/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');

/* CSS Variables */
:root {
  /* Common variables */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;

  /* Dark Theme variables (default) */
  --bg-main: #000000;
  --bg-card: #0a0a0a;
  --bg-card-hover: #121212;
  --border-color: #222222;
  --border-color-focus: #444444;
  --border-card-hover: #333333;
  
  --text-primary: #ffffff;
  --text-secondary: #888888;
  --text-muted: #555555;
  
  --accent-cyan: #ffffff;
  --accent-blue: #ffffff;
  --accent-purple: #ffffff;
  --accent-success: #10b981;
  --accent-error: #ef4444;
  --accent-warning: #f59e0b;
  
  --gradient-accent: #ffffff;
  --gradient-purple: #111111;
  --gradient-border: #222222;
  
  --shadow-glow: none;
  --shadow-glow-hover: none;
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-modal: 0 10px 40px rgba(0, 0, 0, 0.6);

  /* Button variables */
  --btn-primary-text: #000000;
  --border-spinner: rgba(0, 0, 0, 0.2);
  --shadow-accent-btn: 0 2px 8px rgba(255, 255, 255, 0.15);
  --shadow-accent-btn-hover: 0 4px 12px rgba(255, 255, 255, 0.25);
  --shadow-purple-btn: none;
  --shadow-purple-btn-hover: none;

  /* Radial backgrounds - Removed, replaced with solid */
  --radial-1: transparent;
  --radial-2: transparent;
  --radial-3-start: #000000;
  --radial-3-end: #000000;

  /* Element backgrounds */
  --bg-upload-zone: #050505;
  --border-upload-zone: #333333;
  --bg-table-wrapper: #0a0a0a;
  --bg-table-header: #111111;
  --bg-row-hover: #1a1a1a;
  --bg-instruction-card: #0a0a0a;
  --color-instruction-step: #222222;
  --bg-pill: #1a1a1a;
  --bg-input: #0a0a0a;
  --bg-stat-card: #0a0a0a;
  --console-log-bg: #000000;
  --console-log-color: #888888;
  --bg-overlay: rgba(0, 0, 0, 0.8);
  --bg-toast: #1a1a1a;
  --shadow-toast: 0 10px 25px rgba(0, 0, 0, 0.5);

  --bg-badge-success: rgba(16, 185, 129, 0.1);
  --border-badge-success: rgba(16, 185, 129, 0.2);
  --bg-badge-purple: #111111;
  --border-badge-purple: #333333;
  --bg-badge-cyan: #111111;
  --border-badge-cyan: #333333;
  --bg-badge-warning: rgba(245, 158, 11, 0.1);
  --border-badge-warning: rgba(245, 158, 11, 0.2);
  
  --scrollbar-track: #000000;
  --scrollbar-thumb: #333333;
  --scrollbar-thumb-hover: #555555;
  --btn-pulse-glow: rgba(255, 255, 255, 0.2);
  --btn-pulse-glow-transparent: rgba(255, 255, 255, 0);
}

:root[data-theme="light"] {
  /* Light Theme variables */
  --bg-main: #fafafa;
  --bg-card: #ffffff;
  --bg-card-hover: #fcfcfc;
  --border-color: #eaeaea;
  --border-color-focus: #cccccc;
  --border-card-hover: #d4d4d4;
  
  --text-primary: #111111;
  --text-secondary: #666666;
  --text-muted: #999999;
  
  --accent-cyan: #111111;
  --accent-blue: #111111;
  --accent-purple: #111111;
  --accent-success: #059669;
  --accent-error: #dc2626;
  --accent-warning: #d97706;
  
  --gradient-accent: #111111;
  --gradient-purple: #f5f5f5;
  --gradient-border: #eaeaea;
  
  --shadow-glow: none;
  --shadow-glow-hover: none;
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.04);
  --shadow-modal: 0 10px 40px rgba(0, 0, 0, 0.08);

  /* Button variables */
  --btn-primary-text: #ffffff;
  --border-spinner: rgba(255, 255, 255, 0.2);
  --shadow-accent-btn: 0 2px 6px rgba(0, 0, 0, 0.1);
  --shadow-accent-btn-hover: 0 4px 12px rgba(0, 0, 0, 0.15);
  --shadow-purple-btn: none;
  --shadow-purple-btn-hover: none;

  /* Radial backgrounds */
  --radial-1: transparent;
  --radial-2: transparent;
  --radial-3-start: #fafafa;
  --radial-3-end: #fafafa;

