:root {
  --primary-color: #3b82f6; /* Soft blue */
  --primary-hover: #2563eb;
  --bg-color: #f9fafb; /* Light gray */
  --surface-color: #ffffff;
  --text-main: #111827; /* Dark text */
  --text-muted: #6b7280;
  --border-color: #e5e7eb;
  --error-color: #ef4444;
}

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 2rem;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-main);
}

.logo-img {
  height: 40px;
  width: auto;
  object-fit: contain;
}

@media (max-width: 600px) {
  .logo-img {
    height: 32px;
  }
  .header {
    padding: 0.75rem 1rem;
  }
}

.site-title {
  font-weight: 600;
  font-size: 1.125rem;
}

/* User Account Area */
.login-placeholder .btn-google {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-main);
  transition: background-color 0.2s;
}

.login-placeholder .btn-google:hover {
  background-color: var(--bg-color);
}

/* Main Content */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 3rem 1rem;
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
}

.hero-section {
  text-align: center;
  margin-bottom: 3rem;
  max-width: 600px;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* Buttons */
.btn-primary {
  background-color: var(--primary-color);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 500;
  border-radius: 6px;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: background-color 0.2s;
}

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

.btn-primary:disabled {
  background-color: #93c5fd;
  cursor: not-allowed;
}

.btn-secondary {
  background-color: var(--surface-color);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.2s;
}

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

/* Ad Placeholders */
.ad-container {
  background-color: #f3f4f6;
  border: 1px dashed #d1d5db;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin: 1.5rem 0;
  width: 100%;
}

.ad-banner {
  height: 90px;
  max-width: 728px;
}

.ad-small-banner {
  height: 50px;
  max-width: 320px;
}

.ad-sticky {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 300px;
  height: 250px;
  background-color: #f3f4f6;
  border: 1px solid #d1d5db;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  z-index: 50;
}

.ad-sticky .ad-label {
  color: var(--text-muted);
  font-size: 0.875rem;
}

@media (max-width: 1024px) {
  .ad-sticky {
    display: none;
  }
}

/* Tool Sections */
.tool-section {
  width: 100%;
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.section-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

/* Upload Area */
.upload-area {
  border: 2px dashed var(--border-color);
  border-radius: 6px;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background-color 0.2s;
}

.upload-area:hover, .upload-area.dragover {
  border-color: var(--primary-color);
  background-color: #eff6ff;
}

.upload-icon {
  font-size: 2rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.upload-text {
  margin-bottom: 1rem;
  color: var(--text-muted);
}

.file-input {
  display: none;
}

.preview-container {
  display: none;
  margin-top: 1rem;
  text-align: center;
}

.preview-image {
  max-width: 100%;
  max-height: 300px;
  border-radius: 4px;
  border: 1px solid var(--border-color);
}

/* Account requirements */
.account-message {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 1rem;
}

.login-warning {
  color: var(--error-color);
  font-size: 0.875rem;
  font-weight: 500;
}

/* Generate Area */
.generate-area {
  text-align: center;
}

.loading-text {
  display: none;
  margin-top: 1rem;
  color: var(--text-muted);
  font-size: 0.875rem;
}

/* Result Area */
.result-area {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.prompt-textarea {
  width: 100%;
  min-height: 150px;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-family: inherit;
  font-size: 1rem;
  resize: vertical;
}

.prompt-textarea:focus {
  outline: none;
  border-color: var(--primary-color);
}

.result-actions {
  display: flex;
  gap: 0.5rem;
  justify-content: flex-end;
}

/* Footer */
.footer {
  margin-top: auto;
  padding: 2rem 1rem;
  border-top: 1px solid var(--border-color);
  background-color: var(--surface-color);
  text-align: center;
}

.footer-text {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 1rem;
}