:root {
  --primary: #10b981;
  --primary-dark: #059669;
  --cyan: #06b6d4;
  --bg: #f1f5f9;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --bubble-visitor: linear-gradient(135deg, #10b981, #06b6d4);
  --bubble-agent: #ffffff;
  --border: #e2e8f0;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body {
  margin: 0; padding: 0; height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg); color: var(--text);
}

.app {
  max-width: 480px; margin: 0 auto; height: 100vh; height: 100dvh;
  display: flex; flex-direction: column; background: var(--card);
  box-shadow: 0 0 24px rgba(0, 0, 0, .06);
}

.header {
  flex: 0 0 auto; padding: 14px 16px;
  background: linear-gradient(135deg, var(--primary), var(--cyan));
  color: #fff; display: flex; align-items: center; gap: 10px;
}
.header .avatar {
  width: 38px; height: 38px; border-radius: 50%;
  background: rgba(255, 255, 255, .25);
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; overflow: hidden;
}
.header .avatar img { width: 100%; height: 100%; object-fit: cover; }
.header .title { font-size: 16px; font-weight: 600; line-height: 1.2; }
.header .subtitle { font-size: 12px; opacity: .85; }

.messages {
  flex: 1 1 auto; overflow-y: auto; padding: 16px 12px;
  background: var(--bg); display: flex; flex-direction: column; gap: 10px;
}
.empty-tip {
  margin: auto; color: var(--muted); font-size: 13px;
  text-align: center; line-height: 1.8;
}

.msg { display: flex; max-width: 80%; }
.msg .bubble {
  padding: 9px 13px; border-radius: 16px; font-size: 15px;
  line-height: 1.5; word-break: break-word; box-shadow: 0 1px 2px rgba(0,0,0,.06);
}
.msg .time { font-size: 10px; color: var(--muted); margin-top: 4px; }

.msg.visitor { align-self: flex-end; flex-direction: column; align-items: flex-end; }
.msg.visitor .bubble { background: var(--bubble-visitor); color: #fff; border-bottom-right-radius: 4px; }

.msg.agent { align-self: flex-start; flex-direction: column; align-items: flex-start; }
.msg.agent .bubble { background: var(--bubble-agent); color: var(--text); border-bottom-left-radius: 4px; border: 1px solid var(--border); }

.msg-img {
  display: block; max-width: 200px; max-height: 260px;
  border-radius: 12px; cursor: pointer;
}

.msg.system { align-self: center; }
.msg.system .bubble { background: transparent; color: var(--muted); font-size: 12px; box-shadow: none; }

.input-bar {
  flex: 0 0 auto; display: flex; gap: 8px; padding: 10px 12px;
  background: var(--card); border-top: 1px solid var(--border);
}
.input-bar input {
  flex: 1 1 auto; border: 1px solid var(--border); border-radius: 22px;
  padding: 11px 14px; font-size: 15px; outline: none; background: var(--bg);
}
.input-bar input:focus { border-color: var(--primary); background: #fff; }
.input-bar button {
  flex: 0 0 auto; border: none; border-radius: 22px; padding: 0 18px;
  font-size: 15px; font-weight: 600; color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--cyan)); cursor: pointer;
}
.input-bar button:disabled { opacity: .5; cursor: not-allowed; }
.input-bar .icon-btn {
  flex: 0 0 auto; width: 42px; padding: 0;
  border: none; border-radius: 50%; font-size: 20px; line-height: 42px;
  background: var(--bg); color: var(--primary-dark);
}

.modal-mask {
  position: fixed; inset: 0; background: rgba(15, 23, 42, .5);
  display: flex; align-items: center; justify-content: center; padding: 20px; z-index: 50;
}
.modal {
  background: #fff; border-radius: 16px; padding: 24px 20px;
  width: 100%; max-width: 320px; text-align: center;
}
.modal h3 { margin: 0 0 6px; font-size: 18px; color: var(--primary-dark); }
.modal p { margin: 0 0 16px; font-size: 13px; color: var(--muted); }
.modal input {
  width: 100%; border: 1px solid var(--border); border-radius: 10px;
  padding: 11px 12px; font-size: 15px; margin-bottom: 14px; outline: none;
}
.modal input:focus { border-color: var(--primary); }
.modal button {
  width: 100%; border: none; border-radius: 10px; padding: 12px;
  font-size: 15px; font-weight: 600; color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--cyan)); cursor: pointer;
}

.admin-layout { display: flex; height: 100vh; height: 100dvh; max-width: 1000px; margin: 0 auto; background: var(--card); }
.conv-list { flex: 0 0 38%; border-right: 1px solid var(--border); overflow-y: auto; background: var(--bg); }
.conv-item {
  padding: 12px 14px; border-bottom: 1px solid var(--border);
  cursor: pointer; background: #fff;
}
.conv-item:hover { background: #f8fafc; }
.conv-item.active { background: #ecfdf5; border-left: 3px solid var(--primary); }
.conv-item .name { font-size: 14px; font-weight: 600; }
.conv-item .preview { font-size: 12px; color: var(--muted); margin-top: 3px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 200px; }
.conv-item .time { font-size: 11px; color: var(--muted); float: right; }
.badge { display: inline-block; font-size: 10px; padding: 1px 7px; border-radius: 10px; margin-left: 6px; }
.badge.open { background: #d1fae5; color: var(--primary-dark); }
.badge.closed { background: #e2e8f0; color: var(--muted); }

.admin-main { flex: 1 1 auto; display: flex; flex-direction: column; }
.admin-empty { margin: auto; color: var(--muted); font-size: 14px; text-align: center; }
.admin-toolbar { padding: 8px 12px; border-bottom: 1px solid var(--border); display: flex; gap: 8px; align-items: center; }
.admin-toolbar button {
  border: 1px solid var(--border); background: #fff; border-radius: 8px;
  padding: 6px 12px; font-size: 13px; cursor: pointer; color: var(--text);
}
.admin-toolbar button:hover { border-color: var(--primary); color: var(--primary-dark); }

@media (max-width: 600px) {
  .admin-layout { flex-direction: column; }
  .conv-list { flex: 0 0 40%; }
}