:root {
  font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: #0f172a;
  background-color: #f4f6fb;
  line-height: 1.5;
  font-weight: 400;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --danger: #dc2626;
}

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

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, #eef2ff, #f4f6fb 45%);
  color: inherit;
}

.app-header {
  padding: 2rem clamp(1rem, 4vw, 5rem);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 2rem;
}

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

.brand-mark {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 1.2rem;
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: white;
  display: grid;
  place-items: center;
  font-size: 1.5rem;
  font-weight: 600;
  box-shadow: 0 15px 35px rgba(37, 99, 235, 0.35);
}

.eyebrow {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  margin: 0;
  color: #475569;
}

.brand h1 {
  margin: 0.2rem 0;
  font-size: clamp(1.8rem, 3vw, 2.5rem);
}

.tagline {
  margin: 0;
  color: #475569;
}

.metrics {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.metrics > div {
  min-width: 110px;
  padding: 0.8rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.9rem;
  background: rgba(255, 255, 255, 0.8);
}

.metric-label {
  margin: 0;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: #94a3b8;
}

.metric-value {
  margin: 0.2rem 0 0;
  font-weight: 600;
  font-size: 1.2rem;
}

.app-layout {
  display: grid;
  gap: 1.5rem;
  padding: 0 clamp(1rem, 4vw, 5rem) 3rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card {
  background: var(--card-bg);
  border-radius: 1.2rem;
  border: 1px solid var(--border);
  padding: 1.5rem;
  box-shadow: 0 30px 60px rgba(15, 23, 42, 0.08);
}

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

.drop-card {
  grid-column: span 2;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 1rem;
  padding: 2rem;
  text-align: center;
  background: linear-gradient(180deg, rgba(37, 99, 235, 0.05), rgba(37, 99, 235, 0.02));
  transition: border-color 0.2s ease, background 0.2s ease;
  cursor: pointer;
}

.drop-zone:focus-visible {
  outline: 3px solid var(--accent);
}

.drop-zone.is-dragover {
  border-color: var(--accent);
  background: linear-gradient(180deg, rgba(37, 99, 235, 0.15), rgba(37, 99, 235, 0.05));
}

.drop-icon {
  width: 4rem;
  height: 4rem;
  margin: 0 auto 1rem;
  color: var(--accent);
}

.drop-icon svg {
  width: 100%;
  height: 100%;
}

.drop-title {
  margin: 0;
  font-size: 1.2rem;
  font-weight: 600;
}

.drop-subtitle {
  margin: 0.3rem 0;
  color: #64748b;
}

.file-picker {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.2rem;
  border-radius: 999px;
  background: var(--accent);
  color: white;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 15px 30px rgba(37, 99, 235, 0.35);
}

.file-picker:hover {
  transform: translateY(-1px);
}

.help-text,
.limits-text {
  color: #475569;
  font-size: 0.95rem;
}

.file-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  max-height: 270px;
  overflow: auto;
}

.file-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.9rem 1rem;
  border: 1px solid var(--border);
  border-radius: 0.9rem;
  background: #f8fafc;
  gap: 1rem;
}

.file-meta {
  display: flex;
  flex-direction: column;
}

.file-name {
  font-weight: 600;
  margin: 0;
  word-break: break-word;
}

.file-size {
  margin: 0.2rem 0 0;
  color: #64748b;
  font-size: 0.9rem;
}

.file-actions {
  display: flex;
  gap: 0.4rem;
}

button {
  font: inherit;
  border: none;
  border-radius: 0.8rem;
  padding: 0.75rem 1.3rem;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.primary {
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: white;
  box-shadow: 0 15px 30px rgba(37, 99, 235, 0.35);
}

.primary:hover:not(:disabled) {
  transform: translateY(-1px);
}

.ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: #0f172a;
}

.ghost:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.remove-btn {
  width: 40px;
  height: 40px;
  border-radius: 999px;
  background: white;
  border: 1px solid var(--border);
}

.remove-btn:hover {
  border-color: var(--danger);
  color: var(--danger);
}

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

.status-text-wrap {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.status-label {
  margin: 0;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: #94a3b8;
}

.status-text {
  margin: 0.2rem 0 0;
  font-weight: 600;
}

.status-indicator {
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #cbd5f5;
  display: inline-flex;
  position: relative;
}

.status-indicator.is-active {
  background: var(--accent);
}

.status-indicator.is-active::after {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 999px;
  border: 2px solid rgba(37, 99, 235, 0.4);
  animation: pulse 1.2s ease-out infinite;
}

@keyframes pulse {
  0% {
    transform: scale(0.6);
    opacity: 1;
  }
  100% {
    transform: scale(1.4);
    opacity: 0;
  }
}

.progress-wrapper {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

progress {
  width: 140px;
  height: 8px;
  border-radius: 999px;
  overflow: hidden;
  border: none;
  background-color: #e2e8f0;
}

progress::-webkit-progress-bar {
  background-color: #e2e8f0;
}

progress::-webkit-progress-value {
  background-color: var(--accent);
}

progress::-moz-progress-bar {
  background-color: var(--accent);
}

.progress-label {
  min-width: 60px;
  text-align: right;
  font-weight: 600;
  color: #475569;
}

.button-row {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.error-text {
  min-height: 1.2rem;
  color: var(--danger);
  font-weight: 500;
  margin-top: 1rem;
}

.empty-state {
  color: #94a3b8;
  font-style: italic;
}

.preview-card {
  grid-column: span 2;
}

.preview-frame {
  position: relative;
  border: 1px dashed var(--border);
  border-radius: 1rem;
  height: 420px;
  overflow: hidden;
}

.preview-frame iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: none;
}

.preview-placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: #94a3b8;
  font-weight: 500;
  text-align: center;
  padding: 1rem;
}

.app-footer {
  text-align: center;
  padding: 2rem;
  color: #94a3b8;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .drop-card,
  .preview-card {
    grid-column: span 1;
  }

  .button-row {
    flex-direction: column;
  }

  .progress-wrapper {
    width: 100%;
    justify-content: space-between;
  }
}