:root {
  color-scheme: dark;
  --bg-color: #05060d;
  --bg-gradient-1: rgba(81, 196, 245, 0.2);
  --bg-gradient-2: rgba(244, 114, 182, 0.22);
  --surface: rgba(15, 17, 25, 0.75);
  --surface-alt: rgba(22, 27, 36, 0.85);
  --border: rgba(148, 163, 184, 0.22);
  --border-strong: rgba(148, 163, 184, 0.45);
  --accent: #5bc0ff;
  --accent-strong: #20a4f3;
  --accent-soft: rgba(32, 164, 243, 0.16);
  --accent-pink: rgba(244, 114, 182, 0.7);
  --accent-green: rgba(94, 234, 212, 0.8);
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-tertiary: #64748b;
  --danger: #f87171;
  font-family: "Inter", "Noto Sans TC", "Segoe UI", "PingFang TC", "Microsoft JhengHei", system-ui, -apple-system,
    BlinkMacSystemFont, sans-serif;
}

@font-face {
  font-family: "Inter";
  src: local("Inter"), local("Inter Regular");
  font-weight: 400 700;
  font-display: swap;
}

@font-face {
  font-family: "Noto Sans TC";
  src: local("Noto Sans TC"), local("NotoSansTC-Regular"), local("PingFang TC"), local("Microsoft JhengHei");
  font-weight: 400 700;
  font-display: swap;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at 20% 20%, var(--bg-gradient-1), transparent 55%),
    radial-gradient(circle at 80% 10%, rgba(32, 164, 243, 0.12), transparent 45%),
    radial-gradient(circle at 15% 85%, var(--bg-gradient-2), transparent 60%),
    var(--bg-color);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  padding: 3vh clamp(1rem, 4vw, 3rem);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160' viewBox='0 0 160 160'%3E%3Cg fill='none' stroke='rgba(148,163,184,0.05)' stroke-width='1'%3E%3Cpath d='M0 80h160M80 0v160'/%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.7;
  z-index: -2;
}

.app-shell {
  width: min(1120px, 100%);
  background: linear-gradient(145deg, rgba(17, 24, 39, 0.9), rgba(15, 23, 42, 0.65));
  border: 1px solid rgba(148, 163, 184, 0.12);
  border-radius: 28px;
  backdrop-filter: blur(24px);
  box-shadow: 0 60px 120px -40px rgba(15, 23, 42, 0.75);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.app-header,
.app-footer {
  padding: clamp(1.2rem, 3vw, 1.8rem) clamp(1.8rem, 5vw, 2.8rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.app-header {
  background: linear-gradient(120deg, rgba(32, 164, 243, 0.2), rgba(15, 23, 42, 0.4));
  border-bottom: 1px solid rgba(148, 163, 184, 0.15);
}

.app-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.15);
  background: linear-gradient(180deg, rgba(15, 23, 42, 0.7), rgba(15, 23, 42, 0.85));
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.branding {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-mark {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at 30% 30%, rgba(91, 192, 255, 0.9), rgba(91, 192, 255, 0.3));
  color: #031523;
  font-weight: 700;
  font-size: 1.6rem;
  letter-spacing: -0.03em;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.3), 0 15px 30px -18px rgba(91, 192, 255, 0.8);
}

.branding-text h1 {
  margin: 0;
  font-size: clamp(1.7rem, 2.6vw, 2.4rem);
  letter-spacing: -0.01em;
}

.branding-text p {
  margin: 0.3rem 0 0;
  color: var(--text-secondary);
  max-width: 32ch;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  border-radius: 999px;
  background: rgba(91, 192, 255, 0.18);
  border: 1px solid rgba(91, 192, 255, 0.35);
  color: var(--accent);
  font-size: 0.85rem;
  padding: 0.35rem 0.9rem;
  transition: background 0.2s ease, border 0.2s ease, color 0.2s ease;
}

