:root {
  --bg: #0b1016;
  --surface: #121a23;
  --surface-2: #182433;
  --border: rgba(130, 165, 202, 0.16);
  --text: #edf3fb;
  --muted: #99a9bf;
  --accent: #29b6f6;
  --accent-2: #14b8a6;
  --accent-glow: rgba(41, 182, 246, 0.24);
  --success: #22c55e;
  --radius: 20px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: "Segoe UI", system-ui, sans-serif;
  background:
    radial-gradient(circle at top left, rgba(41, 182, 246, 0.12), transparent 28%),
    radial-gradient(circle at top right, rgba(20, 184, 166, 0.12), transparent 30%),
    var(--bg);
  color: var(--text);
  min-height: 100vh;
}

header, main, .info-grid, footer {
  width: min(1180px, calc(100% - 32px));
  margin-inline: auto;
}

header { padding: 28px 0 18px; }

.brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand { display: flex; align-items: center; gap: 16px; }
.logo {
  width: 58px;
  height: 58px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(41,182,246,0.22), rgba(20,184,166,0.22));
  font-size: 30px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.25);
}
h1 { margin: 0 0 6px; font-size: clamp(1.9rem, 3vw, 2.8rem); }
.subtitle { margin: 0; color: var(--muted); max-width: 760px; line-height: 1.5; }

.hub-link, footer a {
  color: var(--accent);
  text-decoration: none;
}

.hero-card, .file-card, .result-card, .info-card {
  background: linear-gradient(180deg, rgba(255,255,255,0.02), transparent), var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 12px 50px rgba(0,0,0,0.24);
}

.hero-card { padding: 26px; }
.badge-row { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 20px; }
.badge {
  padding: 7px 12px;
  border-radius: 999px;
  font-size: 13px;
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.08);
}
.badge-audio { background: rgba(20,184,166,0.14); }
.badge-video { background: rgba(249,115,22,0.14); }
.badge-sub { background: rgba(41,182,246,0.14); }
.badge-export { background: rgba(168,85,247,0.14); }

.drop-zone {
  border: 2px dashed rgba(41,182,246,0.34);
  border-radius: 22px;
  padding: 36px 24px;
  text-align: center;
  background: rgba(255,255,255,0.015);
}
.drop-zone.dragover {
  border-color: var(--accent-2);
  box-shadow: 0 0 0 6px rgba(20,184,166,0.12);
}
.drop-icon { font-size: 52px; margin-bottom: 8px; }
.drop-zone h2 { margin: 0 0 8px; }
.drop-zone p { margin: 4px 0; color: var(--muted); }
.browse-link { color: var(--accent); cursor: pointer; }

main { display: grid; gap: 18px; padding-bottom: 24px; }
.file-card, .result-card { padding: 24px; }
.hidden { display: none !important; }

.file-card-header, .result-top {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
}
.file-name { font-size: 1.15rem; font-weight: 700; margin-bottom: 6px; }
.file-meta, #resultMeta, .small-note { color: var(--muted); }

.options-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin: 20px 0;
}
.option-group { display: grid; gap: 8px; }
.option-group label { font-size: 14px; color: var(--muted); }
select {
  width: 100%;
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 12px 14px;
}
.checkbox-group { align-content: end; }

.primary-btn, .ghost-btn, .download-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  border: none;
  cursor: pointer;
  border-radius: 14px;
  transition: 0.2s ease;
}
.primary-btn {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #041018;
  font-weight: 700;
  padding: 14px 18px;
  box-shadow: 0 12px 30px var(--accent-glow);
}
.primary-btn:hover { transform: translateY(-1px); }
.primary-btn.small { padding: 10px 14px; }
.ghost-btn {
  padding: 10px 14px;
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.working {
  display: grid;
  place-items: center;
  gap: 10px;
  padding: 30px;
  text-align: center;
}
.spinner {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 4px solid rgba(255,255,255,0.1);
  border-top-color: var(--accent);
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.downloads-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0;
}
.download-chip {
  padding: 10px 14px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.download-chip:hover { border-color: var(--accent); color: var(--accent); }

.preview-card {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px;
}
.preview-header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  margin-bottom: 12px;
}
.preview-text {
  margin: 0;
  white-space: pre-wrap;
  max-height: 340px;
  overflow: auto;
  line-height: 1.6;
  color: #d8e3f3;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  padding-bottom: 30px;
}
.info-card { padding: 18px; }
.info-card h3 { margin-top: 0; }
.info-card p { margin-bottom: 0; color: var(--muted); line-height: 1.6; }

footer {
  padding: 0 0 30px;
  color: var(--muted);
  text-align: center;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  max-width: 360px;
  background: #161f2d;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px 16px;
  box-shadow: 0 14px 40px rgba(0,0,0,0.35);
}

@media (max-width: 900px) {
  .brand-row, .file-card-header, .result-top { flex-direction: column; }
  .options-grid, .info-grid { grid-template-columns: 1fr; }
}