  /* Element backgrounds */
  --bg-upload-zone: #ffffff;
  --border-upload-zone: #dddddd;
  --bg-table-wrapper: #ffffff;
  --bg-table-header: #f5f5f5;
  --bg-row-hover: #f9f9f9;
  --bg-instruction-card: #ffffff;
  --color-instruction-step: #eaeaea;
  --bg-pill: #f5f5f5;
  --bg-input: #ffffff;
  --bg-stat-card: #ffffff;
  --console-log-bg: #f9fafb;
  --console-log-color: #666666;
  --bg-overlay: rgba(0, 0, 0, 0.2);
  --bg-toast: #ffffff;
  --shadow-toast: 0 10px 25px rgba(0, 0, 0, 0.05);

  --bg-badge-success: rgba(5, 150, 105, 0.08);
  --border-badge-success: rgba(5, 150, 105, 0.15);
  --bg-badge-purple: #f5f5f5;
  --border-badge-purple: #eaeaea;
  --bg-badge-cyan: #f5f5f5;
  --border-badge-cyan: #eaeaea;
  --bg-badge-warning: rgba(217, 119, 6, 0.08);
  --border-badge-warning: rgba(217, 119, 6, 0.15);
  
  --scrollbar-track: #fafafa;
  --scrollbar-thumb: #cccccc;
  --scrollbar-thumb-hover: #aaaaaa;
  --btn-pulse-glow: rgba(0, 0, 0, 0.1);
  --btn-pulse-glow-transparent: rgba(0, 0, 0, 0);
}

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

body {
  font-family: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Layout */
.app-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  position: relative;
}

header {
  text-align: center;
  margin-bottom: 3rem;
}

.logo-container {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.logo-svg {
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-text {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.025em;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  font-weight: 350;
  margin-top: 0.5rem;
}

/* Format Tabs */
.format-tabs-container {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 2rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
  scrollbar-width: none;
}

.format-tabs-container::-webkit-scrollbar {
  display: none;
}

.format-tab {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.format-tab:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  border-color: var(--border-color-focus);
}

.format-tab.active {
  background: var(--text-primary);
  color: var(--bg-main);
  border-color: var(--text-primary);
  box-shadow: var(--shadow-accent-btn);
}

/* Panels */
.grid-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: stretch;
}

@media (max-width: 1024px) {
  .grid-layout {
    grid-template-columns: 1fr;
  }
}

.glass-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-panel:hover {
  border-color: var(--border-card-hover);
}

.panel-title {
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.panel-title span.badge {
  background: var(--bg-badge-cyan);
  color: var(--accent-cyan);
  font-size: 0.8rem;
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  border: 1px solid var(--border-badge-cyan);
}

/* Upload Area */
.upload-zone {
  border: 2px dashed var(--border-upload-zone);
  border-radius: 16px;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  background: var(--bg-upload-zone);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--accent-cyan);
  background: rgba(0, 242, 254, 0.03);
  box-shadow: var(--shadow-glow);
}

.upload-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  display: inline-block;
  transition: transform var(--transition-normal);
}

.upload-zone:hover .upload-icon {
  transform: translateY(-5px);
}

.upload-text {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.upload-subtext {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.upload-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.browse-btn {
  border: 1px solid transparent;
  padding: 0.65rem 1.5rem;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.csv-btn {
  background: var(--text-primary);
  color: var(--bg-main);
  box-shadow: var(--shadow-accent-btn);
}

.csv-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-accent-btn-hover);
}

.zip-btn {
  background: transparent;
  border-color: var(--border-color);
  color: var(--text-primary);
}

.zip-btn:hover {
  background: var(--bg-row-hover);
  border-color: var(--text-muted);
}

.file-input {
  display: none;
}

/* File Manager */
.file-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-height: 400px;
  overflow-y: auto;
  padding-right: 0.25rem;
  margin-top: 1.5rem;
}

/* Custom Scrollbar for file list & preview */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}
::-webkit-scrollbar-track {
  background: var(--scrollbar-track);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb);
  border-radius: 4px;
  transition: background var(--transition-fast);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--scrollbar-thumb-hover);
}

.file-item {
  background: var(--bg-card-hover);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  user-select: none;
  transition: all var(--transition-fast);
  position: relative;
}

.file-item.dragging {
  opacity: 0.4;
  border: 1px dashed var(--accent-cyan);
  transform: scale(0.98);
}

