:root {
  --primary: #4f6ef7;
  --primary-hover: #3b5de7;
  --primary-active: #2f4fd6;
  --primary-light: #eef1ff;
  --primary-dark: #3a56d4;
  --accent: #f97316;
  --accent-hover: #ea580c;
  --accent-light: #fff7ed;
  --accent-dark: #ea580c;
  --bg: #e8e8e8;
  --bg-card: #ffffff;
  --bg-toolbar: rgba(255,255,255,0.88);
  --text: #1e293b;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border: #cdcdcd;
  --border-light: #e0e0e0;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --radius-full: 9999px;
  --transition: 0.15s ease;
  --success: #22c55e;
  --danger: #ef4444;
  --canvas-bg: #ffffff;
  --canvas-container-bg: #696969;
  --input-bg: #ffffff;
  --overlay-bg: rgba(0, 0, 0, 0.35);
  --sidebar-bg: rgba(255,255,255,0.92);
  --panel-bg: rgba(255,255,255,0.95);
  --brush-bg: rgba(255,255,255,0.9);
}

[data-theme="dark"] {
  --primary: #6b8aff;
  --primary-hover: #5a7be8;
  --primary-active: #4a6bd7;
  --primary-light: #1e2444;
  --primary-dark: #5a7be8;
  --accent: #fb923c;
  --accent-hover: #f97316;
  --accent-light: #2a1f14;
  --accent-dark: #f97316;
  --bg: #0b0d14;
  --bg-card: #161922;
  --bg-toolbar: rgba(22,25,34,0.88);
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #2a2d3a;
  --border-light: #1e2130;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
  --success: #22c55e;
  --danger: #ef4444;
  --canvas-bg: #161922;
  --canvas-container-bg: #0f1118;
  --input-bg: #1e2130;
  --overlay-bg: rgba(0, 0, 0, 0.6);
  --sidebar-bg: rgba(22,25,34,0.92);
  --panel-bg: rgba(22,25,34,0.95);
  --brush-bg: rgba(22,25,34,0.9);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── 首页 ─── */
.landing {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  min-height: 100vh;
  padding: 48px 24px;
  position: relative;
}

.landing-header { text-align: center; margin-bottom: 48px; }

.landing-header h1 {
  font-size: 52px; font-weight: 800; letter-spacing: -2px; margin-bottom: 8px;
  background: -webkit-linear-gradient(135deg, var(--primary), #8b5cf6, var(--accent));
  background: linear-gradient(135deg, var(--primary), #8b5cf6, var(--accent));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

.landing-subtitle { font-size: 18px; color: var(--text-secondary); font-weight: 400; }

.landing-cards { display: -webkit-flex; display: -ms-flexbox; display: flex; gap: 24px; max-width: 600px; width: 100%; }

.landing-card {
  -webkit-flex: 1; -ms-flex: 1; flex: 1;
  background: var(--bg-card); border: 1px solid var(--border);
  -webkit-border-radius: 16px; -moz-border-radius: 16px; border-radius: 16px;
  padding: 36px 28px 32px; text-align: center; cursor: pointer;
  -webkit-transition: all 0.2s ease; -moz-transition: all 0.2s ease; -ms-transition: all 0.2s ease; -o-transition: all 0.2s ease; transition: all 0.2s ease;
  -webkit-box-shadow: 0 1px 3px rgba(0,0,0,0.04); -moz-box-shadow: 0 1px 3px rgba(0,0,0,0.04); box-shadow: 0 1px 3px rgba(0,0,0,0.04);
  -webkit-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none;
}

.landing-card:active { -webkit-transform: scale(0.97); -moz-transform: scale(0.97); -ms-transform: scale(0.97); -o-transform: scale(0.97); transform: scale(0.97); }

.landing-card.create:hover {
  border-color: var(--primary);
  -webkit-box-shadow: 0 4px 20px rgba(79, 110, 247, 0.12); -moz-box-shadow: 0 4px 20px rgba(79, 110, 247, 0.12); box-shadow: 0 4px 20px rgba(79, 110, 247, 0.12);
  -webkit-transform: translateY(-2px); -moz-transform: translateY(-2px); -ms-transform: translateY(-2px); -o-transform: translateY(-2px); transform: translateY(-2px);
}

.landing-card.join:hover {
  border-color: var(--accent);
  -webkit-box-shadow: 0 4px 20px rgba(249, 115, 22, 0.12); -moz-box-shadow: 0 4px 20px rgba(249, 115, 22, 0.12); box-shadow: 0 4px 20px rgba(249, 115, 22, 0.12);
  -webkit-transform: translateY(-2px); -moz-transform: translateY(-2px); -ms-transform: translateY(-2px); -o-transform: translateY(-2px); transform: translateY(-2px);
}

.card-icon {
  width: 56px; height: 56px; -webkit-border-radius: 16px; -moz-border-radius: 16px; border-radius: 16px;
  display: -webkit-inline-flex; display: -ms-inline-flexbox; display: inline-flex;
  -webkit-align-items: center; -ms-flex-align: center; align-items: center;
  -webkit-justify-content: center; -ms-flex-pack: center; justify-content: center;
  margin-bottom: 16px;
}

.card-icon svg { width: 26px; height: 26px; }
.card-icon.create-icon { background: var(--primary-light); color: var(--primary); }
.card-icon.join-icon { background: var(--accent-light); color: var(--accent); }

