/* ==========================================================================
   YouTube MP3 - Online Video Converter
   Authentic Classic Web 2.0 Utility Aesthetic (Clean, Lightweight, Fast)
   ========================================================================== */

:root {
  --bg-color: #ffffff;
  --text-main: #333333;
  --text-muted: #555555;
  --link-color: #0084c7;
  --link-hover: #006aa6;
  --header-border: #e8ecf1;
  --card-bg: #f2f5f8;
  --card-border: #dbe2ea;
  --input-border: #b8c7d6;
  --input-focus: #0084c7;
  --btn-primary: #0084c7;
  --btn-primary-hover: #0070a8;
  --ribbon-bg: #0084c7;
  --ribbon-active: #006699;
  --divider-color: #d0d7de;
  --preview-bg: #ffffff;
  --preview-border: #d8e2ed;
}

[data-theme="dark"] {
  --bg-color: #1a1d21;
  --text-main: #e2e8f0;
  --text-muted: #cbd5e1;
  --link-color: #38bdf8;
  --link-hover: #7dd3fc;
  --header-border: #2d3748;
  --card-bg: #22262c;
  --card-border: #333b47;
  --input-border: #4a5568;
  --input-focus: #38bdf8;
  --btn-primary: #0284c7;
  --btn-primary-hover: #0369a1;
  --ribbon-bg: #0284c7;
  --ribbon-active: #0369a1;
  --divider-color: #4a5568;
  --preview-bg: #292e36;
  --preview-border: #3d4654;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  transition: background-color 0.2s ease, color 0.2s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--link-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ==========================================================================
   Header Navigation
   ========================================================================== */
.site-header {
  border-bottom: 1px solid var(--header-border);
  padding: 12px 20px;
  background-color: var(--bg-color);
}

.nav-container {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 28px;
  font-size: 14.5px;
}

.nav-link {
  color: var(--link-color);
  font-weight: 500;
  transition: color 0.15s ease;
}

.nav-link:hover {
  color: var(--link-hover);
  text-decoration: none;
}

.nav-link.active {
  color: var(--link-color);
}

/* Language Dropdown */
.lang-dropdown {
  position: relative;
  display: inline-block;
}

.lang-btn {
  background: none;
  border: none;
  color: var(--link-color);
  font-size: 14.5px;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 6px;
}

.lang-btn:hover {
  color: var(--link-hover);
}

.lang-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--bg-color);
  border: 1px solid var(--header-border);
  border-radius: 4px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  min-width: 140px;
  z-index: 50;
  padding: 6px 0;
}

.lang-menu.show {
  display: block;
}

.lang-menu a {
  display: block;
  padding: 6px 14px;
  color: var(--text-main);
  font-size: 13.5px;
  text-decoration: none;
}

.lang-menu a:hover {
  background-color: var(--card-bg);
  color: var(--link-color);
}

/* Theme Toggle Button */
.theme-btn {
  background: none;
  border: none;
  color: var(--link-color);
  cursor: pointer;
  font-size: 17px;
  padding: 4px 6px;
  display: flex;
  align-items: center;
  transition: transform 0.2s ease, color 0.2s ease;
}

.theme-btn:hover {
  color: var(--link-hover);
  transform: scale(1.1);
}

/* ==========================================================================
   Main Content Layout
   ========================================================================== */
.main-wrapper {
  flex: 1;
  max-width: 760px;
  width: 100%;
  margin: 0 auto;
  padding: 30px 20px 50px;
}

/* Logo Section */
.logo-area {
  text-align: center;
  margin-bottom: 25px;
}

.site-logo {
  max-width: 440px;
  width: 100%;
  height: auto;
  display: inline-block;
}

/* ==========================================================================
   Converter Box (Exact Matching Screenshot)
   ========================================================================== */
.converter-card {
  background-color: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 2px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
  overflow: hidden;
  margin-bottom: 30px;
}

.converter-inner {
  padding: 22px 22px 18px;
}

.converter-label {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--link-color);
  margin-bottom: 12px;
}

.converter-form {
  display: flex;
  gap: 0;
  border: 1px solid var(--input-border);
  border-radius: 2px;
  background-color: #ffffff;
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.converter-form:focus-within {
  border-color: var(--input-focus);
  box-shadow: 0 0 0 1px var(--input-focus);
}

.converter-input {
  flex: 1;
  padding: 10px 14px;
  border: none;
  outline: none;
  font-size: 14.5px;
  font-family: inherit;
  color: #111;
  background: transparent;
}

