:root {
  --bg: #f3f4f6;
  --card: #ffffff;
  --card-border: #e5e7eb;
  --text: #111827;
  --muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: rgba(37, 99, 235, 0.08);
  --shadow: 0 12px 30px rgba(17, 24, 39, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  background: var(--bg);
}

.app-shell {
  width: min(1120px, calc(100% - 24px));
  margin: 0 auto;
  padding: 16px 0 24px;
}

.hero {
  max-width: 42rem;
  margin-bottom: 16px;
}

.eyebrow,
.section-label {
  margin: 0 0 8px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-size: 0.7rem;
  color: var(--accent);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 6vw, 3.4rem);
  line-height: 1.02;
}

.lede {
  margin: 10px 0 0;
  max-width: 48ch;
  font-size: 0.98rem;
  color: var(--muted);
}

.editor-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.preview-card,
.controls-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.preview-card {
  padding: 12px;
}

.preview-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}

.preview-header h2 {
  margin: 0;
  font-size: 1rem;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 7px 10px;
  border-radius: 999px;
  background: #f3f4f6;
  color: var(--muted);
  font-size: 0.82rem;
}

.canvas-wrap {
  position: relative;
  overflow: hidden;
  border-radius: 14px;
  background: #eef2f7;
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
}

.controls-card {
  padding: 12px;
}

.control-block + .control-block {
  margin-top: 16px;
}

.upload-zone {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px;
  border: 1px dashed var(--card-border);
  border-radius: 12px;
  background: linear-gradient(180deg, #ffffff, #fbfbfd);
  cursor: pointer;
  transition: box-shadow 0.12s ease, border-color 0.12s ease, transform 0.06s ease;
}

.upload-zone:hover {
  border-color: var(--accent);
  box-shadow: 0 8px 20px rgba(37,99,235,0.06);
  transform: translateY(-2px);
}

.upload-title {
  font-size: 1rem;
  font-weight: 700;
}

.upload-subtitle,
.hint {
  color: var(--muted);
  font-size: 0.84rem;
}

#upload {
  width: 100%;
  color: var(--muted);
}

/* hide default file input UI but keep it accessible */
.upload-zone input[type="file"] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
  width: 0;
  height: 0;
}

.upload-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}

.upload-action {
  background: var(--accent);
  color: #fff;
  border: 0;
  padding: 8px 12px;
  border-radius: 10px;
  font-weight: 700;
  cursor: pointer;
}

.upload-action:active { transform: translateY(0); }

@media (max-width: 480px) {
  .upload-zone { gap: 10px; padding: 12px; }
  .upload-action { padding: 9px 14px; }
}

.slider-group {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.slider-group span,
.slider-group strong {
  font-size: 0.86rem;
}

.slider-group strong {
  color: var(--accent);
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.button-row {
  display: flex;
  gap: 12px;
  margin-top: 18px;
}

button {
  border: 0;
  border-radius: 12px;
  padding: 12px 16px;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
}

button:hover {
  transform: translateY(-1px);
}

button:active {
  transform: translateY(0);
}

.primary-btn {
  flex: 1;
  color: #ffffff;
  background: var(--accent);
}

.secondary-btn {
  color: var(--text);
  background: #f3f4f6;
  border: 1px solid var(--card-border);
}

.hint {
  margin: 12px 0 0;
}

.app-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  justify-content: center;
  align-items: center;
  /* margin-top: 16px; */
  padding: 12px 0 4px;
  color: var(--muted);
  font-size: 0.88rem;
}

.app-footer p {
  margin: 0;
}

.app-footer a {
  color: var(--accent);
  text-decoration: none;
  /* font-weight: 700; */
  font-size: 12px;
}

.app-footer a:hover {
  text-decoration: underline;
}

@media (min-width: 768px) {
  .editor-grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.75fr);
    gap: 16px;
  }

  .preview-card,
  .controls-card {
    border-radius: 20px;
  }
}

@media (min-width: 1024px) {
  .app-shell {
    padding-top: 28px;
    padding-bottom: 32px;
  }

  .preview-header {
    align-items: center;
  }

  .preview-card {
    padding: 16px;
  }

  .controls-card {
    padding: 16px;
  }
}

@media (max-width: 767px) {
  .button-row {
    flex-direction: column;
  }

  .preview-header {
    flex-direction: column;
  }
}