.landing-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; color: var(--text); }
.landing-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.5; margin-bottom: 20px; }

.card-btn {
  display: inline-block; padding: 10px 28px;
  -webkit-border-radius: var(--radius-full); -moz-border-radius: var(--radius-full); border-radius: var(--radius-full);
  font-size: 14px; font-weight: 600; border: none; cursor: pointer;
  -webkit-transition: all 0.15s ease; -moz-transition: all 0.15s ease; -ms-transition: all 0.15s ease; -o-transition: all 0.15s ease; transition: all 0.15s ease;
  text-decoration: none; letter-spacing: 0.3px;
}

.card-btn:active { -webkit-transform: scale(0.95); -moz-transform: scale(0.95); -ms-transform: scale(0.95); -o-transform: scale(0.95); transform: scale(0.95); }
.card-btn.primary-btn { background: var(--primary); color: #fff; }
.card-btn.primary-btn:hover { background: var(--primary-hover); -webkit-box-shadow: 0 4px 12px rgba(79,110,247,0.3); -moz-box-shadow: 0 4px 12px rgba(79,110,247,0.3); box-shadow: 0 4px 12px rgba(79,110,247,0.3); }
.card-btn.accent-btn { background: var(--accent); color: #fff; }
.card-btn.accent-btn:hover { background: var(--accent-hover); -webkit-box-shadow: 0 4px 12px rgba(249,115,22,0.3); -moz-box-shadow: 0 4px 12px rgba(249,115,22,0.3); box-shadow: 0 4px 12px rgba(249,115,22,0.3); }

/* ─── 画布尺寸选择 ─── */
.size-options { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.size-option {
  padding: 12px 16px; border: 1.5px solid var(--border);
  -webkit-border-radius: var(--radius-sm); -moz-border-radius: var(--radius-sm); border-radius: var(--radius-sm);
  font-size: 13px; font-weight: 500; cursor: pointer;
  -webkit-transition: all 0.15s ease; -moz-transition: all 0.15s ease; -ms-transition: all 0.15s ease; -o-transition: all 0.15s ease; transition: all 0.15s ease;
  color: var(--text-secondary); background: var(--bg); -webkit-user-select: none; -moz-user-select: none; -ms-user-select: none; user-select: none;
  text-align: center;
  display: -webkit-flex; display: -ms-flexbox; display: flex;
  -webkit-flex-direction: column; -ms-flex-direction: column; flex-direction: column;
  -webkit-align-items: center; -ms-flex-align: center; align-items: center; gap: 2px;
}
.size-option:active { -webkit-transform: scale(0.96); -moz-transform: scale(0.96); -ms-transform: scale(0.96); -o-transform: scale(0.96); transform: scale(0.96); }
.size-option:hover { border-color: var(--primary); color: var(--primary); }
.size-option.selected { background: var(--primary); color: #fff; border-color: var(--primary); -webkit-box-shadow: 0 2px 8px rgba(79,110,247,0.25); -moz-box-shadow: 0 2px 8px rgba(79,110,247,0.25); box-shadow: 0 2px 8px rgba(79,110,247,0.25); }
.size-option span { font-size: 14px; font-weight: 600; }
.size-option small { font-size: 11px; opacity: 0.7; }
.size-option.selected small { opacity: 0.85; }
.custom-size-row {
  display: -webkit-flex; display: -ms-flexbox; display: flex;
  -webkit-align-items: center; -ms-flex-align: center; align-items: center;
  -webkit-justify-content: center; -ms-flex-pack: center; justify-content: center;
  gap: 4px; margin-top: 12px;
}
.custom-size-row .form-input {
  width: 45%; display: inline-block;
  padding: 8px 10px; border: 1.5px solid var(--border);
  -webkit-border-radius: var(--radius-sm); -moz-border-radius: var(--radius-sm); border-radius: var(--radius-sm);
  font-size: 13px; background: var(--bg); color: var(--text);
  text-align: center; outline: none;
}
.custom-size-row .form-input:focus { border-color: var(--primary); }
.custom-size-row span { color: var(--text-secondary); font-size: 16px; }

