/* ==========================================================================
   THEME CONFIGURATION
   --------------------------------------------------------------------------
   Design tokens shared across the whole site. Tweak these to re-theme
   without touching any other rule below.
   ========================================================================== */
:root {
  /* Backgrounds */
  --color-bg: #0f172a;
  --color-bg-alt: #111c34;
  --color-surface: #16213d;
  --color-surface-hover: #1b2a4d;

  /* Borders */
  --color-border: #263354;
  --color-border-hover: #3b82f6;

  /* Text */
  --color-text-primary: #f1f5f9;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;

  /* Accent / brand */
  --color-accent: #3b82f6;
  --color-accent-alt: #8b5cf6;
  --color-accent-soft: rgba(59, 130, 246, 0.15);

  /* Status */
  --color-success: #34d399;
  --color-success-soft: rgba(52, 211, 153, 0.15);
  --color-success-border: rgba(52, 211, 153, 0.4);
  --color-success-text: #6ee7b7;

  /* Shadows */
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-card-hover: 0 12px 32px rgba(59, 130, 246, 0.25);

  /* Spacing scale */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  /* Typography */
  --font-family-base: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, Helvetica, Arial, sans-serif;

  /* Transitions */
  --transition-fast: 180ms ease;
  --transition-medium: 320ms cubic-bezier(0.22, 1, 0.36, 1);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: var(--font-family-base);
}

body {
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ==========================================================================
   NAVBAR
   ========================================================================== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  display: flex;
  justify-content: center;
  background-color: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  padding: 0 16px;
  box-shadow: var(--shadow-card);
}

.nav-button {
  background: none;
  border: none;
  color: var(--color-text-secondary);
  padding: 14px 20px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast);
  border-bottom: 3px solid transparent;
}

.nav-button:hover {
  color: var(--color-text-primary);
}

.nav-button.active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  font-weight: 600;
}

/* ==========================================================================
   TAB CONTAINER
   ========================================================================== */
.tab-container {
  max-width: 750px;
  margin: 0 auto;
}

.tab-content {
  padding: 24px 16px;
}

.tab-content h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 16px;
}

/* ==========================================================================
   QR GRID & CARDS
   ========================================================================== */
.qr-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 16px;
}

.qr-card {
  background: linear-gradient(160deg, var(--color-surface), var(--color-bg-alt));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  box-shadow: var(--shadow-card);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}

.qr-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-border-hover);
  box-shadow: var(--shadow-card-hover);
}

.qr-card h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 12px;
  word-break: break-word;
}

.qr-code-container {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  background: #ffffff;
  padding: 8px;
  border-radius: var(--radius-sm);
  max-width: 100%;
}

.qr-code-container img,
.qr-code-container canvas {
  display: block;
  max-width: 100%;
  height: auto;
}

/* ==========================================================================
   SECTION DIVIDER
   ========================================================================== */
.divider {
  margin: 32px 0;
  border: 0;
  border-top: 1px solid var(--color-border);
}

/* ==========================================================================
   CUSTOM GENERATOR BOX
   ========================================================================== */
.custom-qr-section {
  background: linear-gradient(160deg, var(--color-surface), var(--color-bg-alt));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.custom-layout {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  margin-top: 16px;
}

.form-grid {
  flex: 1;
  max-width: 380px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

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

.form-group label {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
}

.form-group input,
.form-group select {
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 13px;
  outline: none;
  background-color: var(--color-bg-alt);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input::placeholder {
  color: var(--color-text-muted);
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--color-border-hover);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.custom-card {
  width: 230px;
  margin: 0;
  background: var(--color-bg-alt);
  flex-shrink: 0;
  align-self: flex-start;
}

.url-preview {
  margin-top: 12px;
  padding: 6px 10px;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  font-family: monospace;
  font-size: 10px;
  color: var(--color-text-secondary);
  word-break: break-all;
  border: 1px solid var(--color-border);
}

/* ==========================================================================
   LINK ROWS
   ========================================================================== */
.link-row {
  display: flex;
  align-items: center;
  gap: 8px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 4px 12px 4px 8px;
  transition: all var(--transition-fast);
}

.link-row + .link-row {
  margin-top: 8px;
}

.search-group {
  margin-bottom: 16px;
}

.search-input-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.search-input-wrap input {
  width: 100%;
  padding-right: 36px;
}

.search-clear-btn {
  position: absolute;
  right: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 18px;
  line-height: 1;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.search-clear-btn:hover {
  color: var(--color-text-primary);
  background-color: var(--color-surface-hover);
}

.search-clear-btn[hidden] {
  display: none;
}

.empty-state {
  padding: 24px 0;
  text-align: center;
  font-size: 13px;
  color: var(--color-text-secondary);
}

.link-row:hover {
  border-color: var(--color-border-hover);
  background-color: var(--color-surface-hover);
  transform: translateX(2px);
  box-shadow: var(--shadow-card);
}

.copy-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.copy-btn:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-accent);
  border-color: var(--color-border-hover);
}

.copy-btn.copied {
  background-color: var(--color-success-soft);
  border-color: var(--color-success-border);
  color: var(--color-success);
}

.link-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex: 1;
  min-width: 0;
  padding: 8px 0;
  text-decoration: none;
  color: var(--color-text-primary);
}

.link-info {
  display: flex;
  flex-direction: column;
  min-width: 0;
  flex: 1;
}

.link-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-primary);
}

.link-url {
  font-size: 11px;
  color: var(--color-text-secondary);
  margin-top: 2px;
  font-family: monospace;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.link-arrow {
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: bold;
  margin-left: 8px;
  transition: color var(--transition-fast), transform var(--transition-fast);
}

.link-row:hover .link-arrow {
  color: var(--color-accent);
  transform: translateX(2px);
}

/* ==========================================================================
   CUSTOM LINK INPUT BOX
   ========================================================================== */
.custom-link-box {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 16px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-card);
}

.flex-1 {
  flex: 1;
}

.button-group {
  display: flex;
  gap: 8px;
}

/* ==========================================================================
   ACTION BUTTONS
   ========================================================================== */
.action-btn {
  padding: 9px 14px;
  font-size: 13px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.primary-btn {
  background-color: var(--color-accent);
  color: #ffffff;
}

.primary-btn:hover {
  background-color: #2563eb;
}

.secondary-btn {
  background-color: var(--color-bg-alt);
  color: var(--color-text-primary);
  border-color: var(--color-border);
}

.secondary-btn:hover {
  background-color: var(--color-surface-hover);
  border-color: var(--color-border-hover);
}

.secondary-btn.copied {
  background-color: var(--color-success-soft);
  border-color: var(--color-success-border);
  color: var(--color-success-text);
}

/* ==========================================================================
   RESPONSIVE ADJUSTMENTS
   ========================================================================== */
@media (max-width: 640px) {
  .custom-layout {
    flex-direction: column;
  }

  .form-grid,
  .custom-card {
    width: 100%;
    max-width: 100%;
  }

  .custom-link-box {
    flex-direction: column;
    align-items: stretch;
  }

  .button-group {
    margin-top: 8px;
  }

  .action-btn {
    flex: 1;
  }
}