.status-badge.ready {
  background: rgba(94, 234, 212, 0.18);
  border-color: rgba(94, 234, 212, 0.45);
  color: #22d3ee;
}

.status-badge.error {
  background: rgba(248, 113, 113, 0.18);
  border-color: rgba(248, 113, 113, 0.45);
  color: #fca5a5;
}

.lang-toggle {
  display: inline-flex;
  padding: 0.25rem;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.12);
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.lang-toggle button {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  padding: 0.45rem 1rem;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 500;
  transition: color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.lang-toggle button.active {
  background: rgba(91, 192, 255, 0.22);
  color: var(--text-primary);
  box-shadow: 0 8px 16px -12px rgba(91, 192, 255, 0.6);
}

.lang-toggle button:focus-visible {
  outline: 2px solid rgba(91, 192, 255, 0.6);
  outline-offset: 2px;
}

.app-main {
  display: grid;
  grid-template-columns: minmax(320px, 360px) 1fr;
  gap: clamp(1.6rem, 4vw, 2.4rem);
  padding: clamp(1.8rem, 4vw, 2.4rem) clamp(1.8rem, 5vw, 3rem) clamp(2.6rem, 6vw, 3.4rem);
}

.upload-panel,
.preview-panel {
  border-radius: 24px;
  border: 1px solid var(--border);
  background: var(--surface);
  padding: clamp(1.4rem, 4vw, 1.8rem);
  display: flex;
  flex-direction: column;
  gap: clamp(1.2rem, 3vw, 1.8rem);
  box-shadow: inset 0 1px 0 rgba(148, 163, 184, 0.12), 0 30px 60px -40px rgba(15, 23, 42, 0.9);
}

.panel-header h2 {
  margin: 0;
  font-size: clamp(1.2rem, 2vw, 1.6rem);
}

.panel-header p {
  margin: 0.5rem 0 0;
  color: var(--text-secondary);
  line-height: 1.5;
}

.drop-zone {
  position: relative;
  border: 1.5px dashed rgba(91, 192, 255, 0.35);
  border-radius: 20px;
  padding: clamp(1.6rem, 4vw, 2.2rem);
  text-align: center;
  cursor: pointer;
  transition: border-color 0.25s ease, background 0.25s ease, transform 0.25s ease;
  background: linear-gradient(180deg, rgba(32, 164, 243, 0.14), rgba(15, 23, 42, 0.2));
  display: grid;
  gap: 1rem;
  justify-items: center;
}

.drop-zone:focus-visible {
  outline: 3px solid rgba(91, 192, 255, 0.6);
  outline-offset: 4px;
}

.drop-zone.dragover,
.drop-zone:focus-visible {
  border-color: var(--accent);
  background: rgba(32, 164, 243, 0.22);
  transform: translateY(-2px);
}

.drop-zone.processing {
  opacity: 0.7;
  pointer-events: none;
}

.drop-illustration {
  width: 72px;
  height: 72px;
  border-radius: 20px;
  background: radial-gradient(circle at 30% 30%, rgba(91, 192, 255, 0.4), rgba(91, 192, 255, 0.05));
  position: relative;
}

.drop-illustration::before,
.drop-illustration::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  border: 1px solid rgba(91, 192, 255, 0.2);
  transform: rotate(8deg);
}

.drop-illustration::after {
  transform: rotate(-8deg);
}

.drop-title {
  font-size: 1.05rem;
  font-weight: 600;
}

.drop-hint {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #021725;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, filter 0.2s ease;
}

.primary:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 14px 30px -18px rgba(91, 192, 255, 0.85);
}

.primary:disabled {
  filter: grayscale(0.5);
  opacity: 0.5;
  cursor: not-allowed;
}

.analysis-summary {
  border-radius: 18px;
  padding: 1rem 1.2rem;
  background: rgba(148, 163, 184, 0.08);
  border: 1px solid rgba(148, 163, 184, 0.18);
  color: var(--text-secondary);
  line-height: 1.55;
  font-size: 0.95rem;
  min-height: 4.5rem;
}

