:root {
        --auth-bg-left: radial-gradient(circle at 0% 0%, rgba(99, 102, 241, 0.08) 0%, transparent 40%), radial-gradient(circle at 100% 100%, rgba(6, 182, 212, 0.08) 0%, transparent 40%), #f8fafc;
        --auth-bg-right: var(--bg-base);
        --auth-card-bg: rgba(255, 255, 255, 0.72);
        --auth-card-border: rgba(99, 102, 241, 0.15);
        --auth-card-shadow: 0 20px 45px rgba(99, 102, 241, 0.06);
        --auth-feature-bg: rgba(255, 255, 255, 0.45);
        --auth-feature-border: rgba(99, 102, 241, 0.1);
        --auth-feature-hover-bg: rgba(255, 255, 255, 0.85);
        --auth-telemetry-bg: rgba(255, 255, 255, 0.55);
        --auth-telemetry-border: rgba(99, 102, 241, 0.1);
        --auth-blob-opacity: 0.14;
    }

    [data-theme="dark"] {
        --auth-bg-left: radial-gradient(circle at 0% 0%, rgba(99, 102, 241, 0.22) 0%, transparent 45%), radial-gradient(circle at 100% 100%, rgba(236, 72, 153, 0.18) 0%, transparent 45%), #050811;
        --auth-bg-right: var(--bg-base);
        --auth-card-bg: rgba(15, 23, 42, 0.55);
        --auth-card-border: rgba(255, 255, 255, 0.08);
        --auth-card-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5),
                            inset 0 1px 1px rgba(255, 255, 255, 0.05),
                            0 0 45px rgba(139, 92, 246, 0.08);
        --auth-feature-bg: rgba(255, 255, 255, 0.02);
        --auth-feature-border: rgba(255, 255, 255, 0.05);
        --auth-feature-hover-bg: rgba(255, 255, 255, 0.05);
        --auth-telemetry-bg: rgba(0, 0, 0, 0.35);
        --auth-telemetry-border: rgba(255, 255, 255, 0.05);
        --auth-blob-opacity: 0.22;
    }

    body {
        margin: 0;
        padding: 0;
        background: var(--auth-bg-right);
        color: var(--text-primary);
        font-family: 'Inter', sans-serif;
        min-height: 100vh;
        display: flex;
        align-items: stretch;
        justify-content: stretch;
        overflow-x: hidden;
        transition: background 0.3s ease, color 0.3s ease;
    }

    .auth-split-wrapper {
        display: flex;
        width: 100%;
        min-height: 100vh;
    }

    /* Left Panel: Statistics & Telemetry */
    .auth-left-panel {
        flex: 1.25;
        background: var(--auth-bg-left);
        border-right: 1px solid var(--border-color);
        display: flex;
        flex-direction: column;
        justify-content: space-between;
        padding: 60px;
        position: relative;
        overflow: hidden;
        transition: background 0.3s ease, border-color 0.3s ease;
    }
    @media (max-width: 1024px) {
        .auth-left-panel {
            display: none; /* Hide on mobile/tablet */
        }
    }

    /* Left Panel Decorative Blob */
    .auth-left-panel::before {
        content: '';
        position: absolute;
        top: -10%;
        left: -10%;
        width: 400px;
        height: 400px;
        background: var(--accent-purple);
        filter: blur(140px);
        opacity: var(--auth-blob-opacity);
        pointer-events: none;
        border-radius: 50%;
        transition: opacity 0.3s ease;
    }

    .left-panel-header {
        display: flex;
        align-items: center;
        gap: 12px;
        z-index: 10;
    }
    .left-logo-text {
        font-family: 'Outfit', sans-serif;
        font-size: 1.8rem;
        font-weight: 800;
        letter-spacing: -0.02em;
    }

