/* 全局样式：对齐 yymuse.com 暖色调 — 米白背景 + 土系配色 + 极简边框 */

:root {
  /* 暖色调配色（参考 yymuse.com） */
  --color-nav-bg: rgba(250, 248, 243, 0.95);  /* 浅色毛玻璃导航 */
  --color-nav-text: #1c1a16;                   /* 深褐黑 */
  --color-nav-hover: #7a6a3a;                  /* 金褐强调 */
  --color-primary: #7a6a3a;                    /* 金褐主色 */
  --color-primary-hover: #5a4e2b;              /* 深金褐 hover */
  --color-primary-light: #f5f0e4;             /* 浅米暖色 */
  --color-secondary: #a09a8e;                  /* 雾灰 */
  --color-bg: #faf8f3;                         /* 米白主背景 */
  --color-bg-secondary: #f2efe8;               /* 次级米色 */
  --color-bg-white: #ffffff;
  --color-text: #1c1a16;                       /* 深褐黑主文字 */
  --color-text-muted: #4a4740;                /* 褐灰次文字 */
  --color-text-weak: #a09a8e;                  /* 雾灰弱文字 */
  --color-border: #e0ddd6;                     /* 暖灰边框 */
  --color-border-hover: #c8c4ba;               /* 深暖灰 hover 边框 */
  --color-success: #3a6a3a;                    /* 暗绿 */
  --color-warning: #8a6a1a;                    /* 暗琥珀 */
  --color-danger: #8a2a2a;                     /* 暗红 */
  --color-user-bubble: #f2efe8;               /* 用户气泡米色 */
  --color-tag-law: #ede8d8;
  --color-tag-law-text: #5a4e2b;
  --color-tag-reg: #e0e8d8;
  --color-tag-reg-text: #3a5a3a;

  /* 字体 */
  --font-family: "PingFang SC", "Microsoft YaHei", "微软雅黑",
                 -apple-system, BlinkMacSystemFont, sans-serif;
  --font-family-heading: Georgia, "Times New Roman", "宋体", serif;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;

  /* 圆角收窄（yymuse.com 风格极简） */
  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 6px;
  --radius-xl: 8px;
  --radius-full: 9999px;

  /* 阴影极简化，以边框为主 */
  --shadow-sm: 0 1px 0 rgba(0,0,0,0.04);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);

  --sidebar-width: 260px;
  --nav-height: 52px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

img { max-width: 100%; }

/* ===== Navigation ===== */
.nav {
  background: var(--color-nav-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  padding: 0 2.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

.nav-logo {
  font-family: var(--font-family-heading);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-nav-text);
  letter-spacing: -0.01em;
}
.nav-logo:hover { color: var(--color-primary); }

.nav-links { display: flex; align-items: center; gap: 0.5rem; }

.nav-links a {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  padding: 0.375rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
}
.nav-links a:hover {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.nav-links .btn-nav-primary {
  background: var(--color-text);
  color: var(--color-bg);
  padding: 0.375rem 1rem;
  border-radius: var(--radius-sm);
}
.nav-links .btn-nav-primary:hover {
  background: var(--color-primary);
  color: var(--color-bg);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.5rem;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  font-family: var(--font-family);
  border: none;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  text-decoration: none;
}
.btn:active { opacity: 0.85; }

.btn-primary {
  background: var(--color-text);
  color: var(--color-bg);
}
.btn-primary:hover { background: var(--color-primary); color: var(--color-bg); }

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-hover);
}
.btn-outline:hover { border-color: var(--color-primary); color: var(--color-primary); background: var(--color-primary-light); }

.btn-secondary {
  background: var(--color-bg-white);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover { border-color: var(--color-border-hover); background: var(--color-bg); }

.btn-danger { background: var(--color-danger); color: #fff; }
.btn-danger:hover { background: #6a1a1a; color: #fff; }