/* ─── 弹窗 ─── */
.modal-overlay {
  position: fixed; top: 0; right: 0; bottom: 0; left: 0;
  background: var(--overlay-bg); -webkit-backdrop-filter: blur(4px); backdrop-filter: blur(4px);
  display: none; -webkit-align-items: center; -ms-flex-align: center; align-items: center;
  -webkit-justify-content: center; -ms-flex-pack: center; justify-content: center;
  z-index: 1000; padding: 20px;
}
.modal-overlay.open { display: -webkit-flex !important; display: -ms-flexbox !important; display: flex !important; }
.modal {
  background: var(--bg-card); -webkit-border-radius: 16px; -moz-border-radius: 16px; border-radius: 16px;
  padding: 0; width: 100%; max-width: 420px;
  -webkit-box-shadow: 0 20px 60px rgba(0,0,0,0.15); -moz-box-shadow: 0 20px 60px rgba(0,0,0,0.15); box-shadow: 0 20px 60px rgba(0,0,0,0.15);
  overflow: hidden; -webkit-animation: modalIn 0.2s ease; -moz-animation: modalIn 0.2s ease; animation: modalIn 0.2s ease;
}
@-webkit-keyframes modalIn { from { opacity: 0; -webkit-transform: scale(0.95) translateY(10px); transform: scale(0.95) translateY(10px); } to { opacity: 1; -webkit-transform: scale(1) translateY(0); transform: scale(1) translateY(0); } }
@keyframes modalIn { from { opacity: 0; -webkit-transform: scale(0.95) translateY(10px); transform: scale(0.95) translateY(10px); } to { opacity: 1; -webkit-transform: scale(1) translateY(0); transform: scale(1) translateY(0); } }
.modal-header { display: -webkit-flex; display: -ms-flexbox; display: flex; -webkit-align-items: center; -ms-flex-align: center; align-items: center; -webkit-justify-content: space-between; -ms-flex-pack: justify; justify-content: space-between; padding: 20px 24px 0; }
.modal-header h2 { font-size: 20px; font-weight: 700; color: var(--text); }
.modal-close { width: 30px; height: 30px; border: none; background: var(--bg); -webkit-border-radius: 8px; -moz-border-radius: 8px; border-radius: 8px; font-size: 20px; color: var(--text-muted); cursor: pointer; display: -webkit-flex; display: -ms-flexbox; display: flex; -webkit-align-items: center; -ms-flex-align: center; align-items: center; -webkit-justify-content: center; -ms-flex-pack: center; justify-content: center; -webkit-transition: all 0.15s ease; -moz-transition: all 0.15s ease; -ms-transition: all 0.15s ease; -o-transition: all 0.15s ease; transition: all 0.15s ease; }
.modal-close:hover { background: var(--border-light); color: var(--text); }
.modal-close:active { -webkit-transform: scale(0.9); -moz-transform: scale(0.9); -ms-transform: scale(0.9); -o-transform: scale(0.9); transform: scale(0.9); }
.modal-body { padding: 16px 24px; }
.modal-footer { display: -webkit-flex; display: -ms-flexbox; display: flex; gap: 10px; padding: 0 24px 20px; }
.modal-footer .btn { -webkit-flex: 1; -ms-flex: 1; flex: 1; padding: 10px 20px; -webkit-border-radius: var(--radius-sm); -moz-border-radius: var(--radius-sm); border-radius: var(--radius-sm); font-size: 14px; font-weight: 600; border: none; cursor: pointer; -webkit-transition: all 0.15s ease; -moz-transition: all 0.15s ease; -ms-transition: all 0.15s ease; -o-transition: all 0.15s ease; transition: all 0.15s ease; text-align: center; }
.modal-footer .btn:active { -webkit-transform: scale(0.96); -moz-transform: scale(0.96); -ms-transform: scale(0.96); -o-transform: scale(0.96); transform: scale(0.96); }
.btn-secondary { background: var(--bg); color: var(--text-secondary); border: 1px solid var(--border) !important; }
.btn-secondary:hover { background: var(--border-light); color: var(--text); }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); -webkit-box-shadow: 0 4px 12px rgba(79,110,247,0.3); -moz-box-shadow: 0 4px 12px rgba(79,110,247,0.3); box-shadow: 0 4px 12px rgba(79,110,247,0.3); }
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 13px; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.form-input { width: 100%; padding: 10px 14px; border: 1.5px solid var(--border); -webkit-border-radius: var(--radius-sm); -moz-border-radius: var(--radius-sm); border-radius: var(--radius-sm); font-size: 14px; color: var(--text); background: var(--input-bg); outline: none; -webkit-transition: all 0.15s ease; -moz-transition: all 0.15s ease; -ms-transition: all 0.15s ease; -o-transition: all 0.15s ease; transition: all 0.15s ease; }
.form-input:focus { border-color: var(--primary); -webkit-box-shadow: 0 0 0 3px rgba(79,110,247,0.1); -moz-box-shadow: 0 0 0 3px rgba(79,110,247,0.1); box-shadow: 0 0 0 3px rgba(79,110,247,0.1); }
.form-input::-webkit-input-placeholder { color: var(--text-muted); }
.form-input:-moz-placeholder { color: var(--text-muted); }
.form-input::-moz-placeholder { color: var(--text-muted); }
.form-input:-ms-input-placeholder { color: var(--text-muted); }
.form-input::placeholder { color: var(--text-muted); }

/* ─── 画板页面 ─── */
.draw-app {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

.draw-body {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  overflow: hidden;
}

/* ─── 顶部栏 ─── */
.topbar {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: space-between;
  -ms-flex-pack: justify;
  justify-content: space-between;
  height: 44px;
  padding: 0 12px;
  background: var(--bg-toolbar);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
  z-index: 20;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

.topbar-left {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 12px;
}

.topbar-brand {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: var(--primary);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.3px;
  padding: 4px 8px;
  background: var(--primary-light);
  -webkit-border-radius: 8px;
  -moz-border-radius: 8px;
  border-radius: 8px;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

.topbar-brand:hover { opacity: 0.8; }

.room-badge-top {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--text-muted);
  padding: 3px 8px;
  background: var(--bg);
  -webkit-border-radius: var(--radius-full);
  -moz-border-radius: var(--radius-full);
  border-radius: var(--radius-full);
  border: 1px solid var(--border);
  white-space: nowrap;
}

.room-badge-top span { font-weight: 500; }

.users-badge-top {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: var(--text-secondary);
}

.users-badge-top .dot {
  width: 6px;
  height: 6px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  background: var(--success);
  -webkit-animation: pulse 2s infinite;
  animation: pulse 2s infinite;
}

