:root {
  --bg: #050814;
  --bg-card: rgba(255, 255, 255, 0.06);
  --accent: #4cafef;
  --accent-soft: #7bd3ff;
  --text-main: #ffffff;
  --text-muted: #b0c4de;
  --danger: #ff6b6b;
  --radius: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at top, #1a2a4a 0, #050814 55%);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text-main);
  display: flex;
  flex-direction: column;
}

.header {
  text-align: center;
  padding: 24px 16px 8px;
}

.title {
  margin: 0;
  font-size: 2rem;
  animation: fadeIn 1s ease;
}

.subtitle {
  margin: 8px 0 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.main {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 16px;
}

.card {
  width: 100%;
  max-width: 720px;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
  backdrop-filter: blur(12px);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
  animation: slideUp 0.8s ease;
}

.drop-zone {
  border: 2px dashed rgba(255, 255, 255, 0.25);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s ease, background-color 0.2s ease, transform 0.2s ease;
}

.drop-zone.drag-over {
  border-color: var(--accent);
  background-color: rgba(76, 175, 239, 0.08);
  transform: translateY(-2px);
}

.drop-text {
  margin: 0;
  font-size: 1rem;
}

.drop-sub {
  display: block;
  margin-top: 4px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.file-input {
  display: none;
}

.info-row,
.controls-row,
.result-row,
.download-row {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.info-item {
  flex: 1 1 200px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.info-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.info-value {
  font-size: 0.9rem;
}

.format-select {
  width: 100%;
  padding: 8px 10px;
  border-radius: 10px;
  border: none;
  background: rgba(0, 0, 0, 0.35);
  color: var(--text-main);
  font-size: 0.9rem;
}

.btn {
  flex: 1;
  padding: 10px 14px;
  border-radius: 10px;
  border: none;
  background: var(--accent);
  color: #000;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.1s ease, box-shadow 0.1s ease;
}

.btn:hover:not(:disabled) {
  background: var(--accent-soft);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
}

.progress-container {
  margin-top: 16px;
}

.progress-bar {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  overflow: hidden;
}

.progress-fill {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent-soft));
  transition: width 0.15s ease;
}

.progress-text {
  display: block;
  margin-top: 6px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.download-link {
  display: inline-block;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(76, 175, 239, 0.15);
  color: var(--accent-soft);
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.2s ease, transform 0.1s ease;
}

.download-link:hover {
  background: rgba(76, 175, 239, 0.25);
  transform: translateY(-1px);
}

.status {
  margin-top: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.status.error {
  color: var(--danger);
}

.footer {
  text-align: center;
  padding: 12px 16px 18px;
}

.footer-text {
  margin: 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(16px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@media (max-width: 600px) {
  .card {
    padding: 16px;
  }
  .title {
    font-size: 1.7rem;
  }
}