:root {
            --bg-color: #041124;
            --panel-bg: rgba(10, 25, 50, 0.7);
            --panel-border: rgba(255, 255, 255, 0.1);
            --text-primary: #f8fafc;
            --text-secondary: #94a3b8;
            --accent-color: #0066FF;
            --accent-hover: #3385FF;
            --fc-page-bg-color: transparent;
            --fc-neutral-bg-color: rgba(10, 25, 50, 0.5);
            --fc-neutral-text-color: #94a3b8;
            --fc-border-color: rgba(255, 255, 255, 0.1);
            --fc-button-text-color: #fff;
            --fc-button-bg-color: rgba(10, 25, 50, 0.8);
            --fc-button-border-color: rgba(255, 255, 255, 0.2);
            --fc-button-hover-bg-color: rgba(255, 255, 255, 0.1);
            --fc-button-hover-border-color: rgba(255, 255, 255, 0.3);
            --fc-button-active-bg-color: var(--accent-color);
            --fc-button-active-border-color: var(--accent-hover);
            --fc-event-bg-color: rgba(0, 102, 255, 0.2);
            --fc-event-border-color: var(--accent-color);
            --fc-event-text-color: #e2e8f0;
            --fc-today-bg-color: rgba(255, 255, 255, 0.05);
        }

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

        body {
            font-family: 'Inter', sans-serif;
            background: linear-gradient(135deg, #020d1c 0%, #001f4d 100%);
            color: var(--text-primary);
            height: 100vh;
            display: flex;
            overflow: hidden;
        }

        .app-container {
            display: flex;
            width: 100%;
            height: 100%;
            padding: 16px;
            gap: 16px;
        }

        .sidebar {
            width: 320px;
            background: var(--panel-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--panel-border);
            border-radius: 16px;
            padding: 24px;
            display: flex;
            flex-direction: column;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
            flex-shrink: 0;
        }

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

        .sidebar-header h4 {
            font-size: 0.8rem;
            text-transform: uppercase;
            letter-spacing: 1px;
            color: var(--text-secondary);
            font-weight: 500;
            margin-bottom: 4px;
        }

        .sidebar-header h1 {
            font-size: 1.8rem;
            font-weight: 600;
            line-height: 1.2;
            color: #fff;
        }

        .sidebar-header h1 span {
            color: var(--accent-color);
        }

        .sidebar-header h6 {
            font-size: 0.75rem;
            color: var(--accent-hover);
            margin-top: 4px;
            font-weight: 400;
        }

        hr {
            border: none;
            border-top: 1px solid var(--panel-border);
            margin: 16px 0;
        }

        .instructions {
            font-size: 0.85rem;
            color: var(--text-secondary);
            margin-bottom: 20px;
            line-height: 1.5;
        }

        .instructions a.btn-link-action {
            display: block;
            margin-top: 12px;
            padding: 10px 16px;
            border: 1px solid var(--accent-color);
            border-radius: 8px;
            color: var(--accent-hover);
            text-decoration: none;
            font-size: 0.9rem;
            font-weight: 500;
            transition: all 0.2s ease;
            text-align: center;
            background: rgba(0, 102, 255, 0.05);
        }

        .instructions a.btn-link-action:hover {
            background: rgba(0, 102, 255, 0.15);
            color: #fff;
            border-color: var(--accent-hover);
            transform: translateY(-1px);
        }

        .form-group {
            margin-bottom: 16px;
        }

        .form-group label {
            display: block;
            font-size: 0.8rem;
            color: var(--text-secondary);
            margin-bottom: 6px;
        }

        .form-control {
            width: 100%;
            background: rgba(0, 0, 0, 0.2);
            border: 1px solid var(--panel-border);
            color: #fff;
            padding: 10px 12px;
            border-radius: 8px;
            font-family: inherit;
            font-size: 0.9rem;
            transition: border-color 0.2s ease, box-shadow 0.2s ease;
            outline: none;
        }

        .form-control:focus {
            border-color: var(--accent-color);
            box-shadow: 0 0 0 2px rgba(0, 102, 255, 0.2);
        }

