/**
 * public/css/tools/dev-tools-shared.css
 * Shared UI system for all Developer Tool pages — v2 premium
 * Matches the PDF-tools design language:
 *   rounded cards · soft shadows · clean spacing · hover animations
 *   touch-friendly buttons (≥ 44 px) · fully responsive
 */

/* ================================================================
   CUSTOM PROPERTIES — DEV TOOLS ACCENT
================================================================ */
:root {
  --dt-blue:      #3b82f6;
  --dt-blue-dk:   #2563eb;
  --dt-blue-lt:   #eff6ff;
  --dt-surface:   #ffffff;
  --dt-bg:        #f8fafc;
  --dt-border:    #e5e7eb;
  --dt-border-2:  #d1d5db;
  --dt-text:      #0f172a;
  --dt-muted:     #6b7280;
  --dt-radius:    16px;
  --dt-radius-sm: 10px;
  --dt-shadow-sm: 0 1px 3px rgba(0,0,0,.05), 0 4px 16px rgba(0,0,0,.07);
  --dt-shadow-md: 0 4px 12px rgba(0,0,0,.06), 0 16px 48px rgba(0,0,0,.08);
  --dt-shadow-hover: 0 8px 24px rgba(59,130,246,.15), 0 20px 60px rgba(0,0,0,.08);
  --dt-transition: all .22s cubic-bezier(.4,0,.2,1);
}

/* ================================================================
   HERO — neutral white to match PDF tools
   (overrides any inline gradient on .tool-hero-simple)
================================================================ */
.tool-hero-simple {
  background: var(--surface, #ffffff) !important;
  border-bottom-color: var(--border) !important;
}

/* ================================================================
   TOOL PAGE WRAPPER
================================================================ */
.dt-page-wrapper {
  padding: 40px 0 64px;
  background: var(--dt-bg);
  min-height: calc(100vh - 120px);
}

/* ================================================================
   MAIN TOOL CARD — premium container
================================================================ */
.dt-card {
  background: var(--dt-surface);
  border: 1px solid rgba(226,232,240,.8);
  border-radius: 20px;
  box-shadow: var(--dt-shadow-sm);
  overflow: hidden;
  margin-bottom: 32px;
  transition: box-shadow .25s;
  position: relative;
}
.dt-card:hover {
  box-shadow: var(--dt-shadow-md);
}

/* Card top accent stripe */
.dt-card::before {
  content: '';
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--dt-blue), #6366f1 50%, #8b5cf6);
  border-radius: 20px 20px 0 0;
}

/* ================================================================
   TOOLBAR INSIDE CARD
================================================================ */
.dt-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  padding: 16px 22px;
  background: var(--dt-bg);
  border-bottom: 1px solid var(--dt-border);
}
.dt-toolbar-left,
.dt-toolbar-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

/* ================================================================
   BUTTONS — touch-friendly (≥ 44 px tap target)
================================================================ */
.dt-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 10px;
  font-family: inherit;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--dt-transition);
  line-height: 1;
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}
.dt-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: currentColor;
  opacity: 0;
  transition: opacity .15s;
  border-radius: inherit;
}
.dt-btn:hover::after { opacity: .06; }
.dt-btn:active::after { opacity: .12; }

/* Primary */
.dt-btn--primary {
  background: var(--dt-blue);
  color: #fff;
  box-shadow: 0 2px 8px rgba(59,130,246,.3);
}
.dt-btn--primary:hover {
  background: var(--dt-blue-dk);
  box-shadow: 0 4px 16px rgba(59,130,246,.4);
  transform: translateY(-1px);
}
.dt-btn--primary:active { transform: translateY(0); }

/* Secondary */
.dt-btn--secondary {
  background: #e0e7ff;
  color: #3730a3;
  border: 1.5px solid #c7d2fe;
}
.dt-btn--secondary:hover {
  background: #c7d2fe;
  transform: translateY(-1px);
}

/* Ghost */
.dt-btn--ghost {
  background: #f3f4f6;
  color: #374151;
  border: 1.5px solid var(--dt-border);
}
.dt-btn--ghost:hover {
  background: #e9ecef;
  border-color: var(--dt-border-2);
  transform: translateY(-1px);
}

