:root {
  --primary-color: #6366f1;
  --primary-hover: #4f46e5;
  --primary-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --secondary-color: #10b981;
  --secondary-hover: #059669;
  --secondary-gradient: linear-gradient(135deg, #10b981 0%, #3b82f6 100%);
  --danger-color: #ef4444;
  --danger-hover: #dc2626;
  
  --bg-color: #f8fafc;
  --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  
  --surface-color: rgba(255, 255, 255, 0.85);
  --glass-border: 1px solid rgba(255, 255, 255, 0.5);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --border-color: rgba(226, 232, 240, 0.8);
  
  --header-bg: rgba(255, 255, 255, 0.8);
  --footer-bg: rgba(241, 245, 249, 0.8);
  
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 10px 30px -5px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 20px 40px -10px rgb(0 0 0 / 0.15);
  --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.4);
  
  --radius: 16px;
  --radius-sm: 8px;
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --primary-color: #818cf8;
  --primary-hover: #6366f1;
  --primary-gradient: linear-gradient(135deg, #818cf8 0%, #c084fc 100%);
  
  --bg-color: #0f172a;
  --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  
  --surface-color: rgba(30, 41, 59, 0.7);
  --glass-border: 1px solid rgba(255, 255, 255, 0.1);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --border-color: rgba(51, 65, 85, 0.8);
  
  --header-bg: rgba(15, 23, 42, 0.8);
  --footer-bg: rgba(15, 23, 42, 0.8);
  
  --shadow-md: 0 10px 30px -5px rgb(0 0 0 / 0.4);
  --shadow-lg: 0 20px 40px -10px rgb(0 0 0 / 0.5);
  --shadow-glow: 0 0 20px rgba(129, 140, 248, 0.2);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  position: relative;
}

/* Subtle background glowing orbs */
body::before, body::after {
  content: '';
  position: fixed;
  border-radius: 50%;
  filter: blur(100px);
  z-index: -1;
  opacity: 0.5;
  transition: var(--transition);
}

body::before {
  top: -10%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: var(--primary-color);
  opacity: 0.15;
}

body::after {
  bottom: -10%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: var(--secondary-color);
  opacity: 0.1;
}

[data-theme="dark"] body::before { opacity: 0.1; }
[data-theme="dark"] body::after { opacity: 0.05; }

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

a:hover {
  text-decoration: underline;
}

/* Header - Glassmorphism */
header {
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: var(--glass-border);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: var(--transition);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  letter-spacing: -0.5px;
}

.logo svg {
  stroke: url(#primary-grad) var(--primary-color); /* Fallback */
}

.logo:hover {
  text-decoration: none;
  transform: scale(1.02);
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.95rem;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--primary-gradient);
  transition: var(--transition);
  border-radius: 2px;
}

.nav-links a:hover::after, .nav-links a.active::after {
  width: 100%;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--text-primary);
  text-decoration: none;
}

#theme-toggle {
  background: var(--surface-color);
  border: var(--glass-border);
  box-shadow: var(--shadow-sm);
  color: var(--text-primary);
  cursor: pointer;
  font-size: 1.2rem;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: var(--transition);
}

#theme-toggle:hover {
  transform: rotate(15deg) scale(1.1);
  box-shadow: var(--shadow-glow);
}

/* Main Content */
main {
  flex: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 3rem 2rem;
  width: 100%;
}

.hero-section {
  text-align: center;
  margin-bottom: 4rem;
  animation: fadeInDown 0.8s ease-out;
}

.hero-section h1 {
  font-size: 3.5rem;
  font-weight: 800;
  margin-bottom: 1.2rem;
  color: var(--text-primary);
  letter-spacing: -1px;
  line-height: 1.2;
}

.hero-section p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
  font-weight: 400;
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* AdSense Placeholders */
.ad-container {
  width: 100%;
  margin: 2rem 0;
  text-align: center;
  min-height: 90px;
  background-color: var(--surface-color);
  border: 1px dashed var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  backdrop-filter: blur(8px);
}

/* Glassmorphism Cards */
.converter-container, .content-page {
  background-color: var(--surface-color);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 3rem;
  margin-bottom: 3rem;
  transition: var(--transition);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.converter-container:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.input-section {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

@media (min-width: 768px) {
  .input-section {
    grid-template-columns: 1fr 1fr;
  }
}

.upload-box {
  background: rgba(99, 102, 241, 0.03);
  border: 2px dashed var(--primary-color);
  border-radius: var(--radius);
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.2rem;
  position: relative;
  overflow: hidden;
}

.upload-box::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: var(--primary-gradient);
  opacity: 0;
  transition: var(--transition);
  z-index: 0;
}

