/* ============================================================
   Seed Code Chat — Layout / Shell
   Sidebar · Header · Main · Composer · Responsive
   ============================================================ */

#app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--header-h) 1fr auto;
  grid-template-areas:
    "sidebar header"
    "sidebar main"
    "sidebar composer";
}

/* ==================== Sidebar ==================== */

.sidebar {
  grid-area: sidebar;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  min-height: 0;
  z-index: var(--z-drawer);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}

.brand-mark {
  width: 30px;
  height: 30px;
  flex: none;
  color: var(--brand-strong);
  filter: drop-shadow(0 0 6px var(--brand-glow));
}

.brand-name {
  font-weight: 700;
  font-size: var(--fs-16);
  letter-spacing: -0.02em;
  color: var(--text);
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.brand-name .accent {
  color: var(--brand-strong);
}

.brand-tag {
  font-size: var(--fs-11);
  color: var(--muted);
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  padding: 1px 7px;
  letter-spacing: 0.04em;
}

.sidebar-actions {
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-bottom: 1px solid var(--border);
}

.btn-new-chat {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 10px 14px;
  background: linear-gradient(180deg, var(--surface-4), var(--surface-3));
  border: 1px solid var(--border-strong);
  border-radius: var(--r-md);
  color: var(--text);
  font-weight: 600;
  font-size: var(--fs-14);
  transition: border-color var(--t-fast), background var(--t-fast),
    box-shadow var(--t-fast), transform var(--t-fast);
}

.btn-new-chat:hover {
  border-color: var(--brand-deep);
  box-shadow: var(--shadow-glow);
}

.btn-new-chat:active {
  transform: translateY(1px) scale(0.99);
}

.btn-new-chat svg {
  color: var(--brand-strong);
}

.sidebar-search {
  position: relative;
  padding: 0 10px;
}

.sidebar-search .search-icon {
  position: absolute;
  left: 22px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  pointer-events: none;
}

.sidebar-search input {
  width: 100%;
  padding: 9px 12px 9px 38px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  color: var(--text);
  font-size: var(--fs-13);
  transition: border-color var(--t-fast);
}

.sidebar-search input::placeholder {
  color: var(--muted-2);
}

.sidebar-search input:focus {
  border-color: var(--brand-deep);
  outline: none;
}

.conv-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-height: 0;
}

.conv-list-empty {
  color: var(--muted);
  font-size: var(--fs-13);
  text-align: center;
  padding: 28px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
}

.conv-list-empty svg {
  color: var(--muted-2);
  opacity: 0.7;
}

.conv-item {
  position: relative;
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 10px;
  border-radius: var(--r-md);
  color: var(--text-2);
  font-size: var(--fs-13);
  text-align: left;
  transition: background var(--t-fast), color var(--t-fast);
  min-width: 0;
}

.conv-item:hover {
  background: var(--surface-2);
  color: var(--text);
}

.conv-item.active {
  background: var(--brand-dim);
  color: var(--text);
  box-shadow: inset 0 0 0 1px var(--brand-deep);
}

.conv-item .conv-icon {
  flex: none;
  color: var(--muted);
}

.conv-item.active .conv-icon {
  color: var(--brand-strong);
}

.conv-item .conv-title {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.conv-item .conv-actions {
  display: none;
  align-items: center;
  gap: 2px;
  flex: none;
}

.conv-item:hover .conv-actions,
.conv-item.active .conv-actions {
  display: flex;
}

.conv-item .icon-btn {
  width: 26px;
  height: 26px;
}

.sidebar-footer {
  border-top: 1px solid var(--border);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.provider-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: var(--r-md);
  border: 1px solid var(--border);
  background: var(--surface-2);
  font-size: var(--fs-12);
  color: var(--muted);
}

.provider-status .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--muted-2);
  flex: none;
}

.provider-status .dot.online {
  background: var(--brand-strong);
  box-shadow: 0 0 6px var(--brand-glow-strong);
}

.provider-status .ps-label {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ==================== Header ==================== */

.main-header {
  grid-area: header;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  min-width: 0;
}

.header-menu {
  display: none;
}

.header-title {
  flex: 1;
  min-width: 0;
  font-weight: 600;
  font-size: var(--fs-15);
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-title.is-placeholder {
  color: var(--muted);
  font-weight: 500;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 4px;
}

