:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --bg: #f8fafc;
    --panel-bg: #ffffff;
    --border: #e2e8f0;
    --viewer-bg: #525659;
    --text-main: #334155;
}

body { margin: 0; font-family: 'Inter', system-ui, sans-serif; height: 100vh; display: flex; flex-direction: column; overflow: hidden; background: var(--bg); color: var(--text-main); }

/* --- Header & Tabs --- */
header { background: var(--panel-bg); border-bottom: 1px solid var(--border); display: flex; flex-direction: column; z-index: 20; box-shadow: 0 2px 4px rgba(0,0,0,0.05); }
.top-bar { padding: 8px 12px; display: flex; align-items: center; gap: 15px; height: 40px; }
.logo { font-weight: 800; color: var(--primary); font-size: 1.1rem; letter-spacing: -0.5px; margin-right: 10px; }

.tabs-track { flex: 1; overflow-x: auto; display: flex; gap: 6px; padding-bottom: 2px; }
/* .tabs-track::-webkit-scrollbar { display: none; } */

.doc-tab {
    background: #f1f5f9; border: 1px solid #cbd5e1; padding: 6px 12px; border-radius: 6px;
    font-size: 13px; display: flex; align-items: center; gap: 8px; cursor: pointer; user-select: none;
    transition: all 0.2s; max-width: 200px;
}
.doc-tab:hover { background: #e2e8f0; }
.doc-tab.active { background: var(--primary); color: white; border-color: var(--primary-dark); }
.doc-tab span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.close-tab { opacity: 0.6; font-size: 14px; width: 16px; height: 16px; display: flex; align-items: center; justify-content: center; border-radius: 50%; }
.close-tab:hover { background: rgba(0,0,0,0.2); opacity: 1; }

.sortable-ghost { opacity: 0.4; background: #c7d2fe; border: 1px dashed #6366f1; }
.sortable-drag { cursor: grabbing; opacity: 1; background: white; box-shadow: 0 5px 15px rgba(0,0,0,0.2); transform: scale(1.02); z-index: 1000; transition: none !important; }

.btn { padding: 6px 12px; border-radius: 6px; border: 1px solid var(--border); background: white; cursor: pointer; font-size: 13px; font-weight: 500; transition: 0.1s; }
.btn:hover { background: #f8fafc; border-color: #cbd5e1; }
.btn-primary { background: var(--primary); color: white; border: none; }
.btn-primary:hover { background: var(--primary-dark); }
.btn.active { background: #fee2e2; color: #b91c1c; border-color: #fca5a5; }

.toolbar { padding: 8px 15px; border-top: 1px solid var(--border); display: flex; gap: 15px; align-items: center; background: white; font-size: 13px; }

/* --- Layout --- */
.workspace { flex: 1; display: flex; overflow: hidden; }

/* --- Viewer (Center) --- */
#viewer-container { flex: 1; background: var(--viewer-bg); overflow: auto; padding: 40px; display: flex; flex-direction: column; align-items: center; gap: 30px; position: relative; }

/* Page Wrapper Logic */
.page-wrapper {
    position: relative;
    background: white;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    transition: transform 0.2s;
}

/* Stack Layers: Canvas(PDF) -> TextLayer(Selection) -> Canvas(Draw) */
.pdf-canvas { display: block; }
.textLayer { opacity: 1; mix-blend-mode: multiply; }
.draw-canvas { position: absolute; top: 0; left: 0; cursor: crosshair; touch-action: none; pointer-events: none; z-index: 10; }
.page-wrapper.draw-mode .draw-canvas { pointer-events: auto; }
.page-wrapper.erase-mode .draw-canvas { pointer-events: auto; cursor: no-drop; }
.page-wrapper.text-mode .draw-canvas { pointer-events: auto; cursor: text; }