@-webkit-keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }

.users-count { color: var(--text); font-weight: 600; }

.topbar-center {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 2px;
}

.topbar-right {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 2px;
}

.topbar-btn {
  width: 30px;
  height: 30px;
  border: 1px solid transparent;
  -webkit-border-radius: 6px;
  -moz-border-radius: 6px;
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.topbar-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.topbar-btn:active {
  -webkit-transform: scale(0.88);
  -moz-transform: scale(0.88);
  -ms-transform: scale(0.88);
  -o-transform: scale(0.88);
  transform: scale(0.88);
}

.topbar-btn.select-toggle.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  -webkit-box-shadow: 0 0 0 2px rgba(79,110,247,0.3);
  -moz-box-shadow: 0 0 0 2px rgba(79,110,247,0.3);
  box-shadow: 0 0 0 2px rgba(79,110,247,0.3);
}

.topbar-btn svg {
  width: 15px;
  height: 15px;
}

.topbar-sep {
  width: 1px;
  height: 16px;
  background: var(--border);
  margin: 0 4px;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

/* ─── 左侧工具栏 ─── */
.left-toolbar {
  width: 46px;
  background: var(--sidebar-bg);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-right: 1px solid var(--border);
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
  z-index: 15;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: none;
}

.left-toolbar::-webkit-scrollbar { display: none; }

.left-toolbar-inner {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  padding: 6px 0;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 0;
}

.tool-group {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  padding: 4px 0;
  width: 100%;
  position: relative;
}

.tool-group::after {
  content: '';
  display: block;
  width: 20px;
  height: 1px;
  background: var(--border);
  margin-top: 4px;
}

.tool-group:last-child::after { display: none; }

.tool-group-label {
  font-size: 9px;
  color: var(--text-muted);
  letter-spacing: 0.8px;
  margin-bottom: 3px;
  font-weight: 700;
  text-align: center;
  text-transform: uppercase;
}

.tool-group .tool-btn {
  width: 32px;
  height: 32px;
  border: 1px solid transparent;
  -webkit-border-radius: 6px;
  -moz-border-radius: 6px;
  border-radius: 6px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
  position: relative;
  margin: 1px 0;
}

.tool-group .tool-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.tool-group .tool-btn:active {
  -webkit-transform: scale(0.88);
  -moz-transform: scale(0.88);
  -ms-transform: scale(0.88);
  -o-transform: scale(0.88);
  transform: scale(0.88);
}

.tool-group .tool-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  -webkit-box-shadow: 0 2px 6px rgba(79,110,247,0.3);
  -moz-box-shadow: 0 2px 6px rgba(79,110,247,0.3);
  box-shadow: 0 2px 6px rgba(79,110,247,0.3);
}

.tool-group .tool-btn svg {
  width: 16px;
  height: 16px;
}

/* ─── 画布容器 ─── */
.canvas-stage {
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  position: relative;
  overflow: hidden;
  background: var(--canvas-container-bg);
}

#drawCanvas {
  display: block;
  -ms-touch-action: none;
  touch-action: none;
  background: transparent !important;
  image-rendering: auto;
}

.canvas-container {
  position: relative !important;
}

.canvas-container canvas {
  background: transparent !important;
  image-rendering: auto;
}

/* ─── 浮动笔刷栏 ─── */
.float-brush {
  display: none;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  position: absolute;
  bottom: 24px;
  left: 50%;
  -webkit-transform: translateX(-50%);
  -moz-transform: translateX(-50%);
  -ms-transform: translateX(-50%);
  -o-transform: translateX(-50%);
  transform: translateX(-50%);
  background: var(--brush-bg);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid var(--border);
  -webkit-border-radius: var(--radius-full);
  -moz-border-radius: var(--radius-full);
  border-radius: var(--radius-full);
  padding: 6px 14px;
  gap: 6px;
  z-index: 30;
  -webkit-box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  -moz-box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

.float-brush.visible {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
}

.float-brush .brush-group {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 2px;
}

.brush-btn {
  padding: 3px 8px;
  font-size: 11px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
  white-space: nowrap;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
  height: 26px;
  line-height: 1;
  font-weight: 500;
}

.brush-btn:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: var(--primary);
}

.brush-btn:active {
  -webkit-transform: scale(0.93);
  -moz-transform: scale(0.93);
  -ms-transform: scale(0.93);
  -o-transform: scale(0.93);
  transform: scale(0.93);
}

.brush-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.float-sep {
  width: 1px;
  height: 18px;
  background: var(--border);
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

.color-picker-wrap {
  position: relative;
  width: 28px;
  height: 28px;
  -webkit-border-radius: 6px;
  -moz-border-radius: 6px;
  border-radius: 6px;
  overflow: hidden;
  border: 2px solid var(--border);
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
  cursor: pointer;
}

.color-picker-wrap:active {
  -webkit-transform: scale(0.88);
  -moz-transform: scale(0.88);
  -ms-transform: scale(0.88);
  -o-transform: scale(0.88);
  transform: scale(0.88);
}

.color-picker-wrap input[type="color"] {
  position: absolute;
  top: -4px;
  left: -4px;
  width: calc(100% + 8px);
  height: calc(100% + 8px);
  border: none;
  padding: 0;
  cursor: pointer;
  background: none;
}

