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

:root {
  --color-primary: #0066cc;
  --color-primary-light: #e6f0ff;
  --color-secondary: #f5f5f5;
  --color-text-primary: #1a1a1a;
  --color-text-secondary: #666666;
  --color-border: #e0e0e0;
  --color-success: #10b981;
  --color-error: #ef4444;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --transition-smooth: 0.2s ease-out;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu",
    "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
  background: linear-gradient(135deg, #f8f9fa 0%, #e8eef5 100%);
  min-height: 100vh;
  color: var(--color-text-primary);
  line-height: 1.6;
}

.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 700px;
  margin: 0 auto;
  padding: 0;
}

/* Header */
.app-header {
  background: white;
  padding: 32px 24px 32px;
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

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

.app-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

/* Main Content */
.app-content {
  flex: 1;
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Input Section */
.input-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.input-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.input-label {
  display: block;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text-primary);
}

.char-count {
  font-size: 12px;
  color: var(--color-text-secondary);
  background: var(--color-secondary);
  padding: 4px 8px;
  border-radius: 4px;
}

.input-textarea {
  width: 100%;
  height: 280px;
  padding: 16px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: 14px;
  resize: vertical;
  min-height: 200px;
  transition:
    border-color var(--transition-smooth),
    box-shadow var(--transition-smooth),
    background-color var(--transition-smooth);
  background-color: #fafbfc;
}

.input-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-primary-light);
  background-color: white;
}

.input-textarea::placeholder {
  color: #aaa;
  opacity: 0.8;
}

/* Action Section */
.action-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

/* Buttons */
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: none;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition:
    all var(--transition-smooth);
  white-space: nowrap;
}

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

.btn-primary:hover {
  background: #0052a3;
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

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

.btn-secondary:hover {
  background: #efefef;
  box-shadow: var(--shadow-sm);
}

.btn-icon {
  font-size: 16px;
}

.btn-text {
  flex: 1;
}

/* Footer */
.app-footer {
  padding: 20px 24px;
  text-align: center;
  font-size: 12px;
  color: var(--color-text-secondary);
  border-top: 1px solid var(--color-border);
  background: white;
}

/* Responsive */
@media (max-width: 600px) {
  .app-header {
    padding: 32px 16px 24px;
  }

  .app-title {
    font-size: 28px;
  }

  .app-content {
    padding: 20px 16px;
    gap: 20px;
  }

  .action-section {
    grid-template-columns: 1fr;
  }

  .input-textarea {
    height: 240px;
  }
}