/* ============================================================================
   TSI Foundation v2.1.0
   2026-04-04

   GLOBAL COMPONENT LIBRARY for the TSI App (219 pages).

   This stylesheet provides reusable components, micro-interactions, skeleton
   loading states, and the dark-mode-first base layer consumed by every page
   in the application.

   DEPENDS ON:
     tsi-tokens.css  --  all --tsi-* custom properties are defined there.
                         This file REFERENCES tokens only; it never redefines them.

   LOAD ORDER (every <head>):
     1. tsi-tokens.css      (custom properties)
     2. tsi-foundation.css  (this file -- reset, components, utilities)
     3. page-specific CSS   (feature styles)

   SECTIONS:
     A. Import & View Transitions
     B. Base Reset & Defaults
     C. Accessibility (reduced motion, high contrast, skip link)
     D. Glass Panel
     E. Card System
     F. Button System
     G. Badge System
     H. Status Indicators
     I. Form Inputs
     J. Audio Player Component
     K. Skeleton Loading
     L. Toast / Notification
     M. Modal
     N. Stats / Metric Display
     O. Grid Utilities
     P. Flex Utilities
     Q. Spacing Utilities
     R. Text Utilities
     S. Micro-Interaction Keyframes
     T. Scroll-Driven Animations
     U. Achievement Celebration
     V. Responsive Breakpoints
   ========================================================================= */


/* ============================================================================
   A. IMPORT & VIEW TRANSITIONS
   ========================================================================= */

@import url('tsi-tokens.css');

/* Native MPA view transitions (Chrome 126+, progressive enhancement) */
@view-transition {
  navigation: auto;
}

::view-transition-old(root) {
  animation: tsi-vt-fade-out 200ms ease-out;
}

::view-transition-new(root) {
  animation: tsi-vt-fade-in 200ms ease-in;
}

@keyframes tsi-vt-fade-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

@keyframes tsi-vt-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}


/* ============================================================================
   B. BASE RESET & DEFAULTS
   ========================================================================= */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--tsi-font-primary);
  font-size: var(--tsi-text-base);
  font-weight: var(--tsi-weight-normal);
  line-height: var(--tsi-leading-normal);
  color: var(--tsi-text);
  background-color: var(--tsi-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
}

::selection {
  background-color: var(--tsi-orange);
  color: var(--tsi-text-inverse);
}

::-moz-selection {
  background-color: var(--tsi-orange);
  color: var(--tsi-text-inverse);
}

/* Scrollbar (WebKit + standard) */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--tsi-bg-deep);
}

::-webkit-scrollbar-thumb {
  background: var(--tsi-orange-dark);
  border-radius: var(--tsi-radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--tsi-orange);
}

* {
  scrollbar-width: thin;
  scrollbar-color: var(--tsi-orange-dark) var(--tsi-bg-deep);
}

/* Focus-visible for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--tsi-orange);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* Base elements */
img,
svg,
video {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--tsi-orange);
  text-decoration: none;
  transition: color var(--tsi-duration-fast) var(--tsi-ease);
}

a:hover {
  color: var(--tsi-orange-bright);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--tsi-font-heading);
  line-height: var(--tsi-leading-tight);
  color: var(--tsi-text);
}

ul, ol {
  list-style: none;
}

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

table {
  border-collapse: collapse;
  width: 100%;
}


/* ============================================================================
   C. ACCESSIBILITY
   ========================================================================= */

/* Reduced motion -- disable all transitions and animations */
@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;
  }
}

/* High contrast -- solid backgrounds, stronger borders */
@media (prefers-contrast: more) {
  .tsi-glass {
    background: var(--tsi-bg-elevated) !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    border-color: var(--tsi-border-strong) !important;
  }

  .tsi-card {
    border-color: var(--tsi-border-strong) !important;
    background: var(--tsi-bg-elevated) !important;
  }

  .tsi-input,
  .tsi-select,
  .tsi-textarea {
    border-color: var(--tsi-border-strong) !important;
  }
}