/* Copy / success */
.dt-btn--copy {
  background: #dcfce7;
  color: #15803d;
  border: 1.5px solid #bbf7d0;
}
.dt-btn--copy:hover {
  background: #bbf7d0;
  transform: translateY(-1px);
}
.dt-btn--copy.copied,
.dt-btn--copy.copied:hover {
  background: #15803d;
  color: #fff;
  border-color: #15803d;
  transform: translateY(0);
}

/* Reset / danger-lite */
.dt-btn--reset {
  background: #fff1f2;
  color: #be123c;
  border: 1.5px solid #fecdd3;
}
.dt-btn--reset:hover {
  background: #ffe4e6;
  border-color: #fca5a5;
  transform: translateY(-1px);
}

/* Icon-only */
.dt-btn--icon {
  min-height: 44px;
  min-width: 44px;
  padding: 0 12px;
}

/* ================================================================
   STATUS / RESULT BAR
================================================================ */
.dt-status {
  padding: 10px 22px;
  font-size: .83rem;
  font-weight: 600;
  border-bottom: 1px solid var(--dt-border);
  transition: background .2s, color .2s;
  display: flex;
  align-items: center;
  gap: 8px;
}
.dt-status::before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}
.dt-status--idle   { background: var(--dt-bg);   color: var(--dt-muted);  }
.dt-status--idle::before   { background: #d1d5db; }
.dt-status--ok     { background: #f0fdf4;  color: #15803d; }
.dt-status--ok::before     { background: #22c55e; }
.dt-status--error  { background: #fef2f2;  color: #b91c1c; }
.dt-status--error::before  { background: #ef4444; }
.dt-status--info   { background: #eff6ff;  color: #1d4ed8; }
.dt-status--info::before   { background: var(--dt-blue); }

/* ================================================================
   SPLIT PANES (input | output)
================================================================ */
.dt-panes {
  display: grid;
  grid-template-columns: 1fr 1fr;
}
@media (max-width: 680px) {
  .dt-panes { grid-template-columns: 1fr; }
}

.dt-pane {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--dt-border);
}
.dt-pane:last-child { border-right: none; }

.dt-pane-label {
  font-size: .7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--dt-muted);
  padding: 9px 18px;
  border-bottom: 1px solid var(--dt-border);
  background: #fafafa;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

/* ================================================================
   TEXTAREA / CODE INPUT
================================================================ */
.dt-textarea {
  flex: 1;
  border: none;
  outline: none;
  resize: none;
  padding: 18px;
  font-family: 'Fira Mono', 'Cascadia Code', 'Menlo', monospace;
  font-size: .83rem;
  line-height: 1.7;
  color: #1e293b;
  background: #fff;
  min-height: 240px;
  transition: background .15s;
}
.dt-textarea:focus {
  background: #fafeff;
}

/* ================================================================
   OUTPUT / PRE block
================================================================ */
.dt-output {
  flex: 1;
  overflow: auto;
  padding: 18px;
  margin: 0;
  font-family: 'Fira Mono', 'Cascadia Code', 'Menlo', monospace;
  font-size: .83rem;
  line-height: 1.7;
  background: #0f172a;
  color: #e2e8f0;
  white-space: pre;
  min-height: 240px;
}

/* Light output variant */
.dt-output--light {
  background: #f8fafc;
  color: #1e293b;
  border: 1.5px solid var(--dt-border);
  border-radius: var(--dt-radius-sm);
  padding: 16px 18px;
  white-space: pre-wrap;
  word-break: break-all;
}

/* ================================================================
   RESULT PANEL — highlighted display
================================================================ */
.dt-result-panel {
  margin: 24px;
  padding: 20px 24px;
  background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
  border: 2px solid #bae6fd;
  border-radius: var(--dt-radius);
  position: relative;
}
.dt-result-panel--success {
  background: linear-gradient(135deg, #f0fdf4, #dcfce7);
  border-color: #86efac;
}
.dt-result-panel--purple {
  background: linear-gradient(135deg, #faf5ff, #f3e8ff);
  border-color: #d8b4fe;
}

.dt-result-label {
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--dt-muted);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.dt-result-value {
  font-family: 'Fira Mono', 'Cascadia Code', 'Menlo', monospace;
  font-size: 1rem;
  font-weight: 600;
  color: var(--dt-text);
  word-break: break-all;
  line-height: 1.5;
}

.dt-result-actions {
  position: absolute;
  top: 14px;
  right: 14px;
  display: flex;
  gap: 6px;
}

