#iserv-kalender-tool {
      --bg: #f5f7fb;
      --card: #ffffff;
      --border: #dbe3ee;
      --text: #16202a;
      --muted: #5f6b7a;
      --muted-2: #7d8794;
      --accent: #1f4f82;
      --accent-soft: #eaf2fb;
      --danger-bg: #fff4f4;
      --danger-border: #f1caca;
      --shadow: 0 8px 26px rgba(15, 23, 42, 0.08);
      --radius: 18px;
    }

    #iserv-kalender-tool, #iserv-kalender-tool * { box-sizing: border-box; }
    
    #iserv-kalender-tool {
      font-family: Arial, Helvetica, sans-serif;
      background: var(--bg);
      color: var(--text);
      line-height: 1.45;
    }

    #iserv-kalender-tool .iserv-wrap {
      max-width: 1400px;
      margin: 0 auto;
      padding: 24px;
      display: grid;
      grid-template-columns: 360px 1fr;
      gap: 24px;
    }

    #iserv-kalender-tool .panel, #iserv-kalender-tool .preview {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      box-shadow: var(--shadow);
    }

    #iserv-kalender-tool .panel {
      overflow: hidden;
      margin-bottom: 16px;
    }

    #iserv-kalender-tool .panel-header, #iserv-kalender-tool .preview-header {
      padding: 20px 20px 8px;
      border-bottom: 1px solid #edf1f6;
    }

    #iserv-kalender-tool .panel-body, #iserv-kalender-tool .preview-body {
      padding: 20px;
    }

    #iserv-kalender-tool h1, #iserv-kalender-tool h2, #iserv-kalender-tool h3, #iserv-kalender-tool h4, #iserv-kalender-tool p { margin: 0; }
    #iserv-kalender-tool h1 { font-size: 1.35rem; }
    #iserv-kalender-tool h2 { font-size: 1.1rem; }
    #iserv-kalender-tool h3 { font-size: 1.05rem; }
    #iserv-kalender-tool .subtle { color: var(--muted); font-size: 0.92rem; margin-top: 6px; }

    #iserv-kalender-tool .stack { display: grid; gap: 14px; }
    #iserv-kalender-tool label { display: block; font-size: 0.92rem; font-weight: 700; margin-bottom: 6px; }
    #iserv-kalender-tool input[type="text"], #iserv-kalender-tool input[type="url"], #iserv-kalender-tool input[type="file"], #iserv-kalender-tool select {
      width: 100%;
      padding: 11px 12px;
      border: 1px solid #cfd8e3;
      border-radius: 12px;
      font-size: 0.95rem;
      background: #fff;
    }

    #iserv-kalender-tool .row { display: flex; gap: 10px; }
    #iserv-kalender-tool .row > * { flex: 1; }

    #iserv-kalender-tool button {
      border: 0;
      border-radius: 12px;
      background: var(--accent);
      color: #fff;
      padding: 11px 14px;
      cursor: pointer;
      font-size: 0.95rem;
      font-weight: 700;
    }
    #iserv-kalender-tool button.secondary {
      background: #eef3f8;
      color: var(--text);
      border: 1px solid var(--border);
    }
    #iserv-kalender-tool button:disabled {
      opacity: 0.5;
      cursor: not-allowed;
    }

    #iserv-kalender-tool .note, #iserv-kalender-tool .error {
      border-radius: 14px;
      padding: 12px 14px;
      font-size: 0.92rem;
    }
    #iserv-kalender-tool .note {
      background: var(--accent-soft);
      border: 1px solid #d7e7fb;
    }
    #iserv-kalender-tool .error {
      background: var(--danger-bg);
      border: 1px solid var(--danger-border);
    }

    #iserv-kalender-tool .checkbox-line {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 0.94rem;
    }
    #iserv-kalender-tool .checkbox-line input { width: 16px; height: 16px; }

    #iserv-kalender-tool .preview {
      min-height: calc(100vh - 48px);
      overflow: hidden;
    }