    .left-hero-section {
        max-width: 580px;
        margin: auto 0;
        z-index: 10;
    }
    .left-hero-tag {
        display: inline-block;
        padding: 6px 14px;
        background: rgba(139, 92, 246, 0.1);
        border: 1px solid rgba(139, 92, 246, 0.2);
        color: var(--accent-purple);
        border-radius: 20px;
        font-size: 0.82rem;
        font-weight: 700;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        margin-bottom: 20px;
    }
    .left-hero-title {
        font-family: 'Outfit', sans-serif;
        font-size: 3rem;
        font-weight: 800;
        line-height: 1.15;
        color: var(--text-primary);
        letter-spacing: -0.03em;
        margin-bottom: 20px;
        transition: color 0.3s ease;
    }
    .left-hero-title span {
        background: linear-gradient(135deg, var(--accent-cyan) 0%, var(--accent-purple) 50%, #f472b6 100%);
        -webkit-background-clip: text;
        background-clip: text;
        -webkit-text-fill-color: transparent;
    }
    .left-hero-desc {
        color: var(--text-secondary);
        font-size: 1.1rem;
        line-height: 1.5;
        margin-bottom: 40px;
        transition: color 0.3s ease;
    }

    /* Left Hero Features Grid */
    .left-features-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 24px;
    }
    .left-feature-card {
        background: var(--auth-feature-bg);
        border: 1px solid var(--auth-feature-border);
        padding: 20px;
        border-radius: 16px;
        transition: background 0.3s ease, transform 0.3s ease, border-color 0.3s ease;
    }
    .left-feature-card:hover {
        background: var(--auth-feature-hover-bg);
        transform: translateY(-2px);
    }
    .left-feature-icon {
        font-size: 1.6rem;
        margin-bottom: 12px;
    }
    .left-feature-title {
        color: var(--text-primary);
        font-family: 'Outfit', sans-serif;
        font-size: 1rem;
        font-weight: 700;
        margin-bottom: 6px;
        transition: color 0.3s ease;
    }
    .left-feature-desc {
        color: var(--text-secondary);
        font-size: 0.82rem;
        line-height: 1.4;
        transition: color 0.3s ease;
    }

    /* Telemetry Panel at bottom */
    .left-telemetry-panel {
        display: flex;
        align-items: center;
        gap: 30px;
        background: var(--auth-telemetry-bg);
        border: 1px solid var(--auth-telemetry-border);
        padding: 16px 28px;
        border-radius: 20px;
        width: fit-content;
        z-index: 10;
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        transition: all 0.3s ease;
    }
    .telemetry-item {
        display: flex;
        flex-direction: column;
    }
    .telemetry-num {
        font-family: 'Outfit', sans-serif;
        font-size: 1.25rem;
        font-weight: 800;
        color: var(--text-primary);
        transition: color 0.3s ease;
    }
    .telemetry-lbl {
        font-size: 0.72rem;
        color: var(--text-secondary);
        text-transform: uppercase;
        letter-spacing: 0.05em;
        margin-top: 2px;
        transition: color 0.3s ease;
    }
    .telemetry-dot-live {
        width: 8px;
        height: 8px;
        background: var(--accent-green);
        border-radius: 50%;
        box-shadow: 0 0 10px var(--accent-green);
        animation: pulse-live 1.5s infinite;
        align-self: center;
        margin-right: -10px;
    }
    @keyframes pulse-live {
        0% { transform: scale(0.9); opacity: 0.8; }
        50% { transform: scale(1.2); opacity: 1; }
        100% { transform: scale(0.9); opacity: 0.8; }
    }

    /* Right Panel: Auth Glass Card Column */
    .auth-right-panel {
        flex: 1;
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 40px 20px;
        position: relative;
        background: var(--auth-bg-right);
        transition: background 0.3s ease;
    }

    /* Floating theme switcher */
    .theme-toggle-btn {
        position: absolute;
        top: 24px;
        right: 24px;
        width: 40px;
        height: 40px;
        border-radius: 50%;
        background: var(--auth-feature-bg);
        border: 1px solid var(--auth-feature-border);
        color: var(--text-primary);
        display: flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        z-index: 100;
        outline: none;
    }
    .theme-toggle-btn:hover {
        background: var(--auth-feature-hover-bg);
        border-color: var(--accent-purple);
        transform: scale(1.05) rotate(15deg);
        box-shadow: 0 4px 12px rgba(99, 102, 241, 0.1);
    }

