/* Modern Dark Theme CSS Variables */
:root {
  /* Colors */
  --background-dark: #2B2E3B;
  --background-darker: #252830;
  --card-background: #343845;
  --accent-blue: #688db1;
  --accent-green: #9cb68f;
  --accent-red: #e16162;
  --text-primary: #d1d5db;
  --text-secondary: #9ca3af;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);

  /* Spacing */
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-3: 0.75rem;
  --spacing-4: 1rem;
  --spacing-6: 1.5rem;
  --spacing-8: 2rem;
  --spacing-12: 3rem;
  --spacing-16: 4rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius: 0.5rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
                 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
                 sans-serif;
}

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

body {
  font-family: var(--font-family);
  background: linear-gradient(135deg, var(--background-dark) 0%, var(--background-darker) 100%);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

/* Container */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--spacing-4);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: var(--spacing-12);
  padding-top: var(--spacing-8);
}

.header-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-2);
}

.title {
  font-size: 2.5rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  color: var(--text-primary);
  margin-bottom: var(--spacing-2);
}

.title .icon {
  font-size: 2.8rem;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

.subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  font-weight: 400;
}

/* Main Content */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-8);
}

/* Cards */
.card {
  background: var(--card-background);
  border-radius: var(--radius-lg);
  padding: var(--spacing-8);
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: all 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-lg);
  border-color: rgba(255, 255, 255, 0.2);
}

.card-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--spacing-2);
  color: var(--text-primary);
}

.card-description {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-6);
  font-size: 0.875rem;
}

/* Upload Zone */
.upload-zone {
  border: 2px dashed var(--accent-blue);
  border-radius: var(--radius-lg);
  padding: var(--spacing-12);
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-bottom: var(--spacing-6);
  background: rgba(104, 141, 177, 0.05);
}

.upload-zone:hover {
  border-color: var(--accent-green);
  background: rgba(156, 182, 143, 0.08);
  transform: translateY(-2px);
}

.upload-zone.drag-over {
  border-color: var(--accent-green);
  background: rgba(156, 182, 143, 0.15);
  transform: scale(1.02);
}

.upload-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-4);
}

.upload-icon {
  font-size: 3rem;
  opacity: 0.7;
}

.upload-text {
  font-size: 1rem;
  color: var(--text-primary);
}

.upload-text strong {
  color: var(--accent-blue);
}

.upload-limits {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: var(--spacing-2);
}

/* File Info */
.file-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(156, 182, 143, 0.1);
  padding: var(--spacing-4);
  border-radius: var(--radius);
  margin-bottom: var(--spacing-6);
  border: 1px solid var(--accent-green);
}

.file-details {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-1);
}

.file-name {
  font-weight: 500;
  color: var(--text-primary);
}

.file-size {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-6);
  border: none;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  font-family: inherit;
  min-height: 44px;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
}

.btn-primary {
  background: var(--accent-blue);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover:not(:disabled) {
  background: #5a7ba3;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-success {
  background: var(--accent-green);
  color: white;
  box-shadow: var(--shadow-sm);
}

.btn-success:hover {
  background: #8aa67d;
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

.btn-danger {
  background: var(--accent-red);
  color: white;
  padding: var(--spacing-2);
  min-height: auto;
  border-radius: 50%;
  width: 32px;
  height: 32px;
  justify-content: center;
}

.btn-danger:hover {
  background: #d14545;
  transform: scale(1.1);
}

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

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--text-primary);
  transform: translateY(-1px);
}

.btn-icon {
  font-size: 1rem;
}

/* Progress Section */
.progress-container {
  margin-bottom: var(--spacing-6);
}

.progress-bar {
  width: 100%;
  height: 12px;
  background: var(--background-darker);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: var(--spacing-4);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-green));
  border-radius: var(--radius);
  transition: width 0.5s ease;
  width: 0%;
  position: relative;
  overflow: hidden;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

.progress-text {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
}

#progressPercent {
  font-weight: 600;
  color: var(--accent-blue);
}

#progressStage {
  color: var(--text-secondary);
}

/* Status Messages */
.status-messages {
  background: var(--background-darker);
  border-radius: var(--radius);
  padding: var(--spacing-4);
  max-height: 200px;
  overflow-y: auto;
}

.status-message {
  display: flex;
  gap: var(--spacing-3);
  padding: var(--spacing-2) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.875rem;
}

.status-message:last-child {
  border-bottom: none;
}

.status-time {
  color: var(--text-secondary);
  font-family: 'Monaco', 'Menlo', monospace;
  min-width: 60px;
}

.status-text {
  color: var(--text-primary);
  flex: 1;
}

/* App Info Grid */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-4);
  margin-bottom: var(--spacing-6);
}

.info-item {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-1);
}

.info-item label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 500;
}

.info-item span {
  font-size: 1rem;
  color: var(--text-primary);
  font-weight: 500;
  word-break: break-all;
}

/* Download Section */
.download-section {
  text-align: center;
  margin-bottom: var(--spacing-6);
}

.download-info {
  margin-top: var(--spacing-3);
  font-size: 0.875rem;
  color: var(--text-secondary);
  max-width: 400px;
  margin-left: auto;
  margin-right: auto;
}

/* Error Section */
.error-card {
  border: 1px solid var(--accent-red);
  background: rgba(225, 97, 98, 0.1);
}

.error-content {
  text-align: center;
  margin-bottom: var(--spacing-6);
}

.error-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-4);
}

.error-message {
  font-size: 1rem;
  color: var(--accent-red);
  margin-bottom: var(--spacing-4);
  font-weight: 500;
}

.error-details {
  background: var(--background-darker);
  padding: var(--spacing-4);
  border-radius: var(--radius);
  font-family: 'Monaco', 'Menlo', monospace;
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-align: left;
  word-break: break-all;
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--spacing-8) 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  margin-top: auto;
}

.footer p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-2);
}

.footer .accent {
  color: var(--accent-blue);
  font-weight: 500;
}

.footer-note {
  font-size: 0.75rem;
  opacity: 0.8;
}

/* Connection Status */
.connection-status {
  position: fixed;
  top: var(--spacing-4);
  right: var(--spacing-4);
  background: var(--card-background);
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: 0.75rem;
  z-index: 1000;
  transition: all 0.3s ease;
}

.status-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-red);
  animation: pulse 2s infinite;
}

.status-indicator.connected {
  background: var(--accent-green);
  animation: none;
}

.status-indicator.connecting {
  background: var(--accent-blue);
  animation: pulse 2s infinite;
}

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

/* Responsive Design */
@media (max-width: 640px) {
  .container {
    padding: var(--spacing-2);
  }

  .title {
    font-size: 2rem;
  }

  .card {
    padding: var(--spacing-6);
  }

  .upload-zone {
    padding: var(--spacing-8);
  }

  .info-grid {
    grid-template-columns: 1fr;
  }

  .connection-status {
    top: var(--spacing-2);
    right: var(--spacing-2);
  }
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.5s ease forwards;
}

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

.text-center {
  text-align: center;
}

.mb-4 {
  margin-bottom: var(--spacing-4);
}