.btn-success { background: var(--color-success); color: #fff; }
.btn-success:hover { background: #2a5a2a; color: #fff; }

.btn-sm { padding: 0.3rem 0.75rem; font-size: var(--font-size-sm); }
.btn-lg { padding: 0.875rem 2rem; font-size: var(--font-size-base); }

/* ===== Cards ===== */
.card {
  background: var(--color-bg-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-text);
  color: rgba(250, 248, 243, 0.5);
  text-align: center;
  padding: 1.5rem 2rem;
  font-size: var(--font-size-sm);
  line-height: 1.8;
}
.footer a { color: rgba(250, 248, 243, 0.5); }
.footer a:hover { color: rgba(250, 248, 243, 0.9); }

/* ===== Messages (Django messages framework) ===== */
.messages-container { max-width: 800px; margin: 1rem auto; padding: 0 1rem; }
.message {
  padding: 0.875rem 1.25rem;
  border-radius: var(--radius-md);
  margin-bottom: 0.5rem;
  font-size: var(--font-size-sm);
}
.message-success { background: #e8f0e8; color: #2a4a2a; border: 1px solid #b8d4b8; }
.message-warning { background: #f0ece0; color: #5a4010; border: 1px solid #d4c890; }
.message-error { background: #f0e0e0; color: #5a1a1a; border: 1px solid #d4a0a0; }

/* ===== Home Page ===== */
.hero {
  background: linear-gradient(135deg, #1c1a16 0%, #2d2822 50%, #3d3428 100%);
  padding: 6rem 2rem 5rem;
  text-align: center;
  color: #faf8f3;
}
.hero-title {
  font-family: var(--font-family-heading);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
  line-height: 1.2;
  color: #faf8f3;
}
.hero-subtitle {
  font-size: var(--font-size-lg);
  color: rgba(250, 248, 243, 0.7);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}
.hero-actions { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.hero-actions .btn-primary { background: var(--color-primary); color: #faf8f3; }
.hero-actions .btn-primary:hover { background: var(--color-primary-hover); color: #faf8f3; }
.hero-actions .btn-outline { color: rgba(250,248,243,0.85); border-color: rgba(250,248,243,0.35); background: transparent; }
.hero-actions .btn-outline:hover { background: rgba(250,248,243,0.1); color: #faf8f3; border-color: rgba(250,248,243,0.6); }

.section { padding: 5rem 2rem; }
.section-inner { max-width: 1100px; margin: 0 auto; }
.section-title {
  font-family: var(--font-family-heading);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  text-align: center;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}
.section-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  margin-bottom: 3rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 0;
}
.feature-card {
  padding: 2rem;
  border: 1px solid var(--color-border);
  border-right: none;
  background: var(--color-bg-white);
  transition: background 0.15s;
}
.feature-card:last-child { border-right: 1px solid var(--color-border); }
.feature-card:hover { background: var(--color-bg); }
.feature-icon { font-size: 1.5rem; margin-bottom: 1rem; }
.feature-title { font-family: var(--font-family-heading); font-size: var(--font-size-base); font-weight: 700; margin-bottom: 0.5rem; }
.feature-desc { color: var(--color-text-muted); line-height: 1.7; font-size: var(--font-size-sm); }

.regulations-section { background: var(--color-bg-secondary); }
.regulations-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1px;
  background: var(--color-border);
  border: 1px solid var(--color-border);
}
.regulation-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--color-bg-secondary);
  transition: background 0.15s;
}
.regulation-item:hover { background: var(--color-bg); }
.regulation-tag {
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
  flex-shrink: 0;
  letter-spacing: 0.02em;
}
.tag-law { background: var(--color-tag-law); color: var(--color-tag-law-text); }
.tag-regulation { background: var(--color-tag-reg); color: var(--color-tag-reg-text); }
.regulation-info h4 { font-size: var(--font-size-sm); font-weight: 600; margin-bottom: 0.25rem; }
.regulation-info p { font-size: 0.8125rem; color: var(--color-text-muted); line-height: 1.5; }

