/* ===== CSS Variables ===== */
:root {
  --bg-primary: #f8f9fa;
  --bg-secondary: #ffffff;
  --text-primary: #2d3436;
  --text-secondary: #636e72;
  --border-color: #e9ecef;
  --accent-color: #0984e3;
  --accent-hover: #74b9ff;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --radius: 8px;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

/* ===== Dark Mode ===== */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --text-primary: #eaeaea;
    --text-secondary: #a0a0a0;
    --border-color: #2d2d44;
    --accent-color: #5dade2;
    --accent-hover: #85c1e9;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
  }
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  .header {
    padding: 2rem 0 1.5rem;
  }

  .header h1 {
    font-size: 1.5rem;
  }

  .tool-selector {
    flex-direction: row;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 0.5rem;
  }

  .tool-tab {
    white-space: nowrap;
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
  }

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

  .btn-group {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .tool-content {
    padding: 1.25rem;
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 1.25rem;
  }

  .tool-header h1 {
    font-size: 1.25rem;
  }

  textarea {
    min-height: 150px;
  }
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-hover);
}

/* ===== Layout ===== */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem;
}

/* ===== Header ===== */
.header {
  text-align: center;
  padding: 3rem 0 2rem;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 2rem;
}

.header h1 {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.header p {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ===== Tool Grid ===== */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
}

/* ===== Tool Card ===== */
.tool-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tool-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tool-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}

.tool-card .icon {
  font-size: 1.5rem;
}

/* ===== Tool Content ===== */
.tool-header {
  margin-bottom: 2rem;
}

.tool-header h1 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

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

.tool-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

/* Mobile adjustments */
@media (max-width: 768px) {
  .tool-header {
    margin-bottom: 1.25rem;
  }

  .tool-header h1 {
    font-size: 1.25rem;
  }

  .tool-content {
    padding: 1.25rem;
  }
}

/* ===== Form Elements ===== */
.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

textarea,
input[type="text"],
input[type="email"],
select {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: border-color 0.2s, box-shadow 0.2s;
}

textarea:focus,
input[type="text"]:focus,
input[type="email"]:focus,
select:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px rgba(9, 132, 227, 0.15);
}

textarea {
  min-height: 200px;
  resize: vertical;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

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

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

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

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

.btn-group {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* ===== Output Area ===== */
.output-area {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

.output-area pre {
  background: var(--bg-primary);
  padding: 1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  white-space: pre-wrap;
  word-break: break-all;
  max-width: 100%;
}

/* Mobile: adjust output area */
@media (max-width: 768px) {
  .output-area {
    margin-top: 1rem;
    padding-top: 1rem;
  }

  .output-area pre {
    font-size: 0.75rem;
    padding: 0.75rem;
  }
}

/* ===== Back Link ===== */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.back-link:hover {
  color: var(--accent-color);
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 2rem 0;
  margin-top: 3rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* ===== Tool Selector ===== */
.tool-selector {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.tool-tab {
  padding: 0.75rem 1.25rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.tool-tab:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

.tool-tab.active {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: white;
}

/* ===== Q&A Section ===== */
.qa-section {
  margin-top: 3rem;
}

.qa-section h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
}

.qa-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1rem;
}

.qa-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.25rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  transition: transform 0.2s, box-shadow 0.2s;
}

.qa-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.qa-card .question {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}

.qa-card .question::before {
  content: 'Q';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent-color);
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  flex-shrink: 0;
}

.qa-card .answer {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  padding-left: 1.5rem;
}

/* Mobile: reduce answer padding */
@media (max-width: 768px) {
  .qa-card .answer {
    padding-left: 1.25rem;
  }

  .qa-section {
    margin-top: 2rem;
  }
}

/* ===== Utility ===== */
.hidden {
  display: none;
}

.text-muted {
  color: var(--text-secondary);
}

.logo-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.logo {
  width: 48px;
  height: 48px;
  border-radius: 8px;
}