.color-picker-wrap input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
.color-picker-wrap input[type="color"]::-webkit-color-swatch { border: none; -webkit-border-radius: 2px; border-radius: 2px; }
.color-picker-wrap input[type="color"]::-moz-color-swatch { border: none; -moz-border-radius: 2px; border-radius: 2px; }

.float-size-group {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 4px;
}

.size-slider {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  width: 56px;
  height: 4px;
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
  border-radius: 2px;
  background: var(--border);
  outline: none;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

.size-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  -webkit-border-radius: 50%;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: 2px solid #fff;
  -webkit-box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  -webkit-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.size-slider::-webkit-slider-thumb:active { -webkit-transform: scale(1.2); transform: scale(1.2); }
.size-slider::-moz-range-thumb { width: 14px; height: 14px; -moz-border-radius: 50%; border-radius: 50%; background: var(--primary); cursor: pointer; border: 2px solid #fff; -moz-box-shadow: 0 1px 3px rgba(0,0,0,0.2); box-shadow: 0 1px 3px rgba(0,0,0,0.2); }
.size-slider::-ms-thumb { width: 14px; height: 14px; border-radius: 50%; background: var(--primary); cursor: pointer; border: 2px solid #fff; box-shadow: 0 1px 3px rgba(0,0,0,0.2); }

.size-label {
  font-size: 11px;
  color: var(--text-muted);
  min-width: 20px;
  text-align: center;
  font-weight: 600;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

.float-zoom-group {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 2px;
}

.tool-btn-xs {
  width: 24px;
  height: 24px;
  border: 1px solid transparent;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.tool-btn-xs:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.tool-btn-xs:active {
  -webkit-transform: scale(0.85);
  -moz-transform: scale(0.85);
  -ms-transform: scale(0.85);
  -o-transform: scale(0.85);
  transform: scale(0.85);
}

.tool-btn-xs svg { width: 13px; height: 13px; }

.size-btn {
  font-size: 16px;
  font-weight: 700;
  line-height: 1;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

.zoom-label {
  font-size: 11px;
  color: var(--text-secondary);
  min-width: 36px;
  text-align: center;
  font-weight: 600;
  -webkit-flex-shrink: 0;
  -ms-flex-negative: 0;
  flex-shrink: 0;
}

/* ─── 右侧属性面板 ─── */
.right-panel {
  position: absolute;
  top: 0;
  right: -260px;
  width: 240px;
  height: 100%;
  background: var(--panel-bg);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-left: 1px solid var(--border);
  z-index: 38;
  -webkit-transition: right 0.25s ease;
  -moz-transition: right 0.25s ease;
  -ms-transition: right 0.25s ease;
  -o-transition: right 0.25s ease;
  transition: right 0.25s ease;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-shadow: -4px 0 20px rgba(0,0,0,0.06);
  -moz-box-shadow: -4px 0 20px rgba(0,0,0,0.06);
  box-shadow: -4px 0 20px rgba(0,0,0,0.06);
}

.right-panel.open {
  right: 0;
}

.right-panel-header {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: space-between;
  -ms-flex-pack: justify;
  justify-content: space-between;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-light);
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.right-panel-close {
  width: 24px;
  height: 24px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  border-radius: 4px;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.right-panel-close:hover {
  background: var(--border-light);
  color: var(--text);
}

.right-panel-close:active {
  -webkit-transform: scale(0.85);
  -moz-transform: scale(0.85);
  -ms-transform: scale(0.85);
  -o-transform: scale(0.85);
  transform: scale(0.85);
}

.right-panel-close svg { width: 14px; height: 14px; }

.right-panel-body {
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  padding: 14px;
  overflow-y: auto;
}

.rp-section {
  margin-bottom: 14px;
}

.rp-label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.3px;
}

.rp-color {
  width: 36px;
  height: 36px;
  -webkit-border-radius: 8px;
  -moz-border-radius: 8px;
  border-radius: 8px;
}

.rp-color input[type="color"] {
  top: -3px;
  left: -3px;
  width: calc(100% + 6px);
  height: calc(100% + 6px);
}

.rp-slider {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
  border-radius: 2px;
  background: var(--border);
  outline: none;
}

.rp-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  -webkit-border-radius: 50%;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: 2px solid #fff;
  -webkit-box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.rp-slider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  -moz-border-radius: 50%;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: 2px solid #fff;
}

.rp-slider-val {
  font-size: 11px;
  color: var(--text-muted);
  text-align: right;
  display: block;
  margin-top: 2px;
  font-weight: 600;
}

/* ─── 光标层 ─── */
.cursors-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 5;
}

.remote-cursor {
  position: absolute;
  pointer-events: none;
  z-index: 5;
}

.remote-cursor-dot {
  width: 10px;
  height: 10px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  border: 2px solid #fff;
  -webkit-box-shadow: 0 1px 3px rgba(0,0,0,0.25);
  -moz-box-shadow: 0 1px 3px rgba(0,0,0,0.25);
  box-shadow: 0 1px 3px rgba(0,0,0,0.25);
}

.remote-cursor-label {
  position: absolute;
  top: -22px;
  left: 50%;
  -webkit-transform: translateX(-50%);
  -moz-transform: translateX(-50%);
  -ms-transform: translateX(-50%);
  -o-transform: translateX(-50%);
  transform: translateX(-50%);
  background: rgba(0,0,0,0.8);
  color: #fff;
  font-size: 10px;
  padding: 2px 7px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  border-radius: 4px;
  white-space: nowrap;
  font-weight: 500;
  pointer-events: none;
}

