:root {
            --ds-bg: #07090F;
            --ds-bg1: #0B0F1A;
            --ds-bg2: #0F1623;
            --ds-accent: #3B82F6;
            --ds-accent-s: rgba(59,130,246,0.08);
            --ds-gold: #F59E0B;
            --ds-green: #10B981;
            --ds-violet: #8B5CF6;
            --ds-red: #EF4444;
            --ds-t1: #EEF2FF;
            --ds-t2: #7B92B2;
            --ds-t3: #344D69;
            --ds-border: #1A2740;
            --ds-border-hover: #243550;
            --radius: 10px;
            --transition: 0.18s ease;
        }

        /* ── LIGHT MODE ── */
        :root.light {
            --ds-bg: #F0F4FA;
            --ds-bg1: #FFFFFF;
            --ds-bg2: #E8EEF8;
            --ds-accent: #2563EB;
            --ds-accent-s: rgba(37,99,235,0.07);
            --ds-gold: #D97706;
            --ds-green: #059669;
            --ds-violet: #7C3AED;
            --ds-red: #DC2626;
            --ds-t1: #0F172A;
            --ds-t2: #475569;
            --ds-t3: #94A3B8;
            --ds-border: #CBD5E1;
            --ds-border-hover: #94A3B8;
        }

        :root.light .brand-panel::before {
            opacity: 0.18;
        }

        :root.light .brand-panel::after {
            background: radial-gradient(circle, rgba(37,99,235,0.07) 0%, transparent 70%);
        }

        :root.light .brand-pillar {
            background: rgba(240,244,250,0.8);
        }

        :root.light .stat-item {
            background: rgba(240,244,250,0.8);
        }

        /* ── THEME TOGGLE ── */
        .theme-toggle {
            position: fixed;
            top: 1.25rem;
            right: 1.25rem;
            z-index: 100;
            background: var(--ds-bg1);
            border: 1px solid var(--ds-border);
            border-radius: 20px;
            display: flex;
            align-items: center;
            padding: 0.25rem;
            gap: 0.125rem;
            box-shadow: 0 2px 8px rgba(0,0,0,0.12);
            transition: all var(--transition);
        }

        .theme-btn {
            background: none;
            border: none;
            cursor: pointer;
            width: 30px;
            height: 30px;
            border-radius: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--ds-t3);
            transition: all var(--transition);
        }

        .theme-btn.active {
            background: var(--ds-accent-s);
            color: var(--ds-accent);
        }

        .theme-btn:hover:not(.active) {
            color: var(--ds-t2);
        }

        .theme-btn svg {
            width: 15px;
            height: 15px;
            stroke: currentColor;
            fill: none;
            stroke-width: 2.2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

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

        html, body {
            height: 100%;
            font-family: 'Segoe UI', system-ui, sans-serif;
            background: var(--ds-bg);
            color: var(--ds-t1);
            overflow: hidden;
        }

        /* ── LAYOUT ── */
        .auth-root {
            display: grid;
            grid-template-columns: 1fr 480px;
            min-height: 100vh;
        }

        /* ── LEFT — BRAND PANEL ── */
        .brand-panel {
            position: relative;
            background: var(--ds-bg1);
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            padding: 2.5rem 3rem;
            overflow: hidden;
            border-right: 1px solid var(--ds-border);
        }

        /* Grid background */
        .brand-panel::before {
            content: '';
            position: absolute;
            inset: 0;
            background-image:
                linear-gradient(var(--ds-border) 1px, transparent 1px),
                linear-gradient(90deg, var(--ds-border) 1px, transparent 1px);
            background-size: 40px 40px;
            opacity: 0.35;
            pointer-events: none;
        }

        /* Glow orb */
        .brand-panel::after {
            content: '';
            position: absolute;
            width: 500px;
            height: 500px;
            border-radius: 50%;
            background: radial-gradient(circle, rgba(59,130,246,0.12) 0%, transparent 70%);
            top: 20%;
            left: -100px;
            pointer-events: none;
        }

        .brand-logo {
            position: relative;
            display: flex;
            align-items: center;
            gap: 0.75rem;
            z-index: 1;
        }

        .brand-logo-mark {
            width: 36px;
            height: 36px;
            background: var(--ds-accent);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .brand-logo-mark svg {
            width: 20px;
            height: 20px;
            stroke: white;
            fill: none;
            stroke-width: 2.2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        .brand-logo-text {
            font-size: 1.125rem;
            font-weight: 700;
            color: var(--ds-t1);
            letter-spacing: -0.02em;
        }

        .brand-center {
            position: relative;
            z-index: 1;
        }

        .brand-tagline {
            font-size: 0.6875rem;
            font-weight: 600;
            letter-spacing: 0.12em;
            text-transform: uppercase;
            color: var(--ds-accent);
            margin-bottom: 1.25rem;
        }

