/* Variables & Theme Properties - Light / Clean / Neutral */
:root {
  --bg-main: #f8fafc;
  --card-bg: #ffffff;
  --card-border: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  
  --accent-primary: #2563eb;
  --accent-primary-hover: #1d4ed8;
  --accent-glow: rgba(37, 99, 235, 0.15);

  --neutral-bg: #f1f5f9;
  --neutral-border: #cbd5e1;

  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;

  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 32px 20px;
  line-height: 1.5;
}

.app-container {
  width: 100%;
  max-width: 960px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

/* Header */
.app-header {
  text-align: center;
}

.logo-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 6px;
}

.logo-icon {
  background: var(--text-primary);
  color: #ffffff;
  padding: 8px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.12);
}

.app-header h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Two-Column Main Grid */
.main-content {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 820px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

/* Cards */
.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.03);
}

/* Generator Card */
.generator-card {
  display: flex;
  flex-direction: column;
}

/* Password Display */
.display-box {
  background: var(--neutral-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
  transition: var(--transition);
}

.display-box:hover {
  border-color: var(--neutral-border);
}

.password-output {
  flex: 1;
  overflow-x: auto;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.05em;
  user-select: all;
  cursor: pointer;
  padding: 4px 0;
}

.password-output::-webkit-scrollbar {
  height: 4px;
}
.password-output::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 2px;
}

.password-text.hidden-password {
  letter-spacing: 0.25em;
  font-size: 1.2rem;
  color: var(--text-secondary);
}

.display-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 10px 16px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition);
}

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

.btn-primary:hover {
  background: #334155;
}

.btn-action {
  width: 100%;
  padding: 14px;
  background: var(--text-primary);
  color: white;
  font-size: 1rem;
  border-radius: var(--radius-md);
  margin-top: 20px;
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.12);
}

.btn-action:hover {
  background: #334155;
  transform: translateY(-1px);
}

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

.icon-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.icon-btn:hover {
  color: var(--text-primary);
  background: #e2e8f0;
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  padding: 6px 12px;
  font-size: 0.85rem;
}

.btn-ghost:hover {
  background: #f1f5f9;
}

.text-danger {
  color: #ef4444;
}

.text-danger:hover {
  color: #dc2626;
  background: #fef2f2;
}

/* Strength Meter */
.strength-meter-container {
  margin-bottom: 20px;
}

.strength-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  margin-bottom: 6px;
}

.strength-info .label {
  color: var(--text-secondary);
}

.strength-text {
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}

.strength-bars {
  display: flex;
  gap: 6px;
  height: 6px;
}

.strength-bars .bar {
  flex: 1;
  background: #e2e8f0;
  border-radius: 3px;
  transition: var(--transition);
}

/* Mode Selector */
.mode-selector {
  display: flex;
  background: var(--neutral-bg);
  border-radius: var(--radius-md);
  padding: 4px;
  margin-bottom: 20px;
  border: 1px solid var(--card-border);
}

.mode-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 12px;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.mode-btn.active {
  background: var(--card-bg);
  color: var(--text-primary);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  font-weight: 600;
}

/* Controls */
.controls-group {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.control-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 0.9rem;
  font-weight: 500;
}

.length-badge {
  background: #e2e8f0;
  color: var(--text-primary);
  padding: 2px 10px;
  border-radius: 20px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid var(--neutral-border);
}

/* Slider Custom Styling */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: #cbd5e1;
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: white;
  border: 2px solid var(--text-primary);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  transition: var(--transition);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  background: var(--text-primary);
  border-color: white;
}

/* Checkboxes Options Grid */
.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

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

.checkbox-container {
  display: flex;
  align-items: center;
  position: relative;
  padding-left: 32px;
  cursor: pointer;
  font-size: 0.88rem;
  user-select: none;
  color: var(--text-primary);
}

.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkmark {
  position: absolute;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  height: 20px;
  width: 20px;
  background-color: var(--neutral-bg);
  border: 1px solid var(--neutral-border);
  border-radius: 5px;
  transition: var(--transition);
}

.checkbox-container:hover input ~ .checkmark {
  border-color: var(--text-primary);
}

.checkbox-container input:checked ~ .checkmark {
  background-color: var(--text-primary);
  border-color: var(--text-primary);
}

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}

.checkbox-container input:checked ~ .checkmark:after {
  display: block;
}

.checkbox-container .checkmark:after {
  left: 6px;
  top: 2px;
  width: 5px;
  height: 10px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.option-label small {
  color: var(--text-secondary);
  font-weight: normal;
}

/* History Card - Left Column */
.history-card {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.history-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.history-title h2 {
  font-size: 1.1rem;
  font-weight: 600;
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 420px;
  overflow-y: auto;
  padding-right: 4px;
}

.history-list::-webkit-scrollbar {
  width: 4px;
}
.history-list::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 2px;
}

.history-empty {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 32px 0;
}

.history-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--neutral-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  transition: var(--transition);
}

.history-item:hover {
  border-color: var(--neutral-border);
}

.history-item-left {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow: hidden;
}

.history-value {
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.history-type-tag {
  font-size: 0.7rem;
  font-family: var(--font-sans);
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
  font-weight: 600;
  background: #e2e8f0;
  color: var(--text-primary);
}

.history-item-actions {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text-primary);
  color: white;
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 500;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  pointer-events: none;
  z-index: 1000;
}

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