/* ===== CSS Variables ===== */
:root {
  --color-primary: #1a1a2e;
  --color-accent: #4d2df9;
  --color-accent-hover: #5a52e0;
  --color-bg: #ffffff;
  --color-card-bg: #f7f7f8;
  --color-card-border: #e8e8e8;
  --color-text: #1a1a2e;
  --color-text-secondary: #6b7280;
  --color-text-light: #9ca3af;
  --color-border: #e5e7eb;
  --color-dashed: #d1d5db;
  --color-success: #10b981;
  --color-danger: #ef4444;
  --color-warning: #f59e0b;
  --radius-card: 12px;
  --radius-btn: 8px;
  --radius-sm: 6px;
  --font-family: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --shadow-card: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-card-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
  --shadow-upload: 0 0 0 2px var(--color-accent);
  --max-width: 1400px;
  --transition: 0.2s ease;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ===== Navigation ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-card-border);
  padding: 0 24px;
}

.navbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: var(--color-primary);
}

.navbar-logo svg { flex-shrink: 0; }

.navbar-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-accent);
  background: rgba(108,99,255,0.08);
  transition: background var(--transition);
}

.lang-switch:hover {
  background: rgba(108,99,255,0.15);
}

.nav-home-link {
  font-size: 14px;
  color: var(--color-text-secondary);
  transition: color var(--transition);
}

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

.nav-links {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav-links a {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition);
  white-space: nowrap;
}

.nav-links a:hover {
  color: var(--color-primary);
}

.tutorial-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--color-accent);
  text-decoration: none;
  margin-top: 8px;
  transition: opacity var(--transition);
}

.tutorial-link:hover {
  opacity: 0.8;
}



/* ===== Hero Section ===== */
.hero {
  text-align: center;
  padding: 72px 24px 48px;
  max-width: var(--max-width);
  margin: 0 auto;
}

.hero h1 {
  font-size: 42px;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: 18px;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto 20px;
  line-height: 1.6;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  border-radius: 24px;
  background: #ecfdf5;
  color: #059669;
  font-size: 14px;
  font-weight: 500;
}

.hero-badge svg { flex-shrink: 0; }

/* ===== Tools Grid ===== */
.tools-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.tool-card {
  background: var(--color-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: box-shadow var(--transition), transform var(--transition);
  cursor: pointer;
}

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

.tool-card.featured {
  grid-column: span 2;
}

.tool-card-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  background: var(--color-card-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  flex-shrink: 0;
  transition: background var(--transition);
}

.tool-card-icon svg {
  width: 24px;
  height: 24px;
  stroke: var(--color-primary);
  stroke-width: 1.5;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: stroke var(--transition);
}

.tool-card:hover .tool-card-icon {
  background: var(--color-primary);
}

.tool-card:hover .tool-card-icon svg {
  stroke: #fff;
}

.tool-card.featured .tool-card-icon {
  width: 56px;
  height: 56px;
}

.tool-card.featured .tool-card-icon svg {
  width: 28px;
  height: 28px;
}

.tool-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 6px;
}

.tool-card.featured h3 {
  font-size: 18px;
}

.tool-card p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

.tool-card-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  font-weight: 700;
  color: var(--color-primary);
  transition: gap var(--transition);
}

.tool-card:hover .tool-card-btn { gap: 8px; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--color-card-border);
  padding: 40px 24px 32px;
  text-align: center;
  margin-top: 60px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 8px;
}

.footer-links a {
  font-size: 14px;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

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

.footer p {
  font-size: 13px;
  color: var(--color-text-light);
}

/* ===== Tool Page Layout ===== */
.tool-page {
  max-width: 1400px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.tool-header {
  text-align: center;
  margin-bottom: 36px;
}

.tool-header h1 {
  font-size: 30px;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.tool-header p {
  font-size: 16px;
  color: var(--color-text-secondary);
}

/* Upload Area */
.upload-area {
  border: 2px dashed var(--color-dashed);
  border-radius: var(--radius-card);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color var(--transition), box-shadow var(--transition);
  position: relative;
}

.upload-area:hover,
.upload-area.drag-over {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-upload);
}