/* ─── 选择框 ─── */
.selection-box {
  position: absolute;
  border: 2px solid var(--primary);
  background: rgba(79,110,247,0.06);
  pointer-events: none;
  z-index: 25;
}

.selection-handle {
  position: absolute;
  width: 8px;
  height: 8px;
  background: #fff;
  border: 2px solid var(--primary);
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
  border-radius: 2px;
  z-index: 26;
}

/* ─── 便签 ─── */
.sticky-note {
  position: absolute;
  min-width: 140px;
  min-height: 90px;
  padding: 10px;
  -webkit-border-radius: 6px;
  -moz-border-radius: 6px;
  border-radius: 6px;
  font-size: 13px;
  outline: none;
  resize: both;
  overflow: hidden;
  cursor: move;
  z-index: 30;
  font-family: inherit;
  border: 1px solid transparent;
}

.sticky-note:focus { border-color: var(--primary); }

/* ─── 评论 ─── */
.comment-marker {
  position: absolute;
  width: 24px;
  height: 24px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  font-size: 12px;
  font-weight: bold;
  cursor: pointer;
  z-index: 30;
  border: 2px solid var(--primary);
  background: var(--primary-light);
  color: var(--primary);
}

.comment-bubble {
  position: fixed;
  min-width: 220px;
  max-width: 320px;
  padding: 12px;
  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  border-radius: 10px;
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
  -webkit-box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  -moz-box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
  z-index: 60;
}

/* ─── 容器/分组框 ─── */
.container-box {
  position: absolute;
  border: 2px dashed var(--border);
  -webkit-border-radius: 10px;
  -moz-border-radius: 10px;
  border-radius: 10px;
  z-index: 5;
  pointer-events: none;
}

.container-title {
  position: absolute;
  top: 10px;
  left: 14px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  pointer-events: none;
}

/* ─── 激光笔 ─── */
.laser-spot {
  position: absolute;
  width: 10px;
  height: 10px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  background: #ff4444;
  pointer-events: none;
  z-index: 100;
  -webkit-transform: translate(-50%, -50%);
  -moz-transform: translate(-50%, -50%);
  -ms-transform: translate(-50%, -50%);
  -o-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

/* ─── 聊天面板 ─── */
.chat-panel {
  position: absolute;
  right: -280px;
  top: 0;
  width: 260px;
  height: 100%;
  background: var(--panel-bg);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-left: 1px solid var(--border);
  z-index: 35;
  -webkit-transition: right 0.25s ease;
  -moz-transition: right 0.25s ease;
  -ms-transition: right 0.25s ease;
  -o-transition: right 0.25s ease;
  transition: right 0.25s ease;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  -webkit-box-shadow: -4px 0 20px rgba(0,0,0,0.06);
  -moz-box-shadow: -4px 0 20px rgba(0,0,0,0.06);
  box-shadow: -4px 0 20px rgba(0,0,0,0.06);
}

.chat-panel.open { right: 0; }

.chat-header {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: space-between;
  -ms-flex-pack: justify;
  justify-content: space-between;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-light);
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.chat-close {
  width: 24px;
  height: 24px;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  border-radius: 4px;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.chat-close:hover { background: var(--border-light); color: var(--text); }
.chat-close:active { -webkit-transform: scale(0.85); -moz-transform: scale(0.85); -ms-transform: scale(0.85); -o-transform: scale(0.85); transform: scale(0.85); }
.chat-close svg { width: 14px; height: 14px; }

.chat-messages {
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  overflow-y: auto;
  padding: 10px 12px;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-flex-direction: column;
  -ms-flex-direction: column;
  flex-direction: column;
  gap: 6px;
}

.chat-msg {
  font-size: 13px;
  line-height: 1.4;
  padding: 6px 10px;
  -webkit-border-radius: 8px;
  -moz-border-radius: 8px;
  border-radius: 8px;
  max-width: 90%;
  word-break: break-word;
}

.chat-msg.self {
  background: var(--primary);
  color: #fff;
  -webkit-align-self: flex-end;
  -ms-flex-item-align: end;
  align-self: flex-end;
  border-bottom-right-radius: 2px;
}

.chat-msg.other {
  background: var(--bg);
  color: var(--text);
  -webkit-align-self: flex-start;
  -ms-flex-item-align: start;
  align-self: flex-start;
  border-bottom-left-radius: 2px;
}

.chat-msg .chat-msg-name {
  font-size: 11px;
  font-weight: 600;
  margin-bottom: 2px;
  opacity: 0.7;
}

.chat-msg .chat-msg-time {
  font-size: 10px;
  opacity: 0.5;
  margin-top: 2px;
  text-align: right;
}

.chat-msg.system {
  background: transparent;
  color: var(--text-muted);
  font-size: 11px;
  text-align: center;
  -webkit-align-self: center;
  -ms-flex-item-align: center;
  align-self: center;
  max-width: 100%;
}

.chat-input-row {
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  padding: 8px 10px;
  border-top: 1px solid var(--border-light);
  gap: 6px;
}

.chat-input {
  -webkit-flex: 1;
  -ms-flex: 1;
  flex: 1;
  padding: 8px 10px;
  border: 1.5px solid var(--border);
  -webkit-border-radius: var(--radius-sm);
  -moz-border-radius: var(--radius-sm);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--text);
  background: var(--input-bg);
  outline: none;
}

