:root {
  color-scheme: light;
  font-family: "Microsoft YaHei UI", "PingFang SC", system-ui, sans-serif;
  color: #202124;
  background: #eef1f4;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  background: #eef1f4;
}

button,
input,
select {
  font: inherit;
}

button,
label[for] {
  -webkit-tap-highlight-color: transparent;
}

button {
  cursor: pointer;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  padding: 12px 24px;
  border-bottom: 1px solid #d9dee3;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(12px);
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-size: 20px;
  font-weight: 650;
  line-height: 1.35;
  letter-spacing: 0;
}

.app-header p {
  margin-top: 3px;
  color: #6b737c;
  font-size: 13px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-button,
.primary-button,
.secondary-button,
.text-button,
.segmented button,
.stepper button {
  border: 0;
  border-radius: 6px;
}

.icon-button {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border: 1px solid #d8dde2;
  background: #fff;
  color: #30363c;
  font-size: 23px;
}

.primary-button {
  height: 40px;
  padding: 0 18px;
  background: #137a4c;
  color: #fff;
  font-weight: 600;
}

.primary-button:hover {
  background: #0f6840;
}

.workspace {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  min-height: calc(100vh - 76px);
}

.controls {
  padding: 8px 22px 32px;
  border-right: 1px solid #d9dee3;
  background: #fff;
}

.full-select {
  width: 100%;
  margin: 2px 0 8px;
}

.control-section {
  padding: 20px 0;
  border-bottom: 1px solid #e8ebee;
}

.control-section.compact {
  border-bottom: 0;
}

.control-section h2,
.control-section label,
.control-section .label-row > span:first-child {
  font-size: 14px;
  font-weight: 600;
}

.control-section .label-row h2 {
  margin: 0;
}

.label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 28px;
  margin-bottom: 10px;
}

.muted {
  color: #77808a;
  font-size: 12px;
}

.file-drop {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 82px;
  margin-top: 0;
  border: 1px dashed #aeb7bf;
  border-radius: 6px;
  background: #f8fafb;
  cursor: pointer;
}

.file-drop:hover,
body.is-file-dragging .file-drop {
  border-color: #137a4c;
  background: #f2f8f5;
}

body.is-file-dragging .file-drop {
  background: #e7f5ee;
  box-shadow: inset 0 0 0 1px #137a4c;
}

.file-drop-title {
  font-size: 14px;
  font-weight: 600;
}

.file-drop-detail {
  margin-top: 5px;
  color: #78818a;
  font-size: 12px;
}

.stepper {
  display: grid;
  grid-template-columns: 34px 1fr 34px;
  align-items: center;
  gap: 8px;
}

.stepper button {
  width: 34px;
  height: 34px;
  border: 1px solid #d7dde2;
  background: #f7f8f9;
  color: #353b41;
  font-size: 19px;
}

input[type="range"] {
  width: 100%;
  accent-color: #137a4c;
}

.number-input {
  width: 100%;
  height: 38px;
  margin-top: 10px;
  padding: 0 10px;
  border: 1px solid #d7dde2;
  border-radius: 6px;
  background: #fff;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  padding: 3px;
  border-radius: 7px;
  background: #edf0f2;
}

.segmented button {
  height: 32px;
  background: transparent;
  color: #66707a;
  font-size: 13px;
}

.segmented button.active {
  background: #fff;
  color: #202124;
  box-shadow: 0 1px 3px rgba(18, 28, 36, 0.13);
  font-weight: 600;
}

.text-button {
  padding: 4px 0;
  background: transparent;
  color: #137a4c;
  font-size: 12px;
}

.secondary-button {
  display: block;
  width: 100%;
  height: 38px;
  margin-top: 8px;
  padding: 0 12px;
  border: 1px solid #d7dde2;
  background: #fff;
  color: #30363c;
  line-height: 36px;
  text-align: center;
  cursor: pointer;
}

.secondary-button:hover,
.icon-button:hover,
.stepper button:hover {
  background: #f4f6f7;
}

select {
  min-width: 82px;
  height: 34px;
  padding: 0 8px;
  border: 1px solid #d7dde2;
  border-radius: 6px;
  background: #fff;
}

.preview-area {
  display: flex;
  min-width: 0;
  padding: 28px 32px 18px;
  flex-direction: column;
  align-items: center;
}

.canvas-shell {
  position: relative;
  display: flex;
  width: min(100%, 720px);
  height: calc(100vh - 146px);
  min-height: 480px;
  align-items: flex-start;
  justify-content: center;
  overflow: auto;
  border: 1px solid #d5dbe0;
  border-radius: 8px;
  background-color: #dfe4e7;
  background-image: linear-gradient(45deg, #d6dce0 25%, transparent 25%), linear-gradient(-45deg, #d6dce0 25%, transparent 25%), linear-gradient(45deg, transparent 75%, #d6dce0 75%), linear-gradient(-45deg, transparent 75%, #d6dce0 75%);
  background-position: 0 0, 0 8px, 8px -8px, -8px 0;
  background-size: 16px 16px;
  box-shadow: 0 8px 24px rgba(43, 54, 63, 0.1);
}

canvas {
  display: block;
  max-width: 100%;
  height: auto;
  cursor: grab;
}

canvas.dragging {
  cursor: grabbing;
}

.empty-state {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 24px;
  color: #68727b;
  font-size: 14px;
  background: #f7f8f9;
}

.empty-state[hidden] {
  display: none;
}

.empty-state-action {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  max-width: 320px;
  padding: 28px 22px;
  border: 1px dashed #aeb7bf;
  border-radius: 10px;
  background: #fff;
  color: inherit;
  cursor: pointer;
}

.empty-state-action:hover,
body.is-file-dragging .empty-state-action {
  border-color: #137a4c;
  background: #f2f8f5;
}

body.is-file-dragging .canvas-shell {
  box-shadow: 0 8px 24px rgba(43, 54, 63, 0.1), inset 0 0 0 2px #137a4c;
}

body.is-file-dragging .empty-state-action {
  background: #e7f5ee;
}

.empty-state-title {
  color: #2b3137;
  font-size: 15px;
  font-weight: 600;
}

.empty-state-detail {
  color: #78818a;
  font-size: 12px;
  line-height: 1.5;
  text-align: center;
}

.preview-meta {
  display: flex;
  width: min(100%, 720px);
  justify-content: space-between;
  padding: 10px 2px 0;
  color: #727b84;
  font-size: 12px;
}

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 20;
  max-width: min(360px, calc(100vw - 44px));
  padding: 11px 15px;
  border-radius: 6px;
  background: #20252a;
  color: #fff;
  font-size: 13px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 780px) {
  .app-header {
    padding: 10px 14px;
  }

  .app-header p {
    display: none;
  }

  h1 {
    font-size: 16px;
  }

  .workspace {
    display: flex;
    flex-direction: column;
  }

  .controls {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 18px;
    padding: 4px 16px 12px;
    border-right: 0;
    border-bottom: 1px solid #d9dee3;
  }

  .control-section {
    padding: 14px 0;
  }

  .preview-area {
    padding: 18px 12px 12px;
  }

  .canvas-shell {
    height: 72vh;
    min-height: 420px;
  }
}

@media (max-width: 500px) {
  .controls {
    grid-template-columns: 1fr;
  }

  .header-actions {
    gap: 6px;
  }

  .primary-button {
    padding: 0 12px;
  }

  .preview-meta span:last-child {
    display: none;
  }
}