/* ================================================================
   FORM CONTROLS — select, number input, range
================================================================ */
.dt-select {
  padding: 0 14px;
  height: 44px;
  border: 1.5px solid var(--dt-border-2);
  border-radius: 10px;
  font-size: .88rem;
  font-family: inherit;
  color: var(--dt-text);
  background: #fff;
  cursor: pointer;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}
.dt-select:focus {
  border-color: var(--dt-blue);
  box-shadow: 0 0 0 3px rgba(59,130,246,.15);
}

.dt-number-input {
  width: 72px;
  height: 44px;
  padding: 0 12px;
  border: 1.5px solid var(--dt-border-2);
  border-radius: 10px;
  font-size: .9rem;
  font-family: inherit;
  color: var(--dt-text);
  text-align: center;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
.dt-number-input:focus {
  border-color: var(--dt-blue);
  box-shadow: 0 0 0 3px rgba(59,130,246,.15);
}

/* Custom range slider */
.dt-range {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: #e5e7eb;
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}
.dt-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  background: var(--dt-blue);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(59,130,246,.4);
  transition: transform .15s, box-shadow .15s;
}
.dt-range::-webkit-slider-thumb:hover {
  transform: scale(1.18);
  box-shadow: 0 4px 12px rgba(59,130,246,.5);
}
.dt-range::-moz-range-thumb {
  width: 22px;
  height: 22px;
  background: var(--dt-blue);
  border-radius: 50%;
  border: none;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(59,130,246,.4);
}

/* Radio pill group */
.dt-radio-group {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.dt-radio-opt {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  min-height: 36px;
  padding: 0 14px;
  border: 1.5px solid var(--dt-border);
  border-radius: 8px;
  background: #f9fafb;
  font-size: .83rem;
  color: #374151;
  cursor: pointer;
  transition: var(--dt-transition);
  user-select: none;
}
.dt-radio-opt input[type=radio] { display: none; }
.dt-radio-opt:has(input:checked) {
  border-color: var(--dt-blue);
  background: var(--dt-blue-lt);
  color: #1d4ed8;
  font-weight: 600;
}
.dt-radio-opt:hover {
  border-color: #93c5fd;
  background: #f0f7ff;
}

/* Checkbox option */
.dt-check-opt {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  font-size: .88rem;
  color: #374151;
  cursor: pointer;
  user-select: none;
}
.dt-check-opt input[type=checkbox] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--dt-blue);
}

/* ================================================================
   STATS / METRIC GRID
================================================================ */
.dt-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 12px;
  padding: 20px 24px;
}

.dt-stat {
  background: #f8fafc;
  border: 1px solid var(--dt-border);
  border-radius: 12px;
  padding: 14px 12px;
  text-align: center;
  transition: var(--dt-transition);
}
.dt-stat:hover {
  border-color: #93c5fd;
  background: var(--dt-blue-lt);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59,130,246,.1);
}
.dt-stat-val {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--dt-text);
  line-height: 1;
  margin-bottom: 5px;
  font-family: 'Sora', sans-serif;
}
.dt-stat-label {
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--dt-muted);
}

/* ================================================================
   BODY SECTION
================================================================ */
.dt-body {
  padding: 24px;
}
.dt-body + .dt-body {
  border-top: 1px solid var(--dt-border);
}

.dt-section-title {
  font-size: .78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--dt-muted);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ================================================================
   LIST ITEMS (UUID list, etc.)
================================================================ */
.dt-item-list {
  display: flex;
  flex-direction: column;
  gap: 7px;
  list-style: none;
  padding: 0;
  margin: 0;
}
.dt-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 16px;
  background: #f8fafc;
  border: 1.5px solid var(--dt-border);
  border-radius: 10px;
  transition: var(--dt-transition);
}
.dt-item:hover {
  border-color: #bfdbfe;
  background: #f0f9ff;
  transform: translateX(2px);
}
.dt-item-val {
  font-family: 'Fira Mono', 'Cascadia Code', 'Menlo', monospace;
  font-size: .88rem;
  color: #1e293b;
  flex: 1;
  word-break: break-all;
  letter-spacing: .02em;
}
.dt-item-copy {
  padding: 5px 14px;
  min-height: 34px;
  border-radius: 7px;
  border: 1.5px solid var(--dt-border);
  background: #fff;
  color: #374151;
  font-size: .78rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--dt-transition);
  flex-shrink: 0;
  font-family: inherit;
}
.dt-item-copy:hover {
  border-color: #93c5fd;
  background: var(--dt-blue-lt);
  color: var(--dt-blue);
}
.dt-item-copy.copied {
  background: #15803d;
  color: #fff;
  border-color: #15803d;
}

