/* ===== CSS Variables & Reset ===== */
:root {
  --bg-primary: #faf6f1;
  --bg-secondary: #f3ece4;
  --bg-card: #ffffff;
  --bg-card-hover: #fff8f0;
  --bg-input: #f7f2ec;
  --border: #e0d5c8;
  --border-focus: #b07d4f;
  --text-primary: #3a2e24;
  --text-secondary: #7a6b5d;
  --text-muted: #a89888;
  --accent: #b07d4f;
  --accent-hover: #c48c5a;
  --accent-glow: rgba(176, 125, 79, 0.2);
  --success: #4caf50;
  --warning: #f59e0b;
  --danger: #e74c3c;
  --gradient-1: linear-gradient(135deg, #b07d4f, #d4a574);
  --gradient-2: linear-gradient(135deg, #8b6f47, #b07d4f);
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(58, 46, 36, 0.08);
  --transition: 0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 246, 241, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-size: 1.3rem;
  font-weight: 700;
}

.logo-icon { font-size: 1.5rem; }
.logo-accent { color: var(--accent); }

.nav { display: flex; gap: 8px; }

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-primary);
  background: var(--bg-card);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

.mobile-nav {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  z-index: 99;
  flex-direction: column;
  gap: 8px;
}

.mobile-nav.open { display: flex; }

.mobile-nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-weight: 500;
  transition: var(--transition);
}

.mobile-nav-link:hover { color: var(--text-primary); background: var(--bg-card); }

/* ===== Main Content ===== */
.main {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 32px 24px;
}

/* ===== Hero Section ===== */
.hero {
  text-align: center;
  padding: 60px 0 48px;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  margin-bottom: 16px;
  background: var(--gradient-1);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 12px;
}

.hero-badges {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 24px;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ===== Tools Grid ===== */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.tool-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.tool-card-icon {
  width: 48px;
  height: 48px;
  background: var(--gradient-1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.tool-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
}

.tool-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== Tool Page ===== */
.tool-page { animation: fadeIn 0.3s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.tool-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  transition: var(--transition);
  background: none;
  cursor: pointer;
}

.back-btn:hover { color: var(--text-primary); border-color: var(--accent); }

.tool-title {
  font-size: 1.6rem;
  font-weight: 700;
}

.tool-desc {
  color: var(--text-secondary);
  margin-bottom: 24px;
  font-size: 0.95rem;
}

/* ===== Form Elements ===== */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  margin-bottom: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  transition: var(--transition);
  outline: none;
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.85rem;
  line-height: 1.6;
}

.form-select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238888a8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  font-family: inherit;
  text-decoration: none;
}

.btn-primary {
  background: var(--gradient-1);
  color: white;
}

.btn-primary:hover { opacity: 0.9; transform: translateY(-1px); }

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

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

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

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

.btn-sm { padding: 8px 16px; font-size: 0.8rem; }

.btn-block { width: 100%; }

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.btn-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

/* ===== Cards & Panels ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
}

.panel {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 20px;
}

/* ===== File Upload ===== */
.file-drop {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  background: var(--bg-input);
}

.file-drop:hover, .file-drop.dragover {
  border-color: var(--accent);
  background: rgba(176, 125, 79, 0.05);
}

.file-drop-icon { font-size: 2.5rem; margin-bottom: 12px; }
.file-drop-text { color: var(--text-secondary); font-size: 0.9rem; }
.file-drop-text strong { color: var(--text-primary); }

.file-input { display: none; }

/* ===== File List ===== */
.file-list {
  list-style: none;
  margin-top: 16px;
}

.file-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  font-size: 0.85rem;
}

.file-item-name {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-item-size { color: var(--text-muted); font-size: 0.8rem; }

.file-item-remove {
  background: none;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 1.1rem;
  padding: 4px;
  transition: var(--transition);
}

.file-item-remove:hover { opacity: 0.7; }

/* ===== Result / Output ===== */
.result-box {
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-top: 20px;
  position: relative;
}

.result-box pre {
  white-space: pre-wrap;
  word-break: break-all;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--text-primary);
  max-height: 400px;
  overflow-y: auto;
}

.copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.75rem;
  font-weight: 600;
  transition: var(--transition);
}