.chat-input:focus { border-color: var(--primary); }

.chat-send-btn {
  padding: 8px 14px;
  border: none;
  -webkit-border-radius: var(--radius-sm);
  -moz-border-radius: var(--radius-sm);
  border-radius: var(--radius-sm);
  background: var(--primary);
  color: #fff;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
  white-space: nowrap;
}

.chat-send-btn:hover { background: var(--primary-hover); }
.chat-send-btn:active { -webkit-transform: scale(0.95); -moz-transform: scale(0.95); -ms-transform: scale(0.95); -o-transform: scale(0.95); transform: scale(0.95); }

.chat-badge {
  display: none;
  position: absolute;
  top: -2px;
  right: -2px;
  width: 16px;
  height: 16px;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  background: var(--danger);
  color: #fff;
  font-size: 9px;
  font-weight: 700;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
}

.chat-badge.show { display: -webkit-flex; display: -ms-flexbox; display: flex; }

/* ─── 状态栏 ─── */
.status-bar {
  position: fixed;
  bottom: 16px;
  left: 50%;
  -webkit-transform: translateX(-50%);
  -moz-transform: translateX(-50%);
  -ms-transform: translateX(-50%);
  -o-transform: translateX(-50%);
  transform: translateX(-50%);
  background: var(--bg-card);
  border: 1px solid var(--border);
  -webkit-border-radius: var(--radius-full);
  -moz-border-radius: var(--radius-full);
  border-radius: var(--radius-full);
  padding: 6px 16px;
  font-size: 12px;
  color: var(--text-secondary);
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  gap: 8px;
  opacity: 0;
  -webkit-transition: opacity 0.25s ease;
  -moz-transition: opacity 0.25s ease;
  -ms-transition: opacity 0.25s ease;
  -o-transition: opacity 0.25s ease;
  transition: opacity 0.25s ease;
  z-index: 100;
  pointer-events: none;
  -webkit-box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  -moz-box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.status-bar.visible { opacity: 1; }

.status-bar .status-dot { width: 6px; height: 6px; -webkit-border-radius: 50%; -moz-border-radius: 50%; border-radius: 50%; background: var(--success); }
.status-bar .status-dot.disconnected { background: var(--danger); }

/* ─── 主题切换按钮（首页用） ─── */
.theme-toggle-corner {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 100;
}

.theme-toggle-corner .theme-toggle {
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  -webkit-border-radius: 8px;
  -moz-border-radius: 8px;
  border-radius: 8px;
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-align-items: center;
  -ms-flex-align: center;
  align-items: center;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-transition: all 0.12s ease;
  -moz-transition: all 0.12s ease;
  -ms-transition: all 0.12s ease;
  -o-transition: all 0.12s ease;
  transition: all 0.12s ease;
}

.theme-toggle-corner .theme-toggle:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.theme-toggle-corner .theme-toggle:active {
  -webkit-transform: scale(0.9);
  -moz-transform: scale(0.9);
  -ms-transform: scale(0.9);
  -o-transform: scale(0.9);
  transform: scale(0.9);
}

.theme-toggle-corner .theme-toggle svg { width: 17px; height: 17px; }

/* ─── 滚动条 ─── */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); -webkit-border-radius: 3px; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ─── 响应式：平板 1024px ─── */
@media (max-width: 1024px) {
  .landing-header h1 { font-size: 44px; }
  .landing-subtitle { font-size: 16px; }
  .landing-cards { gap: 20px; max-width: 520px; }
  .left-toolbar { width: 42px; }
  .tool-group .tool-btn { width: 30px; height: 30px; }
  .tool-group .tool-btn svg { width: 15px; height: 15px; }
  .float-brush { padding: 5px 10px; gap: 4px; }
  .float-brush .size-slider { width: 48px; }
  .right-panel { width: 210px; right: -230px; }
}

/* ─── 响应式：手机/小平板 768px ─── */
@media (max-width: 768px) {
  body { font-size: 13px; }
  .landing { padding: 32px 16px; }
  .landing-header { margin-bottom: 36px; }
  .landing-header h1 { font-size: 36px; }
  .landing-subtitle { font-size: 15px; }
  .landing-cards { -webkit-flex-direction: column; -ms-flex-direction: column; flex-direction: column; max-width: 360px; gap: 14px; }
  .landing-card { padding: 28px 24px 24px; }
  .landing-card h3 { font-size: 18px; }
  .landing-card p { font-size: 13px; margin-bottom: 16px; }
  .card-icon { width: 48px; height: 48px; }
  .card-icon svg { width: 22px; height: 22px; }
  .card-btn { padding: 9px 24px; font-size: 13px; }
  .modal-header { padding: 18px 20px 0; }
  .modal-body { padding: 14px 20px; }
  .modal-footer { padding: 0 20px 18px; }
  .modal-header h2 { font-size: 18px; }
  .form-input { padding: 9px 12px; font-size: 14px; }

  .topbar { height: 40px; padding: 0 8px; }
  .topbar-brand { font-size: 13px; padding: 3px 6px; }
  .topbar-brand svg { width: 15px; height: 15px; }
  .topbar-btn { width: 28px; height: 28px; }
  .topbar-btn svg { width: 14px; height: 14px; }
  .room-badge-top { font-size: 11px; padding: 2px 6px; }
  .users-badge-top { font-size: 11px; }
  .topbar-sep { margin: 0 2px; }