        .btn-action {
            background: rgba(0, 0, 0, 0.2);
            color: var(--text-primary);
            border: 1px solid var(--panel-border);
            padding: 8px 12px;
            border-radius: 8px;
            font-family: inherit;
            font-size: 0.85rem;
            cursor: pointer;
            flex: 1;
            transition: background 0.2s ease, border-color 0.2s ease;
        }

        .btn-action:hover {
            background: rgba(255, 255, 255, 0.1);
            border-color: rgba(255, 255, 255, 0.3);
        }

        .input-group {
            display: flex;
            flex-direction: column;
        }

        .input-group .form-control {
            border-bottom-left-radius: 0;
            border-bottom-right-radius: 0;
        }
        
        .input-group .form-control:focus {
            position: relative;
            z-index: 2;
        }

        .input-group .input-actions {
            display: flex;
        }

        .input-group .btn-action {
            border-top-left-radius: 0;
            border-top-right-radius: 0;
            border-top: none;
            background: rgba(0, 0, 0, 0.3);
            font-size: 0.8rem;
            padding: 8px;
        }

        .input-group .btn-action:hover {
            background: rgba(255, 255, 255, 0.15);
        }

        .input-group .btn-action:first-child {
            border-bottom-right-radius: 0;
            border-right: none;
        }

        .input-group .btn-action:nth-child(2) {
            border-bottom-left-radius: 0;
        }

        .form-control option {
            background-color: var(--bg-color);
            color: var(--text-primary);
        }

        .settings-group {
            background: rgba(0, 0, 0, 0.15);
            border: 1px solid var(--panel-border);
            border-radius: 12px;
            padding: 12px 16px;
            margin-bottom: 16px;
        }

        .settings-group .form-group:last-child {
            margin-bottom: 0;
        }

        .form-row {
            display: flex;
            gap: 12px;
            align-items: center;
        }

        .form-row .form-group {
            flex: 1;
        }

        input[type="number"] {
            width: 60px;
        }

        .btn {
            background: linear-gradient(135deg, var(--accent-color) 0%, #003399 100%);
            color: #fff;
            border: none;
            padding: 12px;
            border-radius: 8px;
            font-weight: 500;
            font-size: 1rem;
            cursor: pointer;
            width: 100%;
            transition: transform 0.2s ease, box-shadow 0.2s ease;
            margin-top: 8px;
        }

        .btn:hover {
            transform: translateY(-1px);
            box-shadow: 0 6px 20px rgba(0, 102, 255, 0.4);
        }

        .btn:active {
            transform: translateY(1px);
        }

        .footer {
            margin-top: auto;
            text-align: center;
            font-size: 0.8rem;
            color: var(--text-secondary);
        }

        .footer a {
            color: var(--text-primary);
            text-decoration: none;
        }

        .footer a:hover {
            text-decoration: underline;
        }

        .main-content {
            flex: 1;
            background: var(--panel-bg);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid var(--panel-border);
            border-radius: 16px;
            padding: 24px;
            display: flex;
            flex-direction: column;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
            overflow: hidden;
        }

        #calendar {
            flex: 1;
            height: 100%;
        }

        /* FullCalendar dark mode tweaks */
        .fc-theme-standard td,
        .fc-theme-standard th {
            border-color: var(--fc-border-color);
        }

        .fc-toolbar-title {
            font-weight: 500;
        }

        .fc .fc-col-header-cell-cushion,
        .fc .fc-daygrid-day-number {
            color: var(--text-primary);
            text-decoration: none;
        }

        .fc .fc-list-event:hover td {
            background-color: rgba(255, 255, 255, 0.05);
        }

        .custom-tooltip {
            position: absolute;
            z-index: 9999;
            background: rgba(15, 23, 42, 0.95);
            color: #fff;
            padding: 12px;
            border-radius: 8px;
            font-size: 0.85rem;
            max-width: 300px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
            border: 1px solid var(--accent-color);
            pointer-events: none;
            backdrop-filter: blur(8px);
            white-space: pre-wrap;
            line-height: 1.4;
        }