/* Skip-to-content link */
.tsi-skip-link {
  position: absolute;
  top: -100%;
  left: var(--tsi-space-4);
  z-index: var(--tsi-z-max);
  padding: var(--tsi-space-2) var(--tsi-space-4);
  background: var(--tsi-orange);
  color: var(--tsi-text-inverse);
  font-weight: var(--tsi-weight-bold);
  border-radius: var(--tsi-radius-md);
  transition: top var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-skip-link:focus {
  top: var(--tsi-space-4);
}


/* ============================================================================
   D. GLASS PANEL
   ========================================================================= */

.tsi-glass {
  background: var(--tsi-glass-bg);
  backdrop-filter: blur(var(--tsi-glass-blur));
  -webkit-backdrop-filter: blur(var(--tsi-glass-blur));
  border: 1px solid var(--tsi-glass-border);
  border-radius: var(--tsi-radius-lg);
}


/* ============================================================================
   E. CARD SYSTEM
   ========================================================================= */

.tsi-card {
  background: var(--tsi-bg-raised);
  border: 1px solid var(--tsi-border);
  border-radius: var(--tsi-radius-lg);
  padding: var(--tsi-space-5);
  transition:
    transform var(--tsi-duration-normal) var(--tsi-ease),
    box-shadow var(--tsi-duration-normal) var(--tsi-ease);
}

.tsi-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--tsi-shadow-lg);
}

.tsi-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--tsi-space-3);
  margin-bottom: var(--tsi-space-4);
}

.tsi-card-header h3,
.tsi-card-header h4 {
  margin: 0;
  flex: 1;
}

.tsi-card-body {
  padding: var(--tsi-space-2) 0;
}

.tsi-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--tsi-space-3);
  border-top: 1px solid var(--tsi-border);
  padding-top: var(--tsi-space-4);
  margin-top: var(--tsi-space-4);
  color: var(--tsi-text-muted);
  font-size: var(--tsi-text-sm);
}


/* ============================================================================
   F. BUTTON SYSTEM
   ========================================================================= */

.tsi-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--tsi-space-2);
  padding: var(--tsi-space-2) var(--tsi-space-5);
  font-family: var(--tsi-font-primary);
  font-size: var(--tsi-text-sm);
  font-weight: var(--tsi-weight-semibold);
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--tsi-radius-md);
  cursor: pointer;
  white-space: nowrap;
  user-select: none;
  text-decoration: none;
  transition: all var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-btn:hover {
  filter: brightness(1.15);
}

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

/* Primary -- orange gradient */
.tsi-btn-primary {
  background: linear-gradient(135deg, var(--tsi-orange), var(--tsi-orange-bright));
  color: var(--tsi-text-inverse);
  box-shadow: var(--tsi-glow-orange);
}

.tsi-btn-primary:hover {
  box-shadow: 0 0 28px rgba(255, 102, 0, 0.6);
}

/* Secondary -- dark bg, orange border */
.tsi-btn-secondary {
  background: var(--tsi-bg-elevated);
  border-color: var(--tsi-orange);
  color: var(--tsi-orange);
}

.tsi-btn-secondary:hover {
  background: rgba(255, 102, 0, 0.1);
}

/* Success -- green gradient */
.tsi-btn-success {
  background: linear-gradient(135deg, var(--tsi-green-soft), var(--tsi-green-dark));
  color: #fff;
}

/* Danger -- red gradient */
.tsi-btn-danger {
  background: linear-gradient(135deg, var(--tsi-red), var(--tsi-red-dark));
  color: #fff;
}

/* Ghost -- transparent */
.tsi-btn-ghost {
  background: transparent;
  color: var(--tsi-text);
}

.tsi-btn-ghost:hover {
  background: var(--tsi-bg-hover);
  filter: none;
}

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

/* Size variants */
.tsi-btn-sm {
  padding: var(--tsi-space-1) var(--tsi-space-3);
  font-size: var(--tsi-text-xs);
}

.tsi-btn-lg {
  padding: var(--tsi-space-3) var(--tsi-space-8);
  font-size: var(--tsi-text-lg);
}

/* Disabled */
.tsi-btn:disabled,
.tsi-btn[disabled] {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.tsi-btn:disabled:hover,
.tsi-btn[disabled]:hover {
  filter: none;
  transform: none;
  box-shadow: none;
}


