:root {
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #1f2937;
  background: #f5f7fb;
}
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
.hidden { display: none !important; }
.muted { color: #6b7280; }

.auth-shell { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.auth-card { width: min(440px, 100%); background: #fff; padding: 32px; border-radius: 18px; box-shadow: 0 18px 60px rgba(15,23,42,.09); }
.brand { font-weight: 800; font-size: 24px; margin-bottom: 8px; }
.brand.small { font-size: 20px; }
.tabs { display: flex; gap: 8px; margin: 24px 0 16px; }
.tab, .nav-btn, .ghost { border: 0; background: transparent; }
.tab { padding: 10px 16px; border-radius: 10px; color: #6b7280; }
.tab.active { background: #eef2ff; color: #4338ca; font-weight: 700; }
.form-stack { display: grid; gap: 14px; }
.form-stack.compact { gap: 10px; }
label { display: grid; gap: 7px; font-size: 14px; font-weight: 650; }
input, textarea { width: 100%; border: 1px solid #dbe1ea; border-radius: 11px; padding: 11px 12px; background: #fff; outline: none; }
input:focus, textarea:focus { border-color: #818cf8; box-shadow: 0 0 0 3px rgba(99,102,241,.12); }
textarea { min-height: 90px; resize: vertical; }
.primary, .secondary, .danger, .small-btn { border: 0; border-radius: 10px; padding: 10px 14px; font-weight: 700; }
.primary { background: #4f46e5; color: #fff; }
.secondary { background: #eef2ff; color: #3730a3; }
.danger { background: #fee2e2; color: #991b1b; }
.small-btn { padding: 7px 10px; background: #f3f4f6; color: #374151; }

.app-shell { min-height: 100vh; display: grid; grid-template-columns: 240px 1fr; }
.sidebar { background: #111827; color: #fff; padding: 22px 16px; display: flex; flex-direction: column; gap: 18px; }
.me-card { background: rgba(255,255,255,.08); border-radius: 12px; padding: 12px; font-size: 14px; }
.sidebar nav { display: grid; gap: 6px; }
.nav-btn { color: #d1d5db; text-align: left; padding: 11px 12px; border-radius: 10px; }
.nav-btn:hover, .nav-btn.active { background: rgba(255,255,255,.10); color: #fff; }
.sidebar .ghost { margin-top: auto; color: #d1d5db; padding: 10px; }
.content { min-width: 0; }
.topbar { height: 70px; display: flex; align-items: center; gap: 12px; padding: 0 28px; background: #fff; border-bottom: 1px solid #e5e7eb; }
.topbar h1 { font-size: 20px; margin: 0; }
.page { padding: 28px; }
.hero-card, .panel { background: #fff; border-radius: 16px; padding: 24px; box-shadow: 0 8px 32px rgba(15,23,42,.05); }
.hero-card { max-width: 820px; }
.hero-card h2 { margin-top: 0; }
.hero-actions { display: flex; gap: 10px; margin-top: 20px; }

.chat-layout { display: grid; grid-template-columns: 280px 1fr; min-height: calc(100vh - 126px); gap: 16px; }
.contact-list, .chat-panel { background: #fff; border-radius: 16px; overflow: hidden; box-shadow: 0 8px 32px rgba(15,23,42,.05); }
.contact-item { padding: 14px; border-bottom: 1px solid #f0f2f5; cursor: pointer; }
.contact-item:hover, .contact-item.active { background: #f5f7ff; }
.contact-name { font-weight: 750; }
.contact-meta { color: #9ca3af; font-size: 12px; margin-top: 4px; }
.chat-panel { display: grid; grid-template-rows: auto 1fr auto; min-height: 560px; }
.chat-panel.standalone { margin-top: 18px; min-height: 620px; }
.chat-header { padding: 16px 18px; font-weight: 800; border-bottom: 1px solid #edf0f4; }
.messages { padding: 18px; overflow-y: auto; min-height: 0; max-height: calc(100vh - 250px); background: #fafbfe; }
.message-row { display: flex; margin: 9px 0; }
.message-row.mine { justify-content: flex-end; }
.bubble { max-width: min(72%, 640px); padding: 10px 12px; border-radius: 14px; background: #fff; border: 1px solid #edf0f4; }
.mine .bubble { background: #4f46e5; color: #fff; border-color: #4f46e5; }
.message-meta { font-size: 11px; opacity: .68; margin-bottom: 4px; }
.message-tools { margin-top: 7px; }
.composer { display: grid; grid-template-columns: 1fr auto; gap: 10px; padding: 14px; border-top: 1px solid #edf0f4; background: #fff; }
.pinned { background: #fff7d6; padding: 10px 16px; border-bottom: 1px solid #f5e7a8; font-size: 14px; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 14px; }
.group-card { background: #fff; border-radius: 14px; padding: 18px; box-shadow: 0 8px 28px rgba(15,23,42,.05); }
.group-card h3 { margin: 0 0 8px; }
.group-card p { color: #6b7280; min-height: 42px; }
.badge { display: inline-block; border-radius: 999px; background: #f3f4f6; padding: 4px 8px; font-size: 12px; margin-bottom: 12px; }
.admin-grid { display: grid; grid-template-columns: minmax(300px, .8fr) minmax(360px, 1.2fr); gap: 16px; }
.panel h3 { margin-top: 0; }
.admin-group-row, .request-row, .member-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 10px 0; border-bottom: 1px solid #edf0f4; }
.row-actions { display: flex; flex-wrap: wrap; gap: 7px; }
.manage-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.toast { position: fixed; z-index: 1000; right: 20px; top: 20px; background: #111827; color: #fff; padding: 12px 14px; border-radius: 10px; box-shadow: 0 10px 30px rgba(0,0,0,.18); }
.mobile-only { display: none; }

@media (max-width: 820px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar { position: fixed; inset: 0 auto 0 0; width: 240px; z-index: 50; transform: translateX(-100%); transition: .2s; }
  .sidebar.open { transform: translateX(0); }
  .mobile-only { display: inline-block; }
  .page { padding: 16px; }
  .topbar { padding: 0 16px; }
  .chat-layout { grid-template-columns: 1fr; min-height: auto; }
  .contact-list { max-height: 220px; }
  .messages { max-height: 55vh; }
  .admin-grid, .manage-columns { grid-template-columns: 1fr; }
}