.drag-handle {
  color: var(--text-muted);
  cursor: grab;
  font-size: 1.25rem;
  padding: 0.25rem;
  display: flex;
  align-items: center;
  transition: color var(--transition-fast);
}

.drag-handle:hover {
  color: var(--text-primary);
}

.file-icon {
  font-size: 1.75rem;
  display: flex;
  align-items: center;
}

.file-details {
  flex-grow: 1;
  min-width: 0;
}

.file-name {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-meta {
  display: flex;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.15rem;
}

.file-meta span.rows-badge {
  color: var(--accent-cyan);
}

.file-meta span.cols-badge {
  color: var(--accent-purple);
  text-decoration: underline;
  cursor: pointer;
}

.file-delete {
  color: var(--text-muted);
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 0.4rem;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.file-delete:hover {
  color: var(--accent-error);
  background: rgba(239, 68, 68, 0.1);
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2.5rem 1rem;
  font-size: 0.95rem;
}

/* Settings Form */
.settings-group {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.format-settings {
  display: none;
  animation: fadeIn 0.3s ease;
}

.format-settings.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-5px); }
  to { opacity: 1; transform: translateY(0); }
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

@media (max-width: 640px) {
  .form-row {
    grid-template-columns: 1fr;
  }
}

.form-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

select, input[type="text"] {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

select:focus, input[type="text"]:focus {
  outline: none;
  border-color: var(--border-color-focus);
  box-shadow: 0 0 10px var(--border-color-focus);
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  user-select: none;
  font-size: 0.9rem;
  text-transform: none;
  letter-spacing: normal;
  color: var(--text-primary);
}

.checkbox-label input[type="checkbox"] {
  accent-color: var(--accent-cyan);
  width: 16px;
  height: 16px;
}

/* Info Banner */
.info-banner {
  background: var(--bg-badge-purple);
  border: 1px solid var(--border-badge-purple);
  border-radius: 12px;
  padding: 0.85rem 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
}

.info-icon {
  color: var(--accent-purple);
  font-weight: bold;
  font-size: 1.1rem;
  line-height: 1;
}

/* Next Step Dynamic Tip */
.next-step-tip {
  background: var(--bg-badge-warning);
  border: 1px solid var(--border-badge-warning);
  border-radius: 12px;
  padding: 0.85rem 1rem;
  font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  margin-top: 1rem;
  box-shadow: 0 0 15px var(--bg-badge-warning);
}

.tip-icon {
  color: var(--accent-warning);
  font-size: 1.1rem;
  line-height: 1;
}

/* Actions Section */
.actions-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.primary-btn {
  background: var(--text-primary);
  color: var(--bg-main);
  border: none;
  padding: 0.85rem 2rem;
  font-size: 1.05rem;
  font-weight: 600;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  box-shadow: var(--shadow-accent-btn);
}

.primary-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: var(--shadow-accent-btn-hover);
  opacity: 0.9;
}

.primary-btn:active:not(:disabled) {
  transform: translateY(0);
}

.primary-btn:disabled {
  background: var(--bg-pill);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  cursor: not-allowed;
  box-shadow: none;
}

.primary-btn.pulse-active:not(:disabled) {
  animation: button-pulse 2s infinite;
}

@keyframes button-pulse {
  0% {
    box-shadow: 0 0 0 0 var(--btn-pulse-glow), var(--shadow-accent-btn);
  }
  70% {
    box-shadow: 0 0 0 10px var(--btn-pulse-glow-transparent), var(--shadow-accent-btn);
  }
  100% {
    box-shadow: 0 0 0 0 var(--btn-pulse-glow-transparent), var(--shadow-accent-btn);
  }
}

.btn-spinner {
  width: 20px;
  height: 20px;
  border: 2.5px solid var(--border-spinner);
  border-top: 2.5px solid var(--btn-primary-text);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Progress Section */
.progress-panel {
  margin-top: 2rem;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
}

.progress-title {
  font-weight: 500;
  color: var(--text-primary);
}

.progress-pct {
  color: var(--accent-cyan);
  font-weight: 600;
}

.progress-bar-container {
  height: 8px;
  background: var(--bg-pill);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-bar {
  height: 100%;
  width: 0%;
  background: var(--gradient-accent);
  border-radius: 4px;
  transition: width var(--transition-fast) ease-out;
  position: relative;
  overflow: hidden;
}

