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

:root {
  --bg-primary: #0f1117;
  --bg-secondary: #1a1d27;
  --bg-tertiary: #242833;
  --bg-card: #1e2130;
  --border: #2e3348;
  --border-focus: #d97706;
  --text-primary: #e8e6e3;
  --text-secondary: #9ca3af;
  --text-muted: #6b7280;
  --accent: #d97706;
  --accent-hover: #f59e0b;
  --accent-light: rgba(217, 119, 6, 0.12);
  --accent-glow: rgba(245, 158, 11, 0.25);
  --success: #22c55e;
  --danger: #ef4444;
  --info: #3b82f6;
  --diff-add: rgba(34, 197, 94, 0.15);
  --diff-del: rgba(239, 68, 68, 0.15);
  --diff-add-text: #4ade80;
  --diff-del-text: #f87171;
  --radius: 10px;
  --radius-lg: 14px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.35);
  --transition: 0.2s ease;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

::selection {
  background: var(--accent);
  color: #000;
}

/* ===== HEADER ===== */
.site-header {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(26, 29, 39, 0.88);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  transition: opacity var(--transition);
}

.logo:hover {
  color: var(--text-primary);
  opacity: 0.85;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent), var(--accent-hover));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: #000;
  font-weight: 800;
  flex-shrink: 0;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.header-nav a {
  color: var(--text-secondary);
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition);
}

.header-nav a:hover,
.header-nav a.active {
  color: var(--accent);
  background: var(--accent-light);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem;
}

/* ===== AD SLOTS ===== */
.ad-slot {
  max-width: var(--max-width);
  margin: 1rem auto;
  padding: 0 1.25rem;
}

.ad-slot > div {
  background: var(--bg-tertiary);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ===== MAIN CONTENT ===== */
.main-content {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.25rem;
  width: 100%;
}

/* ===== TOOL CONTAINER ===== */
.tool-hero {
  text-align: center;
  margin-bottom: 2.5rem;
}

.tool-hero h1 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 0.6rem;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--text-primary), var(--accent-hover));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tool-hero p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.tool-card:hover {
  border-color: rgba(46, 51, 72, 0.8);
}

.tool-card h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

/* ===== FORM ELEMENTS ===== */
label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

textarea {
  width: 100%;
  min-height: 180px;
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.95rem;
  padding: 1rem;
  resize: vertical;
  transition: border-color var(--transition), box-shadow var(--transition);
  line-height: 1.7;
}

textarea:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

textarea::placeholder {
  color: var(--text-muted);
  opacity: 0.7;
}

textarea.mono {
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

input[type="number"],
select {
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  padding: 0.6rem 0.9rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

input[type="number"]:focus,
select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

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='%239ca3af' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2rem;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 1.2rem;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  background: var(--bg-tertiary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  user-select: none;
}

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

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

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-hover));
  border-color: transparent;
  color: #000;
  font-weight: 700;
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-hover), #fbbf24);
  color: #000;
  box-shadow: 0 4px 20px var(--accent-glow);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 8px var(--accent-glow);
}

.btn-sm {
  padding: 0.4rem 0.8rem;
  font-size: 0.8rem;
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
}

/* ===== STATS DISPLAY ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
}

.stat-item {
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1rem;
  text-align: center;
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.stat-item:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.stat-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--accent-hover);
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 0.35rem;
  font-weight: 500;
}

/* ===== TABS ===== */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1.5px solid var(--border);
  margin-bottom: 1.25rem;
  overflow-x: auto;
}

.tab-btn {
  padding: 0.7rem 1.2rem;
  background: none;
  border: none;
  border-bottom: 2.5px solid transparent;
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.03);
}

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

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* ===== DIFF ===== */
.diff-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.diff-output {
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.8;
  overflow-x: auto;
  min-height: 200px;
  white-space: pre-wrap;
  word-break: break-word;
}