    /* Dynamic Background Blobs on Right Column */
    .auth-bg-blob {
        position: absolute;
        width: 320px;
        height: 320px;
        border-radius: 50%;
        filter: blur(100px);
        z-index: 1;
        opacity: var(--auth-blob-opacity);
        pointer-events: none;
        transition: opacity 0.3s ease;
    }
    .blob-1 {
        background: var(--accent-purple);
        top: 10%;
        right: 10%;
    }
    .blob-2 {
        background: #ec4899;
        bottom: 10%;
        left: 10%;
    }

    .auth-card {
        width: 100%;
        max-width: 440px;
        padding: 40px;
        background: var(--auth-card-bg);
        border: 1px solid var(--auth-card-border);
        box-shadow: var(--auth-card-shadow);
        backdrop-filter: blur(25px);
        -webkit-backdrop-filter: blur(25px);
        border-radius: 28px;
        position: relative;
        z-index: 10;
        overflow: hidden;
        transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.1), background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    }
    .auth-card:hover {
        transform: translateY(-3px);
        border-color: var(--accent-purple);
        box-shadow: var(--auth-card-shadow), 0 0 50px rgba(139, 92, 246, 0.12);
    }

    /* Card Gradient Border Strip */
    .auth-card::after {
        content: '';
        position: absolute;
        top: 0; left: 0; right: 0; height: 3px;
        background: linear-gradient(90deg, #4f46e5, #8b5cf6, #ec4899, #f59e0b, #10b981, #4f46e5);
        background-size: 200% 100%;
        animation: gradient-move 5s linear infinite;
        z-index: 20;
    }
    @keyframes gradient-move {
        0% { background-position: 0% 50%; }
        100% { background-position: 200% 50%; }
    }

    .auth-header {
        text-align: center;
        margin-bottom: 30px;
    }
    .auth-title {
        font-family: 'Outfit', sans-serif;
        font-weight: 800;
        font-size: 2.2rem;
        letter-spacing: -0.02em;
        background: linear-gradient(135deg, var(--accent-cyan) 0%, var(--accent-purple) 50%, #f472b6 100%);
        -webkit-background-clip: text;
        background-clip: text;
        -webkit-text-fill-color: transparent;
        margin-bottom: 8px;
    }
    .auth-subtitle {
        font-size: 0.9rem;
        color: var(--text-secondary);
        line-height: 1.4;
        transition: color 0.3s ease;
    }

    /* Enhanced Tab Switcher */
    .auth-tabs {
        display: flex;
        background: var(--bg-input);
        border: 1px solid var(--border-color);
        border-radius: 14px;
        padding: 5px;
        margin-bottom: 25px;
        position: relative;
        transition: background-color 0.3s ease, border-color 0.3s ease;
    }
    .auth-tab-btn {
        flex: 1;
        border: none;
        background: none;
        color: var(--text-secondary);
        font-family: 'Inter', sans-serif;
        font-weight: 600;
        font-size: 0.92rem;
        padding: 10px;
        cursor: pointer;
        z-index: 2;
        transition: all 0.3s ease;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        outline: none;
    }
    .auth-tab-btn.active {
        color: #ffffff;
    }
    .auth-tabs-slider {
        position: absolute;
        top: 5px;
        bottom: 5px;
        left: 5px;
        width: calc(50% - 5px);
        background: linear-gradient(135deg, var(--accent-purple) 0%, var(--accent-cyan) 100%);
        border-radius: 10px;
        z-index: 1;
        transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.1);
        box-shadow: 0 4px 15px rgba(124, 58, 237, 0.3);
    }

