/* ==========================================================================
   Serials Hold Validator - Design System & Stylesheet
   Modern, Accessible, and Responsive Academic Web Application
   ========================================================================== */

:root {
  /* Color Palette - Light Mode */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-input: #ffffff;
  --bg-accent-soft: #eff6ff;
  
  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --border-focus: #3b82f6;

  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-primary-gradient: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);

  --color-success: #10b981;
  --color-success-bg: #ecfdf5;
  --color-success-border: #a7f3d0;
  --color-success-text: #065f46;

  --color-danger: #ef4444;
  --color-danger-bg: #fef2f2;
  --color-danger-border: #fecaca;
  --color-danger-text: #991b1b;
  --color-danger-highlight: #fee2e2;

  --color-warning: #f59e0b;
  --color-warning-bg: #fffbeb;
  --color-warning-border: #fde68a;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans JP", sans-serif;
  --font-mono: 'JetBrains Mono', SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

[data-theme="dark"] {
  --bg-primary: #0b0f19;
  --bg-secondary: #131b2e;
  --bg-tertiary: #1e293b;
  --bg-input: #0f172a;
  --bg-accent-soft: #172554;

  --border-subtle: #1e293b;
  --border-strong: #334155;
  --border-focus: #60a5fa;

  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-inverse: #0f172a;

  --color-primary: #3b82f6;
  --color-primary-hover: #60a5fa;
  --color-primary-light: #1e3a8a;
  --color-primary-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);

  --color-success: #34d399;
  --color-success-bg: rgba(16, 185, 129, 0.15);
  --color-success-border: rgba(16, 185, 129, 0.3);
  --color-success-text: #6ee7b7;

  --color-danger: #f87171;
  --color-danger-bg: rgba(239, 68, 68, 0.15);
  --color-danger-border: rgba(239, 68, 68, 0.3);
  --color-danger-text: #fca5a5;
  --color-danger-highlight: rgba(239, 68, 68, 0.25);

  --color-warning: #fbbf24;
  --color-warning-bg: rgba(245, 158, 11, 0.15);
  --color-warning-border: rgba(245, 158, 11, 0.3);

  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
}

/* Header & Navigation */
.site-header {
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-subtle);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: inherit;
}

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: var(--color-primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.25rem;
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.3);
}

.brand-title-area {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
  line-height: 1.2;
}

.brand-subtitle {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-toggle-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background: var(--border-subtle);
  color: var(--text-main);
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  background: var(--bg-accent-soft);
  color: var(--color-primary);
  border: 1px solid rgba(37, 99, 235, 0.2);
}

/* Main Layout */
.main-wrapper {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

/* Intro Section */
.hero-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.hero-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-primary-gradient);
}

.hero-title {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.6rem;
  color: var(--text-main);
}

.hero-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.security-badges-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.sec-pill {
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  color: var(--text-muted);
  border: 1px solid var(--border-subtle);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.sec-pill-icon {
  font-size: 0.85rem;
  color: var(--color-success);
}

/* Grid Layout for Work Area */
.app-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
}

@media (min-width: 960px) {
  .app-grid {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }
}

/* Section Cards */
.panel-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.panel-card:focus-within {
  border-color: var(--border-focus);
  box-shadow: var(--shadow-md);
}

.panel-header {
  padding: 1.1rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  background: var(--bg-secondary);
}

.panel-title {
  font-size: 1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-main);
}

.panel-title-icon {
  color: var(--color-primary);
}

.panel-body {
  padding: 1.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Input Area Elements */
.textarea-wrapper {
  position: relative;
  display: flex;
  flex-direction: column;
}

.app-textarea {
  width: 100%;
  min-height: 220px;
  padding: 0.85rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.55;
  background: var(--bg-input);
  color: var(--text-main);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  resize: vertical;
  transition: all var(--transition-fast);
  outline: none;
}

.app-textarea:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.textarea-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.4rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.char-counter {
  font-weight: 500;
  font-family: var(--font-mono);
  transition: color var(--transition-fast);
}