  .left-toolbar { width: 38px; }
  .tool-group { padding: 3px 0; }
  .tool-group .tool-btn { width: 28px; height: 28px; }
  .tool-group .tool-btn svg { width: 14px; height: 14px; }
  .tool-group-label { font-size: 7px; }
  .tool-group::after { width: 16px; }

  .float-brush { padding: 5px 10px; gap: 4px; bottom: 16px; max-width: calc(100vw - 60px); overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; white-space: nowrap; -webkit-flex-wrap: nowrap; -ms-flex-wrap: nowrap; flex-wrap: nowrap; }
  .float-brush::-webkit-scrollbar { display: none; }
  .brush-btn { font-size: 10px; padding: 2px 6px; height: 24px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .float-brush .color-picker-wrap { width: 26px; height: 26px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .float-brush .size-slider { width: 40px; }
  .float-brush .size-label { font-size: 10px; min-width: 18px; }
  .float-brush .zoom-label { font-size: 10px; min-width: 30px; }
  .tool-btn-xs { width: 22px; height: 22px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .tool-btn-xs svg { width: 12px; height: 12px; }
  .float-sep { height: 16px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .size-btn { font-size: 18px; }

  .right-panel { width: 200px; right: -220px; }

  .chat-panel { width: 220px; right: -240px; }

  .status-bar { font-size: 11px; padding: 5px 12px; bottom: 12px; }
}

/* ─── 响应式：手机 480px ─── */
@media (max-width: 480px) {
  body { font-size: 12px; }
  .landing-header h1 { font-size: 30px; letter-spacing: -1px; }
  .landing-subtitle { font-size: 14px; }
  .landing-card { padding: 24px 20px 20px; }
  .landing-card h3 { font-size: 17px; }
  .card-icon { width: 44px; height: 44px; margin-bottom: 12px; }
  .card-icon svg { width: 20px; height: 20px; }
  .modal { max-width: 100%; -webkit-border-radius: 14px; -moz-border-radius: 14px; border-radius: 14px; }
  .modal-header { padding: 16px 16px 0; }
  .modal-body { padding: 12px 16px; }
  .modal-footer { padding: 0 16px 16px; }
  .modal-header h2 { font-size: 17px; }
  .size-options { gap: 6px; }
  .size-option { padding: 10px 12px; }
  .size-option span { font-size: 13px; }
  .size-option small { font-size: 10px; }

  .topbar { height: 38px; padding: 0 6px; }
  .topbar-brand { font-size: 12px; padding: 2px 5px; gap: 4px; }
  .topbar-brand svg { width: 13px; height: 13px; }
  .topbar-btn { width: 26px; height: 26px; }
  .topbar-btn svg { width: 13px; height: 13px; }
  .room-badge-top { font-size: 10px; padding: 2px 5px; gap: 3px; }
  .room-badge-top svg { width: 10px; height: 10px; }
  .users-badge-top { font-size: 10px; }
  .users-badge-top .dot { width: 5px; height: 5px; }
  .topbar-sep { height: 14px; margin: 0 1px; }

  .left-toolbar { width: 38px; }
  .tool-group { padding: 2px 0; }
  .tool-group .tool-btn { width: 30px; height: 30px; }
  .tool-group .tool-btn svg { width: 14px; height: 14px; }
  .tool-group-label { font-size: 7px; }
  .tool-group::after { width: 14px; margin-top: 3px; }

  .float-brush {
    padding: 5px 10px;
    gap: 4px;
    bottom: 16px;
    max-width: calc(100vw - 50px);
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    white-space: nowrap;
    -webkit-flex-wrap: nowrap;
    -ms-flex-wrap: nowrap;
    flex-wrap: nowrap;
    -webkit-justify-content: flex-start;
    -ms-flex-pack: start;
    justify-content: flex-start;
  }
  .float-brush::-webkit-scrollbar { display: none; }
  .brush-btn { font-size: 10px; padding: 3px 7px; height: 26px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .float-brush .color-picker-wrap { width: 26px; height: 26px; border-width: 1.5px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .float-brush .size-slider { width: 50px; }
  .float-brush .size-label { font-size: 10px; min-width: 18px; }
  .float-brush .zoom-label { font-size: 10px; min-width: 30px; }
  .tool-btn-xs { width: 24px; height: 24px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .tool-btn-xs svg { width: 12px; height: 12px; }
  .float-sep { height: 16px; -webkit-flex-shrink: 0; -ms-flex-negative: 0; flex-shrink: 0; }
  .size-btn { font-size: 18px; width: 24px; height: 24px; }

  .right-panel { width: 180px; right: -200px; }
  .right-panel-header { padding: 10px 12px; font-size: 12px; }
  .right-panel-body { padding: 12px; }

  .chat-panel { width: 200px; right: -220px; }
  .chat-header { padding: 10px 12px; font-size: 12px; }
  .chat-messages { padding: 8px 10px; }
  .chat-input-row { padding: 6px 8px; }
  .chat-input { font-size: 12px; padding: 6px 8px; }
  .chat-send-btn { font-size: 12px; padding: 6px 10px; }

  .status-bar { font-size: 10px; padding: 4px 10px; bottom: 60px; }
  .remote-cursor-dot { width: 8px; height: 8px; }
  .remote-cursor-label { font-size: 9px; padding: 2px 5px; top: -18px; }
}