/* ============================================================
   DevBox - Design System
   ============================================================ */

/* --- CSS Variables --- */
:root {
  /* Colors */
  --color-text: #1e293b;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-bg: #f8fafc;
  --color-bg-card: #ffffff;
  --color-bg-elevated: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;

  --color-primary: #2563EB;
  --color-primary-light: #3B82F6;
  --color-primary-bg: #EFF6FF;
  --color-primary-hover: #1D4ED8;

  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  --color-error: #ef4444;
  --color-error-bg: #fef2f2;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.08);
  --shadow-xl: 0 16px 48px rgba(0,0,0,0.1);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Layout */
  --nav-height: 64px;
  --sidebar-width: 240px;
  --content-max-width: 1200px;
}

/* --- Dark Mode --- */
[data-theme="dark"] {
  --color-text: #e2e8f0;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  --color-bg: #0f172a;
  --color-bg-card: #1e293b;
  --color-bg-elevated: #334155;
  --color-border: #334155;
  --color-border-light: #1e293b;
  --color-primary-bg: #1e3a5f;
  --color-success-bg: #14532d;
  --color-warning-bg: #451a03;
  --color-error-bg: #450a0a;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.35);
  --shadow-xl: 0 16px 48px rgba(0,0,0,0.4);
}

[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.85);
  border-bottom-color: var(--color-border);
}

[data-theme="dark"] .sidebar {
  background: var(--color-bg-card);
  border-right-color: var(--color-border);
}

[data-theme="dark"] .icon-encode { background: #1e3a5f; }
[data-theme="dark"] .icon-data { background: #14532d; }
[data-theme="dark"] .icon-time { background: #451a03; }
[data-theme="dark"] .icon-security { background: #450a0a; }
[data-theme="dark"] .icon-dev { background: #0c4a6e; }
[data-theme="dark"] .icon-text { background: #3b0764; }
[data-theme="dark"] .icon-color { background: #4c0519; }
[data-theme="dark"] .icon-hash { background: #14532d; }

[data-theme="dark"] .match-highlight { background: #854d0e; color: #fef9c3; }
[data-theme="dark"] .match-highlight:nth-child(even) { background: #166534; color: #bbf7d0; }

[data-theme="dark"] .hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
}

[data-theme="dark"] .footer {
  border-top-color: var(--color-border);
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

html {
  scrollbar-gutter: stable;
}

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

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

img {
  max-width: 100%;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p {
  color: var(--color-text-secondary);
  line-height: 1.7;
}

code, .mono {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

/* --- Navbar --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  display: flex;
  align-items: center;
  padding: 0 var(--space-xl);
}

.navbar-inner {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
  gap: var(--space-lg);
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text);
  white-space: nowrap;
  text-decoration: none;
}

.navbar-logo .logo-icon {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.navbar-logo .logo-icon svg {
  display: block;
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-left: auto;
}

.navbar-actions a,
.navbar-actions button {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  font-size: 18px;
}

.navbar-actions a:hover,
.navbar-actions button:hover {
  background: var(--color-bg-elevated);
  color: var(--color-text);
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* --- Hero Section --- */
.hero {
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-2xl);
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 6px 16px;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: 0.8125rem;
  font-weight: 500;
  margin-bottom: var(--space-lg);
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-md);
  background: linear-gradient(135deg, var(--color-text) 0%, var(--color-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto var(--space-xl);
}

/* --- Category Tags --- */
.categories {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0 var(--space-xl);
  margin-bottom: var(--space-xl);
  flex-wrap: wrap;
}

.category-tag {
  padding: 8px 20px;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.category-tag:hover {
  border-color: var(--color-primary-light);
  color: var(--color-primary);
  background: var(--color-primary-bg);
}

.category-tag.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

/* --- Tool Cards Grid --- */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-lg);
  padding-bottom: var(--space-3xl);
}

.tool-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-lg);
  transition: all var(--transition-normal);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 0;
  text-decoration: none;
  color: inherit;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), #6366f1);
  opacity: 0;
  transition: opacity var(--transition-normal);
  z-index: 1;
}

.tool-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.tool-card:hover::before {
  opacity: 1;
  height: 3px;
}

.tool-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-sm);
}

.tool-card-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 17px;
  flex-shrink: 0;
  transition: transform var(--transition-normal);
}

.tool-card:hover .tool-card-icon {
  transform: scale(1.06);
}

.tool-card-tag {
  padding: 3px 8px;
  border-radius: var(--radius-full);
  font-size: 0.65rem;
  font-weight: 500;
  background: var(--color-bg-elevated);
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}

.tool-card-body {
  flex: 1;
}

.tool-card-title {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
  line-height: 1.4;
}