/* ============================================================================
   G. BADGE SYSTEM
   ========================================================================= */

.tsi-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--tsi-space-1);
  padding: 2px var(--tsi-space-2);
  font-size: var(--tsi-text-xs);
  font-weight: var(--tsi-weight-semibold);
  line-height: 1.4;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-radius: var(--tsi-radius-full);
  white-space: nowrap;
}

.tsi-badge-orange {
  background: rgba(255, 102, 0, 0.2);
  color: var(--tsi-orange-bright);
}

.tsi-badge-green {
  background: rgba(76, 175, 80, 0.2);
  color: var(--tsi-green-soft);
}

.tsi-badge-red {
  background: rgba(244, 67, 54, 0.2);
  color: var(--tsi-red);
}

.tsi-badge-blue {
  background: rgba(33, 150, 243, 0.2);
  color: var(--tsi-blue);
}

.tsi-badge-gold {
  background: rgba(255, 215, 0, 0.2);
  color: var(--tsi-gold);
}

/* Outline variant */
.tsi-badge-outline {
  background: transparent;
  border: 1px solid currentColor;
}

/* Pulse animation for live/active */
.tsi-badge-pulse {
  animation: tsi-pulse 2s ease-in-out infinite;
}


/* ============================================================================
   H. STATUS INDICATORS
   ========================================================================= */

.tsi-status-dot {
  display: inline-flex;
  align-items: center;
  gap: var(--tsi-space-2);
}

.tsi-status-dot::before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: var(--tsi-radius-round);
  flex-shrink: 0;
}

.tsi-status-dot--active::before {
  background: var(--tsi-status-active);
  box-shadow: 0 0 6px var(--tsi-status-active);
  animation: tsi-pulse 2s ease-in-out infinite;
}

.tsi-status-dot--warning::before {
  background: var(--tsi-status-warning);
  box-shadow: 0 0 6px var(--tsi-status-warning);
}

.tsi-status-dot--error::before {
  background: var(--tsi-status-error);
  box-shadow: 0 0 6px var(--tsi-status-error);
}

.tsi-status-dot--inactive::before {
  background: var(--tsi-status-inactive);
}


/* ============================================================================
   I. FORM INPUTS
   ========================================================================= */

.tsi-label {
  display: block;
  font-size: var(--tsi-text-xs);
  font-weight: var(--tsi-weight-semibold);
  color: var(--tsi-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: var(--tsi-space-1);
}

.tsi-input {
  display: block;
  width: 100%;
  padding: var(--tsi-space-2) var(--tsi-space-3);
  font-family: var(--tsi-font-primary);
  font-size: var(--tsi-text-base);
  color: var(--tsi-text);
  background: var(--tsi-bg-input);
  border: 1px solid var(--tsi-border);
  border-radius: var(--tsi-radius-md);
  transition:
    border-color var(--tsi-duration-fast) var(--tsi-ease),
    box-shadow var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-input::placeholder {
  color: var(--tsi-text-dim);
}

.tsi-input:focus {
  outline: none;
  border-color: var(--tsi-border-focus);
  box-shadow: 0 0 0 3px rgba(255, 102, 0, 0.2);
}

/* Select */
.tsi-select {
  display: block;
  width: 100%;
  padding: var(--tsi-space-2) var(--tsi-space-8) var(--tsi-space-2) var(--tsi-space-3);
  font-family: var(--tsi-font-primary);
  font-size: var(--tsi-text-base);
  color: var(--tsi-text);
  background: var(--tsi-bg-input);
  border: 1px solid var(--tsi-border);
  border-radius: var(--tsi-radius-md);
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' fill='none'%3E%3Cpath d='M1 1.5l5 5 5-5' stroke='rgba(255,255,255,0.6)' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--tsi-space-3) center;
  cursor: pointer;
  transition:
    border-color var(--tsi-duration-fast) var(--tsi-ease),
    box-shadow var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-select:focus {
  outline: none;
  border-color: var(--tsi-border-focus);
  box-shadow: 0 0 0 3px rgba(255, 102, 0, 0.2);
}