.char-counter.warning {
  color: var(--color-warning);
  font-weight: 700;
}

.char-counter.limit {
  color: var(--color-danger);
  font-weight: 700;
}

/* Button Toolbar */
.btn-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  line-height: 1;
}

.btn-primary {
  background: var(--color-primary-gradient);
  color: #ffffff;
  box-shadow: 0 2px 6px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
  transform: translateY(-1px);
}

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

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-main);
  border-color: var(--border-strong);
}

.btn-secondary:hover {
  background: var(--border-subtle);
  color: var(--text-main);
}

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border-strong);
}

.btn-outline:hover {
  background: var(--bg-tertiary);
  color: var(--text-main);
}

.btn-sm {
  padding: 0.4rem 0.75rem;
  font-size: 0.8rem;
  border-radius: var(--radius-sm);
}

/* Result Area */
.result-tabs {
  display: flex;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: 0.25rem;
  gap: 0.25rem;
}

.tab-btn {
  flex: 1;
  padding: 0.45rem 0.75rem;
  font-size: 0.82rem;
  font-weight: 600;
  border: none;
  background: transparent;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
}

.tab-btn.active {
  background: var(--bg-secondary);
  color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.summary-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  border: 1px solid var(--border-subtle);
}

.summary-badges {
  display: flex;
  gap: 0.5rem;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-full);
}

.status-badge.ok {
  background: var(--color-success-bg);
  color: var(--color-success-text);
  border: 1px solid var(--color-success-border);
}

.status-badge.err {
  background: var(--color-danger-bg);
  color: var(--color-danger-text);
  border: 1px solid var(--color-danger-border);
}

/* Rich Preview Records */
.records-container {
  max-height: 400px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding-right: 0.25rem;
}

.record-row {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  background: var(--bg-input);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  transition: all var(--transition-fast);
}

.record-row:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-sm);
}

.record-row.has-error {
  background: var(--color-danger-bg);
  border-color: var(--color-danger-border);
}

.record-indicator {
  font-weight: 800;
  font-size: 0.8rem;
  padding: 0.15rem 0.45rem;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.record-indicator.code-0 {
  background: var(--color-success);
  color: #fff;
}

.record-indicator.code-1 {
  background: var(--color-danger);
  color: #fff;
}

.record-content {
  flex: 1;
  word-break: break-all;
  white-space: pre-wrap;
  line-height: 1.5;
}

/* Highlight for <Ng> Tag */
.ng-highlight {
  display: inline-block;
  background: #dc2626;
  color: #ffffff;
  padding: 0.05rem 0.4rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  margin: 0 0.1rem;
  border: 1px solid #b91c1c;
  box-shadow: 0 1px 3px rgba(220, 38, 38, 0.3);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 2.5rem 1rem;
  color: var(--text-muted);
}

.empty-state-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  opacity: 0.6;
}

/* Sample Section */
.samples-card {
  margin-top: 2rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
}

.samples-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
}

.samples-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sample-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.75rem;
}

.sample-chip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-main);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.sample-chip:hover {
  background: var(--bg-accent-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-1px);
}

.sample-chip-text {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sample-chip-action {
  font-size: 0.7rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--color-primary);
  margin-left: 0.5rem;
  flex-shrink: 0;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 100;
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  background: #0f172a;
  color: #ffffff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 600;
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  opacity: 0;
  transform: translateY(10px);
  transition: all var(--transition-normal);
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* Footer */
.site-footer {
  margin-top: auto;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: 2rem 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  text-align: center;
}

@media (min-width: 768px) {
  .footer-container {
    flex-direction: row;
    justify-content: space-between;
    text-align: left;
  }
}

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

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--color-primary);
  text-decoration: underline;
}

/* Security Notice Box */
.security-notice {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-top: 1rem;
}

.security-notice strong {
  color: var(--text-main);
}

.code-inline {
  font-family: var(--font-mono);
  background: rgba(0, 0, 0, 0.05);
  padding: 0.1rem 0.3rem;
  border-radius: var(--radius-sm);
  font-size: 0.85em;
}

[data-theme="dark"] .code-inline {
  background: rgba(255, 255, 255, 0.1);
}