.header-model {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 320px;
}

/* ==================== Main ==================== */

.main {
  grid-area: main;
  overflow-y: auto;
  position: relative;
  min-height: 0;
  scroll-behavior: smooth;
}

.chat-scroll {
  max-width: var(--chat-max-w);
  margin: 0 auto;
  padding: 24px 24px 40px;
  min-height: 100%;
  display: flex;
  flex-direction: column;
}

/* ==================== Composer ==================== */

.composer-wrap {
  grid-area: composer;
  position: relative;
  z-index: 20;
  padding: 12px 16px 16px;
  background: linear-gradient(180deg, transparent, var(--bg) 30%);
}

.composer {
  max-width: var(--composer-max-w);
  margin: 0 auto;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-lg);
  transition: border-color var(--t-base), box-shadow var(--t-base);
  box-shadow: var(--shadow-2);
}

.composer:focus-within {
  border-color: var(--brand-deep);
  box-shadow: var(--shadow-glow);
}

.composer .composer-inner {
  padding: 12px 12px 8px;
}

.composer textarea {
  width: 100%;
  border: none;
  background: none;
  resize: none;
  color: var(--text);
  font-size: var(--fs-15);
  line-height: 1.5;
  min-height: 28px;
  max-height: 200px;
  padding: 2px 4px;
}

.composer textarea::placeholder {
  color: var(--muted-2);
}

.composer textarea:focus {
  outline: none;
}

.composer-attachments {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 0 4px 8px;
}

.attach-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  padding: 3px 8px;
  font-size: var(--fs-12);
  color: var(--text-2);
  max-width: 220px;
}

.attach-chip .chip-name {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.attach-chip button {
  color: var(--muted);
  display: flex;
  transition: color var(--t-fast);
}

.attach-chip button:hover {
  color: var(--danger);
}

.composer-bar {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  padding-top: 4px;
}

.composer-bar .grow {
  flex: 1;
}

.composer-tools {
  display: flex;
  align-items: center;
  gap: 2px;
  padding-left: 4px;
}

.composer-hint {
  text-align: center;
  font-size: var(--fs-11);
  color: var(--muted-2);
  margin-top: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.composer-hint kbd {
  background: var(--surface-3);
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0 5px;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--muted);
}

/* Send button */
.btn-send {
  width: 40px;
  height: 40px;
  border-radius: var(--r-md);
  background: var(--brand);
  color: #062A15;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--t-fast), transform var(--t-fast),
    box-shadow var(--t-fast), opacity var(--t-fast);
  box-shadow: 0 0 0 1px rgba(46, 204, 113, 0.4);
  flex: none;
}

.btn-send:hover:not(:disabled) {
  background: var(--brand-strong);
  box-shadow: var(--shadow-glow);
  transform: translateY(-1px);
}

.btn-send:active:not(:disabled) {
  transform: translateY(0) scale(0.96);
}

.btn-send:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

/* ==================== Scrim (mobile) ==================== */

.scrim {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(2px);
  z-index: var(--z-scrim);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--t-med);
}

.scrim.show {
  opacity: 1;
  pointer-events: auto;
}

/* ==================== Responsive ==================== */

@media (max-width: 900px) {
  #app {
    grid-template-columns: 1fr;
    grid-template-areas:
      "header"
      "main"
      "composer";
  }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    width: min(84vw, 320px);
    transform: translateX(-102%);
    transition: transform var(--t-med) var(--ease-out);
    box-shadow: var(--shadow-3);
  }

  body.sidebar-open .sidebar {
    transform: translateX(0);
  }

  .header-menu {
    display: flex;
  }

  .composer-wrap {
    padding: 8px 12px 12px;
  }

  .chat-scroll {
    padding: 16px 16px 32px;
  }
}

@media (max-width: 600px) {
  :root {
    --header-h: 56px;
  }

  .header-model .model-btn .model-name {
    max-width: 120px;
  }

  .composer-hint {
    display: none;
  }

  .composer-bar {
    gap: 4px;
  }

  .chat-scroll {
    padding: 12px 12px 24px;
  }
}