.upload-area.drag-over {
  background: rgba(108,99,255,0.03);
}

.upload-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 16px;
  stroke: var(--color-text-light);
  stroke-width: 1.5;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.upload-area h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 4px;
}

.upload-area span {
  font-size: 13px;
  color: var(--color-text-light);
}

.upload-area .browse-link {
  color: var(--color-accent);
  font-weight: 600;
  text-decoration: underline;
}

.upload-area input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

/* File List */
.file-list {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.file-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
}

.file-item-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: #fef2f2;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.file-item-icon svg {
  width: 18px;
  height: 18px;
  stroke: #ef4444;
  stroke-width: 1.5;
  fill: none;
}

.file-item-info {
  flex: 1;
  min-width: 0;
}

.file-item-name {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-item-size {
  font-size: 12px;
  color: var(--color-text-light);
}

.file-item-remove {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-light);
  transition: background var(--transition), color var(--transition);
}

.file-item-remove:hover {
  background: #fef2f2;
  color: var(--color-danger);
}

/* Options Area */
.options-area {
  margin-top: 24px;
  padding: 20px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  background: var(--color-card-bg);
}

.options-area h3 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--color-primary);
}

.option-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.option-row:last-child { margin-bottom: 0; }

.option-row label {
  font-size: 14px;
  color: var(--color-text-secondary);
  min-width: 80px;
}

.option-row input[type="text"],
.option-row input[type="number"],
.option-row input[type="password"],
.option-row select {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-text);
  background: var(--color-bg);
  outline: none;
  transition: border-color var(--transition);
}

.option-row input:focus,
.option-row select:focus {
  border-color: var(--color-accent);
}

.option-row input[type="color"] {
  width: 40px;
  height: 36px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  padding: 2px;
  cursor: pointer;
}

.option-row input[type="range"] {
  flex: 1;
  accent-color: var(--color-accent);
}

/* Action Buttons */
.action-area {
  margin-top: 24px;
  max-width: 1400px;
  display: flex;
  gap: 12px;
  justify-content: center;
}

.btn-primary {
  padding: 12px 32px;
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius-btn);
  font-size: 15px;
  font-weight: 600;
  transition: background var(--transition), transform var(--transition);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px);
}

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

.btn-secondary {
  padding: 12px 24px;
  background: var(--color-card-bg);
  color: var(--color-text);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-btn);
  font-size: 15px;
  font-weight: 500;
  transition: background var(--transition);
}

.btn-secondary:hover { background: #e5e5e5; }

/* Privacy Notice */
.privacy-notice {
  margin-top: 32px;
  text-align: center;
  font-size: 13px;
  color: var(--color-text-light);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.privacy-notice svg {
  width: 14px;
  height: 14px;
  stroke: var(--color-text-light);
  stroke-width: 1.5;
  fill: none;
}

/* Progress / Status */
.progress-area {
  margin-top: 24px;
  text-align: center;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--color-card-bg);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 8px;
}

.progress-bar-fill {
  height: 100%;
  background: var(--color-accent);
  border-radius: 3px;
  transition: width 0.3s ease;
  width: 0%;
}

.progress-text {
  font-size: 13px;
  color: var(--color-text-secondary);
}

/* Sortable List (Merge) */
.sortable-list {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-width: 1400px;
}

.sortable-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  cursor: grab;
  user-select: none;
}

.sortable-item:active { cursor: grabbing; }

.sortable-handle {
  display: flex;
  flex-direction: column;
  gap: 2px;
  color: var(--color-text-light);
}

.sortable-handle svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
  stroke-width: 1.5;
  fill: none;
}

/* Backend Notice */
.backend-notice {
  margin-top: 24px;
  padding: 16px 20px;
  border: 1px solid #fde68a;
  border-radius: var(--radius-sm);
  background: #fffbeb;
  font-size: 14px;
  color: #92400e;
  text-align: center;
}

.backend-notice svg {
  width: 18px;
  height: 18px;
  stroke: #f59e0b;
  fill: none;
  stroke-width: 1.5;
  vertical-align: middle;
  margin-right: 6px;
}