.tool-card-desc {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}


/* Card icon colors */
.icon-encode { background: #eff6ff; color: #2563eb; }
.icon-data { background: #ecfdf5; color: #10b981; }
.icon-time { background: #fffbeb; color: #f59e0b; }
.icon-security { background: #fef2f2; color: #ef4444; }
.icon-dev { background: #f0f9ff; color: #0ea5e9; }
.icon-text { background: #faf5ff; color: #a855f7; }
.icon-color { background: #fff1f2; color: #f43f5e; }
.icon-hash { background: #f0fdf4; color: #22c55e; }

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  margin-top: auto;
}

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

.footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
}

/* ============================================================
   Tool Page Layout
   ============================================================ */

.tool-page {
  display: flex;
  min-height: 100vh;
  padding-top: var(--nav-height);
}

/* --- Sidebar (collapsible) --- */
.sidebar {
  width: var(--sidebar-width);
  position: fixed;
  top: var(--nav-height);
  left: 0;
  bottom: 0;
  background: var(--color-bg-card);
  border-right: 1px solid var(--color-border);
  overflow: hidden;
  z-index: 100;
  transition: width var(--transition-normal);
}

.sidebar.collapsed {
  width: 48px;
}

.sidebar.collapsed .sidebar-inner {
  display: none;
}

.sidebar-inner {
  height: 100%;
  padding: var(--space-lg) 0 64px;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: transparent transparent;
  transition: scrollbar-color var(--transition-fast);
}

.sidebar-inner:hover {
  scrollbar-color: var(--color-border) transparent;
}

.sidebar-inner::-webkit-scrollbar {
  width: 4px;
}

.sidebar-inner::-webkit-scrollbar-thumb {
  background: transparent;
  border-radius: 2px;
  transition: background var(--transition-fast);
}

.sidebar-inner:hover::-webkit-scrollbar-thumb {
  background: var(--color-border);
}

/* Collapse button: sits outside sidebar overflow via fixed positioning */
.sidebar-collapse-btn {
  position: fixed;
  bottom: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  padding-left: var(--space-md);
  background: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-normal);
  z-index: 101;
}

.sidebar-collapse-btn:hover {
  color: var(--color-text);
  background: var(--color-bg-elevated);
}

.sidebar-collapse-btn svg {
  transition: transform var(--transition-normal);
  flex-shrink: 0;
}

.sidebar.collapsed .sidebar-collapse-btn {
  width: 48px;
  justify-content: center;
  padding-left: 0;
  border-right: 1px solid var(--color-border);
}

.sidebar.collapsed .sidebar-collapse-btn svg {
  transform: rotate(180deg);
}

/* Mobile: collapsed by default */
@media (max-width: 768px) {
  .sidebar {
    width: 48px;
    border-right: 1px solid var(--color-border);
  }

  .sidebar .sidebar-inner {
    display: none;
  }

  .sidebar:not(.collapsed) {
    width: var(--sidebar-width);
    box-shadow: var(--shadow-xl);
    border-right: none;
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
  }

  .sidebar:not(.collapsed) .sidebar-inner {
    display: block;
  }

  .sidebar-collapse-btn {
    width: 48px;
    justify-content: center;
    padding-left: 0;
  }

  .sidebar:not(.collapsed) .sidebar-collapse-btn {
    width: var(--sidebar-width);
    justify-content: flex-start;
    padding-left: var(--space-md);
    border-right: none;
  }
}

.sidebar-section {
  margin-bottom: var(--space-lg);
}

.sidebar-label {
  padding: 0 var(--space-lg);
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 8px var(--space-lg);
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  text-decoration: none;
  border-left: 3px solid transparent;
}

.sidebar-link:hover {
  background: var(--color-bg-elevated);
  color: var(--color-text);
}

.sidebar-link.active {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

.sidebar-link .link-icon {
  font-size: 16px;
  width: 20px;
  text-align: center;
  flex-shrink: 0;
}

/* --- Tool Content --- */
.tool-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: var(--space-xl) var(--space-xl) var(--space-3xl);
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: margin-left var(--transition-normal);
}

.tool-content > * {
  width: 100%;
  max-width: 960px;
}

.sidebar.collapsed ~ .tool-page .tool-content,
body.sidebar-collapsed .tool-content {
  margin-left: 48px;
}

@media (max-width: 768px) {
  .tool-content {
    margin-left: 48px;
  }

  .sidebar:not(.collapsed) ~ .tool-page .tool-content {
    margin-left: var(--sidebar-width);
  }
}

.tool-header {
  margin-bottom: var(--space-xl);
}

.tool-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.tool-header h1 .tool-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.tool-header p {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
}

/* --- Tool Panel --- */
.tool-panel {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
}

.panel-title {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.panel-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.panel-body {
  padding: var(--space-lg);
}

/* --- Tool I/O Layout --- */
.tool-io {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
}

