* {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            font-family: 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
        }

        body {
            background-color: #f0f4f9;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            min-height: 100vh;
            padding: 20px;
            overflow-x: hidden;
        }

        #splash-screen {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: #ffffff;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            z-index: 9999;
            transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.6s;
        }

        .sun-icon {
            width: 72px;
            height: 72px;
            margin-bottom: 24px;
            animation: pulse 2s infinite ease-in-out;
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); opacity: 1; }
            50% { transform: scale(1.08); opacity: 0.85; }
        }

        .header-title {
            font-size: 28px;
            font-weight: 500;
            color: #1f1f1f;
            margin-bottom: 8px;
            text-align: center;
        }

        .header-subtitle {
            font-size: 32px;
            font-weight: 700;
            text-align: center;
            margin-bottom: 20px;
        }

        .text-tro { color: #f27254; }
        .text-ly { color: #b08bb7; }
        .text-ho { color: #8e95c9; }
        .text-tro2 { color: #4fa3f7; }
        .text-mon { color: #1a73e8; }
        .text-fansub { color: #4fa3f7; }

        #persistent-header {
            display: none;
            flex-direction: column;
            align-items: center;
            margin-bottom: 24px;
            animation: fadeInDown 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }

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

        .google-card {
            background: #ffffff;
            border-radius: 28px;
            padding: 40px;
            width: 100%;
            max-width: 450px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
            display: none;
            position: relative;
            overflow: hidden;
            animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }

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

        .card-header {
            margin-bottom: 24px;
        }

        .card-title {
            font-size: 24px;
            font-weight: 500;
            color: #1f1f1f;
            margin-bottom: 8px;
        }

        .card-desc {
            font-size: 14px;
            color: #444746;
        }

        .user-chip {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 6px 12px;
            border: 1px solid #747775;
            border-radius: 16px;
            font-size: 14px;
            color: #1f1f1f;
            cursor: pointer;
            margin-top: 8px;
            transition: background 0.2s;
        }

        .user-chip:hover {
            background-color: #f1f3f4;
        }

        /* Progress Dots / Thanh tiến trình */
        .progress-bar {
            display: flex;
            gap: 6px;
            margin-bottom: 24px;
        }

        .dot {
            height: 4px;
            flex: 1;
            background-color: #e0e0e0;
            border-radius: 2px;
            transition: background-color 0.3s;
        }

        .dot.active {
            background-color: #1a73e8;
        }

        .steps-container {
            position: relative;
            min-height: 120px;
        }

        .step {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            opacity: 0;
            transform: translateX(50px);
            pointer-events: none;
            transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .step.active {
            opacity: 1;
            transform: translateX(0);
            pointer-events: auto;
            position: relative;
        }

        .step.exit-left {
            opacity: 0;
            transform: translateX(-50px);
        }

        .input-group {
            position: relative;
            margin-bottom: 20px;
        }

        .input-group input {
            width: 100%;
            height: 56px;
            padding: 16px;
            border: 1px solid #747775;
            border-radius: 8px;
            font-size: 16px;
            outline: none;
            background: transparent;
            transition: border-color 0.2s, box-shadow 0.2s;
        }

        .input-group input:focus {
            border-color: #1a73e8;
            border-width: 2px;
            padding: 15px;
        }

        .input-group label {
            position: absolute;
            left: 16px;
            top: 50%;
            transform: translateY(-50%);
            background: #ffffff;
            padding: 0 4px;
            color: #444746;
            font-size: 16px;
            pointer-events: none;
            transition: 0.2s ease all;
        }

        .input-group input:focus ~ label,
        .input-group input:not(:placeholder-shown) ~ label {
            top: 0;
            font-size: 12px;
            color: #1a73e8;
            font-weight: 500;
        }

        .actions {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-top: 28px;
        }

        .btn-text {
            background: none;
            border: none;
            color: #1a73e8;
            font-weight: 500;
            font-size: 14px;
            cursor: pointer;
            padding: 10px 12px;
            border-radius: 20px;
            transition: background 0.2s;
        }

        .btn-text:hover {
            background-color: #f1f3f4;
        }

        .btn-primary {
            background-color: #1a73e8;
            color: white;
            border: none;
            padding: 10px 24px;
            border-radius: 20px;
            font-weight: 500;
            font-size: 14px;
            cursor: pointer;
            transition: background 0.2s, box-shadow 0.2s;
        }

        .btn-primary:hover {
            background-color: #1557b0;
            box-shadow: 0 1px 3px rgba(0,0,0,0.2);
        }

        .alert {
            padding: 12px 16px;
            border-radius: 8px;
            font-size: 14px;
            margin-bottom: 20px;
        }
        .alert-danger { background-color: #fdeded; color: #d32f2f; }
        .alert-success { background-color: #edf7ed; color: #2e7d32; }

.upgrade-banner {
    background: linear-gradient(135deg, #1a73e8, #4fa3f7);
    color: white;
    border-radius: 20px;
    padding: 24px;
    margin-top: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 4px 15px rgba(26, 115, 232, 0.2);
}

.upgrade-content h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 6px;
}

.upgrade-content p {
    font-size: 14px;
    opacity: 0.9;
    line-height: 1.4;
}

.upgrade-btn {
    background-color: #ffffff;
    color: #1a73e8;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.2s, transform 0.2s;
    white-space: nowrap;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.upgrade-btn:hover {
    background-color: #f8f9fa;
    transform: translateY(-2px);
}