        .brand-headline {
            font-size: clamp(1.75rem, 2.5vw, 2.5rem);
            font-weight: 800;
            line-height: 1.15;
            letter-spacing: -0.03em;
            color: var(--ds-t1);
            margin-bottom: 1.5rem;
        }

        .brand-headline span {
            color: var(--ds-accent);
        }

        .brand-sub {
            font-size: 0.9375rem;
            color: var(--ds-t2);
            line-height: 1.65;
            max-width: 420px;
            margin-bottom: 2.5rem;
        }

        .brand-pillars {
            display: flex;
            flex-direction: column;
            gap: 1rem;
        }

        .brand-pillar {
            display: flex;
            align-items: flex-start;
            gap: 0.875rem;
            padding: 1rem 1.25rem;
            background: rgba(15,22,35,0.7);
            border: 1px solid var(--ds-border);
            border-radius: var(--radius);
            backdrop-filter: blur(8px);
            transition: border-color var(--transition);
        }

        .brand-pillar:hover {
            border-color: var(--ds-border-hover);
        }

        .pillar-icon {
            width: 36px;
            height: 36px;
            flex-shrink: 0;
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .pillar-icon svg {
            width: 18px;
            height: 18px;
            stroke-width: 2.2;
            stroke-linecap: round;
            stroke-linejoin: round;
            fill: none;
        }

        .pillar-icon.blue { background: rgba(59,130,246,0.12); }
        .pillar-icon.blue svg { stroke: var(--ds-accent); }
        .pillar-icon.green { background: rgba(16,185,129,0.12); }
        .pillar-icon.green svg { stroke: var(--ds-green); }
        .pillar-icon.gold { background: rgba(245,158,11,0.12); }
        .pillar-icon.gold svg { stroke: var(--ds-gold); }
        .pillar-icon.violet { background: rgba(139,92,246,0.12); }
        .pillar-icon.violet svg { stroke: var(--ds-violet); }

        .pillar-text strong {
            display: block;
            font-size: 0.875rem;
            font-weight: 600;
            color: var(--ds-t1);
            margin-bottom: 0.2rem;
        }

        .pillar-text span {
            font-size: 0.8125rem;
            color: var(--ds-t2);
            line-height: 1.4;
        }

        .brand-stats {
            position: relative;
            z-index: 1;
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 0.75rem;
        }

        .stat-item {
            text-align: center;
            padding: 0.875rem;
            background: rgba(15,22,35,0.6);
            border: 1px solid var(--ds-border);
            border-radius: var(--radius);
        }

        .stat-value {
            font-size: 1.25rem;
            font-weight: 800;
            color: var(--ds-t1);
            letter-spacing: -0.02em;
        }

        .stat-label {
            font-size: 0.6875rem;
            color: var(--ds-t3);
            text-transform: uppercase;
            letter-spacing: 0.08em;
            margin-top: 0.2rem;
        }

        /* ── RIGHT — AUTH PANEL ── */
        .auth-panel {
            display: flex;
            flex-direction: column;
            background: var(--ds-bg);
            overflow-y: auto;
            position: relative;
        }

        .auth-inner {
            flex: 1;
            display: flex;
            flex-direction: column;
            justify-content: center;
            padding: 2.5rem 2.5rem;
            min-height: 100vh;
        }

        /* ── VIEWS ── */
        .auth-view {
            display: none;
            animation: fadeSlideIn 0.22s ease;
        }

        .auth-view.active {
            display: block;
        }

        @keyframes fadeSlideIn {
            from { opacity: 0; transform: translateY(10px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* ── FORM ELEMENTS ── */
        .view-title {
            font-size: 1.625rem;
            font-weight: 800;
            color: var(--ds-t1);
            letter-spacing: -0.03em;
            margin-bottom: 0.375rem;
        }

        .view-sub {
            font-size: 0.875rem;
            color: var(--ds-t2);
            margin-bottom: 2rem;
            line-height: 1.5;
        }

        .form-group {
            margin-bottom: 1.125rem;
        }

        .form-label {
            display: block;
            font-size: 0.8125rem;
            font-weight: 600;
            color: var(--ds-t2);
            margin-bottom: 0.4rem;
            letter-spacing: 0.02em;
        }

        .form-input {
            width: 100%;
            background: var(--ds-bg1);
            border: 1px solid var(--ds-border);
            border-radius: var(--radius);
            color: var(--ds-t1);
            font-size: 0.9375rem;
            padding: 0.75rem 1rem;
            outline: none;
            transition: border-color var(--transition), box-shadow var(--transition);
            font-family: inherit;
        }

        .form-input::placeholder { color: var(--ds-t3); }

        .form-input:focus {
            border-color: var(--ds-accent);
            box-shadow: 0 0 0 3px rgba(59,130,246,0.12);
        }

