/**
 * 小虾米 PWA - Friendly Assistant Design System
 * Complete visual overhaul with shrimp mascot integration
 */

/* ============================================
   CSS VARIABLES & DESIGN TOKENS
   ============================================ */
:root {
  /* Primary Palette - Extracted from shrimp logo */
  --coral: #F27059;
  --coral-dark: #E85A4F;
  --coral-light: #FF8A75;
  --teal: #2EC4B6;
  --teal-dark: #25A59A;
  --teal-light: #4DD4C7;
  
  /* Neutral Palette - Warm, not cold */
  --cream: #FDF8F5;
  --cream-dark: #F5F0ED;
  --white: #FFFFFF;
  --charcoal: #1F2937;
  --gray-700: #374151;
  --gray-500: #6B7280;
  --gray-400: #9CA3AF;
  --gray-200: #E5E7EB;
  --gray-100: #F3F4F6;
  
  /* Semantic Colors */
  --success: #10B981;
  --success-light: #D1FAE5;
  --warning: #F59E0B;
  --warning-light: #FEF3C7;
  --error: #EF4444;
  --error-light: #FEE2E2;
  
  /* Shadows - Soft, organic */
  --shadow-sm: 0 1px 2px rgba(31, 41, 55, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(31, 41, 55, 0.1), 0 2px 4px -1px rgba(31, 41, 55, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(31, 41, 55, 0.1), 0 4px 6px -2px rgba(31, 41, 55, 0.05);
  --shadow-coral: 0 4px 12px rgba(242, 112, 89, 0.3);
  --shadow-teal: 0 4px 12px rgba(46, 196, 182, 0.3);
  --shadow-card: 0 2px 8px rgba(46, 196, 182, 0.08);
  --shadow-card-hover: 0 8px 24px rgba(46, 196, 182, 0.12);
  
  /* Spacing Scale - 8px grid */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  
  /* Border Radius - Organic curves */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;
  
  /* Safe Areas */
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
  
  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans CJK SC', sans-serif;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
  :root {
    --cream: #0F172A;
    --cream-dark: #1E293B;
    --white: #1E293B;
    --charcoal: #F1F5F9;
    --gray-700: #E2E8F0;
    --gray-500: #94A3B8;
    --gray-400: #64748B;
    --gray-200: #334155;
    --gray-100: #1E293B;
    --shadow-card: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-card-hover: 0 8px 24px rgba(0, 0, 0, 0.4);
  }
}

/* ============================================
   BASE & RESET
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  background: var(--cream);
  color: var(--charcoal);
  line-height: 1.6;
  min-height: 100vh;
  min-height: 100dvh;
  padding-top: var(--safe-top);
  padding-bottom: var(--safe-bottom);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ============================================
   APP CONTAINER
   ============================================ */
#app {
  max-width: 100%;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ============================================
   HEADER
   ============================================ */
.header {
  background: linear-gradient(135deg, var(--cream) 0%, var(--white) 100%);
  padding: var(--space-5);
  padding-top: calc(var(--space-5) + var(--safe-top));
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-content {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.header-logo {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--coral) 0%, var(--coral-light) 100%);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  box-shadow: var(--shadow-coral);
  flex-shrink: 0;
  animation: gentle-float 3s ease-in-out infinite;
}

.header-text {
  flex: 1;
}

.header-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--charcoal);
  line-height: 1.2;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-subtitle {
  font-size: 14px;
  color: var(--gray-500);
  margin-top: var(--space-1);
  font-weight: 500;
}

/* ============================================
   NAVIGATION TABS
   ============================================ */
.nav-tabs {
  display: flex;
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  padding: 0 var(--space-5);
  gap: var(--space-6);
}

.nav-tabs::-webkit-scrollbar {
  display: none;
}

.nav-tab {
  flex: 0 0 auto;
  padding: var(--space-4) 0;
  font-size: 15px;
  font-weight: 600;
  color: var(--gray-500);
  background: none;
  border: none;
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--transition-fast);
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-tab:hover {
  color: var(--teal);
}

.nav-tab.active {
  color: var(--teal);
}

.nav-tab.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal) 0%, var(--teal-light) 100%);
  border-radius: var(--radius-full) var(--radius-full) 0 0;
  animation: slide-in var(--transition-base);
}

.nav-tab-icon {
  font-size: 18px;
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.main-content {
  flex: 1;
  padding: var(--space-5);
  padding-bottom: calc(var(--space-10) + var(--safe-bottom));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