.copy-btn:hover { color: var(--text-primary); border-color: var(--accent); }

/* ===== Range Slider ===== */
.range-group {
  display: flex;
  align-items: center;
  gap: 16px;
}

.range-input {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 6px;
  background: var(--bg-input);
  border-radius: 3px;
  outline: none;
  border: 1px solid var(--border);
}

.range-input::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
}

.range-value {
  min-width: 48px;
  text-align: center;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent);
}

/* ===== Grid Layouts ===== */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

/* ===== Color Swatch ===== */
.color-swatch {
  width: 100%;
  height: 120px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 16px;
}

.color-values {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.color-value-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  font-family: 'SF Mono', monospace;
  font-size: 0.85rem;
}

/* ===== Diff View ===== */
.diff-container {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.8rem;
  line-height: 1.7;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: auto;
  max-height: 500px;
  background: var(--bg-input);
}

.diff-line { padding: 2px 16px; white-space: pre-wrap; }
.diff-added { background: rgba(76, 175, 80, 0.1); color: var(--success); }
.diff-removed { background: rgba(231, 76, 60, 0.1); color: var(--danger); }
.diff-unchanged { color: var(--text-muted); }

/* ===== Password Strength ===== */
.strength-bar {
  height: 6px;
  background: var(--bg-input);
  border-radius: 3px;
  overflow: hidden;
  margin-top: 12px;
}

.strength-fill {
  height: 100%;
  border-radius: 3px;
  transition: width 0.3s ease, background 0.3s ease;
}

.strength-text {
  font-size: 0.8rem;
  margin-top: 6px;
  font-weight: 600;
}

/* ===== QR Output ===== */
.qr-output {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: 32px;
  background: white;
  border-radius: var(--radius);
  margin-top: 20px;
}

.qr-output canvas { max-width: 100%; }

/* ===== Image Preview ===== */
.image-preview {
  max-width: 100%;
  max-height: 400px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  object-fit: contain;
  display: block;
  margin: 16px auto;
}

.image-info {
  display: flex;
  gap: 24px;
  padding: 12px 16px;
  background: var(--bg-input);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-secondary);
  justify-content: center;
  flex-wrap: wrap;
}

.image-info span { display: flex; align-items: center; gap: 6px; }
.image-info strong { color: var(--text-primary); }

/* ===== Checkbox / Toggle ===== */
.toggle-group {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.toggle-label { font-size: 0.9rem; color: var(--text-secondary); }

.toggle {
  position: relative;
  width: 44px;
  height: 24px;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  inset: 0;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  left: 2px;
  top: 2px;
  background: var(--text-secondary);
  border-radius: 50%;
  transition: var(--transition);
}

.toggle input:checked + .toggle-slider {
  background: var(--accent);
  border-color: var(--accent);
}

.toggle input:checked + .toggle-slider::before {
  transform: translateX(20px);
  background: white;
}

/* ===== Notification / Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  padding: 14px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 500;
  z-index: 1000;
  animation: slideUp 0.3s ease, fadeOut 0.3s ease 2.7s forwards;
  box-shadow: var(--shadow);
}

.toast.success { border-color: var(--success); }
.toast.error { border-color: var(--danger); }

@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

@keyframes fadeOut {
  to { opacity: 0; transform: translateY(-10px); }
}

/* ===== Tabs ===== */
.tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0;
}

.tab-btn {
  padding: 10px 20px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
  font-family: inherit;
}

.tab-btn:hover { color: var(--text-primary); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }

/* ===== Utility ===== */
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.text-sm { font-size: 0.8rem; }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--warning); }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-12 { gap: 12px; }
.gap-16 { gap: 16px; }
.hidden { display: none !important; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
}

.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.footer p { color: var(--text-secondary); font-size: 0.85rem; }
.footer-sub { margin-top: 8px; color: var(--text-muted); font-size: 0.8rem; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav { display: none; }
  .mobile-menu-btn { display: flex; }

  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }

  .tools-grid { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .grid-3 { grid-template-columns: 1fr; }

  .tool-header { flex-direction: column; align-items: flex-start; }
  .main { padding: 20px 16px; }
  .hero { padding: 32px 0 24px; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .btn-group { flex-direction: column; }
  .btn-group .btn { width: 100%; }
}