.diff-line {
  padding: 1px 6px;
  border-radius: 3px;
  display: block;
}

.diff-add {
  background: var(--diff-add);
  color: var(--diff-add-text);
}

.diff-del {
  background: var(--diff-del);
  color: var(--diff-del-text);
}

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

.diff-stats {
  display: flex;
  gap: 1.5rem;
  font-size: 0.85rem;
  margin-top: 1rem;
  font-weight: 500;
}

.diff-stat-add { color: var(--diff-add-text); }
.diff-stat-del { color: var(--diff-del-text); }
.diff-stat-same { color: var(--text-muted); }

/* ===== TOOLBAR ===== */
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.toolbar-right {
  display: flex;
  gap: 0.4rem;
}

/* ===== INLINE FORM ROW ===== */
.form-row {
  display: flex;
  gap: 1rem;
  align-items: flex-end;
  flex-wrap: wrap;
  margin-bottom: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

/* ===== TOAST ===== */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--bg-tertiary);
  border: 1px solid var(--accent);
  color: var(--text-primary);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  opacity: 0;
  transition: all 0.3s ease;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== INFO SECTION ===== */
.info-section {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.info-section h2 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.info-section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.info-section p {
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  line-height: 1.75;
}

.info-section ul {
  color: var(--text-secondary);
  margin-left: 1.5rem;
  margin-bottom: 1rem;
  line-height: 1.9;
}

.info-section li {
  margin-bottom: 0.25rem;
}

/* ===== MORE TOOLS SECTION ===== */
.more-tools {
  margin-top: 3rem;
  padding: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

.more-tools h2 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
  text-align: center;
  letter-spacing: -0.01em;
}

.more-tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.75rem;
}

.more-tools-grid a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 1rem;
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition);
  text-decoration: none;
}

.more-tools-grid a:hover {
  border-color: var(--accent);
  color: var(--accent-hover);
  background: var(--accent-light);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.more-tools-grid .mt-icon {
  width: 28px;
  height: 28px;
  background: var(--accent-light);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
}

/* ===== FOOTER ===== */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 2rem 1.25rem;
  margin-top: auto;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

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

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--text-secondary);
  transition: color var(--transition);
}

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

/* ===== INDEX PAGE ===== */
.hero {
  text-align: center;
  padding: 3.5rem 0 2.5rem;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1rem;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--accent-hover));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.7;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.tool-link-card {
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.tool-link-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, var(--accent-light), transparent 60%);
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.tool-link-card:hover::before {
  opacity: 1;
}

.tool-link-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent), 0 8px 32px rgba(0,0,0,0.3);
  transform: translateY(-4px);
}

.tool-link-card .card-icon {
  width: 44px;
  height: 44px;
  background: var(--accent-light);
  border: 1px solid rgba(217, 119, 6, 0.2);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent);
  position: relative;
  z-index: 1;
  transition: background var(--transition), border-color var(--transition);
}

.tool-link-card:hover .card-icon {
  background: rgba(217, 119, 6, 0.2);
  border-color: rgba(217, 119, 6, 0.4);
}

.tool-link-card h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  position: relative;
  z-index: 1;
}

.tool-link-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  position: relative;
  z-index: 1;
}

.tool-link-card .card-arrow {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap var(--transition), color var(--transition);
  position: relative;
  z-index: 1;
}

.tool-link-card:hover .card-arrow {
  gap: 0.6rem;
  color: var(--accent-hover);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .tool-hero h1 { font-size: 1.5rem; }
  .tools-grid { grid-template-columns: 1fr; }
  .diff-container { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .stat-value { font-size: 1.35rem; }
  .tool-card { padding: 1.25rem; }
  .more-tools { padding: 1.5rem; }
  .more-tools-grid { grid-template-columns: 1fr 1fr; }

  .header-nav {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 0.5rem;
  }

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

  .header-nav a {
    padding: 0.7rem 1rem;
  }

  .nav-toggle {
    display: block;
  }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .hero p { font-size: 1rem; }
  .btn-group { gap: 0.35rem; }
  .btn { padding: 0.5rem 0.8rem; font-size: 0.8rem; }
  .form-row { flex-direction: column; align-items: stretch; }
  .more-tools-grid { grid-template-columns: 1fr; }
}