        .form-input.error {
            border-color: var(--ds-red);
            box-shadow: 0 0 0 3px rgba(239,68,68,0.1);
        }

        .form-input.valid {
            border-color: var(--ds-green);
        }

        .form-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 0.875rem;
        }

        .form-help {
            font-size: 0.75rem;
            color: var(--ds-t3);
            margin-top: 0.35rem;
        }

        /* Password wrapper */
        .pw-wrap {
            position: relative;
        }

        .pw-wrap .form-input {
            padding-right: 2.75rem;
        }

        .pw-toggle {
            position: absolute;
            right: 0.875rem;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            cursor: pointer;
            color: var(--ds-t3);
            display: flex;
            align-items: center;
            padding: 0;
            transition: color var(--transition);
        }

        .pw-toggle:hover { color: var(--ds-t2); }

        .pw-toggle svg {
            width: 18px;
            height: 18px;
            stroke-width: 2;
            stroke-linecap: round;
            stroke-linejoin: round;
            fill: none;
            stroke: currentColor;
        }

        /* UNE Preview */
        .une-preview {
            display: none;
            margin-top: 0.5rem;
            padding: 0.625rem 0.875rem;
            background: var(--ds-accent-s);
            border: 1px solid rgba(59,130,246,0.2);
            border-radius: 7px;
            font-size: 0.8125rem;
        }

        .une-preview.visible { display: flex; align-items: center; gap: 0.5rem; }

        .une-preview-label { color: var(--ds-t2); }

        .une-preview-domain {
            font-weight: 700;
            color: var(--ds-accent);
        }

        /* Validation feedback */
        .validation-msg {
            font-size: 0.75rem;
            margin-top: 0.35rem;
            display: none;
        }

        .validation-msg.show { display: block; }
        .validation-msg.ok { color: var(--ds-green); }
        .validation-msg.err { color: var(--ds-red); }
        .validation-msg.checking { color: var(--ds-t3); }

        /* Username suggestions */
        .suggestions {
            display: flex;
            flex-wrap: wrap;
            gap: 0.4rem;
            margin-top: 0.5rem;
        }

        .suggestion-chip {
            font-size: 0.75rem;
            padding: 0.25rem 0.6rem;
            background: var(--ds-bg2);
            border: 1px solid var(--ds-border);
            border-radius: 20px;
            color: var(--ds-t2);
            cursor: pointer;
            transition: all var(--transition);
        }

        .suggestion-chip:hover {
            border-color: var(--ds-accent);
            color: var(--ds-accent);
        }

        /* Alert */
        .alert {
            padding: 0.75rem 1rem;
            border-radius: var(--radius);
            font-size: 0.875rem;
            margin-bottom: 1.25rem;
            display: none;
        }

        .alert.show { display: block; }
        .alert.error { background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.25); color: #FCA5A5; }
        .alert.success { background: rgba(16,185,129,0.1); border: 1px solid rgba(16,185,129,0.25); color: #6EE7B7; }

        /* Buttons */
        .btn-primary {
            width: 100%;
            padding: 0.8125rem 1.5rem;
            background: var(--ds-accent);
            border: none;
            border-radius: var(--radius);
            color: white;
            font-size: 0.9375rem;
            font-weight: 700;
            cursor: pointer;
            font-family: inherit;
            letter-spacing: -0.01em;
            transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            margin-top: 0.5rem;
        }

        .btn-primary:hover {
            background: #2563EB;
            box-shadow: 0 4px 20px rgba(59,130,246,0.3);
            transform: translateY(-1px);
        }

        .btn-primary:active { transform: translateY(0); }

        .btn-primary:disabled {
            opacity: 0.5;
            cursor: not-allowed;
            transform: none;
        }

        .btn-primary svg {
            width: 18px;
            height: 18px;
            stroke: white;
            fill: none;
            stroke-width: 2.2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        .btn-secondary {
            width: 100%;
            padding: 0.75rem 1.5rem;
            background: transparent;
            border: 1px solid var(--ds-border);
            border-radius: var(--radius);
            color: var(--ds-t2);
            font-size: 0.875rem;
            font-weight: 600;
            cursor: pointer;
            font-family: inherit;
            transition: all var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            margin-top: 0.5rem;
        }

        .btn-secondary:hover {
            border-color: var(--ds-border-hover);
            color: var(--ds-t1);
        }

        .btn-secondary svg {
            width: 16px;
            height: 16px;
            stroke: currentColor;
            fill: none;
            stroke-width: 2.2;
            stroke-linecap: round;
            stroke-linejoin: round;
        }

        /* Divider */
        .divider {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            margin: 1.375rem 0;
        }

        .divider::before, .divider::after {
            content: '';
            flex: 1;
            height: 1px;
            background: var(--ds-border);
        }

        .divider span {
            font-size: 0.75rem;
            color: var(--ds-t3);
            white-space: nowrap;
        }