.tool-io.full-width {
  grid-template-columns: 1fr;
}

.io-box {
  display: flex;
  flex-direction: column;
}

.io-label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.io-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  align-self: center;
  color: var(--color-text-muted);
  font-size: 20px;
}

/* --- Form Elements --- */
.input-field,
.textarea-field {
  width: 100%;
  padding: 10px var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 0.875rem;
  outline: none;
  transition: all var(--transition-fast);
}

.input-field:focus,
.textarea-field:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-bg);
  background: var(--color-bg-card);
}

.textarea-field {
  min-height: 200px;
  resize: vertical;
  font-family: var(--font-mono);
  line-height: 1.6;
}

.select-field {
  padding: 10px var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 0.875rem;
  outline: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2394a3b8' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.select-field:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-bg);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition-fast);
  white-space: nowrap;
  line-height: 1;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  color: #fff;
  box-shadow: 0 4px 12px rgba(37,99,235,0.3);
}

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

.btn-ghost {
  color: var(--color-text-secondary);
  padding: 8px 12px;
}
.btn-ghost:hover {
  background: var(--color-bg-elevated);
  color: var(--color-text);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 0.8125rem;
}

.btn-icon {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: var(--radius-md);
}

.btn-group {
  display: flex;
  gap: 0;
}

.btn-group .btn {
  border-radius: 0;
}

.btn-group .btn:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.btn-group .btn:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.btn-group .btn + .btn {
  margin-left: -1px;
}

.btn-group .btn.active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  z-index: 1;
}

/* --- Swap Button --- */
.swap-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--color-text-secondary);
  font-size: 18px;
  flex-shrink: 0;
}

.swap-btn:hover {
  background: var(--color-primary-bg);
  border-color: var(--color-primary-light);
  color: var(--color-primary);
  transform: rotate(180deg);
}

/* --- Toast --- */
.toast-container {
  position: fixed;
  top: calc(var(--nav-height) + var(--space-md));
  right: var(--space-lg);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  animation: toast-in 0.3s ease;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  max-width: 360px;
}

.toast-success {
  background: var(--color-success);
  color: #fff;
}

.toast-error {
  background: var(--color-error);
  color: #fff;
}

.toast-info {
  background: var(--color-primary);
  color: #fff;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(40px); }
  to { opacity: 1; transform: translateX(0); }
}

.toast-out {
  animation: toast-out 0.3s ease forwards;
}

@keyframes toast-out {
  from { opacity: 1; transform: translateX(0); }
  to { opacity: 0; transform: translateX(40px); }
}

/* --- Result Box --- */
.result-box {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  word-break: break-all;
  white-space: pre-wrap;
  min-height: 200px;
  max-height: 400px;
  overflow-y: auto;
  color: var(--color-text);
}

.result-box.success {
  border-color: var(--color-success);
  background: var(--color-success-bg);
}

.result-box.error {
  border-color: var(--color-error);
  background: var(--color-error-bg);
  color: var(--color-error);
}

/* --- Info Cards --- */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.info-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.info-card-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 4px;
}

.info-card-value {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  font-family: var(--font-mono);
}

/* --- Color Preview --- */
.color-preview {
  width: 100%;
  height: 120px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  margin-bottom: var(--space-md);
  transition: background-color var(--transition-fast);
}

/* --- File Upload Zone --- */
.upload-zone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: var(--color-bg);
}

.upload-zone:hover {
  border-color: var(--color-primary-light);
  background: var(--color-primary-bg);
}

.upload-zone.dragover {
  border-color: var(--color-primary);
  background: var(--color-primary-bg);
}

.upload-zone-icon {
  font-size: 40px;
  color: var(--color-text-muted);
  margin-bottom: var(--space-md);
}

.upload-zone-text {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xs);
}

.upload-zone-hint {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* --- Image Preview --- */
.image-preview {
  max-width: 100%;
  max-height: 300px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  margin-top: var(--space-md);
  object-fit: contain;
}

/* --- Empty State --- */
.empty-state {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl);
  color: var(--color-text-muted);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: var(--space-md);
}

.empty-state-text {
  font-size: 0.9375rem;
}

/* --- Table --- */
.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th,
.data-table td {
  padding: 10px var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.875rem;
}

.data-table th {
  font-weight: 600;
  color: var(--color-text-secondary);
  background: var(--color-bg-elevated);
  font-size: 0.8125rem;
}

.data-table td {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
}

.data-table tr:last-child td {
  border-bottom: none;
}

/* --- Tabs --- */
.tabs {
  display: flex;
  border-bottom: 1px solid var(--color-border);
  gap: 0;
  margin-bottom: var(--space-lg);
}

.tab {
  padding: 10px 20px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
  margin-bottom: -1px;
}