.upload-box:hover::before, .upload-box.dragover::before {
  opacity: 0.05;
}

.upload-box > * {
  position: relative;
  z-index: 1;
}

.upload-box:hover, .upload-box.dragover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.upload-icon {
  font-size: 3.5rem;
  color: var(--primary-color);
  transition: var(--transition);
}

.upload-box:hover .upload-icon {
  transform: scale(1.1) translateY(-5px);
}

.text-input-box {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.text-input-box label {
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.text-input-box textarea {
  width: 100%;
  height: 220px;
  padding: 1.5rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 0.9rem;
  resize: vertical;
  transition: var(--transition);
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.02);
}

.text-input-box textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
}

/* Modern Buttons */
.action-buttons {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.btn {
  padding: 0.875rem 2rem;
  border: none;
  border-radius: 50px;
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  top: 0; left: 0; width: 100%; height: 100%;
  background: linear-gradient(rgba(255,255,255,0.2), transparent);
  opacity: 0;
  transition: var(--transition);
}

.btn:hover::after {
  opacity: 1;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
}

.btn-primary:hover {
  text-decoration: none;
  box-shadow: 0 10px 20px -10px var(--primary-color);
}

.btn-secondary {
  background: var(--secondary-gradient);
  color: white;
}

.btn-secondary:hover {
  text-decoration: none;
  box-shadow: 0 10px 20px -10px var(--secondary-color);
}

.btn-danger {
  background-color: var(--surface-color);
  color: var(--danger-color);
  border: 2px solid var(--danger-color);
  box-shadow: none;
}

.btn-danger:hover {
  background-color: var(--danger-color);
  color: white;
  box-shadow: 0 10px 20px -10px var(--danger-color);
}

/* Loader */
.loader-container {
  display: none;
  justify-content: center;
  align-items: center;
  margin: 3rem 0;
  flex-direction: column;
  gap: 1.5rem;
}

.loader {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: conic-gradient(#0000 10%, var(--primary-color));
  -webkit-mask: radial-gradient(farthest-side,#0000 calc(100% - 8px),#000 0);
  animation: spin 1s infinite linear;
}

.loader-container p {
  font-weight: 600;
  color: var(--primary-color);
  animation: pulse 1.5s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* Preview Table */
.preview-section {
  display: none;
  margin-top: 3rem;
  padding-top: 3rem;
  border-top: 1px solid var(--border-color);
  animation: fadeInUp 0.5s ease-out;
}

.preview-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.preview-header h3 {
  font-size: 1.5rem;
  color: var(--text-primary);
}

.table-responsive {
  overflow-x: auto;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color);
  background: var(--bg-color);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

th, td {
  padding: 1.2rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

th {
  background-color: rgba(99, 102, 241, 0.05);
  font-weight: 700;
  color: var(--text-primary);
  text-transform: uppercase;
  font-size: 0.85rem;
  letter-spacing: 0.5px;
}

tr:last-child td {
  border-bottom: none;
}

tr {
  transition: var(--transition);
}

tr:hover {
  background-color: rgba(99, 102, 241, 0.08);
}

/* Content Pages (About, Terms, etc.) */
.content-page h1 {
  margin-bottom: 2rem;
  font-size: 2.5rem;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 800;
}

.content-page h2 {
  margin-top: 2.5rem;
  margin-bottom: 1.2rem;
  font-size: 1.8rem;
  color: var(--text-primary);
}

.content-page p, .content-page ul {
  margin-bottom: 1.2rem;
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.content-page ul {
  padding-left: 2rem;
}

.content-page li {
  margin-bottom: 0.5rem;
}

/* Contact Form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.8rem;
  max-width: 600px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.form-group label {
  font-weight: 600;
  color: var(--text-primary);
}

.form-group input, .form-group textarea {
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-color);
  color: var(--text-primary);
  transition: var(--transition);
  font-family: inherit;
  font-size: 1rem;
}

.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
}

/* Footer */
footer {
  background-color: var(--footer-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-top: var(--glass-border);
  padding: 3rem 2rem;
  text-align: center;
  margin-top: auto;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.footer-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.footer-links a:hover {
  color: var(--primary-color);
}

.copyright {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Utilities */
.hidden {
  display: none !important;
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.8rem;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}

@media (max-width: 768px) {
  .hero-section h1 {
    font-size: 2.5rem;
  }
  
  .converter-container, .content-page {
    padding: 2rem 1.5rem;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--header-bg);
    backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    border-bottom: var(--glass-border);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .mobile-nav-toggle {
    display: block;
  }
  
  .action-buttons {
    flex-direction: column;
  }
  
  .btn {
    width: 100%;
  }
}