/* ============================================================================
   BrowserCAD — Professional CAD UI
   ============================================================================ */
:root {
  --bg-primary: #1e1e22;
  --bg-secondary: #27272b;
  --bg-tertiary: #2f2f35;
  --bg-panel: #252529;
  --border: #3a3a42;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0a8;
  --text-muted: #6a6a72;
  --accent: #0078d4;
  --accent-hover: #1a8ae8;
  --success: #22aa44;
  --warning: #dd8800;
  --error: #dd3333;
  --hover: rgba(255,255,255,0.06);
  --panel-width: 250px;
  --ribbon-height: 88px;
  --status-height: 24px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --mono: 'Consolas','Monaco',monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
html,body{width:100%;height:100%;overflow:hidden;font-family:var(--font);font-size:13px;color:var(--text-primary);background:var(--bg-primary);user-select:none}
#app{display:flex;flex-direction:column;width:100%;height:100%}

/* Ribbon */
#ribbon{height:var(--ribbon-height);background:var(--bg-secondary);border-bottom:1px solid var(--border);display:flex;flex-direction:column;flex-shrink:0}
.ribbon-tabs{display:flex;height:26px;background:var(--bg-tertiary);border-bottom:1px solid var(--border);align-items:center;padding:0 8px;gap:0}
.ribbon-tabs .app-title{font-weight:700;color:var(--accent);margin-right:16px;font-size:13px}
.rtab{padding:3px 14px;cursor:pointer;color:var(--text-secondary);font-size:12px;border-bottom:2px solid transparent;transition:all .15s}
.rtab:hover{color:var(--text-primary);background:var(--hover)}
.rtab.active{color:var(--text-primary);border-bottom-color:var(--accent)}
.ribbon-content{flex:1;display:flex;align-items:center;padding:2px 6px;gap:1px;overflow-x:auto}
.rgroup{display:flex;align-items:center;gap:1px;padding:0 8px;border-right:1px solid var(--border);height:100%}
.rgroup:last-child{border-right:none}
.rbtn{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1px;padding:3px 7px;border:none;background:transparent;color:var(--text-secondary);cursor:pointer;border-radius:3px;min-width:44px;height:50px;font-size:10px;transition:all .12s;font-family:var(--font)}
.rbtn:hover{background:var(--hover);color:var(--text-primary)}
.rbtn:active{background:rgba(255,255,255,.1)}
.rbtn.active{background:var(--accent);color:#fff}
.rbtn .ico{font-size:18px;line-height:1}
.rbtn .lbl{font-size:10px;white-space:nowrap}

/* Main area */
#main{flex:1;display:flex;overflow:hidden;position:relative}

/* Panels */
.panel{width:var(--panel-width);background:var(--bg-panel);display:flex;flex-direction:column;flex-shrink:0;overflow:hidden}
.panel.left{border-right:1px solid var(--border)}
.panel.right{border-left:1px solid var(--border)}
.panel-hdr{padding:7px 12px;font-size:11px;font-weight:600;color:var(--text-secondary);background:var(--bg-tertiary);border-bottom:1px solid var(--border);text-transform:uppercase;letter-spacing:.5px}
.panel-body{flex:1;overflow-y:auto;padding:4px}
.panel-body::-webkit-scrollbar{width:6px}
.panel-body::-webkit-scrollbar-track{background:transparent}
.panel-body::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}

/* Tree items */
.tree-sec{padding:6px 8px 3px;font-size:10px;color:var(--text-muted);font-weight:600;text-transform:uppercase;letter-spacing:.5px}
.tree-item{display:flex;align-items:center;padding:3px 8px;cursor:pointer;border-radius:3px;font-size:12px;gap:6px;transition:background .1s}
.tree-item:hover{background:var(--hover)}
.tree-item.sel{background:rgba(0,120,212,.2);color:var(--accent)}
.tree-ico{font-size:13px;width:16px;text-align:center;flex-shrink:0}
.tree-lbl{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.tree-dot{width:7px;height:7px;border-radius:50%;flex-shrink:0}
.tree-dot.ok{background:var(--success)}
.tree-dot.warn{background:var(--warning)}
.tree-dot.err{background:var(--error)}
.tree-dot.sup{background:var(--text-muted)}
.tree-indent{width:14px;flex-shrink:0}

