:root {
  --primary: #2563eb;
  --primary-dark: #1e3fae;
  --secondary: #9333ea;
  --accent: #38bdf8;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --card-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.12);
  --transition-speed: 0.25s;
  --radius: 14px;
  --primary-gradient: linear-gradient(120deg, var(--primary), var(--secondary));
}

* {
  box-sizing: border-box;
}

body {
  font-family: 'Roboto', system-ui, -apple-system, sans-serif;
  background: radial-gradient(circle at 20% 20%, rgba(37, 99, 235, 0.07), transparent 25%),
    radial-gradient(circle at 80% 0%, rgba(147, 51, 234, 0.07), transparent 25%),
    linear-gradient(135deg, #f8fafc, #e5e7eb);
  color: var(--text);
  min-height: 100vh;
  margin: 0;
  padding: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.app-body {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.page-shell {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  padding: 2.5rem;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
}

.page-title {
  font-size: clamp(1.8rem, 3vw + 1rem, 2.6rem);
  font-weight: 800;
  margin: 0 0 0.75rem;
  background: var(--primary-gradient);
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.page-subtitle {
  margin: 0 0 1.75rem;
  color: var(--muted);
  font-size: 1rem;
  max-width: 60ch;
}

.page-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.page-header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 1rem 0 0.5rem;
  color: var(--text);
}

.text-muted {
  color: var(--muted);
}

.link-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5rem;
  margin-top: 1rem;
}

.link-group {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.08), rgba(147, 51, 234, 0.08));
  border: 1px solid rgba(37, 99, 235, 0.15);
  border-radius: var(--radius);
  padding: 1.5rem 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  transition: transform var(--transition-speed), box-shadow var(--transition-speed), border-color var(--transition-speed);
}

.link-group:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow);
  border-color: rgba(147, 51, 234, 0.35);
}

.sprite-image {
  width: 140px;
  height: 220px;
  background: url('images/main_navigation_images.webp') no-repeat;
  border-radius: calc(var(--radius) - 2px);
  transition: transform var(--transition-speed), box-shadow var(--transition-speed);
  background-size: auto;
  border: 4px solid rgba(37, 99, 235, 0.25);
}

.mosaic-sprite { background-position: 3px 15px; }
.fit-sprite { background-position: -134px 15px; }

.sprite-image:hover {
  transform: scale(1.04);
  box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem 1.25rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

label {
  font-weight: 600;
  color: var(--text);
}

.form-control,
select,
input[type="number"],
input[type="text"],
input[type="file"],
textarea {
  width: 100%;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) - 2px);
  font-size: 1rem;
  color: var(--text);
  background: #fff;
  transition: border-color var(--transition-speed), box-shadow var(--transition-speed);
}

.form-control:focus,
select:focus,
input[type="number"]:focus,
input[type="text"]:focus,
input[type="file"]:focus,
textarea:focus {
  outline: none;
  border-color: rgba(37, 99, 235, 0.5);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.input-row {
  display: flex;
  gap: 0.35rem;
}

.input-row button {
  min-width: 42px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1rem;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  font-weight: 700;
  transition: transform var(--transition-speed), box-shadow var(--transition-speed), filter var(--transition-speed);
  text-decoration: none;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #fff;
  box-shadow: 0 10px 30px -12px rgba(37, 99, 235, 0.7);
}

.btn-primary:hover { filter: brightness(1.05); }

.btn-secondary {
  background: rgba(37, 99, 235, 0.08);
  color: var(--text);
  border: 1px solid rgba(37, 99, 235, 0.25);
}

.btn-ghost {
  background: #f8fafc;
  color: var(--text);
  border: 1px solid var(--border);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.75);
}

.btn-ghost:hover {
  filter: brightness(1.02);
  box-shadow: 0 12px 28px -16px rgba(15, 23, 42, 0.25);
}

.helper-text {
  font-size: 0.92rem;
  color: var(--muted);
}

.preview-box {
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  min-height: 240px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #f8fafc 0%, #eef2ff 100%);
}

.preview-canvas {
  max-width: 100%;
  height: auto;
  background: #fff;
  border-radius: calc(var(--radius) - 4px);
}

.canvas-frame {
  max-width: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(145deg, #f8fafc 0%, #eef2ff 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
}

.paper-surface {
  background: #ffffff !important;
  border-radius: calc(var(--radius) - 2px);
  border: 2px solid rgba(15, 23, 42, 0.08);
  box-shadow:
    0 18px 32px -18px rgba(15, 23, 42, 0.45),
    0 6px 16px rgba(15, 23, 42, 0.08);
}

.canvas-frame .canvas-container.paper-surface {
  background: #ffffff;
  border-radius: calc(var(--radius) - 2px);
  border: 2px solid rgba(15, 23, 42, 0.08);
  box-shadow:
    0 18px 32px -18px rgba(15, 23, 42, 0.45),
    0 6px 16px rgba(15, 23, 42, 0.08);
  overflow: hidden;
}

.canvas-frame .canvas-container.paper-surface canvas {
  border-radius: calc(var(--radius) - 2px);
}

canvas {
  max-width: 100%;
  aspect-ratio: auto;
  border-radius: var(--radius);
}

.footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.95rem;
}

.footer a {
  color: var(--primary);
  font-weight: 600;
}

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