:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a26;
  --bg-card-hover: #222233;
  --border: #2a2a3e;
  --text-primary: #f0f0f5;
  --text-secondary: #8888aa;
  --text-muted: #555577;
  --accent: #00c853;
  --accent-hover: #00e060;
  --accent-glow: rgba(0, 200, 83, 0.15);
  --danger: #ff4444;
  --warning: #ffaa00;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.2s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

.container { max-width: 900px; margin: 0 auto; padding: 0 24px; }

/* Navigation */
nav {
  position: fixed; top: 0; left: 0; right: 0;
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

nav .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 1.3rem; font-weight: 800;
  background: linear-gradient(135deg, var(--accent), #69f0ae);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
}

.nav-links { display: flex; align-items: center; gap: 4px; }

.nav-links a {
  color: var(--text-secondary); text-decoration: none;
  padding: 8px 16px; border-radius: var(--radius-sm);
  font-size: 0.85rem; font-weight: 500;
  transition: var(--transition);
}

.nav-links a:hover { color: var(--text-primary); background: var(--bg-card); }
.nav-links a.active { color: var(--accent); }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px; border-radius: var(--radius-sm);
  font-size: 0.9rem; font-weight: 600;
  border: none; cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  font-family: inherit;
}

.btn-primary {
  background: var(--accent); color: #000;
}

.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: 0 4px 20px var(--accent-glow); }

.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }

.btn-secondary {
  background: var(--bg-card); color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover { background: var(--bg-card-hover); border-color: var(--accent); }

.btn-ghost {
  background: transparent; color: var(--text-secondary);
}

.btn-ghost:hover { color: var(--text-primary); background: var(--bg-card); }

.btn-large { padding: 14px 32px; font-size: 1rem; }

/* Steps */
main.container { padding-top: 100px; padding-bottom: 80px; }

.step { display: none; margin-bottom: 40px; }

.step.active { display: block; }

.step-header { display: flex; gap: 16px; align-items: flex-start; margin-bottom: 32px; }

.step-number {
  width: 40px; height: 40px; min-width: 40px;
  background: var(--accent); color: #000;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.1rem;
}

.step-header h2 { font-size: 1.3rem; font-weight: 700; }

.step-header p { color: var(--text-secondary); font-size: 0.9rem; margin-top: 4px; }

/* Input Tabs */
.input-tabs { display: flex; gap: 4px; margin-bottom: 24px; background: var(--bg-card); border-radius: var(--radius-sm); padding: 4px; width: fit-content; }

.input-tab {
  padding: 8px 20px; border-radius: 6px; border: none;
  background: transparent; color: var(--text-secondary);
  font-size: 0.9rem; font-weight: 500; cursor: pointer;
  transition: var(--transition); font-family: inherit;
}

.input-tab.active { background: var(--accent); color: #000; }

.tab-content { display: none; }

.tab-content.active { display: block; }

/* Upload Zone */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 60px 40px;
  text-align: center;
  transition: var(--transition);
  cursor: pointer;
}

.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-glow);
}

.upload-icon { color: var(--text-muted); margin-bottom: 16px; }

.upload-text { font-size: 1.1rem; font-weight: 600; margin-bottom: 8px; }

.upload-hint { color: var(--text-muted); font-size: 0.85rem; margin-bottom: 20px; }

.upload-preview {
  margin-top: 20px; padding: 16px;
  background: var(--bg-card); border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: space-between;
}

.file-info { display: flex; flex-direction: column; align-items: flex-start; gap: 4px; }

.file-name { font-weight: 600; font-size: 0.95rem; }

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

/* URL Input */
.url-input-wrapper {
  display: flex; gap: 12px; align-items: center;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 4px;
}

.url-icon { padding: 8px 0 8px 16px; color: var(--text-muted); }

.url-input {
  flex: 1; padding: 12px 8px;
  background: transparent; border: none;
  color: var(--text-primary); font-size: 0.95rem;
  outline: none; font-family: inherit;
}

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

.supported-platforms {
  display: flex; gap: 12px; margin-top: 16px;
  justify-content: center;
}

.platform-tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 14px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: 100px;
  font-size: 0.8rem; color: var(--text-secondary);
}

/* Language Settings */
.language-settings { display: grid; gap: 32px; }

.form-group { display: flex; flex-direction: column; gap: 8px; }

.form-group label { font-size: 0.9rem; font-weight: 600; color: var(--text-secondary); }

.form-select {
  padding: 10px 16px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  color: var(--text-primary); font-size: 0.9rem;
  outline: none; cursor: pointer; font-family: inherit;
  transition: var(--transition);
}

.form-select:focus { border-color: var(--accent); }

.language-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 8px;
}

.lang-checkbox {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 12px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  cursor: pointer; font-size: 0.9rem;
  transition: var(--transition);
}

.lang-checkbox:hover { border-color: var(--accent); }

.lang-checkbox input[type="checkbox"] {
  accent-color: var(--accent); width: 16px; height: 16px;
}

/* Customization */
.customize-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}

.form-range { width: 100%; accent-color: var(--accent); }

.range-value { font-size: 0.8rem; color: var(--text-muted); }

.form-color {
  width: 48px; height: 48px; padding: 2px;
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  background: var(--bg-card); cursor: pointer;
}