/* Page Controls (Floating) */
.page-meta {
    position: absolute; top: 0; left: -50px; width: 40px; text-align: right;
    color: rgba(255,255,255,0.7); font-size: 14px; font-weight: bold;
}
.page-controls {
    position: absolute; top: 10px; right: -140px; width: 130px;
    display: flex; flex-direction: column; gap: 5px;
}
.add-btn {
    background: var(--primary); color: white; border: none; padding: 8px; border-radius: 4px;
    cursor: pointer; font-weight: 600; text-align: left; display: flex; align-items: center; gap: 6px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2); transition: 0.2s;
}
.add-btn:hover { transform: translateX(-2px); }
.add-btn.added { background: #10b981; }

/* --- Sidebar (Right) --- */
#sidebar { width: 320px; background: white; border-left: 1px solid var(--border); display: flex; flex-direction: column; z-index: 30; }
.sidebar-header { padding: 15px; border-bottom: 1px solid var(--border); background: #f8fafc; }
#basket-list { flex: 1; overflow-y: auto; padding: 10px; }

.basket-item {
    background: white; border: 1px solid var(--border); border-radius: 6px; padding: 10px;
    margin-bottom: 8px; display: flex; align-items: center; gap: 10px; cursor: grab;
    position: relative; transition: border-color 0.2s;
}
.basket-item:hover { border-color: var(--primary); }
.basket-item:active { cursor: grabbing; }
.basket-thumb { width: 30px; height: 40px; background: #eee; border-radius: 2px; flex-shrink: 0; overflow: hidden; position: relative; }
.basket-info { flex: 1; min-width: 0; }
.doc-name { font-size: 11px; color: #64748b; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.page-num { font-weight: 600; font-size: 14px; }

/* Hover Preview */
#hover-preview {
    position: fixed; display: none; border: 2px solid var(--primary);
    background: white; box-shadow: 0 10px 25px rgba(0,0,0,0.3); z-index: 100; pointer-events: none;
}

/* Loading Overlay */
#loader {
    position: fixed; top:0; left:0; width:100%; height:100%; background:rgba(255,255,255,0.9);
    display: flex; flex-direction: column; justify-content: center; align-items: center; z-index: 1000;
}
.spinner { width: 40px; height: 40px; border: 4px solid #e2e8f0; border-top-color: var(--primary); border-radius: 50%; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* --- Resizer --- */
#resizer {
    width: 6px;
    background: #f1f5f9;
    cursor: col-resize;
    border-left: 1px solid #e2e8f0;
    border-right: 1px solid #e2e8f0;
    z-index: 35;
    transition: background 0.2s;
    flex-shrink: 0;
}
#resizer:hover, #resizer.resizing {
    background: var(--primary);
}

/* Updated Sidebar for Resizing */
#sidebar {
    width: 320px; /* Default */
    min-width: 200px;
    max-width: 600px;
    /* other props remain from original CSS */
}

/* --- Color Picker --- */
.color-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6px;
    width: 34px;
    height: 32px;
    box-sizing: border-box;
}
#color-preview {
    width: 20px;
    height: 20px;
    border-radius: 4px;
    border: 1px solid rgba(0,0,0,0.1);
    pointer-events: none; /* Let clicks pass to parent */
}
#color-picker {
    position: absolute;
    width: 0;
    height: 0;
    opacity: 0;
    pointer-events: none;
}

/* --- Modal --- */
.modal-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.5); z-index: 2000;
    display: flex; align-items: center; justify-content: center;
    backdrop-filter: blur(2px);
}
.modal-content {
    background: white; width: 500px; max-width: 90%;
    border-radius: 8px; box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    overflow: hidden; animation: popIn 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.modal-header {
    background: #f8fafc; padding: 15px 20px; border-bottom: 1px solid var(--border);
    display: flex; justify-content: space-between; align-items: center;
}
.modal-header h3 { margin: 0; color: var(--text-main); font-size: 18px; }
.close-modal {
    background: none; border: none; font-size: 18px; cursor: pointer; color: #64748b;
    width: 28px; height: 28px; border-radius: 50%; display: flex; align-items: center; justify-content: center;
}
.close-modal:hover { background: rgba(0,0,0,0.1); color: var(--text-main); }
.modal-body { padding: 20px; font-size: 14px; line-height: 1.5; color: #334155; }

@keyframes popIn {
    from { transform: scale(0.9); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}