.tab:hover {
  color: var(--color-text);
}

.tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

/* --- JWT Specific --- */
.jwt-section {
  margin-bottom: var(--space-lg);
}

.jwt-part-label {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.jwt-header { background: #dbeafe; color: #2563eb; }
.jwt-payload { background: #dcfce7; color: #16a34a; }
.jwt-signature { background: #fef3c7; color: #d97706; }

/* --- Responsive --- */

@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }

  .navbar {
    padding: 0 var(--space-md);
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero p {
    font-size: 0.9375rem;
  }

  .categories {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: var(--space-sm);
    -webkit-overflow-scrolling: touch;
  }

  .category-tag {
    flex-shrink: 0;
  }

  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }

  .tool-io {
    grid-template-columns: 1fr;
  }

  .io-arrow {
    transform: rotate(90deg);
  }

  .tool-content {
    padding: var(--space-md);
  }

  .container {
    padding: 0 var(--space-md);
  }

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

}

@media (max-width: 480px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }

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

  .panel-header {
    flex-direction: column;
    gap: var(--space-sm);
    align-items: flex-start;
  }
}

/* --- Animations --- */
@keyframes fade-in {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-in {
  animation: fade-in 0.4s ease;
}

.tool-card {
  animation: fade-in 0.4s ease backwards;
  animation-delay: calc(var(--i, 0) * 0.05s);
}

/* --- No results --- */
.no-results {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl);
  display: none;
}

.no-results.visible {
  display: block;
}

.no-results-icon {
  font-size: 48px;
  margin-bottom: var(--space-md);
}

.no-results-text {
  font-size: 1rem;
  color: var(--color-text-secondary);
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-muted);
}

/* --- Selection --- */
::selection {
  background: var(--color-primary-bg);
  color: var(--color-primary);
}

/* ============================================================
   Accessibility & Interaction Enhancements
   ============================================================ */

/* --- Focus States --- */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.btn:focus-visible,
.category-tag:focus-visible,
.tool-card:focus-visible,
.sidebar-link:focus-visible,
.swap-btn:focus-visible,
.navbar-actions a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  box-shadow: 0 0 0 4px var(--color-primary-bg);
}

.input-field:focus-visible,
.textarea-field:focus-visible,
.select-field:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-bg);
}

/* --- Cursor Pointer on Interactive Elements --- */
.tool-card,
.category-tag,
.btn,
.swap-btn,
.tab,
.sidebar-link,
.upload-zone,
.navbar-logo,
.navbar-actions a,
.navbar-actions button {
  cursor: pointer;
}

/* --- Touch Target Size (min 44x44) --- */
.btn {
  min-height: 40px;
}

.btn-sm {
  min-height: 34px;
}

.category-tag {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
}

.sidebar-link {
  min-height: 40px;
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .tool-card {
    animation: none;
    opacity: 1;
  }

  .animate-in {
    animation: none;
  }

  .toast {
    animation: none;
  }

  .swap-btn:hover {
    transform: none;
  }
}

/* --- Skip Link (Accessibility) --- */
.skip-link {
  position: fixed;
  top: -100%;
  left: var(--space-md);
  z-index: 10000;
  padding: 12px 24px;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: 0.875rem;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
}

/* --- SVG Icon Inline Alignment --- */
.svg-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  vertical-align: middle;
}

.svg-icon svg {
  display: block;
}

/* --- Utility Classes --- */
.mb-lg { margin-bottom: var(--space-lg); }
.mt-md { margin-top: var(--space-md); }
.mt-sm { margin-top: var(--space-sm); }
.mt-xl { margin-top: var(--space-xl); }

.flex-row {
  display: flex;
  gap: var(--space-lg);
  align-items: center;
  flex-wrap: wrap;
}

.flex-row-end {
  display: flex;
  gap: var(--space-lg);
  align-items: flex-end;
  flex-wrap: wrap;
}

.flex-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.gap-sm {
  display: flex;
  gap: var(--space-sm);
}

.panel-actions-row {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.text-muted {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.text-sm {
  font-size: 0.875rem;
}

.w-full { width: 100%; }
.ml-auto { margin-left: auto; }

.min-h-sm { min-height: 120px; }
.min-h-md { min-height: 150px; }
.min-h-lg { min-height: 300px; }

.grid-auto {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-lg);
}

.grid-auto-sm {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-lg);
}

.grid-compact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}

/* --- Theme Toggle --- */
.theme-toggle {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
  cursor: pointer;
  background: none;
  border: none;
}

.theme-toggle:hover {
  background: var(--color-bg-elevated);
  color: var(--color-text);
}

/* --- High Contrast Mode --- */
@media (forced-colors: active) {
  .tool-card {
    border: 1px solid ButtonText;
  }

  .btn-primary {
    background: ButtonText;
    color: ButtonFace;
  }

  .category-tag.active {
    background: Highlight;
    color: HighlightText;
  }
}