute;
            left: 18px;
            top: 50%;
            transform: translateY(-50%);
            color: #6200ea;
            font-size: 1.1rem;
            transition: all 0.2s;
            pointer-events: none;
            z-index: 2;
            opacity: 0.6;
        }

        .input-group input {
            width: 100%;
            padding: 1rem 1.2rem 1rem 3rem;
            background: white;
            border: 1.5px solid #e9e4f2;
            border-radius: 18px;
            font-size: 0.95rem;
            font-weight: 500;
            color: #1a1f36;
            outline: none;
            transition: all 0.2s ease;
            font-family: 'Inter', sans-serif;
            box-shadow: 0 2px 6px rgba(0,0,0,0.02);
        }

        .input-group input::placeholder {
            color: #919bae;
            font-weight: 400;
            font-size: 0.95rem;
        }

        .input-group input:hover {
            border-color: #b7a6df;
            background: #fcfaff;
        }

        .input-group input:focus {
            border-color: #6200ea;
            background: #ffffff;
            box-shadow: 0 0 0 4px rgba(98, 0, 234, 0.1);
        }

        .input-group input:focus + i {
            color: #0071e3;
            opacity: 1;
        }

        /* Double input row for password fields */
        .password-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1rem;
            margin-bottom: 0.25rem;
        }

        .password-row .input-group {
            margin-bottom: 0;
        }

        /* Password strength - professional minimal */
        .password-strength {
            display: flex;
            align-items: center;
            gap: 1rem;
            margin: 0.5rem 0 1.75rem 0.25rem;
        }

        .strength-bars {
            display: flex;
            gap: 6px;
            flex: 1;
            max-width: 160px;
        }

        .bar {
            height: 5px;
            width: 100%;
            background: #e2dcf0;
            border-radius: 20px;
            transition: all 0.2s;
        }

        .bar.fill {
            background: linear-gradient(90deg, #6200ea, #3b7bff);
        }

        .strength-label {
            font-size: 0.75rem;
            font-weight: 600;
            color: #4a4d6b;
            text-transform: uppercase;
            letter-spacing: 0.3px;
        }

        /* Checkbox - clean & professional */
        .terms-wrapper {
            display: flex;
            align-items: center;
            gap: 1rem;
            margin: 2rem 0 2rem;
            padding: 0.5rem 0;
        }

        .terms-wrapper input[type="checkbox"] {
            width: 20px;
            height: 20px;
            accent-color: #6200ea;
            border-radius: 6px;
            cursor: pointer;
            margin: 0;
        }

        .terms-wrapper label {
            color: #2d3648;
            font-size: 0.95rem;
            font-weight: 500;
            flex: 1;
        }

        .terms-wrapper label a {
            color: #6200ea;
            font-weight: 600;
            text-decoration: none;
            border-bottom: 1px solid transparent;
            transition: 0.2s;
        }

        .terms-wrapper label a:hover {
            border-bottom-color: #6200ea;
        }

        /* Primary button */
        .btn-primary {
            background: #1e293b;
            border: none;
            color: white;
            font-weight: 600;
            font-size: 1rem;
            padding: 1.1rem 2rem;
            width: 100%;
            border-radius: 18px;
            cursor: pointer;
            box-shadow: 0 10px 20px -8px rgba(30, 41, 59, 0.3);
            transition: all 0.25s ease;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.75rem;
            letter-spacing: 0.3px;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }

        .btn-primary:hover {
            background: #0f172a;
            transform: translateY(-2px);
            box-shadow: 0 15px 25px -8px #1e293b;
        }

        .btn-primary i {
            font-size: 1rem;
            transition: transform 0.2s;
        }

        .btn-primary:hover i {
            transform: translateX(4px);
        }

        /* Login link */
        .login-link {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            margin-top: 2rem;
            color: #4a5578;
            font-size: 0.95rem;
            flex-wrap: wrap;
        }

        .login-link a {
            color: #1e293b;
            font-weight: 600;
            text-decoration: none;
            padding: 0.4rem 1.2rem;
            border-radius: 40px;
            background: #f0f2f8;
            transition: 0.2s;
            display: inline-flex;
            align-items: center;
            gap: 0.4rem;
            border: 1px solid #e0e4ed;
        }

        .login-link a:hover {
            background: #e2e6f0;
            border-color: #b3b9cc;
        }

        /* Library footer */
        .library-footer {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 1.5rem;
            margin-top: 2rem;
            padding-top: 1rem;
            border-top: 1px solid #edecf2;
            font-size: 0.7rem;
            color: #737a91;
            flex-wrap: wrap;
        }

        .library-footer span i {
            color: #6200ea;
            margin-right: 0.3rem;
            font-size: 0.6rem;
        }

        /* Responsive design - fully responsive */
        @media (max-width: 640px) {
            body {
                padding: 0.8rem;
            }
            
            .signup-card {
                padding: 1.8rem 1.5rem;
                border-radius: 1.5rem;
            }
            
            .rid-text {
                font-size: 1.4rem;
            }
            
            .rid-logo {
                width: 40px;
                height: 40px;
            }
            
            .rid-logo i {
                font-size: 1.4rem;
            }
            
            .header-sub h2 {
                font-size: 1.2rem;
            }
            
            .password-row {
                grid-template-columns: 1fr;
                gap: 1.25rem;
            }
            
            .library-footer {
                gap: 1rem;
                flex-direction: column;
                align-items: flex-start;
            }
        }

        @media (max-width: 480px) {
            .signup-card {
                padding: 1.5rem 1.2rem;
            }
            
            .header-sub {
                flex-direction: column;
                align-items: flex-start;
            }
            
            .terms-wrapper {
                align-items: flex-start;
            }
            
            .terms-wrapper input[type="checkbox"] {
                margin-top: 0.2rem;
            }
            
            .btn-primary {
                padding: 1rem;
            }
        }

        /* Small height screens */
        @media (max-height: 700px) {
            .signup-card {
                padding: 1.5rem 2rem;
            }
            
            .card-header {
                margin-bottom: 1.2rem;
            }
            
            .input-group {
                margin-bottom: 0.9rem;
            }
        }

        /* Landscape mode */
        @media (max-height: 500px) and (orientation: landscape) {
            body {
                align-items: flex-start;
                padding: 1rem;
            }
            
            .signup-card {
                margin: 1rem auto;
            }
        }