    /* Colorful Inputs styling */
    .input-group {
        margin-bottom: 20px;
    }
    .input-label {
        font-size: 0.75rem;
        font-weight: 700;
        color: var(--text-secondary);
        text-transform: uppercase;
        letter-spacing: 0.06em;
        margin-bottom: 6px;
        display: block;
        transition: color 0.3s ease;
    }
    .input-wrapper {
        position: relative;
    }
    .input-icon {
        position: absolute;
        left: 16px;
        top: 50%;
        transform: translateY(-50%);
        color: var(--text-secondary);
        opacity: 0.7;
        transition: color 0.3s ease, opacity 0.3s ease;
        display: flex;
    }
    .input-field {
        width: 100%;
        background: var(--bg-input);
        border: 1px solid var(--border-color);
        color: var(--text-primary);
        padding: 13px 18px 13px 44px;
        border-radius: 12px;
        font-size: 0.95rem;
        outline: none;
        transition: all 0.3s ease;
    }
    .input-field:focus {
        background: var(--bg-input);
        border-color: var(--accent-purple);
        box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
    }
    .input-wrapper:focus-within .input-icon {
        color: var(--accent-purple);
        opacity: 1;
    }
    .input-suffix-btn {
        position: absolute;
        right: 16px;
        top: 50%;
        transform: translateY(-50%);
        background: none;
        border: none;
        color: var(--text-secondary);
        opacity: 0.6;
        cursor: pointer;
        transition: color 0.3s ease, opacity 0.3s ease;
        padding: 0;
        display: flex;
    }
    .input-suffix-btn:hover {
        color: var(--text-primary);
        opacity: 1;
    }

    /* Buttons */
    .btn {
        width: 100%;
        padding: 13px;
        border-radius: 12px;
        font-family: 'Outfit', sans-serif;
        font-weight: 700;
        font-size: 1rem;
        cursor: pointer;
        border: none;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.1);
        margin-top: 10px;
    }
    .btn-primary {
        background: linear-gradient(135deg, var(--accent-purple) 0%, var(--accent-cyan) 100%);
        background-size: 150% 150%;
        color: #ffffff;
        box-shadow: 0 8px 20px rgba(139, 92, 246, 0.2);
        animation: gradient-shimmer 6s ease infinite;
    }
    @keyframes gradient-shimmer {
        0% { background-position: 0% 50%; }
        50% { background-position: 100% 50%; }
        100% { background-position: 0% 50%; }
    }
    .btn-primary:hover {
        transform: translateY(-2px);
        box-shadow: 0 12px 25px rgba(139, 92, 246, 0.3);
    }
    .btn-secondary {
        background: var(--auth-feature-bg);
        border: 1px solid var(--auth-feature-border);
        color: var(--text-primary);
    }
    .btn-secondary:hover {
        background: var(--auth-feature-hover-bg);
        border-color: var(--accent-purple);
    }

    /* Button loading spinner styles */
    .btn.btn-loading {
        position: relative;
        color: transparent !important;
        pointer-events: none;
    }
    .btn.btn-loading::after {
        content: '';
        position: absolute;
        width: 20px;
        height: 20px;
        top: calc(50% - 10px);
        left: calc(50% - 10px);
        border: 2px solid rgba(255, 255, 255, 0.3);
        border-radius: 50%;
        border-top-color: #ffffff;
        animation: spin 0.8s linear infinite;
    }
    .btn-secondary.btn-loading::after {
        border-color: rgba(0, 0, 0, 0.1);
        border-top-color: var(--text-primary);
    }
    [data-theme="dark"] .btn-secondary.btn-loading::after {
        border-color: rgba(255, 255, 255, 0.1);
        border-top-color: #ffffff;
    }

    .auth-footer {
        text-align: center;
        margin-top: 20px;
        font-size: 0.85rem;
        color: var(--text-secondary);
        transition: color 0.3s ease;
    }
    .auth-link {
        color: var(--accent-cyan);
        text-decoration: none;
        font-weight: 700;
        transition: all 0.3s ease;
        margin-left: 5px;
    }
    .auth-link:hover {
        color: var(--accent-purple);
        text-shadow: 0 0 10px rgba(139, 92, 246, 0.2);
    }

    .card-shimmer {
        position: absolute;
        top: 0; left: -100%;
        width: 100%; height: 100%;
        background: linear-gradient(120deg, transparent, rgba(255,255,255,0.02), transparent);
        animation: shimmer 5s infinite;
        pointer-events: none;
    }
    @keyframes shimmer {
        0% { left: -100%; }
        30% { left: 100%; }
        100% { left: 100%; }
    }