/* ================================================================
   TABS
================================================================ */
.dt-tabs {
  display: flex;
  gap: 0;
  padding: 0 22px;
  background: #f8fafc;
  border-bottom: 1.5px solid var(--dt-border);
  overflow-x: auto;
  scrollbar-width: none;
}
.dt-tabs::-webkit-scrollbar { display: none; }

.dt-tab {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 0 18px;
  min-height: 48px;
  font-size: .88rem;
  font-weight: 600;
  color: var(--dt-muted);
  background: none;
  border: none;
  border-bottom: 2.5px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: color .15s, border-color .15s;
  font-family: inherit;
  margin-bottom: -1.5px;
}
.dt-tab:hover {
  color: var(--dt-blue);
}
.dt-tab--active {
  color: var(--dt-blue);
  border-bottom-color: var(--dt-blue);
}

/* ================================================================
   STRENGTH / PROGRESS BAR
================================================================ */
.dt-strength-bar {
  height: 6px;
  background: #e5e7eb;
  border-radius: 3px;
  overflow: hidden;
  flex: 1;
}
.dt-strength-fill {
  height: 100%;
  border-radius: 3px;
  transition: width .4s cubic-bezier(.4,0,.2,1), background .4s;
  width: 0;
}
.dt-strength-fill[data-level="1"] { width: 25%; background: #ef4444; }
.dt-strength-fill[data-level="2"] { width: 50%; background: #f97316; }
.dt-strength-fill[data-level="3"] { width: 75%; background: #eab308; }
.dt-strength-fill[data-level="4"] { width: 100%; background: #22c55e; }

/* ================================================================
   PASSWORD DISPLAY
================================================================ */
.dt-pwd-display {
  font-family: 'Fira Mono', 'Cascadia Code', 'Menlo', monospace;
  font-size: 1.1rem;
  font-weight: 600;
  background: #f8fafc;
  border: 2px solid var(--dt-border);
  border-radius: var(--dt-radius-sm);
  padding: 18px 20px;
  color: var(--dt-text);
  word-break: break-all;
  line-height: 1.5;
  letter-spacing: .04em;
  flex: 1;
  min-height: 64px;
  display: flex;
  align-items: center;
  transition: border-color .2s;
}
.dt-pwd-display:not(:empty) {
  border-color: #93c5fd;
  background: var(--dt-blue-lt);
}

/* ================================================================
   CHARSET CHECKBOX GRID
================================================================ */
.dt-charset-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 10px;
  padding: 20px 24px;
}

.dt-charset-opt {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: #f8fafc;
  border: 1.5px solid var(--dt-border);
  border-radius: 10px;
  cursor: pointer;
  transition: var(--dt-transition);
  user-select: none;
}
.dt-charset-opt input { display: none; }
.dt-charset-opt:has(input:checked) {
  background: var(--dt-blue-lt);
  border-color: #93c5fd;
}
.dt-charset-opt:hover {
  border-color: #93c5fd;
  background: #f0f7ff;
}
.dt-charset-code {
  font-family: 'Fira Mono', monospace;
  font-size: .85rem;
  font-weight: 700;
  color: var(--dt-blue);
  background: #fff;
  border: 1.5px solid #bfdbfe;
  border-radius: 6px;
  padding: 3px 8px;
  min-width: 36px;
  text-align: center;
  flex-shrink: 0;
}
.dt-charset-name {
  font-size: .85rem;
  font-weight: 600;
  color: #374151;
}