/* ============================================
   SECTIONS
   ============================================ */
.section-header {
  margin-bottom: var(--space-5);
}

.section-title {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--gray-500);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.section-title-icon {
  font-size: 16px;
}

.section-description {
  font-size: 14px;
  color: var(--gray-500);
  line-height: 1.5;
}

/* ============================================
   SKILL CARDS
   ============================================ */
.skills-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.skill-card {
  background: var(--white);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

/* Shrimp watermark - MORE VISIBLE */
.skill-card::before {
  content: '🦐';
  position: absolute;
  top: -8px;
  right: -8px;
  font-size: 64px;
  opacity: 0.12;
  transform: rotate(25deg);
  pointer-events: none;
  z-index: 0;
  transition: all var(--transition-base);
}

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

.skill-card:hover::before {
  opacity: 0.18;
  transform: rotate(20deg) scale(1.05);
}

.skill-card:active {
  transform: scale(0.98) translateY(2px);
  box-shadow: var(--shadow-sm);
}

.skill-card:active::before {
  transform: rotate(25deg) scale(0.95);
}

/* Premium Card */
.skill-card.premium {
  background: linear-gradient(135deg, var(--white) 0%, #FFF5F3 100%);
  border-color: var(--coral-light);
}

.skill-card.premium::before {
  font-size: 80px;
  opacity: 0.15;
  top: -12px;
  right: -12px;
}

/* Installed Card */
.skill-card.installed {
  border-color: var(--teal);
  box-shadow: 0 2px 12px rgba(46, 196, 182, 0.15);
}

.skill-card.installed::before {
  opacity: 0.2;
}

.skill-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
  position: relative;
  z-index: 1;
}

.skill-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--cream) 0%, var(--cream-dark) 100%);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.skill-icon.premium-icon {
  background: linear-gradient(135deg, var(--coral-light) 0%, var(--coral) 100%);
  box-shadow: var(--shadow-coral);
}

.skill-info {
  flex: 1;
  min-width: 0;
}

.skill-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--charcoal);
  margin-bottom: var(--space-1);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.skill-category {
  font-size: 12px;
  color: var(--gray-500);
  text-transform: capitalize;
  font-weight: 500;
}

.skill-badges {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.skill-badge {
  font-size: 10px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.skill-badge.premium {
  background: linear-gradient(135deg, #FFD700, #FFA500);
  color: #8B4513;
  box-shadow: 0 2px 4px rgba(255, 165, 0, 0.3);
}

.skill-badge.installed {
  background: var(--teal);
  color: white;
}

.skill-badge.new {
  background: var(--coral);
  color: white;
}

.skill-description {
  font-size: 14px;
  color: var(--gray-500);
  line-height: 1.6;
  margin-bottom: var(--space-4);
  position: relative;
  z-index: 1;
}

.skill-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
}

.skill-tags {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.skill-tag {
  font-size: 11px;
  padding: var(--space-1) var(--space-3);
  background: var(--cream);
  border-radius: var(--radius-md);
  color: var(--gray-500);
  font-weight: 500;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  white-space: nowrap;
  min-height: 44px;
  position: relative;
  overflow: hidden;
}

.btn:active {
  transform: scale(0.96);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: linear-gradient(135deg, var(--coral) 0%, var(--coral-dark) 100%);
  color: white;
  box-shadow: var(--shadow-coral);
}

.btn-primary:hover:not(:disabled) {
  box-shadow: 0 6px 16px rgba(242, 112, 89, 0.4);
  transform: translateY(-1px);
}

.btn-primary:active {
  background: var(--coral-dark);
}

.btn-secondary {
  background: linear-gradient(135deg, var(--teal) 0%, var(--teal-dark) 100%);
  color: white;
  box-shadow: var(--shadow-teal);
}

.btn-secondary:hover:not(:disabled) {
  box-shadow: 0 6px 16px rgba(46, 196, 182, 0.4);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--gray-200);
  color: var(--charcoal);
}

.btn-outline:hover:not(:disabled) {
  border-color: var(--teal);
  color: var(--teal);
  background: rgba(46, 196, 182, 0.05);
}

.btn-ghost {
  background: transparent;
  color: var(--teal);
  border: 2px solid var(--teal);
}