        /* Switch links */
        .auth-switch {
            text-align: center;
            font-size: 0.875rem;
            color: var(--ds-t2);
            margin-top: 1.5rem;
        }

        .auth-switch a {
            color: var(--ds-accent);
            text-decoration: none;
            font-weight: 600;
            cursor: pointer;
        }

        .auth-switch a:hover { text-decoration: underline; }

        /* Terms checkbox */
        .terms-row {
            display: flex;
            align-items: flex-start;
            gap: 0.625rem;
            margin: 1rem 0;
        }

        .terms-row input[type="checkbox"] {
            width: 1rem;
            height: 1rem;
            margin-top: 0.125rem;
            accent-color: var(--ds-accent);
            cursor: pointer;
            flex-shrink: 0;
        }

        .terms-row label {
            font-size: 0.8125rem;
            color: var(--ds-t2);
            line-height: 1.5;
            cursor: pointer;
        }

        .terms-row a {
            color: var(--ds-accent);
            text-decoration: none;
            font-weight: 500;
        }

        .terms-row a:hover { text-decoration: underline; }

        /* Footer */
        .auth-footer {
            padding: 1.25rem 2.5rem;
            border-top: 1px solid var(--ds-border);
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .auth-footer-copy {
            font-size: 0.75rem;
            color: var(--ds-t3);
        }

        .auth-footer-links {
            display: flex;
            gap: 1.25rem;
        }

        .auth-footer-links a {
            font-size: 0.75rem;
            color: var(--ds-t3);
            text-decoration: none;
            transition: color var(--transition);
        }

        .auth-footer-links a:hover { color: var(--ds-t2); }

        /* Spinner */
        .spinner {
            width: 18px;
            height: 18px;
            border: 2px solid rgba(255,255,255,0.3);
            border-top-color: white;
            border-radius: 50%;
            animation: spin 0.7s linear infinite;
            display: none;
        }

        @keyframes spin { to { transform: rotate(360deg); } }

        /* ── MODAL ── */
        .modal-backdrop {
            display: none;
            position: fixed;
            inset: 0;
            background: rgba(0,0,0,0.7);
            z-index: 1000;
            align-items: center;
            justify-content: center;
            backdrop-filter: blur(4px);
        }

        .modal-backdrop.open { display: flex; animation: fadeSlideIn 0.2s ease; }

        .modal-box {
            background: var(--ds-bg1);
            border: 1px solid var(--ds-border);
            border-radius: 14px;
            width: 90%;
            max-width: 540px;
            max-height: 80vh;
            display: flex;
            flex-direction: column;
            overflow: hidden;
        }

        .modal-head {
            padding: 1.25rem 1.5rem;
            border-bottom: 1px solid var(--ds-border);
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .modal-head h3 {
            font-size: 1rem;
            font-weight: 700;
            color: var(--ds-t1);
        }

        .modal-close {
            background: none;
            border: none;
            cursor: pointer;
            color: var(--ds-t3);
            display: flex;
            align-items: center;
            padding: 0.25rem;
            border-radius: 6px;
            transition: all var(--transition);
        }

        .modal-close:hover { color: var(--ds-t1); background: var(--ds-bg2); }

        .modal-close svg {
            width: 18px;
            height: 18px;
            stroke: currentColor;
            fill: none;
            stroke-width: 2.2;
            stroke-linecap: round;
        }

        .modal-body {
            padding: 1.5rem;
            overflow-y: auto;
            font-size: 0.875rem;
            color: var(--ds-t2);
            line-height: 1.7;
        }

        .modal-body h4 {
            color: var(--ds-t1);
            font-size: 0.9375rem;
            margin-bottom: 0.75rem;
            margin-top: 1.25rem;
        }

        .modal-body h4:first-child { margin-top: 0; }

        .modal-body ul {
            padding-left: 1.25rem;
            margin-top: 0.5rem;
        }

        .modal-body li { margin-bottom: 0.35rem; }

        /* ── MOBILE ── */
        @media (max-width: 900px) {
            html, body { overflow: auto; }

            .auth-root {
                grid-template-columns: 1fr;
                min-height: 100vh;
            }

            .brand-panel {
                padding: 2rem 1.5rem 1.5rem;
                border-right: none;
                border-bottom: 1px solid var(--ds-border);
            }

            .brand-panel::after { display: none; }

            .brand-center { margin: 1.5rem 0; }

            .brand-pillars { display: none; }

            .brand-stats {
                grid-template-columns: repeat(3, 1fr);
            }

            .brand-headline { font-size: 1.5rem; }

            .auth-inner {
                min-height: auto;
                padding: 2rem 1.5rem;
                justify-content: flex-start;
            }

            .auth-panel { overflow: visible; }

            .form-row { grid-template-columns: 1fr; }
        }