    #iserv-kalender-tool .print-hint {
      margin-bottom: 16px;
      color: var(--muted);
      font-size: 0.92rem;
    }

    #iserv-kalender-tool .doc-title {
      padding-bottom: 12px;
      border-bottom: 1px solid #dce5ef;
      margin-bottom: 18px;
    }

    #iserv-kalender-tool .month-section {
      break-inside: avoid;
      border: 1px solid #e2e9f1;
      border-radius: 18px;
      padding: 16px;
      margin-bottom: 16px;
      background: #fff;
    }

    #iserv-kalender-tool .event-row {
      display: grid;
      grid-template-columns: 140px 120px 1fr;
      gap: 12px;
      border-bottom: 1px solid #edf1f6;
      padding: 9px 0;
      font-size: 0.92rem;
    }
    #iserv-kalender-tool .event-row:last-child { border-bottom: 0; }
    #iserv-kalender-tool .muted { color: var(--muted); }
    #iserv-kalender-tool .muted-2 { color: var(--muted-2); }
    #iserv-kalender-tool .event-title { font-weight: 700; }
    #iserv-kalender-tool .empty {
      border: 1px dashed #cad4df;
      border-radius: 16px;
      padding: 28px;
      text-align: center;
      color: var(--muted);
      background: #fff;
    }

    #iserv-kalender-tool .month-grid-weekdays,
    #iserv-kalender-tool .month-grid {
      display: grid;
      grid-template-columns: repeat(7, 1fr);
      gap: 8px;
    }

    #iserv-kalender-tool .weekday {
      text-align: center;
      background: #eef3f8;
      border-radius: 10px;
      padding: 10px;
      font-weight: 700;
      color: var(--muted);
      font-size: 0.9rem;
    }

    #iserv-kalender-tool .day-cell {
      min-height: 140px;
      background: #fff;
      border: 1px solid #e2e9f1;
      border-radius: 14px;
      padding: 8px;
    }

    #iserv-kalender-tool .day-number {
      font-weight: 700;
      font-size: 0.92rem;
      margin-bottom: 8px;
    }

    #iserv-kalender-tool .day-event {
      background: #f2f5f9;
      border-radius: 8px;
      padding: 5px 7px;
      font-size: 0.76rem;
      margin-bottom: 5px;
      line-height: 1.3;
    }

    #iserv-kalender-tool .year-grid {
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 16px;
    }

    #iserv-kalender-tool .year-card {
      border: 1px solid #e2e9f1;
      border-radius: 16px;
      padding: 14px;
      break-inside: avoid;
    }

    #iserv-kalender-tool .year-item {
      border-bottom: 1px solid #eef2f7;
      padding: 7px 0;
      font-size: 0.88rem;
    }
    #iserv-kalender-tool .year-item:last-child { border-bottom: 0; }

    #iserv-kalender-tool .toolbar-actions { display: flex; gap: 10px; }

    @media (max-width: 1100px) {
      #iserv-kalender-tool .iserv-wrap { grid-template-columns: 1fr; }
      #iserv-kalender-tool .preview { min-height: auto; }
    }

    @media print {
      @page { size: A4 portrait; margin: 12mm; }
      #iserv-kalender-tool { background: #fff; }
      #iserv-kalender-tool .iserv-wrap { display: block; max-width: none; padding: 0; }
      #iserv-kalender-tool .sidebar, #iserv-kalender-tool .preview-header, #iserv-kalender-tool .print-hint { display: none !important; }
      #iserv-kalender-tool .preview { border: 0; box-shadow: none; min-height: auto; }
      #iserv-kalender-tool .preview-body { padding: 0; }
      #iserv-kalender-tool .month-section, #iserv-kalender-tool .year-card, #iserv-kalender-tool .day-cell {
        box-shadow: none;
        border-radius: 0;
      }
      #iserv-kalender-tool .day-cell { min-height: 110px; }
    }