.btn-ghost:hover:not(:disabled) {
  background: var(--teal);
  color: white;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 13px;
  min-height: 36px;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
}

/* ============================================
   EMPTY STATES
   ============================================ */
.empty-state {
  text-align: center;
  padding: var(--space-12) var(--space-5);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
}

.empty-state-illustration {
  width: 160px;
  height: 160px;
  background: linear-gradient(135deg, var(--cream) 0%, var(--cream-dark) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 80px;
  margin-bottom: var(--space-4);
  box-shadow: var(--shadow-md);
  position: relative;
  animation: gentle-float 4s ease-in-out infinite;
}

.empty-state-illustration::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 20px;
  background: rgba(0, 0, 0, 0.1);
  border-radius: 50%;
  filter: blur(8px);
  animation: shadow-pulse 4s ease-in-out infinite;
}

.empty-state-icon {
  font-size: 80px;
  margin-bottom: var(--space-4);
  animation: gentle-float 4s ease-in-out infinite;
}

.empty-state-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--charcoal);
  margin-bottom: var(--space-2);
}

.empty-state-message {
  font-size: 15px;
  color: var(--gray-500);
  line-height: 1.6;
  max-width: 280px;
}

.empty-state-action {
  margin-top: var(--space-6);
}

/* ============================================
   LOADING STATES
   ============================================ */
.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-12) var(--space-5);
  gap: var(--space-6);
}

.loading-shrimp {
  width: 100px;
  height: 100px;
  background: linear-gradient(135deg, var(--cream) 0%, var(--cream-dark) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 60px;
  position: relative;
  animation: thinking 2s ease-in-out infinite;
}

.loading-shrimp::before {
  content: '⋯';
  position: absolute;
  top: -20px;
  font-size: 24px;
  color: var(--teal);
  animation: pulse 1s ease-in-out infinite;
}

.loading-shrimp::after {
  content: '⋯';
  position: absolute;
  top: -20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 24px;
  color: var(--teal);
  animation: pulse 1s ease-in-out infinite 0.2s;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--gray-200);
  border-top-color: var(--teal);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text {
  font-size: 15px;
  color: var(--gray-500);
  font-weight: 500;
}

/* ============================================
   PREMIUM BANNER
   ============================================ */
.premium-banner {
  background: linear-gradient(135deg, #FFE066 0%, #FFD43B 50%, #FFA94D 100%);
  padding: var(--space-5);
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-6);
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(255, 165, 0, 0.3);
}

.premium-banner::before {
  content: '🦐';
  position: absolute;
  right: -20px;
  top: 50%;
  transform: translateY(-50%) rotate(-15deg);
  font-size: 100px;
  opacity: 0.2;
}

.premium-banner-content {
  position: relative;
  z-index: 1;
}

.premium-banner-title {
  font-size: 18px;
  font-weight: 700;
  color: #8B4513;
  margin-bottom: var(--space-1);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.premium-banner-text {
  font-size: 14px;
  color: #A0522D;
  margin-bottom: var(--space-4);
}

.premium-banner-btn {
  background: #8B4513;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.premium-banner-btn:hover {
  background: #A0522D;
  transform: translateY(-1px);
}

/* ============================================
   ERROR STATES
   ============================================ */
.error-state {
  text-align: center;
  padding: var(--space-12) var(--space-5);
}

.error-icon {
  width: 120px;
  height: 120px;
  background: var(--error-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 60px;
  margin: 0 auto var(--space-6);
  animation: shake 0.5s ease-in-out;
}

.error-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--charcoal);
  margin-bottom: var(--space-2);
}

.error-message {
  font-size: 15px;
  color: var(--gray-500);
  margin-bottom: var(--space-6);
}

/* ============================================
   SUCCESS STATES
   ============================================ */
.success-toast {
  position: fixed;
  bottom: calc(20px + var(--safe-bottom));
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--charcoal);
  color: white;
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: 15px;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  opacity: 0;
  transition: all var(--transition-base);
  z-index: 1000;
}

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

.success-toast-icon {
  font-size: 20px;
}

/* ============================================
   PLATFORM BADGE (Debug)
   ============================================ */
.platform-badge {
  position: fixed;
  top: 12px;
  right: 12px;
  background: rgba(31, 41, 55, 0.8);
  color: white;
  font-size: 11px;
  padding: 6px 12px;
  border-radius: var(--radius-full);
  z-index: 1000;
  font-weight: 600;
  backdrop-filter: blur(4px);
}