/* Textarea */
.tsi-textarea {
  display: block;
  width: 100%;
  min-height: 100px;
  padding: var(--tsi-space-3);
  font-family: var(--tsi-font-primary);
  font-size: var(--tsi-text-base);
  color: var(--tsi-text);
  background: var(--tsi-bg-input);
  border: 1px solid var(--tsi-border);
  border-radius: var(--tsi-radius-md);
  resize: vertical;
  transition:
    border-color var(--tsi-duration-fast) var(--tsi-ease),
    box-shadow var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-textarea::placeholder {
  color: var(--tsi-text-dim);
}

.tsi-textarea:focus {
  outline: none;
  border-color: var(--tsi-border-focus);
  box-shadow: 0 0 0 3px rgba(255, 102, 0, 0.2);
}


/* ============================================================================
   J. AUDIO PLAYER COMPONENT
   ========================================================================= */

.tsi-audio-player {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  align-items: center;
  gap: var(--tsi-space-3);
  padding: var(--tsi-space-3) var(--tsi-space-4);
  background: var(--tsi-glass-bg);
  backdrop-filter: blur(var(--tsi-glass-blur));
  -webkit-backdrop-filter: blur(var(--tsi-glass-blur));
  border: 1px solid var(--tsi-glass-border);
  border-radius: var(--tsi-radius-lg);
}

.tsi-audio-player__play-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--tsi-radius-round);
  background: linear-gradient(135deg, var(--tsi-orange), var(--tsi-orange-bright));
  color: var(--tsi-text-inverse);
  border: none;
  cursor: pointer;
  flex-shrink: 0;
  transition: all var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-audio-player__play-btn:hover {
  box-shadow: var(--tsi-glow-orange);
  transform: scale(1.05);
}

.tsi-audio-player__play-btn:active {
  transform: scale(0.95);
}

.tsi-audio-player__waveform {
  min-width: 0;
  height: 40px;
  flex: 1;
}

.tsi-audio-player__time {
  font-family: var(--tsi-font-mono);
  font-size: var(--tsi-text-xs);
  color: var(--tsi-text-muted);
  white-space: nowrap;
}

.tsi-audio-player__volume {
  display: flex;
  align-items: center;
  gap: var(--tsi-space-1);
}

.tsi-audio-player__volume input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 64px;
  height: 4px;
  background: var(--tsi-bg-active);
  border-radius: var(--tsi-radius-full);
  outline: none;
}

.tsi-audio-player__volume input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: var(--tsi-radius-round);
  background: var(--tsi-orange);
  cursor: pointer;
}

.tsi-audio-player__volume input[type="range"]::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border-radius: var(--tsi-radius-round);
  background: var(--tsi-orange);
  border: none;
  cursor: pointer;
}

.tsi-audio-player__credit {
  grid-column: 1 / -1;
  font-size: var(--tsi-text-xs);
  color: var(--tsi-text-dim);
  padding-top: var(--tsi-space-1);
  border-top: 1px solid var(--tsi-border-subtle);
}


/* ============================================================================
   K. SKELETON LOADING
   ========================================================================= */

@keyframes tsi-shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.tsi-skeleton {
  background: linear-gradient(
    90deg,
    var(--tsi-bg-raised) 25%,
    var(--tsi-bg-hover) 50%,
    var(--tsi-bg-raised) 75%
  );
  background-size: 200% 100%;
  animation: tsi-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--tsi-radius-sm);
  pointer-events: none;
  user-select: none;
}

.tsi-skeleton-text {
  height: 1em;
  width: 80%;
  margin-bottom: 0.5em;
}

.tsi-skeleton-title {
  height: 1.5em;
  width: 60%;
  margin-bottom: 0.75em;
}

.tsi-skeleton-avatar {
  width: 48px;
  height: 48px;
  border-radius: var(--tsi-radius-round);
}

.tsi-skeleton-card {
  height: 160px;
  width: 100%;
  border-radius: var(--tsi-radius-lg);
}


/* ============================================================================
   L. TOAST / NOTIFICATION
   ========================================================================= */

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

@keyframes tsi-toast-out {
  from {
    opacity: 1;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(100%);
  }
}

