:root {
  --bg: #f4f7fb;
  --card: #ffffff;
  --line: #d9e1ef;
  --text: #0f1a2e;
  --muted: #63708a;
  --accent: #1f6feb;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, sans-serif;
  background: linear-gradient(135deg, #eef3fb 0%, #f9fbff 50%, #edf4ff 100%);
  color: var(--text);
}

.layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 16px;
  height: 100vh;
  padding: 16px;
}

.sidebar, .chat-panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
}

.sidebar {
  padding: 14px;
  overflow: auto;
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
}

.sidebar h2 {
  font-size: 18px;
  margin: 0;
}

#newConversationBtn,
#attachBtn,
#attachLogBtn {
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
}

#newConversationBtn {
  width: 30px;
  height: 30px;
}

#attachBtn {
  padding: 8px 12px;
}

#attachLogBtn {
  padding: 8px 12px;
}

#conversationList {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

#conversationList li {
  border: 1px solid var(--line);
  border-radius: 10px;
  cursor: pointer;
  position: relative;
  padding: 10px 12px;
  min-height: 48px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
}

#conversationList li.active {
  border-color: var(--accent);
  background: #edf3ff;
}

.conversation-title {
  min-width: 0;
  flex: 1 1 auto;
  line-height: 1.35;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conversation-actions {
  display: flex;
  align-items: center;
  gap: 6px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-2px);
  transition: opacity 120ms ease, transform 120ms ease;
}

#conversationList li:hover .conversation-actions,
#conversationList li.active .conversation-actions,
#conversationList li:focus-within .conversation-actions {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.conversation-action-btn {
  width: 28px;
  height: 28px;
  border: 1px solid rgba(15, 26, 46, 0.08);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.92);
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;
  transition: background 120ms ease, color 120ms ease, border-color 120ms ease;
}

.conversation-action-btn:hover {
  background: #ffffff;
  color: var(--text);
  border-color: rgba(31, 111, 235, 0.22);
}

.conversation-action-btn svg {
  width: 15px;
  height: 15px;
  fill: currentColor;
}

.conversation-action-btn::after {
  content: attr(data-tooltip);
  position: absolute;
  top: -34px;
  right: 0;
  padding: 6px 8px;
  border-radius: 8px;
  background: rgba(15, 26, 46, 0.92);
  color: #ffffff;
  font-size: 12px;
  line-height: 1;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transform: translateY(4px);
  transition: opacity 120ms ease, transform 120ms ease;
}

.conversation-action-btn:hover::after,
.conversation-action-btn:focus-visible::after {
  opacity: 1;
  transform: translateY(0);
}

.chat-panel {
  display: grid;
  grid-template-rows: 1fr auto;
  overflow: hidden;
}

.messages-top {
  padding: 16px;
  overflow: auto;
  border-bottom: 1px solid var(--line);
}

.message {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  margin-bottom: 10px;
  background: #eef0f3;
}

.message.user {
  border-color: rgba(129, 185, 105, 0.35);
  background: rgba(191, 239, 184, 0.45);
}

.message .content {
  line-height: 1.45;
}

.message-attachments {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 180px));
  gap: 10px;
  margin-top: 10px;
}

.message-attachment {
  display: flex;
  flex-direction: column;
  gap: 6px;
  text-decoration: none;
  color: inherit;
}

.message-attachment img {
  width: 100%;
  height: 110px;
  object-fit: cover;
  border-radius: 10px;
  border: 1px solid rgba(15, 26, 46, 0.12);
  background: rgba(255, 255, 255, 0.6);
}

.message-attachment span {
  font-size: 12px;
  color: var(--muted);
  word-break: break-word;
}

.message-attachment.file {
  min-height: 110px;
  justify-content: center;
  align-items: flex-start;
  padding: 12px;
  border: 1px solid rgba(15, 26, 46, 0.12);
  border-radius: 10px;
  background: rgba(244, 247, 251, 0.95);
}

.message-attachment.file .file-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(31, 111, 235, 0.1);
  color: #1854b4;
  font-size: 11px;
  font-weight: 600;
}

.composer {
  padding: 14px;
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 10px;
}

.composer-tools {
  display: flex;
  align-items: center;
  gap: 8px;
}

.composer-hint {
  font-size: 12px;
  color: var(--muted);
}

.selected-files {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 10px;
}

.pending-file {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid rgba(129, 185, 105, 0.35);
  background: rgba(191, 239, 184, 0.35);
  font-size: 13px;
}

.pending-file button {
  border: none;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  padding: 0;
  line-height: 1;
}

#input {
  width: 100%;
  min-height: 96px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px;
  font-size: 15px;
}

#input.drag-over {
  border-color: #72a95a;
  background: rgba(191, 239, 184, 0.22);
  box-shadow: 0 0 0 3px rgba(191, 239, 184, 0.28);
}

#sendBtn {
  justify-self: end;
  border: none;
  background: var(--accent);
  color: white;
  border-radius: 10px;
  padding: 10px 16px;
  cursor: pointer;
}

#sendBtn:disabled,
#newConversationBtn:disabled,
#attachBtn:disabled,
#attachLogBtn:disabled,
#input:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.message.error {
  border-color: #d96a6a;
  background: #fff4f4;
}

pre {
  white-space: pre-wrap;
}

@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
    grid-template-rows: 220px 1fr;
  }

  .message-attachments {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}