/* ============================================
   VOICE CHAT
   ============================================ */

.voice-chat-container {
  position: fixed;
  bottom: 100px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  z-index: 100;
}

.voice-chat-btn {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--coral) 0%, var(--coral-dark) 100%);
  border: none;
  box-shadow: 0 4px 15px rgba(242, 112, 89, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  position: relative;
  transition: all 0.3s ease;
}

.voice-chat-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 20px rgba(242, 112, 89, 0.5);
}

.voice-chat-btn:active {
  transform: scale(0.95);
}

.voice-chat-btn.recording {
  background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
  animation: pulse-red 1.5s ease-in-out infinite;
}

.voice-chat-icon {
  font-size: 28px;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

.voice-chat-pulse {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  border: 2px solid var(--coral);
  opacity: 0;
}

.voice-chat-btn.recording .voice-chat-pulse {
  animation: ripple 1.5s ease-out infinite;
}

.voice-chat-status {
  font-size: 12px;
  color: var(--text-secondary);
  background: rgba(255,255,255,0.9);
  padding: 4px 12px;
  border-radius: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  backdrop-filter: blur(10px);
}

/* Voice Wave Animation */
.voice-wave {
  position: fixed;
  bottom: 180px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 4px;
  height: 40px;
  z-index: 100;
  background: rgba(255,255,255,0.95);
  padding: 8px 16px;
  border-radius: 20px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.voice-wave-bar {
  width: 4px;
  height: 100%;
  background: var(--coral);
  border-radius: 2px;
  animation: voice-wave 1s ease-in-out infinite;
}

.voice-wave-bar:nth-child(1) { animation-delay: 0s; }
.voice-wave-bar:nth-child(2) { animation-delay: 0.1s; }
.voice-wave-bar:nth-child(3) { animation-delay: 0.2s; }
.voice-wave-bar:nth-child(4) { animation-delay: 0.3s; }
.voice-wave-bar:nth-child(5) { animation-delay: 0.4s; }

@keyframes voice-wave {
  0%, 100% { transform: scaleY(0.3); }
  50% { transform: scaleY(1); }
}

@keyframes pulse-red {
  0%, 100% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.4); }
  50% { box-shadow: 0 0 0 15px rgba(239, 68, 68, 0); }
}

@keyframes ripple {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(1.3); opacity: 0; }
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes slide-in {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

@keyframes gentle-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@keyframes shadow-pulse {
  0%, 100% { transform: translateX(-50%) scale(1); opacity: 0.1; }
  50% { transform: translateX(-50%) scale(0.8); opacity: 0.05; }
}

@keyframes thinking {
  0%, 100% { transform: scale(1); }
  25% { transform: scale(1.05) rotate(-2deg); }
  75% { transform: scale(1.05) rotate(2deg); }
}

@keyframes pulse {
  0%, 100% { opacity: 0.3; transform: translateY(0); }
  50% { opacity: 1; transform: translateY(-4px); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

@keyframes fade-in-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes confetti {
  0% { transform: translateY(0) rotate(0deg); opacity: 1; }
  100% { transform: translateY(-100px) rotate(720deg); opacity: 0; }
}

/* Animation Classes */
.fade-in {
  animation: fade-in-up 0.4s ease-out;
}

.animate-float {
  animation: gentle-float 3s ease-in-out infinite;
}

.animate-pulse {
  animation: pulse 2s ease-in-out infinite;
}

/* ============================================
   UTILITIES
   ============================================ */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }
.mt-6 { margin-top: var(--space-6); }

.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-5 { margin-bottom: var(--space-5); }
.mb-6 { margin-bottom: var(--space-6); }

.hidden { display: none !important; }
.visible { display: block !important; }

/* ============================================
   RESPONSIVE (Mobile-first enhancement)
   ============================================ */
@media (min-width: 640px) {
  .main-content {
    max-width: 640px;
    margin: 0 auto;
  }
}

/* ============================================
   REDUCED MOTION
   ============================================ */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================
   PRINT STYLES
   ============================================ */
@media print {
  .header,
  .nav-tabs,
  .platform-badge,
  .btn {
    display: none !important;
  }
  
  body {
    background: white !important;
    color: black !important;
  }
  
  .skill-card {
    break-inside: avoid;
    box-shadow: none !important;
    border: 1px solid #ccc !important;
  }
}