/* ===================================
   FITBURN APP - MAIN STYLESHEET
   Mobile-First Responsive Design
   =================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&family=Inter:wght@300;400;500;600;700&display=swap');

/* ===================================
   CSS VARIABLES - DESIGN TOKENS
   =================================== */
:root {
  /* Brand Colors - From Logo */
  --primary-coral: #EF5A3C;
  --primary-light: #FF7A5C;
  --primary-dark: #D94D2E;
  --primary-gradient: linear-gradient(135deg, #FF7A5C 0%, #EF5A3C 50%, #D94D2E 100%);
  
  /* Neutral Colors */
  --white: #FFFFFF;
  --off-white: #F8F9FA;
  --light-gray: #E9ECEF;
  --medium-gray: #ADB5BD;
  --dark-gray: #495057;
  --charcoal: #2C3E50;
  --black: #1A1A1A;
  
  /* Semantic Colors */
  --success: #28A745;
  --warning: #FFC107;
  --error: #DC3545;
  --info: #17A2B8;
  
  /* Typography */
  --font-heading: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;
  
  /* Font Sizes - Mobile First */
  --fs-xs: 0.75rem;      /* 12px */
  --fs-sm: 0.875rem;     /* 14px */
  --fs-base: 1rem;       /* 16px */
  --fs-lg: 1.125rem;     /* 18px */
  --fs-xl: 1.25rem;      /* 20px */
  --fs-2xl: 1.5rem;      /* 24px */
  --fs-3xl: 1.875rem;    /* 30px */
  --fs-4xl: 2.25rem;     /* 36px */
  --fs-5xl: 3rem;        /* 48px */
  
  /* Spacing */
  --spacing-xs: 0.5rem;   /* 8px */
  --spacing-sm: 1rem;     /* 16px */
  --spacing-md: 1.5rem;   /* 24px */
  --spacing-lg: 2rem;     /* 32px */
  --spacing-xl: 3rem;     /* 48px */
  --spacing-2xl: 4rem;    /* 64px */
  
  /* Border Radius */
  --radius-sm: 0.375rem;  /* 6px */
  --radius-md: 0.5rem;    /* 8px */
  --radius-lg: 1rem;      /* 16px */
  --radius-xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);
  --shadow-glow: 0 0 20px rgba(239, 90, 60, 0.3);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;
  --transition-slow: 500ms ease;
  
  /* Z-Index Scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-tooltip: 1060;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--charcoal);
  background: var(--off-white);
  overflow-x: hidden;
}

/* ===================================
   TYPOGRAPHY
   =================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
  color: var(--charcoal);
}

h1 {
  font-size: var(--fs-3xl);
  font-weight: 800;
}

h2 {
  font-size: var(--fs-2xl);
  font-weight: 700;
}

h3 {
  font-size: var(--fs-xl);
  font-weight: 600;
}

h4 {
  font-size: var(--fs-lg);
  font-weight: 600;
}

p {
  margin-bottom: var(--spacing-sm);
}

a {
  color: var(--primary-coral);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-dark);
}

strong {
  font-weight: 600;
}

/* ===================================
   LAYOUT UTILITIES
   =================================== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-sm);
}

.section {
  padding: var(--spacing-xl) 0;
}

.section-alt {
  background: var(--white);
}

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

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

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

/* Grid System */
.grid {
  display: grid;
  gap: var(--spacing-md);
}

.grid-2 {
  grid-template-columns: 1fr;
}

.grid-3 {
  grid-template-columns: 1fr;
}

.grid-4 {
  grid-template-columns: 1fr;
}

/* Flexbox Utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.flex-center {
  display: flex;
  justify-content: center;
  align-items: center;
}

.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.flex-wrap {
  flex-wrap: wrap;
}

.gap-sm {
  gap: var(--spacing-sm);
}

.gap-md {
  gap: var(--spacing-md);
}

.gap-lg {
  gap: var(--spacing-lg);
}

/* ===================================
   BUTTON COMPONENTS
   =================================== */
.btn {
  display: inline-block;
  padding: 0.875rem 1.75rem;
  font-family: var(--font-heading);
  font-size: var(--fs-base);
  font-weight: 600;
  text-align: center;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  min-width: 140px;
}

.btn-primary {
  background: var(--primary-gradient);
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl), var(--shadow-glow);
  color: var(--white);
}

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

.btn-secondary {
  background: var(--white);
  color: var(--primary-coral);
  border: 2px solid var(--primary-coral);
}

.btn-secondary:hover {
  background: var(--primary-coral);
  color: var(--white);
  transform: translateY(-2px);
}

.btn-large {
  padding: 1.125rem 2.5rem;
  font-size: var(--fs-lg);
}

.btn-block {
  display: block;
  width: 100%;
}

/* ===================================
   CARD COMPONENTS
   =================================== */
.card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.card-header {
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--light-gray);
  margin-bottom: var(--spacing-sm);
}