/* Property rows */
.prop-group{margin-bottom:6px}
.prop-hdr{padding:5px 8px;font-size:10px;color:var(--text-muted);font-weight:600;border-bottom:1px solid var(--border)}
.prop-row{display:flex;align-items:center;padding:3px 8px;gap:8px}
.prop-lbl{font-size:12px;color:var(--text-secondary);min-width:70px}
.prop-val{flex:1;font-family:var(--mono);font-size:12px}
.prop-inp{width:100%;padding:3px 6px;background:var(--bg-tertiary);border:1px solid var(--border);border-radius:3px;color:var(--text-primary);font-size:12px;font-family:var(--mono)}
.prop-inp:focus{outline:none;border-color:var(--accent)}

/* Viewport */
#viewport{flex:1;position:relative;overflow:hidden;background:#2a2a2e}
#viewport canvas{display:block}

/* Status bar */
#status{height:var(--status-height);background:var(--bg-secondary);border-top:1px solid var(--border);display:flex;align-items:center;padding:0 12px;font-size:11px;color:var(--text-muted);gap:20px;flex-shrink:0}
#status span{white-space:nowrap}
#status-msg{flex:1}

/* Context menu */
#ctx-menu{position:fixed;background:var(--bg-secondary);border:1px solid var(--border);border-radius:4px;padding:4px 0;min-width:170px;box-shadow:0 4px 12px rgba(0,0,0,.4);z-index:1000;display:none}
#ctx-menu.show{display:block}
.ctx-item{display:flex;align-items:center;padding:5px 12px;cursor:pointer;font-size:12px;color:var(--text-primary);gap:8px}
.ctx-item:hover{background:var(--accent);color:#fff}
.ctx-sep{height:1px;background:var(--border);margin:3px 0}
.ctx-key{margin-left:auto;color:var(--text-muted);font-size:11px}

/* Overlay */
#overlay{position:absolute;top:0;left:0;width:100%;height:100%;pointer-events:none;z-index:50}

/* Dimension input popup */
.dim-input-popup{position:absolute;pointer-events:auto;z-index:60;display:flex;align-items:center;background:var(--bg-secondary);border:1px solid var(--accent);border-radius:4px;padding:4px 6px;box-shadow:0 2px 8px rgba(0,0,0,0.5)}
.dim-input{width:80px;padding:3px 6px;background:var(--bg-tertiary);border:1px solid var(--border);border-radius:3px;color:var(--text-primary);font-size:13px;font-family:monospace;text-align:center;outline:none}
.dim-input:focus{border-color:var(--accent);box-shadow:0 0 4px var(--accent)}

/* Loading */
#loading{position:fixed;top:0;left:0;width:100%;height:100%;background:var(--bg-primary);display:flex;flex-direction:column;align-items:center;justify-content:center;z-index:9999;gap:16px}
#loading.hidden{display:none}
.spinner{width:40px;height:40px;border:3px solid var(--border);border-top:3px solid var(--accent);border-radius:50%;animation:spin 1s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.load-text{color:var(--text-secondary);font-size:14px}
.load-sub{color:var(--text-muted);font-size:12px}

/* Modal */
.modal-bg{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.5);display:flex;align-items:center;justify-content:center;z-index:2000}
.modal{background:var(--bg-secondary);border:1px solid var(--border);border-radius:6px;padding:20px;min-width:320px;box-shadow:0 8px 24px rgba(0,0,0,.5)}
.modal h3{font-size:14px;font-weight:600;margin-bottom:12px}
.modal-actions{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}
.btn{padding:6px 16px;border:1px solid var(--border);border-radius:3px;background:var(--bg-tertiary);color:var(--text-primary);cursor:pointer;font-size:12px;font-family:var(--font)}
.btn:hover{background:var(--hover)}
.btn-p{background:var(--accent);border-color:var(--accent);color:#fff}
.btn-p:hover{background:var(--accent-hover)}