.cta-section { background: var(--color-text); text-align: center; padding: 4rem 2rem; color: #faf8f3; }
.cta-title { font-family: var(--font-family-heading); font-size: var(--font-size-2xl); font-weight: 700; margin-bottom: 1rem; color: #faf8f3; }
.cta-subtitle { color: rgba(250,248,243,0.65); margin-bottom: 2rem; }

/* ===== Auth Forms ===== */
.auth-page {
  min-height: calc(100vh - var(--nav-height));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
  background: var(--color-bg);
}
.auth-card {
  width: 100%;
  max-width: 400px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2.5rem 2rem;
}
.auth-title {
  font-family: var(--font-family-heading);
  font-size: var(--font-size-2xl);
  font-weight: 700;
  text-align: center;
  margin-bottom: 0.5rem;
}
.auth-subtitle { text-align: center; color: var(--color-text-muted); margin-bottom: 2rem; font-size: var(--font-size-sm); }

.form-group { margin-bottom: 1.25rem; }
.form-label { display: block; font-size: var(--font-size-sm); font-weight: 500; margin-bottom: 0.375rem; color: var(--color-text); }
.form-input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-bg-white);
  transition: border-color 0.15s;
  outline: none;
}
.form-input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 2px rgba(122,106,58,0.12); }
.form-input.is-error { border-color: var(--color-danger); }
.form-error { font-size: 0.8125rem; color: var(--color-danger); margin-top: 0.375rem; }

.form-textarea {
  resize: vertical;
  min-height: 80px;
}

.auth-submit { width: 100%; margin-top: 0.5rem; }
.auth-switch { text-align: center; margin-top: 1.5rem; font-size: var(--font-size-sm); color: var(--color-text-muted); }
.auth-switch a { font-weight: 500; }

.auth-alert {
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.25rem;
  font-size: var(--font-size-sm);
  background: #f0e0e0;
  color: #5a1a1a;
  border: 1px solid #d4a0a0;
}

/* ===== Chat Page ===== */
.chat-layout {
  display: flex;
  height: calc(100vh - var(--nav-height));
  overflow: hidden;
}

/* Sidebar */
.chat-sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  background: var(--color-bg-white);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.sidebar-header { padding: 1rem; border-bottom: 1px solid var(--color-border); }
.btn-new-chat {
  width: 100%;
  justify-content: center;
  background: transparent;
  color: var(--color-text-muted);
  border: 1px dashed var(--color-border-hover);
  padding: 0.5rem;
  font-size: var(--font-size-sm);
  border-radius: var(--radius-sm);
}
.btn-new-chat:hover { background: var(--color-primary-light); color: var(--color-primary); border-color: var(--color-primary); border-style: solid; }

.sidebar-list { flex: 1; overflow-y: auto; padding: 0.5rem; }
.sidebar-item {
  padding: 0.625rem 0.75rem;
  padding-right: 2rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  transition: background 0.12s;
  overflow: hidden;
  border: 1px solid transparent;
  position: relative;
}
.sidebar-item:hover { background: var(--color-bg); }
.sidebar-item.active { background: var(--color-primary-light); color: var(--color-primary); border-color: rgba(122,106,58,0.2); font-weight: 500; }
.sidebar-item .item-title { display: block; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.sidebar-item .item-time { font-size: 0.75rem; color: var(--color-text-weak); display: block; margin-top: 2px; }
.btn-delete-conv { display: none; position: absolute; right: 0.4rem; top: 50%; transform: translateY(-50%); background: none; border: none; color: var(--color-text-weak); cursor: pointer; padding: 2px 5px; font-size: 12px; border-radius: 2px; line-height: 1; }
.sidebar-item:hover .btn-delete-conv { display: inline-block; }
.btn-delete-conv:hover { color: var(--color-danger); background: rgba(138,42,42,0.08); }