.analysis-summary .summary-item {
  display: grid;
  grid-template-columns: max-content 1fr;
  column-gap: 0.75rem;
  row-gap: 0.1rem;
  align-items: start;
  padding: 0.15rem 0;
}

.analysis-summary .summary-item--single {
  grid-template-columns: 1fr;
}

.analysis-summary .summary-label {
  color: var(--text-primary);
  font-weight: 600;
  white-space: nowrap;
}

.analysis-summary .summary-text {
  color: var(--text-secondary);
}

.metrics {
  display: grid;
  gap: 0.9rem;
}

.metric {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 1rem;
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(32, 164, 243, 0.08), rgba(32, 164, 243, 0.02));
  border: 1px solid rgba(148, 163, 184, 0.16);
  align-items: center;
}

.metric-label {
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.metric-value {
  font-weight: 600;
  font-size: 0.98rem;
}

.canvas-stack {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: clamp(1.2rem, 3vw, 1.8rem);
}

.canvas-card {
  background: var(--surface-alt);
  border-radius: 22px;
  border: 1px solid rgba(148, 163, 184, 0.18);
  padding: 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03), 0 25px 50px -35px rgba(91, 192, 255, 0.3);
}

.canvas-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.5rem;
}

.canvas-meta {
  font-size: 0.8rem;
  color: var(--text-tertiary);
}

canvas {
  width: 100%;
  border-radius: 16px;
  border: 1px solid rgba(148, 163, 184, 0.26);
  background: #0b1020;
  aspect-ratio: 4 / 3;
}

.overlay-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  align-items: center;
  justify-content: space-between;
  color: var(--text-secondary);
}

.toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: rgba(148, 163, 184, 0.08);
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
  border: 1px solid rgba(148, 163, 184, 0.12);
}

.toggle input {
  accent-color: var(--accent);
}

.ghost {
  border-radius: 999px;
  padding: 0.45rem 1rem;
  background: transparent;
  border: 1px solid rgba(148, 163, 184, 0.2);
  color: var(--text-secondary);
  cursor: pointer;
  transition: border 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.ghost:hover {
  border-color: rgba(91, 192, 255, 0.6);
  color: var(--accent);
  transform: translateY(-1px);
}

.tip-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.tip-card {
  padding: 1rem 1.1rem;
  border-radius: 18px;
  background: rgba(148, 163, 184, 0.08);
  border: 1px solid rgba(148, 163, 184, 0.14);
  color: var(--text-secondary);
  line-height: 1.5;
}

.tip-card h3 {
  margin: 0 0 0.4rem;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.loading {
  position: fixed;
  inset: 0;
  background: rgba(5, 6, 13, 0.78);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  z-index: 100;
  font-size: 1.1rem;
}

.loading[hidden] {
  display: none !important;
}

.spinner {
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  border: 4px solid rgba(148, 163, 184, 0.2);
  border-top-color: var(--accent);
  animation: spin 0.9s linear infinite;
}

.error-toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  max-width: min(320px, 90vw);
  padding: 0.9rem 1rem;
  border-radius: 16px;
  background: rgba(248, 113, 113, 0.18);
  border: 1px solid rgba(248, 113, 113, 0.5);
  color: #fecaca;
  font-size: 0.95rem;
  box-shadow: 0 15px 40px -24px rgba(248, 113, 113, 0.6);
  z-index: 200;
}

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

@media (max-width: 1024px) {
  body {
    padding: 2rem 1.5rem;
  }

  .app-main {
    grid-template-columns: 1fr;
  }

  .header-actions {
    width: 100%;
    justify-content: space-between;
  }
}

@media (max-width: 720px) {
  body {
    padding: 1rem;
  }

  .app-shell {
    border-radius: 20px;
  }

  .app-header,
  .app-footer {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .status-badge {
    width: 100%;
    justify-content: center;
  }

  .overlay-controls {
    flex-direction: column;
    align-items: flex-start;
  }
}