.progress-bar::after {
  content: '';
  position: absolute;
  top: 0; left: 0; bottom: 0; right: 0;
  background-image: linear-gradient(
    -45deg, 
    rgba(255, 255, 255, .15) 25%, 
    transparent 25%, 
    transparent 50%, 
    rgba(255, 255, 255, .15) 50%, 
    rgba(255, 255, 255, .15) 75%, 
    transparent 75%, 
    transparent
  );
  background-size: 40px 40px;
  animation: progress-slide 1.5s linear infinite;
}

@keyframes progress-slide {
  from { background-position: 0 0; }
  to { background-position: 40px 0; }
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1rem;
}

@media (max-width: 640px) {
  .stats-grid {
    grid-template-columns: 1fr;
  }
}

.stat-card {
  background: var(--bg-stat-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 0.75rem 1rem;
  text-align: center;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
}

.stat-value {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0.15rem;
}

.console-log {
  background: var(--console-log-bg);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 0.75rem;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.8rem;
  color: var(--console-log-color);
  max-height: 120px;
  overflow-y: auto;
  white-space: pre-wrap;
}

/* Preview Section */
.preview-panel {
  grid-column: 1 / -1;
  margin-top: 2rem;
}

.preview-table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  max-height: 350px;
  background: var(--bg-table-wrapper);
}

.preview-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  text-align: left;
}

.preview-table th {
  background: var(--bg-table-header);
  border-bottom: 2px solid var(--border-color);
  padding: 0.75rem 1rem;
  font-weight: 600;
  color: var(--text-primary);
  position: sticky;
  top: 0;
  z-index: 10;
  white-space: nowrap;
}

.preview-table td {
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-secondary);
  white-space: nowrap;
  max-width: 250px;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.preview-table tr:hover td {
  background: var(--bg-row-hover);
  color: var(--text-primary);
}

.preview-badge {
  font-size: 0.7rem;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  margin-left: 0.35rem;
  font-weight: normal;
}

.preview-badge.common {
  background: var(--bg-badge-success);
  color: var(--accent-success);
  border: 1px solid var(--border-badge-success);
}

.preview-badge.unique {
  background: var(--bg-badge-purple);
  color: var(--accent-purple);
  border: 1px solid var(--border-badge-purple);
}

.preview-empty {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-muted);
}

/* Modal */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: var(--bg-overlay);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  width: 90%;
  max-width: 500px;
  padding: 2rem;
  box-shadow: var(--shadow-modal);
  transform: translateY(20px);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .modal-content {
  transform: translateY(0);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
}

.modal-title {
  font-size: 1.2rem;
  font-weight: 600;
}

.modal-close {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 1.5rem;
  cursor: pointer;
  line-height: 1;
}

.modal-close:hover {
  color: var(--text-primary);
}

.modal-body {
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-height: 300px;
  overflow-y: auto;
}

.columns-badge-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.column-pill {
  background: var(--bg-pill);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
}

/* Instructions section */
.instructions-section {
  grid-column: 1 / -1;
  margin-top: 0;
}

.instruction-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
}

@media (max-width: 768px) {
  .instruction-grid {
    grid-template-columns: 1fr;
  }
}

.instruction-card {
  background: var(--bg-instruction-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
}

.instruction-step {
  position: absolute;
  top: -10px;
  right: -10px;
  font-size: 4rem;
  font-weight: 900;
  color: var(--color-instruction-step);
  line-height: 1;
}

.instruction-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.instruction-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Notification banner */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.toast {
  background: var(--bg-toast);
  border-left: 4px solid var(--accent-cyan);
  border-top: 1px solid var(--border-color);
  border-right: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 1rem 1.25rem;
  border-radius: 0 8px 8px 0;
  box-shadow: var(--shadow-toast);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 280px;
  max-width: 400px;
  animation: slide-in 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.toast.success {
  border-left-color: var(--accent-success);
}

.toast.error {
  border-left-color: var(--accent-error);
}

@keyframes slide-in {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

footer {
  text-align: center;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

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

footer a:hover {
  color: var(--accent-cyan);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  position: absolute;
  top: 2rem;
  right: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-normal);
  z-index: 100;
  outline: none;
}

.theme-toggle-btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2.5px);
}

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

@media (max-width: 640px) {
  .theme-toggle-btn {
    top: 1rem;
    right: 1rem;
    width: 38px;
    height: 38px;
    font-size: 1.1rem;
  }
}