.tsi-toast-container {
  position: fixed;
  bottom: var(--tsi-space-6);
  right: var(--tsi-space-6);
  z-index: var(--tsi-z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--tsi-space-2);
  pointer-events: none;
  max-width: 400px;
}

.tsi-toast {
  display: flex;
  align-items: flex-start;
  gap: var(--tsi-space-3);
  padding: var(--tsi-space-3) var(--tsi-space-4);
  background: var(--tsi-glass-bg);
  backdrop-filter: blur(var(--tsi-glass-blur));
  -webkit-backdrop-filter: blur(var(--tsi-glass-blur));
  border: 1px solid var(--tsi-glass-border);
  border-left: 4px solid var(--tsi-status-info);
  border-radius: var(--tsi-radius-md);
  box-shadow: var(--tsi-shadow-lg);
  color: var(--tsi-text);
  font-size: var(--tsi-text-sm);
  pointer-events: auto;
  animation:
    tsi-toast-in 300ms var(--tsi-ease) forwards,
    tsi-toast-out 300ms var(--tsi-ease) 4s forwards;
}

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

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

.tsi-toast--warning {
  border-left-color: var(--tsi-status-warning);
}

.tsi-toast--info {
  border-left-color: var(--tsi-status-info);
}


/* ============================================================================
   M. MODAL
   ========================================================================= */

@keyframes tsi-modal-overlay-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes tsi-modal-scale-in {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.tsi-modal-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--tsi-z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--tsi-space-6);
  background: rgba(0, 0, 0, 0.7);
  animation: tsi-modal-overlay-in 200ms var(--tsi-ease);
}

.tsi-modal {
  background: var(--tsi-glass-bg-light);
  backdrop-filter: blur(var(--tsi-glass-blur));
  -webkit-backdrop-filter: blur(var(--tsi-glass-blur));
  border: 1px solid var(--tsi-glass-border);
  border-radius: var(--tsi-radius-xl);
  box-shadow: var(--tsi-shadow-xl);
  width: 100%;
  max-width: 600px;
  max-height: 80vh;
  overflow-y: auto;
  animation: tsi-modal-scale-in 200ms var(--tsi-ease);
}

.tsi-modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--tsi-space-3);
  padding: var(--tsi-space-5) var(--tsi-space-6);
  border-bottom: 1px solid var(--tsi-border);
}

.tsi-modal-header h2,
.tsi-modal-header h3 {
  margin: 0;
  flex: 1;
}

.tsi-modal-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: none;
  background: transparent;
  color: var(--tsi-text-muted);
  font-size: var(--tsi-text-xl);
  cursor: pointer;
  border-radius: var(--tsi-radius-md);
  transition: all var(--tsi-duration-fast) var(--tsi-ease);
}

.tsi-modal-close:hover {
  background: var(--tsi-bg-hover);
  color: var(--tsi-text);
}

.tsi-modal-body {
  padding: var(--tsi-space-6);
}

.tsi-modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--tsi-space-3);
  padding: var(--tsi-space-4) var(--tsi-space-6);
  border-top: 1px solid var(--tsi-border);
}


/* ============================================================================
   N. STATS / METRIC DISPLAY
   ========================================================================= */

.tsi-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--tsi-space-1);
}

.tsi-stat-value {
  font-size: var(--tsi-text-3xl);
  font-weight: var(--tsi-weight-bold);
  color: var(--tsi-orange);
  line-height: 1;
}

.tsi-stat-label {
  font-size: var(--tsi-text-sm);
  color: var(--tsi-text-muted);
}

.tsi-stat-row {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--tsi-space-8);
  flex-wrap: wrap;
}


/* ============================================================================
   O. GRID UTILITIES
   ========================================================================= */

.tsi-grid {
  display: grid;
  gap: var(--tsi-space-4);
}

.tsi-grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.tsi-grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.tsi-grid-4 {
  grid-template-columns: repeat(4, 1fr);
}


/* ============================================================================
   P. FLEX UTILITIES
   ========================================================================= */

.tsi-flex          { display: flex; }
.tsi-flex-center   { display: flex; align-items: center; justify-content: center; }
.tsi-flex-between  { display: flex; align-items: center; justify-content: space-between; }
.tsi-flex-col      { display: flex; flex-direction: column; }
.tsi-flex-wrap     { flex-wrap: wrap; }

