:root {
            --primary: #4361ee;
            --secondary: #3a0ca3;
            --accent: #4cc9f0;
            --success: #4ade80;
            --danger: #f72585;
            --warning: #f8961e;
            --dark: #0f172a;
            --dark-2: #1e293b;
            --light: #f8fafc;
            --muted: #94a3b8;
            --card: rgba(30, 41, 59, 0.85);
            --border: rgba(255, 255, 255, 0.08);
            --shadow: 0 12px 28px rgba(0, 0, 0, 0.25);
            --field-bg: rgba(15, 23, 42, 0.82);
            --field-border: rgba(148, 163, 184, 0.38);
            --field-focus: rgba(67, 97, 238, 0.45);
        }

        body.theme-dark {
            background: linear-gradient(135deg, var(--dark) 0%, var(--dark-2) 100%);
            color: var(--light);
            min-height: 100vh;
            font-family: "Manrope", "Microsoft YaHei", "PingFang SC", sans-serif;
        }

        .navbar {
            background: rgba(15, 23, 42, 0.95) !important;
            border-bottom: 1px solid var(--border);
            backdrop-filter: blur(12px);
        }

        .page-title {
            background: linear-gradient(to right, var(--accent), var(--primary));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }

        .card {
            background: var(--card);
            border: 1px solid var(--border);
            box-shadow: var(--shadow);
        }

        .card-header {
            background: rgba(15, 23, 42, 0.6);
            border-bottom: 1px solid var(--border);
            color: var(--light);
        }

        .form-label {
            color: var(--muted);
            font-weight: 600;
        }

        .form-control {
            background: var(--field-bg);
            color: var(--light);
            border: 1px solid var(--field-border);
            border-radius: 12px;
            min-height: 44px;
        }

        .form-control::placeholder {
            color: rgba(148, 163, 184, 0.85);
        }

        .form-control:focus {
            border-color: var(--primary);
            box-shadow: 0 0 0 0.2rem var(--field-focus);
            background: var(--field-bg);
            color: var(--light);
        }

        .btn-primary {
            border: 1px solid rgba(105, 124, 255, 0.6);
            background: linear-gradient(135deg, #4f68ff, #3d56dc);
            border-radius: 12px;
            min-height: 44px;
            font-weight: 600;
            box-shadow: 0 8px 20px rgba(61, 86, 220, 0.35);
            transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
        }

        .btn-primary:hover {
            filter: brightness(1.03);
            transform: translateY(-1px);
            box-shadow: 0 10px 24px rgba(61, 86, 220, 0.42);
        }

        .btn-primary:focus {
            box-shadow: 0 0 0 0.2rem var(--field-focus), 0 10px 24px rgba(61, 86, 220, 0.42);
        }

        .alert-danger {
            background: rgba(247, 37, 133, 0.15);
            color: var(--danger);
            border: 1px solid rgba(247, 37, 133, 0.35);
        }

        .remember-wrap {
            display: flex;
            align-items: center;
            gap: 10px;
            padding: 10px 12px;
            border-radius: 12px;
            border: 1px solid var(--field-border);
            background: var(--field-bg);
            transition: border-color 0.15s ease, box-shadow 0.15s ease;
        }

        .remember-wrap:focus-within {
            border-color: var(--primary);
            box-shadow: 0 0 0 0.2rem var(--field-focus);
        }

        .remember-wrap .form-check-input {
            width: 2.2em;
            height: 1.2em;
            margin-top: 0;
            background-color: rgba(148, 163, 184, 0.35);
            border-color: rgba(148, 163, 184, 0.55);
            box-shadow: none;
        }

        .remember-wrap .form-check-input:checked {
            background-color: #4cc9f0;
            border-color: #4cc9f0;
        }

        .remember-label {
            color: var(--light);
            font-size: 0.9rem;
            font-weight: 600;
            user-select: none;
        }

        .remember-hint {
            color: #94a3b8;
            font-size: 0.78rem;
            margin-top: 2px;
        }

        footer {
            color: var(--muted);
        }