:root {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --secondary-color: #6b7280;
  --success-color: #10b981;
  --error-color: #ef4444;
  --warning-color: #f59e0b;
  --background: #f8fafc;
  --surface: #ffffff;
  --text-primary: #1f2937;
  --text-secondary: #6b7280;
  --border-color: #d1d5db;
  --border-radius: 8px;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--background);
  min-height: 100vh;
}

#app {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

.header {
  text-align: center;
  margin-bottom: 2rem;
  padding: 2rem;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
  color: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  font-weight: 700;
}

.header p {
  font-size: 1.1rem;
  opacity: 0.9;
}

.service-status {
  margin-top: 1rem;
}

.status-indicator {
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: 500;
  display: inline-block;
}

.status-indicator.demo {
  background: rgba(245, 158, 11, 0.2);
  color: #f59e0b;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.status-indicator.emailjs {
  background: rgba(16, 185, 129, 0.2);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.status-indicator.firebase {
  background: rgba(59, 130, 246, 0.2);
  color: #3b82f6;
  border: 1px solid rgba(59, 130, 246, 0.3);
}

.main-container {
  background: var(--surface);
  border-radius: var(--border-radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.mail-form {
  display: grid;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

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

.form-group input,
.form-group select {
  padding: 0.75rem;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius);
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
}

.help-text {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: -0.25rem;
}

.editor-toolbar {
  display: flex;
  gap: 0.5rem;
  padding: 0.5rem;
  background: var(--background);
  border: 2px solid var(--border-color);
  border-bottom: none;
  border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.toolbar-btn {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border-color);
  background: var(--surface);
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.2s;
  font-size: 0.9rem;
}

.toolbar-btn:hover {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.toolbar-btn.active {
  background: var(--primary-color);
  color: white;
  border-color: var(--primary-color);
}

.message-editor {
  min-height: 200px;
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-top: none;
  border-radius: 0 0 var(--border-radius) var(--border-radius);
  font-size: 1rem;
  line-height: 1.6;
  outline: none;
  overflow-y: auto;
  background: var(--surface);
}

.message-editor:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgb(59 130 246 / 0.1);
}

.message-editor:empty:before {
  content: attr(data-placeholder);
  color: var(--text-secondary);
  font-style: italic;
}

.char-counter {
  text-align: right;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

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

.file-input-wrapper input[type="file"] {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

.file-input-label {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: var(--background);
  border: 2px dashed var(--border-color);
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
  width: 100%;
  font-weight: 500;
}

.file-input-label:hover {
  border-color: var(--primary-color);
  background: rgb(59 130 246 / 0.05);
}

.attachment-list {
  margin-top: 0.5rem;
}

.attachment-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem;
  background: var(--background);
  border-radius: var(--border-radius);
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}

.attachment-remove {
  background: var(--error-color);
  color: white;
  border: none;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
}

.form-actions {
  display: flex;
  gap: 1rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
  overflow: hidden;
}

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

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--background);
  color: var(--text-primary);
  border: 2px solid var(--border-color);
}

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

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

.btn-loading {
  display: none;
}

.btn.loading .btn-text {
  display: none;
}

.btn.loading .btn-loading {
  display: inline;
}

.message-status {
  margin-top: 1.5rem;
  padding: 1rem;
  border-radius: var(--border-radius);
  font-weight: 500;
  display: none;
}

.message-status.success {
  background: rgb(16 185 129 / 0.1);
  color: var(--success-color);
  border: 1px solid rgb(16 185 129 / 0.2);
  display: block;
}

.message-status.error {
  background: rgb(239 68 68 / 0.1);
  color: var(--error-color);
  border: 1px solid rgb(239 68 68 / 0.2);
  display: block;
}

.message-status.warning {
  background: rgb(245 158 11 / 0.1);
  color: var(--warning-color);
  border: 1px solid rgb(245 158 11 / 0.2);
  display: block;
}

.drafts-section {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 2px solid var(--border-color);
}

.drafts-section h2 {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.drafts-list {
  display: grid;
  gap: 1rem;
}

.draft-item {
  padding: 1rem;
  background: var(--background);
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all 0.2s;
}

.draft-item:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow);
  border-color: var(--primary-color);
}

.draft-subject {
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.draft-preview {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.4;
  margin-bottom: 0.5rem;
}

.draft-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.draft-actions {
  display: flex;
  gap: 0.5rem;
}

.draft-actions button {
  padding: 0.25rem 0.5rem;
  border: none;
  border-radius: 4px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}

.draft-load {
  background: var(--primary-color);
  color: white;
}

.draft-delete {
  background: var(--error-color);
  color: white;
}

.no-drafts {
  text-align: center;
  color: var(--text-secondary);
  font-style: italic;
  padding: 2rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  #app {
    padding: 10px;
  }

  .header {
    padding: 1.5rem;
  }

  .header h1 {
    font-size: 2rem;
  }

  .main-container {
    padding: 1.5rem;
  }

  .form-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .editor-toolbar {
    flex-wrap: wrap;
  }
}

/* Animation for better UX */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.mail-form {
  animation: fadeIn 0.5s ease-out;
}

.attachment-item {
  animation: fadeIn 0.3s ease-out;
}

.draft-item {
  animation: fadeIn 0.3s ease-out;
}