.tsi-gap-1  { gap: var(--tsi-space-1); }
.tsi-gap-2  { gap: var(--tsi-space-2); }
.tsi-gap-3  { gap: var(--tsi-space-3); }
.tsi-gap-4  { gap: var(--tsi-space-4); }
.tsi-gap-5  { gap: var(--tsi-space-5); }
.tsi-gap-6  { gap: var(--tsi-space-6); }
.tsi-gap-8  { gap: var(--tsi-space-8); }


/* ============================================================================
   Q. SPACING UTILITIES
   ========================================================================= */

/* Padding */
.tsi-p-1  { padding: var(--tsi-space-1); }
.tsi-p-2  { padding: var(--tsi-space-2); }
.tsi-p-3  { padding: var(--tsi-space-3); }
.tsi-p-4  { padding: var(--tsi-space-4); }
.tsi-p-5  { padding: var(--tsi-space-5); }
.tsi-p-6  { padding: var(--tsi-space-6); }
.tsi-p-8  { padding: var(--tsi-space-8); }

/* Margin */
.tsi-m-1  { margin: var(--tsi-space-1); }
.tsi-m-2  { margin: var(--tsi-space-2); }
.tsi-m-3  { margin: var(--tsi-space-3); }
.tsi-m-4  { margin: var(--tsi-space-4); }
.tsi-m-5  { margin: var(--tsi-space-5); }
.tsi-m-6  { margin: var(--tsi-space-6); }
.tsi-m-8  { margin: var(--tsi-space-8); }

/* Margin-top */
.tsi-mt-1 { margin-top: var(--tsi-space-1); }
.tsi-mt-2 { margin-top: var(--tsi-space-2); }
.tsi-mt-3 { margin-top: var(--tsi-space-3); }
.tsi-mt-4 { margin-top: var(--tsi-space-4); }
.tsi-mt-5 { margin-top: var(--tsi-space-5); }
.tsi-mt-6 { margin-top: var(--tsi-space-6); }
.tsi-mt-8 { margin-top: var(--tsi-space-8); }

/* Margin-bottom */
.tsi-mb-1 { margin-bottom: var(--tsi-space-1); }
.tsi-mb-2 { margin-bottom: var(--tsi-space-2); }
.tsi-mb-3 { margin-bottom: var(--tsi-space-3); }
.tsi-mb-4 { margin-bottom: var(--tsi-space-4); }
.tsi-mb-5 { margin-bottom: var(--tsi-space-5); }
.tsi-mb-6 { margin-bottom: var(--tsi-space-6); }
.tsi-mb-8 { margin-bottom: var(--tsi-space-8); }


/* ============================================================================
   R. TEXT UTILITIES
   ========================================================================= */

/* Sizes */
.tsi-text-xs  { font-size: var(--tsi-text-xs); }
.tsi-text-sm  { font-size: var(--tsi-text-sm); }
.tsi-text-base { font-size: var(--tsi-text-base); }
.tsi-text-lg  { font-size: var(--tsi-text-lg); }
.tsi-text-xl  { font-size: var(--tsi-text-xl); }
.tsi-text-2xl { font-size: var(--tsi-text-2xl); }
.tsi-text-3xl { font-size: var(--tsi-text-3xl); }
.tsi-text-4xl { font-size: var(--tsi-text-4xl); }
.tsi-text-5xl { font-size: var(--tsi-text-5xl); }

/* Colors */
.tsi-text-muted  { color: var(--tsi-text-muted); }
.tsi-text-orange { color: var(--tsi-orange); }
.tsi-text-green  { color: var(--tsi-green-soft); }
.tsi-text-red    { color: var(--tsi-red); }
.tsi-text-blue   { color: var(--tsi-blue); }
.tsi-text-gold   { color: var(--tsi-gold); }

/* Alignment */
.tsi-text-center { text-align: center; }
.tsi-text-right  { text-align: right; }
.tsi-text-left   { text-align: left; }

