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

:root {
  --primary: #5B6EE8;
  --primary-light: #EEF0FD;
  --bg: #FAFAFA;
  --surface: #FFFFFF;
  --border: #E5E7EB;
  --text: #111827;
  --text-secondary: #6B7280;
  --danger: #EF4444;
  --success: #10B981;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
}

body {
  font-family: -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

/* Layout */
.app-shell {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
}

/* Top Nav */
.top-nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 16px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
}

.top-nav h1 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.2px;
}

.nav-action {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Bottom Tab Bar */
.tab-bar {
  background: var(--surface);
  border-top: 1px solid var(--border);
  display: flex;
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 480px;
  height: 60px;
  z-index: 100;
}

.tab-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 11px;
  cursor: pointer;
  border: none;
  background: none;
  transition: color 0.15s;
}

.tab-item.active, .tab-item:hover { color: var(--primary); }
.tab-item .icon { font-size: 22px; }

/* Content area */
.content {
  flex: 1;
  padding: 16px;
  padding-bottom: 76px;
}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 12px;
  box-shadow: var(--shadow);
}

.card-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 15px;
  flex-shrink: 0;
}

.card-meta { flex: 1; min-width: 0; }
.card-author { font-weight: 600; font-size: 14px; }
.card-time { font-size: 12px; color: var(--text-secondary); }

.card-title { font-weight: 600; font-size: 15px; margin-bottom: 6px; }
.card-body { color: var(--text-secondary); font-size: 14px; }

/* Badge */
.badge {
  background: var(--primary);
  color: #fff;
  border-radius: 10px;
  padding: 1px 7px;
  font-size: 11px;
  font-weight: 600;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 8px;
  border: none;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
}
.btn:active { transform: scale(0.97); }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { opacity: 0.9; }
.btn-outline { background: none; border: 1px solid var(--border); color: var(--text); }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); }
.btn-full { width: 100%; }

/* Forms */
.form-group { margin-bottom: 16px; }
label { display: block; font-size: 13px; font-weight: 500; color: var(--text-secondary); margin-bottom: 6px; }
input, textarea, select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s;
  font-family: inherit;
}
input:focus, textarea:focus { outline: none; border-color: var(--primary); }
textarea { resize: vertical; min-height: 100px; }

/* Login page */
.login-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 24px;
  background: var(--bg);
}

.login-logo {
  width: 72px;
  height: 72px;
  background: var(--primary);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 36px;
  margin-bottom: 24px;
}

.login-title { font-size: 24px; font-weight: 700; margin-bottom: 8px; text-align: center; }
.login-subtitle { color: var(--text-secondary); font-size: 14px; text-align: center; margin-bottom: 40px; }

.google-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 24px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  width: 100%;
  max-width: 320px;
  transition: box-shadow 0.15s;
}
.google-btn:hover { box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
.google-btn img { width: 20px; height: 20px; }

/* Role selector */
.role-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 20px 0; }
.role-card {
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 12px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}
.role-card.selected { border-color: var(--primary); background: var(--primary-light); }
.role-card .role-icon { font-size: 32px; margin-bottom: 8px; }
.role-card .role-name { font-weight: 600; font-size: 14px; }

/* Messages */
.conversation-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}
.conversation-item:hover { background: var(--bg); }
.conv-info { flex: 1; min-width: 0; }
.conv-name { font-weight: 600; font-size: 14px; }
.conv-preview { font-size: 13px; color: var(--text-secondary); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.conv-time { font-size: 12px; color: var(--text-secondary); }

/* Chat */
.chat-area {
  flex: 1;
  padding: 16px;
  padding-bottom: 80px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.bubble-wrap { display: flex; gap: 8px; }
.bubble-wrap.mine { flex-direction: row-reverse; }

.bubble {
  max-width: 72%;
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 14px;
  line-height: 1.5;
}
.bubble-wrap:not(.mine) .bubble { background: var(--surface); border: 1px solid var(--border); border-bottom-left-radius: 4px; }
.bubble-wrap.mine .bubble { background: var(--primary); color: #fff; border-bottom-right-radius: 4px; }
.bubble-time { font-size: 11px; color: var(--text-secondary); align-self: flex-end; }

.chat-input-bar {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100%;
  max-width: 480px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 10px 16px;
  display: flex;
  gap: 10px;
  align-items: flex-end;
}

.chat-input {
  flex: 1;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 8px 14px;
  font-size: 14px;
  resize: none;
  max-height: 120px;
  overflow-y: auto;
}
.chat-input:focus { outline: none; border-color: var(--primary); }

.send-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  border: none;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 60px 24px;
  color: var(--text-secondary);
}
.empty-state .empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-state p { font-size: 14px; }

/* Modal */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.4);
  display: flex; align-items: flex-end;
  z-index: 200;
  opacity: 0; pointer-events: none;
  transition: opacity 0.2s;
}
.modal-overlay.open { opacity: 1; pointer-events: all; }
.modal {
  background: var(--surface);
  border-radius: 20px 20px 0 0;
  padding: 24px;
  width: 100%;
  max-width: 480px;
  margin: 0 auto;
  transform: translateY(100%);
  transition: transform 0.25s ease;
}
.modal-overlay.open .modal { transform: translateY(0); }
.modal-title { font-size: 17px; font-weight: 700; margin-bottom: 20px; }

/* Loading */
.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  margin: 0 auto;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Chip */
.chip {
  display: inline-flex;
  align-items: center;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 20px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 500;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #1F2937;
  color: #fff;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 13px;
  opacity: 0;
  transition: opacity 0.2s, transform 0.2s;
  pointer-events: none;
  z-index: 300;
  white-space: nowrap;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }