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

:root {
  --bg: #0a0a0c;
  --bg-2: #101012;
  --surface: #16161a;
  --surface-2: #1c1c20;
  --border: #28282e;
  --border-hi: #38383f;
  --border-active: #4a4a52;
  --text: #ececf0;
  --text-dim: #a8a8b0;
  --text-faint: #6a6a72;
  --text-bright: #ffffff;
  --inv-bg: #f4f4f5;
  --inv-fg: #09090b;
  --mono: "SF Mono", "JetBrains Mono", "Fira Code", "Cascadia Code", Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  font-size: 15px;
}

.app {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px 64px;
}

/* === Status bar === */
.statusbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

.sb-brand { color: var(--text); font-weight: 600; }
.sb-sep { width: 1px; height: 10px; background: var(--border-hi); }
.sb-spacer { flex: 1; }
.sb-time { color: var(--text-faint); font-variant-numeric: tabular-nums; }

/* === Title === */
.title-row {
  padding: 36px 0 28px;
}

.title-row h1 {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--text-bright);
}

.title-sub {
  margin-top: 8px;
  font-size: 14px;
  color: var(--text-dim);
}

/* === Mode switch === */
.mode-switch {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
}

.mode-btn {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 14px 20px 14px 0;
  border: none;
  background: none;
  cursor: pointer;
  font-family: var(--mono);
  color: var(--text-faint);
  transition: color 0.12s;
  margin-right: 4px;
  position: relative;
}

.mode-btn:hover { color: var(--text-dim); }

.mode-btn.active {
  color: var(--text-bright);
}

.mode-btn.active::after {
  content: "";
  position: absolute;
  left: 0; right: 0;
  bottom: -1px;
  height: 1px;
  background: var(--text-bright);
}

.mode-num { font-size: 10px; letter-spacing: 0.08em; opacity: 0.5; }
.mode-label { font-size: 13px; font-weight: 600; letter-spacing: 0.02em; }

/* === Grid === */
.grid-main {
  display: grid;
  grid-template-columns: 5fr 7fr;
  border-bottom: 1px solid var(--border);
}

@media (max-width: 880px) {
  .grid-main { grid-template-columns: 1fr; }
}

.col-controls {
  padding: 24px 24px 24px 0;
}

.col-result {
  padding: 24px 0 24px 24px;
  border-left: 1px solid var(--border);
  min-height: 480px;
  display: flex;
  flex-direction: column;
}

@media (max-width: 880px) {
  .col-controls { padding-right: 0; padding-top: 24px; }
  .col-result { border-left: none; border-top: 1px solid var(--border); padding-left: 0; padding-top: 24px; }
}

/* === Sections === */
.sec { margin-bottom: 24px; }

.sec-head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.sec-num {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--text-faint);
  letter-spacing: 0.06em;
}

.sec-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.sec-title.dim { color: var(--text-faint); font-weight: 600; }

/* Collapsible section toggle */
.sec-toggle {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  cursor: pointer;
  font-family: var(--sans);
  padding: 9px 12px;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: border-color 0.12s;
}

.sec-toggle:hover {
  border-color: var(--border-active);
}

.sec-summary {
  flex: 1;
  text-align: right;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.04em;
}

.sec-arrow {
  font-family: var(--mono);
  font-size: 16px;
  color: var(--text-dim);
  width: 16px;
  text-align: center;
  transition: transform 0.15s;
}

.sec-toggle.expanded .sec-arrow { transform: rotate(45deg); }

.size-grid { margin-top: 10px; }
.size-grid.collapsed { display: none; }

.sec-inline {
  display: flex;
  gap: 20px;
}

.sec-inline-item { flex: 1; }
.sec-inline-item .sec-head { margin-bottom: 8px; }

@media (max-width: 520px) {
  .sec-inline { flex-direction: column; gap: 0; }
}

/* === Upload === */
.upload-area.hidden { display: none; }
.upload-area { margin-bottom: 24px; }

.upload-drop {
  display: block;
  cursor: pointer;
  border: 1px dashed var(--border-hi);
  transition: border-color 0.12s;
}

.upload-drop:hover { border-color: var(--border-active); }

.upload-text {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 24px 12px;
}

.upload-main { font-size: 13px; color: var(--text-dim); }
.upload-sub { font-size: 10px; color: var(--text-faint); letter-spacing: 0.04em; }

.upload-preview {
  position: relative;
  border: 1px solid var(--border);
  overflow: hidden;
}

.upload-preview.hidden { display: none; }

.upload-preview img {
  width: 100%;
  display: block;
  max-height: 180px;
  object-fit: contain;
  background: var(--bg-2);
}

/* === Textarea === */
textarea {
  width: 100%;
  padding: 12px 14px;
  font-size: 14px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  resize: vertical;
  font-family: var(--sans);
  line-height: 1.6;
  transition: border-color 0.12s;
}

textarea::placeholder { color: var(--text-faint); }
textarea:focus { outline: none; border-color: var(--border-active); }

/* === Chips === */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  padding: 6px 12px;
  font-size: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  cursor: pointer;
  font-family: var(--sans);
  transition: border-color 0.12s, color 0.12s;
}

.chip:hover {
  border-color: var(--border-active);
  color: var(--text);
}

/* === Size grid === */
.size-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

@media (max-width: 640px) {
  .size-grid { grid-template-columns: repeat(3, 1fr); }
}

.size-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  padding: 10px 4px;
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  font-family: var(--sans);
  color: var(--text-faint);
  transition: all 0.12s;
}

.size-btn:hover { border-color: var(--border-hi); color: var(--text-dim); }

.size-btn.active {
  border-color: var(--inv-bg);
  background: var(--inv-bg);
  color: var(--inv-fg);
}

.size-mark {
  border: 1px solid currentColor;
  flex-shrink: 0;
}

.size-aspect { font-size: 11px; font-weight: 600; }
.size-res { font-size: 9px; opacity: 0.6; letter-spacing: 0.04em; }

/* === Segmented group === */
.seg-group {
  display: flex;
  border: 1px solid var(--border);
}

.seg-btn {
  flex: 1;
  padding: 7px 0;
  font-size: 12px;
  border: none;
  border-right: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-faint);
  cursor: pointer;
  font-family: var(--sans);
  font-weight: 600;
  transition: color 0.12s;
}

.seg-btn:last-child { border-right: none; }
.seg-btn:hover { color: var(--text-dim); }

.seg-btn.active {
  background: var(--inv-bg);
  color: var(--inv-fg);
}

/* === Toggle === */
.toggle {
  position: relative;
  display: inline-block;
  width: 38px;
  height: 20px;
}

.toggle input { opacity: 0; width: 0; height: 0; }

.toggle-track {
  position: absolute;
  inset: 0;
  background: var(--border-hi);
  cursor: pointer;
  transition: background 0.15s;
}

.toggle-track::before {
  content: "";
  position: absolute;
  height: 14px;
  width: 14px;
  left: 3px;
  bottom: 3px;
  background: var(--text-dim);
  transition: transform 0.15s, background 0.15s;
}

.toggle input:checked + .toggle-track { background: var(--inv-bg); }
.toggle input:checked + .toggle-track::before {
  transform: translateX(18px);
  background: var(--inv-fg);
}

/* === Action button === */
.btn-action {
  width: 100%;
  padding: 13px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  border: none;
  background: var(--text-bright);
  color: var(--bg);
  cursor: pointer;
  font-family: var(--sans);
  transition: opacity 0.12s;
}

.btn-action:hover:not(:disabled) { opacity: 0.85; }
.btn-action:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-loading.hidden, .btn-label.hidden { display: none; }

.btn-loading {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.btn-loading::before {
  content: "";
  width: 11px;
  height: 11px;
  border: 1.5px solid var(--bg);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  display: inline-block;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* === Mini button === */
.btn-mini {
  position: absolute;
  top: 6px; right: 6px;
  border: 1px solid var(--border-hi);
  background: var(--surface-2);
  color: var(--text-dim);
  cursor: pointer;
  font-size: 11px;
  padding: 3px 8px;
  font-family: var(--sans);
}

.btn-mini:hover { border-color: var(--border-active); color: var(--text); }

/* === Error === */
.error {
  margin-top: 12px;
  padding: 10px 12px;
  border: 1px solid var(--border-active);
  background: var(--surface-2);
  color: var(--text);
  font-size: 13px;
}

.error.hidden { display: none; }

/* === Result empty === */
.result-empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.empty-frame {
  width: 48px;
  height: 48px;
  border: 1px solid var(--border-hi);
  position: relative;
}

.empty-frame::before {
  content: "";
  position: absolute;
  inset: 6px;
  border: 1px solid var(--border);
}

.result-empty p {
  font-size: 13px;
  color: var(--text-faint);
  font-family: var(--mono);
  letter-spacing: 0.04em;
}

/* === Result loading === */
.result-loading {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.result-loading.hidden { display: none; }
#result.hidden { display: none; }

.loading-bar {
  width: 200px;
  max-width: 80%;
  height: 2px;
  background: var(--border);
  position: relative;
  overflow: hidden;
}

.loading-bar span {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 40%;
  background: var(--text-bright);
  animation: slide 1.2s ease-in-out infinite;
}

@keyframes slide {
  0% { left: -40%; }
  100% { left: 100%; }
}

.loading-text {
  font-size: 12px;
  color: var(--text-dim);
  font-family: var(--mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* === Extended prompt === */
.ext-prompt {
  border-left: 2px solid var(--text-bright);
  padding: 2px 0 2px 12px;
  margin-bottom: 16px;
}

.ext-prompt.hidden { display: none; }

.ext-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 5px;
}

.ext-prompt p {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.7;
}

/* === Generated image === */
#generated-image {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  margin-bottom: 14px;
}

/* === Result bar === */
.result-bar {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.btn-bar {
  padding: 8px 14px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  cursor: pointer;
  font-family: var(--sans);
  transition: all 0.12s;
}

.btn-bar:hover { border-color: var(--border-active); color: var(--text); }

.btn-bar.primary {
  background: var(--text-bright);
  border-color: var(--text-bright);
  color: var(--bg);
}

/* === History === */
.history {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}

.hist-head {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 14px;
}

.hist-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.hist-count {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--text-faint);
}

.hist-empty {
  text-align: center;
  color: var(--text-faint);
  padding: 24px;
  font-size: 12px;
  font-family: var(--mono);
}

.hist-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 6px;
}

.hist-item {
  position: relative;
  border: 1px solid var(--border);
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 1;
  transition: border-color 0.12s;
}

.hist-item:hover { border-color: var(--border-active); }

.hist-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.hist-del {
  position: absolute;
  top: 4px; right: 4px;
  width: 18px; height: 18px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-faint);
  cursor: pointer;
  font-size: 10px;
  display: none;
  align-items: center;
  justify-content: center;
  font-family: var(--sans);
}

.hist-item:hover .hist-del { display: flex; }
.hist-del:hover { border-color: var(--border-active); color: var(--text); }

/* === Scrollbar === */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-hi); }
::-webkit-scrollbar-thumb:hover { background: var(--border-active); }

/* === Responsive === */
@media (max-width: 640px) {
  .app { padding: 0 16px 40px; }
  .title-row { padding: 24px 0 20px; }
  .title-row h1 { font-size: 28px; }
  .statusbar { font-size: 10px; gap: 8px; }
}