.toggle-group { display: flex; align-items: center; gap: 12px; }

.toggle { position: relative; display: inline-block; width: 44px; height: 24px; }

.toggle input { opacity: 0; width: 0; height: 0; }

.toggle-slider {
  position: absolute; inset: 0;
  background: var(--bg-card-hover); border-radius: 24px;
  cursor: pointer; transition: var(--transition);
  border: 1px solid var(--border);
}

.toggle-slider::before {
  content: ''; position: absolute; left: 2px; bottom: 2px;
  width: 18px; height: 18px;
  background: var(--text-secondary); border-radius: 50%;
  transition: var(--transition);
}

.toggle input:checked + .toggle-slider { background: var(--accent); border-color: var(--accent); }

.toggle input:checked + .toggle-slider::before { background: #000; transform: translateX(20px); }

.position-buttons { display: flex; gap: 4px; }

.pos-btn, .align-btn {
  padding: 8px 16px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  color: var(--text-secondary); font-size: 0.85rem;
  cursor: pointer; transition: var(--transition);
  font-family: inherit;
}

.pos-btn:hover, .align-btn:hover { border-color: var(--accent); color: var(--text-primary); }

.pos-btn.active, .align-btn.active { background: var(--accent); color: #000; border-color: var(--accent); }

/* Subtitle Preview */
.subtitle-preview { margin-top: 32px; }

.preview-label { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 8px; }

.preview-box {
  background: #000; border-radius: var(--radius);
  aspect-ratio: 16/9; max-height: 300px;
  display: flex; align-items: flex-end; justify-content: center;
  padding: 24px; position: relative; overflow: hidden;
}

.preview-box::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, #1a1a2e 0%, #0a0a1a 100%);
}

.preview-subtitle {
  position: relative; z-index: 1;
  text-align: center; font-size: 24px;
  color: #fff; max-width: 80%;
  text-shadow: 1px 1px 2px rgba(0,0,0,0.8);
}

/* Process */
.process-actions { text-align: center; padding: 32px 0; }

.progress-bar-wrapper {
  display: flex; align-items: center; gap: 16px;
  margin: 24px 0;
}

.progress-bar {
  flex: 1; height: 8px; background: var(--bg-card);
  border-radius: 4px; overflow: hidden;
}

.progress-fill {
  height: 100%; background: var(--accent);
  border-radius: 4px; transition: width 0.3s ease;
  width: 0%;
}

.progress-text { font-size: 0.9rem; font-weight: 600; color: var(--accent); min-width: 40px; text-align: right; }

.progress-status { text-align: center; color: var(--text-secondary); font-size: 0.9rem; margin-top: 8px; }

/* Results */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
  margin: 24px 0;
}

.download-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px;
  text-align: center; transition: var(--transition);
  cursor: pointer;
}

.download-card:hover { border-color: var(--accent); }

.download-card .lang { font-size: 1.1rem; font-weight: 700; margin-bottom: 4px; }
.download-card .format { font-size: 0.8rem; color: var(--text-muted); margin-bottom: 12px; }
.download-card .dl-btn {
  padding: 8px 16px; background: var(--accent); color: #000;
  border: none; border-radius: var(--radius-sm);
  font-weight: 600; cursor: pointer; font-size: 0.85rem;
  transition: var(--transition); font-family: inherit;
}
.download-card .dl-btn:hover { background: var(--accent-hover); }

.export-actions { display: flex; gap: 12px; justify-content: center; margin-top: 24px; }

/* Auth page */
.auth-page {
  display: flex; align-items: center; justify-content: center;
  min-height: 100vh; padding-top: 60px;
}

.auth-box {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 40px;
  width: 100%; max-width: 420px;
}

.auth-box h2 { text-align: center; margin-bottom: 8px; }
.auth-box .subtitle { text-align: center; color: var(--text-secondary); margin-bottom: 32px; font-size: 0.9rem; }

.form-input {
  width: 100%; padding: 12px 16px;
  background: var(--bg-secondary); border: 1px solid var(--border);
  border-radius: var(--radius-sm); color: var(--text-primary);
  font-size: 0.95rem; outline: none;
  transition: var(--transition); font-family: inherit;
}

.form-input:focus { border-color: var(--accent); }

.form-input-wrapper { position: relative; }

.form-input-wrapper .input-icon {
  position: absolute; left: 12px; top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
}

.form-input-wrapper .form-input { padding-left: 40px; }

.auth-error { color: var(--danger); font-size: 0.85rem; margin-top: 4px; display: none; }

.auth-toggle { text-align: center; margin-top: 16px; font-size: 0.9rem; color: var(--text-secondary); }

.auth-toggle a { color: var(--accent); cursor: pointer; text-decoration: none; }

.auth-toggle a:hover { text-decoration: underline; }

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 768px) {
  .url-input-wrapper { flex-direction: column; padding: 12px; }
  .url-input { width: 100%; padding: 8px 0; }
  .supported-platforms { flex-wrap: wrap; }
  .language-grid { grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); }
  .customize-grid { grid-template-columns: 1fr; }
  .export-actions { flex-direction: column; align-items: center; }
}