/* ================================================================
   RELATED TOOLS SECTION
================================================================ */
.dt-related {
  margin-top: 40px;
}
.dt-related-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--dt-text);
  margin: 0 0 18px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--dt-border);
  letter-spacing: -.01em;
}
.dt-related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}
.dt-related-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 16px;
  background: var(--dt-surface);
  border: 1.5px solid var(--dt-border);
  border-radius: 14px;
  text-decoration: none;
  color: inherit;
  transition: var(--dt-transition);
  box-shadow: 0 1px 4px rgba(0,0,0,.04);
}
.dt-related-card:hover {
  border-color: #93c5fd;
  box-shadow: 0 6px 20px rgba(59,130,246,.12);
  transform: translateY(-2px);
  background: var(--dt-blue-lt);
}
.dt-related-card-icon {
  width: 44px;
  height: 44px;
  border-radius: 11px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.dt-related-card-body h3 {
  font-size: .9rem;
  font-weight: 700;
  color: var(--dt-text);
  margin: 0 0 3px;
}
.dt-related-card-body p {
  font-size: .78rem;
  color: var(--dt-muted);
  margin: 0;
  line-height: 1.4;
}
.dt-related-arrow {
  margin-left: auto;
  color: var(--dt-blue);
  opacity: .4;
  font-size: 1rem;
  font-weight: 700;
  transition: opacity .2s, transform .2s;
}
.dt-related-card:hover .dt-related-arrow {
  opacity: 1;
  transform: translateX(3px);
}

/* ================================================================
   INDEX PAGE — TOOLS GRID
================================================================ */
.dt-index-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding: 40px 0;
}
@media (max-width: 900px) {
  .dt-index-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 580px) {
  .dt-index-grid { grid-template-columns: 1fr; }
}

.dt-index-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  background: var(--dt-surface);
  border: 1.5px solid var(--dt-border);
  border-radius: 18px;
  padding: 26px 22px;
  text-decoration: none;
  color: inherit;
  transition: var(--dt-transition);
  box-shadow: 0 2px 8px rgba(0,0,0,.04);
  position: relative;
  overflow: hidden;
}
.dt-index-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--dt-blue), #6366f1);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s cubic-bezier(.4,0,.2,1);
}
.dt-index-card:hover {
  border-color: #93c5fd;
  box-shadow: 0 8px 28px rgba(59,130,246,.14);
  transform: translateY(-4px);
  background: var(--dt-blue-lt);
}
.dt-index-card:hover::after {
  transform: scaleX(1);
}

.dt-index-card-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: transform .2s cubic-bezier(.34,1.56,.64,1);
}
.dt-index-card:hover .dt-index-card-icon {
  transform: scale(1.1) rotate(-3deg);
}
.dt-index-card-body { flex: 1; }
.dt-index-card-body h2 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--dt-text);
  margin: 0 0 7px;
}
.dt-index-card-body p {
  font-size: .85rem;
  color: var(--dt-muted);
  line-height: 1.6;
  margin: 0;
}
.dt-index-arrow {
  align-self: flex-end;
  font-size: 1.1rem;
  color: var(--dt-blue);
  font-weight: 700;
  opacity: .3;
  transition: opacity .2s, transform .2s;
}
.dt-index-card:hover .dt-index-arrow {
  opacity: 1;
  transform: translateX(4px);
}

/* ================================================================
   RESPONSIVE — TABLET + MOBILE
================================================================ */
@media (max-width: 768px) {
  .dt-toolbar {
    padding: 12px 16px;
    gap: 8px;
  }
  .dt-btn {
    min-height: 48px;
    font-size: .9rem;
    padding: 0 16px;
  }
  .dt-body {
    padding: 18px 16px;
  }
  .dt-stats-grid {
    padding: 16px;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
  }
  .dt-charset-grid {
    padding: 16px;
    grid-template-columns: 1fr 1fr;
  }
  .dt-result-panel {
    margin: 16px;
  }
  .dt-related-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .dt-btn {
    min-height: 52px;
    padding: 0 14px;
    font-size: .88rem;
  }
  .dt-tab {
    min-height: 52px;
    padding: 0 14px;
  }
  .dt-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .dt-charset-grid {
    grid-template-columns: 1fr;
  }
  .dt-related-grid {
    grid-template-columns: 1fr;
  }
  .dt-radio-group {
    gap: 6px;
  }
  .dt-radio-opt {
    min-height: 42px;
    padding: 0 12px;
    font-size: .82rem;
  }
  .dt-select,
  .dt-number-input {
    min-height: 48px;
    height: 48px;
  }
}

/* ================================================================
   UTILITY
================================================================ */
.dt-divider {
  height: 1px;
  background: var(--dt-border);
  margin: 0;
}
.dt-label {
  font-size: .83rem;
  font-weight: 700;
  color: #374151;
}
.dt-hint {
  font-size: .78rem;
  color: var(--dt-muted);
  line-height: 1.5;
}
.dt-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.dt-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
}