/* Main chat area */
.chat-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--color-bg);
}

.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* Empty state */
.chat-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
  gap: 1.5rem;
  text-align: center;
  padding: 2rem;
}
.chat-empty-title { font-family: var(--font-family-heading); font-size: var(--font-size-xl); font-weight: 600; color: var(--color-text); }
.chat-empty-subtitle { color: var(--color-text-muted); font-size: var(--font-size-sm); }
.chat-suggestions { display: flex; flex-direction: column; gap: 0.5rem; width: 100%; max-width: 480px; }
.suggestion-btn {
  padding: 0.75rem 1rem;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-family: var(--font-family);
  color: var(--color-text-muted);
  text-align: left;
  transition: border-color 0.15s, color 0.15s;
}
.suggestion-btn:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* Messages */
.message-row { display: flex; gap: 0.75rem; max-width: 800px; width: 100%; }
.message-row.user { align-self: flex-end; flex-direction: row-reverse; }
.message-row.assistant { align-self: flex-start; }

.message-bubble {
  padding: 0.875rem 1.125rem;
  border-radius: var(--radius-md);
  max-width: 75%;
  line-height: 1.7;
  font-size: var(--font-size-base);
}
.message-row.user .message-bubble {
  background: var(--color-user-bubble);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-bottom-right-radius: var(--radius-sm);
}
.message-row.assistant .message-bubble {
  background: transparent;
  color: var(--color-text);
  padding-left: 0;
  max-width: 85%;
}

/* Markdown rendering in assistant messages */
.message-bubble h1, .message-bubble h2, .message-bubble h3 { font-family: var(--font-family-heading); margin: 1rem 0 0.5rem; font-weight: 700; }
.message-bubble p { margin-bottom: 0.75rem; }
.message-bubble ul, .message-bubble ol { margin: 0.5rem 0 0.75rem 1.5rem; }
.message-bubble li { margin-bottom: 0.25rem; }
.message-bubble blockquote { border-left: 2px solid var(--color-border-hover); padding-left: 1rem; color: var(--color-text-muted); margin: 0.75rem 0; font-size: var(--font-size-sm); }
.message-bubble code { background: var(--color-bg-secondary); padding: 0.125rem 0.375rem; border-radius: var(--radius-sm); font-size: 0.875em; font-family: 'Courier New', monospace; color: var(--color-text); }
.message-bubble pre { background: var(--color-text); color: var(--color-bg); padding: 1rem; border-radius: var(--radius-sm); overflow-x: auto; margin: 0.75rem 0; }
.message-bubble pre code { background: none; padding: 0; color: inherit; }
.message-bubble strong { font-weight: 600; }

/* Sources */
.message-sources { margin-top: 0.75rem; display: flex; flex-wrap: wrap; gap: 0.5rem; }
.source-card {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.625rem;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: border-color 0.12s, color 0.12s;
}
.source-card:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* Loading dots */
.loading-dots { display: flex; gap: 4px; padding: 0.875rem 0; }
.loading-dot {
  width: 6px; height: 6px;
  background: var(--color-border-hover);
  border-radius: 50%;
  animation: bounce 1.2s infinite;
}
.loading-dot:nth-child(2) { animation-delay: 0.2s; }
.loading-dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.4; }
  40% { transform: translateY(-5px); opacity: 1; }
}