/* Weight */
.tsi-text-bold     { font-weight: var(--tsi-weight-bold); }
.tsi-text-semibold { font-weight: var(--tsi-weight-semibold); }
.tsi-text-black    { font-weight: var(--tsi-weight-black); }

/* Special */
.tsi-text-mono      { font-family: var(--tsi-font-mono); }
.tsi-text-uppercase { text-transform: uppercase; letter-spacing: 0.08em; }


/* ============================================================================
   S. MICRO-INTERACTION KEYFRAMES
   ========================================================================= */

@keyframes tsi-pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: 0.6; }
}

@keyframes tsi-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes tsi-fade-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

@keyframes tsi-slide-up {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes tsi-slide-down {
  from { opacity: 0; transform: translateY(-12px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes tsi-spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}


/* ============================================================================
   T. SCROLL-DRIVEN ANIMATIONS
   ========================================================================= */

@supports (animation-timeline: scroll()) {
  .tsi-scroll-fade-in {
    animation: tsi-scroll-reveal linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 100%;
  }

  @keyframes tsi-scroll-reveal {
    from {
      opacity: 0;
      transform: translateY(20px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
}


/* ============================================================================
   U. ACHIEVEMENT CELEBRATION
   ========================================================================= */

@keyframes tsi-celebrate {
  0%   { transform: scale(1);   box-shadow: 0 0 0 0 rgba(255, 215, 0, 0.4); }
  40%  { transform: scale(1.2); box-shadow: 0 0 30px 8px rgba(255, 215, 0, 0.6); }
  60%  { transform: scale(1.1); box-shadow: 0 0 20px 4px rgba(255, 215, 0, 0.3); }
  100% { transform: scale(1);   box-shadow: 0 0 0 0 rgba(255, 215, 0, 0); }
}

.tsi-celebrate {
  animation: tsi-celebrate 600ms var(--tsi-ease-spring);
}


/* ============================================================================
   V. RESPONSIVE BREAKPOINTS
   ========================================================================= */

/* Tablet (768px) */
@media (max-width: 768px) {
  .tsi-grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .tsi-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .tsi-stat-row {
    gap: var(--tsi-space-5);
  }

  .tsi-audio-player {
    grid-template-columns: auto 1fr auto;
  }

  .tsi-audio-player__volume {
    grid-column: 1 / -1;
    justify-content: flex-end;
  }
}

/* Small tablet / large phone (640px) */
@media (max-width: 640px) {
  /* Modal becomes bottom sheet */
  .tsi-modal-overlay {
    align-items: flex-end;
    padding: 0;
  }

  .tsi-modal {
    max-width: 100%;
    max-height: 90vh;
    border-radius: var(--tsi-radius-xl) var(--tsi-radius-xl) 0 0;
    animation: tsi-modal-slide-up 300ms var(--tsi-ease);
  }

  @keyframes tsi-modal-slide-up {
    from {
      opacity: 0;
      transform: translateY(100%);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  .tsi-toast-container {
    left: var(--tsi-space-3);
    right: var(--tsi-space-3);
    bottom: var(--tsi-space-3);
    max-width: 100%;
  }
}

/* Mobile (480px) */
@media (max-width: 480px) {
  body {
    font-size: var(--tsi-text-sm);
  }

  .tsi-grid-2,
  .tsi-grid-3,
  .tsi-grid-4 {
    grid-template-columns: 1fr;
  }

  .tsi-card {
    padding: var(--tsi-space-4);
    border-radius: var(--tsi-radius-md);
  }

  .tsi-card:hover {
    transform: none;
  }

  .tsi-btn-lg {
    padding: var(--tsi-space-2) var(--tsi-space-5);
    font-size: var(--tsi-text-base);
  }

  .tsi-stat-value {
    font-size: var(--tsi-text-2xl);
  }

  .tsi-stat-row {
    gap: var(--tsi-space-4);
  }

  .tsi-modal-header,
  .tsi-modal-body,
  .tsi-modal-footer {
    padding-left: var(--tsi-space-4);
    padding-right: var(--tsi-space-4);
  }

  h1 { font-size: var(--tsi-text-2xl); }
  h2 { font-size: var(--tsi-text-xl); }
  h3 { font-size: var(--tsi-text-lg); }
}