.converter-input::placeholder {
  color: #94a3b8;
}

.btn-convert {
  background-color: var(--btn-primary);
  color: #ffffff;
  border: none;
  padding: 0 24px;
  font-size: 14.5px;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
  transition: background-color 0.15s ease;
  white-space: nowrap;
}

.btn-convert:hover {
  background-color: var(--btn-primary-hover);
}

.btn-convert:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

/* Bottom Format Ribbon (mp3 / mp4 tabs) */
.format-ribbon {
  display: flex;
  background-color: var(--ribbon-bg);
  padding: 0;
  margin: 0;
  height: 38px;
}

.format-tab {
  flex: 0 0 auto;
  width: 76px;
  background: none;
  border: none;
  color: #ffffff;
  font-size: 15px;
  font-weight: 700;
  font-style: italic;
  font-family: inherit;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.15s ease;
}

.format-tab:hover {
  background-color: rgba(255, 255, 255, 0.12);
}

.format-tab.active {
  background-color: var(--ribbon-active);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   Video Conversion Preview & Results Area
   ========================================================================== */
.status-message {
  display: none;
  margin: 15px 0 0;
  padding: 10px 14px;
  border-radius: 3px;
  font-size: 13.5px;
}

.status-message.error {
  display: block;
  background-color: #fee2e2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

.status-message.info {
  display: flex;
  align-items: center;
  gap: 10px;
  background-color: #e0f2fe;
  color: #0369a1;
  border: 1px solid #bae6fd;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid #bae6fd;
  border-top-color: #0284c7;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

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

.result-card {
  display: none;
  margin-top: 16px;
  padding: 16px;
  background: var(--preview-bg);
  border: 1px solid var(--preview-border);
  border-radius: 3px;
}

.result-content {
  display: flex;
  gap: 16px;
  align-items: center;
}

.result-thumb {
  width: 120px;
  height: 68px;
  object-fit: cover;
  border-radius: 3px;
  background-color: #000;
  flex-shrink: 0;
}

.result-info {
  flex: 1;
  min-width: 0;
}

.result-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 4px;
}

.result-author {
  font-size: 12.5px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.result-actions {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-download-action {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: #16a34a;
  color: #ffffff;
  padding: 7px 16px;
  font-size: 13.5px;
  font-weight: 600;
  border-radius: 2px;
  text-decoration: none;
  transition: background-color 0.15s ease;
}

.btn-download-action:hover {
  background-color: #15803d;
  text-decoration: none;
}

.btn-secondary-action {
  display: inline-flex;
  align-items: center;
  background-color: var(--btn-primary);
  color: #ffffff;
  padding: 7px 14px;
  font-size: 13.5px;
  font-weight: 600;
  border-radius: 2px;
  border: none;
  cursor: pointer;
  text-decoration: none;
}

.btn-secondary-action:hover {
  background-color: var(--btn-primary-hover);
  text-decoration: none;
}

/* ==========================================================================
   Small Center Divider
   ========================================================================== */
.center-divider {
  width: 38px;
  height: 4px;
  background-color: var(--divider-color);
  border-radius: 2px;
  margin: 32px auto 26px;
}

/* ==========================================================================
   Editorial Content / Description (Exact Matching Screenshot)
   ========================================================================== */
.content-section {
  color: var(--text-muted);
  font-size: 14.5px;
  line-height: 1.65;
}

.content-title {
  font-size: 32px;
  font-weight: 300;
  text-align: center;
  color: var(--text-main);
  margin-bottom: 22px;
  letter-spacing: -0.5px;
}

.content-section p {
  margin-bottom: 16px;
  text-align: justify;
}

.steps-list {
  list-style: none;
  margin: 16px 0;
  padding-left: 0;
}

.steps-list li {
  margin-bottom: 8px;
  text-align: left;
}

.closing-text {
  margin-top: 18px;
  text-align: left !important;
}

/* ==========================================================================
   Footer & Natural Backlink Anchor
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--header-border);
  padding: 22px 20px;
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  background-color: var(--bg-color);
  margin-top: auto;
}

.footer-links {
  margin-bottom: 8px;
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-credits {
  font-size: 12.5px;
  color: #888888;
}

.footer-credits a {
  color: var(--link-color);
  font-weight: 600;
}

/* ==========================================================================
   Responsive Adaptations
   ========================================================================== */
@media (max-width: 600px) {
  .nav-container {
    gap: 16px;
    font-size: 13.5px;
  }
  
  .converter-inner {
    padding: 16px 14px 14px;
  }
  
  .converter-form {
    flex-direction: column;
  }
  
  .btn-convert {
    padding: 10px;
    width: 100%;
  }

  .result-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .result-thumb {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
  }
}