/* Input area */
.chat-input-area {
  padding: 1rem 1.5rem;
  background: var(--color-bg-white);
  border-top: 1px solid var(--color-border);
}
.chat-input-inner {
  display: flex;
  gap: 0.75rem;
  align-items: flex-end;
  max-width: 800px;
  margin: 0 auto;
}
.chat-textarea {
  flex: 1;
  padding: 0.75rem 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-base);
  font-family: var(--font-family);
  line-height: 1.5;
  resize: none;
  overflow-y: auto;
  max-height: calc(4 * 1.5rem + 1.5rem);
  outline: none;
  transition: border-color 0.15s;
  background: var(--color-bg-white);
  color: var(--color-text);
}
.chat-textarea:focus { border-color: var(--color-primary); }
.chat-textarea::placeholder { color: var(--color-text-weak); }
.btn-send {
  padding: 0.75rem 1.25rem;
  background: var(--color-text);
  color: var(--color-bg);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-family: var(--font-family);
  font-weight: 500;
  transition: background 0.15s;
  white-space: nowrap;
  flex-shrink: 0;
}
.btn-send:hover { background: var(--color-primary); }
.btn-send.stop { background: var(--color-danger); }
.btn-send.stop:hover { background: #6a1a1a; }
.btn-send:disabled { opacity: 0.4; cursor: not-allowed; }

/* ===== Admin Approvals ===== */
.admin-page { max-width: 1000px; margin: 2rem auto; padding: 0 1.5rem; }
.admin-title { font-family: var(--font-family-heading); font-size: var(--font-size-2xl); font-weight: 700; margin-bottom: 2rem; }
.admin-section-title { font-size: var(--font-size-base); font-weight: 600; margin-bottom: 1rem; color: var(--color-text-muted); border-bottom: 1px solid var(--color-border); padding-bottom: 0.5rem; }
.approval-table { width: 100%; border-collapse: collapse; font-size: var(--font-size-sm); }
.approval-table th { background: var(--color-bg); padding: 0.75rem 1rem; text-align: left; font-weight: 600; border-bottom: 2px solid var(--color-border); color: var(--color-text); }
.approval-table td { padding: 0.875rem 1rem; border-bottom: 1px solid var(--color-border); vertical-align: top; }
.approval-table tr:hover td { background: var(--color-bg); }
.purpose-text { max-width: 200px; color: var(--color-text-muted); }
.approval-actions { display: flex; gap: 0.5rem; align-items: flex-start; flex-wrap: wrap; }
.approval-note { width: 100%; padding: 0.375rem 0.5rem; border: 1px solid var(--color-border); border-radius: var(--radius-sm); font-size: var(--font-size-sm); font-family: var(--font-family); margin-top: 0.375rem; }
.status-badge { padding: 0.2rem 0.5rem; border-radius: var(--radius-sm); font-size: 0.75rem; font-weight: 600; letter-spacing: 0.02em; }
.status-pending { background: #f0ece0; color: #5a4010; }
.status-approved { background: #e0ede0; color: #2a4a2a; }
.status-rejected { background: #f0e0e0; color: #5a1a1a; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav { padding: 0 1rem; }
  .hero { padding: 4rem 1.5rem 3rem; }
  .section { padding: 3rem 1rem; }

  /* Chat sidebar becomes drawer on mobile */
  .chat-sidebar {
    position: fixed;
    left: -100%;
    top: var(--nav-height);
    height: calc(100vh - var(--nav-height));
    z-index: 200;
    transition: left 0.3s ease;
    box-shadow: var(--shadow-lg);
  }
  .chat-sidebar.open { left: 0; }

  .chat-sidebar-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-bg-white);
    cursor: pointer;
    font-size: 1.125rem;
    color: var(--color-text-muted);
  }

  .message-bubble { max-width: 90%; }
  .chat-input-area { padding: 0.75rem 1rem; }
  .features-grid { grid-template-columns: 1fr; }
  .features-grid .feature-card { border-right: 1px solid var(--color-border); border-bottom: none; }
  .features-grid .feature-card:last-child { border-bottom: 1px solid var(--color-border); }
  .regulations-grid { grid-template-columns: 1fr; }

  .approval-table { font-size: 0.8125rem; }
  .approval-table th, .approval-table td { padding: 0.5rem 0.625rem; }
}

@media (min-width: 769px) {
  .chat-sidebar-toggle { display: none; }
}