/* Result / Download Area */
.result-area {
  max-width: 1400px;
  margin-top: 24px;
  padding: 20px;
  border: 1px solid #d1fae5;
  border-radius: var(--radius-sm);
  background: #ecfdf5;
  text-align: center;
}

.result-area h3 {
  font-size: 16px;
  font-weight: 600;
  color: #059669;
  margin-bottom: 8px;
}

.result-area p {
  font-size: 13px;
  color: #047857;
  margin-bottom: 16px;
}

/* Responsive */
@media (max-width: 1024px) {
  .tools-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .hero h1 { font-size: 30px; }
  .hero p { font-size: 16px; }
  .hero { padding: 48px 24px 32px; }

  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .tool-card { padding: 18px; }
  .tool-card.featured { grid-column: span 2; }
  .tool-card-icon { width: 40px; height: 40px; }
  .tool-card-icon svg { width: 20px; height: 20px; }

  .tool-page { padding: 24px 16px 60px; }
  .tool-header h1 { font-size: 24px; }
}

@media (max-width: 480px) {
  .navbar-inner { height: 56px; }
  .navbar-logo { font-size: 18px; }
  .hero h1 { font-size: 26px; }

  .tools-grid { gap: 10px; }
  .tool-card { padding: 14px; }
  .tool-card h3 { font-size: 14px; }
  .tool-card p { font-size: 12px; }
  .tool-card.featured { grid-column: span 2; }

  .action-area { flex-direction: column; }
  .btn-primary, .btn-secondary { width: 100%; text-align: center; }
}

/* Why Section */
.why-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px 60px;
  text-align: center;
}
.why-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}
.why-header p {
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  margin-bottom: 48px;
}
.why-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}
.why-card {
  background: #fff;
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 32px 24px;
  text-align: center;
}
.why-card-icon {
  width: 48px;
  height: 48px;
  background: var(--color-accent);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}
.why-card-icon svg {
  width: 24px;
  height: 24px;
  color: #fff;
}
.why-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
}
.why-card p {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  line-height: 1.5;
}
.why-tags {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}
.why-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--color-accent);
  border-radius: 24px;
  font-size: 0.85rem;
  color: var(--color-text);
  background: #fff;
}

@media (max-width: 768px) {
  .why-cards { grid-template-columns: 1fr; }
  .why-tags { gap: 10px; }
}

/* ===== Legal Page ===== */
.legal-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.legal-page h1 {
  font-size: 30px;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 8px;
  text-align: center;
}

.legal-page .legal-updated {
  text-align: center;
  font-size: 14px;
  color: var(--color-text-light);
  margin-bottom: 40px;
}

.legal-page h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-top: 36px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-card-border);
}

.legal-page h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin-top: 20px;
  margin-bottom: 8px;
}

.legal-page p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 12px;
}

.legal-page ul, .legal-page ol {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
  padding-left: 24px;
}

.legal-page li {
  margin-bottom: 6px;
}

.legal-page a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.legal-page a:hover {
  opacity: 0.8;
}

.legal-page hr {
  border: none;
  border-top: 1px solid var(--color-card-border);
  margin: 32px 0;
}

/* Sitemap grid */
.sitemap-section {
  margin-bottom: 36px;
}

.sitemap-section h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-card-border);
}

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 24px;
}

.sitemap-grid a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 15px;
  color: var(--color-accent);
  text-decoration: none;
  padding: 4px 0;
  transition: opacity var(--transition);
}

.sitemap-grid a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

.sitemap-grid a::before {
  content: "→";
  font-size: 13px;
  color: var(--color-text-light);
}

.sitemap-links-list {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.sitemap-links-list a {
  font-size: 15px;
  color: var(--color-accent);
  text-decoration: none;
  transition: opacity var(--transition);
}

.sitemap-links-list a:hover {
  opacity: 0.8;
  text-decoration: underline;
}

@media (max-width: 768px) {
  .legal-page { padding: 24px 16px 60px; }
  .legal-page h1 { font-size: 24px; }
  .legal-page h2 { font-size: 18px; }
  .sitemap-grid { grid-template-columns: 1fr; }
}