.card-title {
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--primary-coral);
  margin-bottom: 0.25rem;
}

.card-glass {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

/* ===================================
   NAVIGATION
   =================================== */
.navbar {
  background: var(--white);
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  padding: var(--spacing-sm) 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--primary-coral);
}

.nav-logo img {
  height: 40px;
  width: auto;
}

.nav-menu {
  display: none;
  list-style: none;
}

.nav-menu.active {
  display: flex;
  flex-direction: column;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--white);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-md);
  gap: var(--spacing-sm);
}

.nav-link {
  display: block;
  padding: var(--spacing-xs) var(--spacing-sm);
  color: var(--charcoal);
  font-weight: 500;
  transition: all var(--transition-fast);
  border-radius: var(--radius-sm);
}

.nav-link:hover,
.nav-link.active {
  background: var(--primary-coral);
  color: var(--white);
}

.nav-toggle {
  display: block;
  background: none;
  border: none;
  font-size: var(--fs-2xl);
  color: var(--primary-coral);
  cursor: pointer;
}

/* ===================================
   HERO SECTION
   =================================== */
.hero {
  background: var(--primary-gradient);
  color: var(--white);
  padding: var(--spacing-2xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.1)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,112C672,96,768,96,864,112C960,128,1056,160,1152,160C1248,160,1344,128,1392,112L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
  background-size: cover;
  opacity: 0.3;
}

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

.hero h1 {
  color: var(--white);
  font-size: var(--fs-4xl);
  margin-bottom: var(--spacing-md);
  animation: fadeInUp 0.8s ease;
}

.hero p {
  font-size: var(--fs-lg);
  margin-bottom: var(--spacing-lg);
  animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-logo {
  width: 120px;
  height: 120px;
  margin: 0 auto var(--spacing-md);
  animation: pulse 2s ease infinite;
}

/* ===================================
   ANIMATIONS
   =================================== */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-fadeIn {
  animation: fadeIn 0.6s ease;
}

.animate-fadeInUp {
  animation: fadeInUp 0.8s ease;
}

.animate-fadeInDown {
  animation: fadeInDown 0.8s ease;
}

.animate-slideInLeft {
  animation: slideInLeft 0.8s ease;
}

.animate-slideInRight {
  animation: slideInRight 0.8s ease;
}

/* ===================================
   BADGE & TAG COMPONENTS
   =================================== */
.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  font-size: var(--fs-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

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

.badge-success {
  background: var(--success);
  color: var(--white);
}

.badge-warning {
  background: var(--warning);
  color: var(--charcoal);
}

/* ===================================
   STATS & METRICS
   =================================== */
.stats-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  margin: var(--spacing-lg) 0;
}

.stat-card {
  text-align: center;
  padding: var(--spacing-md);
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: var(--fs-4xl);
  font-weight: 800;
  color: var(--primary-coral);
  font-family: var(--font-heading);
  display: block;
}

.stat-label {
  font-size: var(--fs-sm);
  color: var(--dark-gray);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: var(--spacing-xs);
}

/* ===================================
   FOOTER
   =================================== */
.footer {
  background: var(--charcoal);
  color: var(--white);
  padding: var(--spacing-xl) 0 var(--spacing-md);
  margin-top: var(--spacing-2xl);
}

.footer-content {
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-md);
}

.footer-link {
  color: var(--light-gray);
  font-size: var(--fs-sm);
}

.footer-link:hover {
  color: var(--primary-light);
}

.footer-social {
  display: flex;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.social-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  color: var(--white);
  transition: all var(--transition-base);
}

.social-icon:hover {
  background: var(--primary-coral);
  transform: translateY(-3px);
}

.copyright {
  font-size: var(--fs-sm);
  color: var(--medium-gray);
  padding-top: var(--spacing-md);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* ===================================
   RESPONSIVE BREAKPOINTS
   =================================== */

/* Tablet (768px and up) */
@media (min-width: 768px) {
  :root {
    --fs-3xl: 2.25rem;   /* 36px */
    --fs-4xl: 3rem;      /* 48px */
    --fs-5xl: 3.75rem;   /* 60px */
  }
  
  .grid-2 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .nav-menu {
    display: flex;
    flex-direction: row;
    gap: var(--spacing-sm);
    position: static;
    background: transparent;
    box-shadow: none;
    padding: 0;
  }
  
  .nav-toggle {
    display: none;
  }
  
  .hero h1 {
    font-size: var(--fs-5xl);
  }
  
  .container {
    padding: 0 var(--spacing-md);
  }
}

/* Desktop (1024px and up) */
@media (min-width: 1024px) {
  .grid-3 {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .section {
    padding: var(--spacing-2xl) 0;
  }
}

/* Large Desktop (1440px and up) */
@media (min-width: 1440px) {
  .container {
    padding: 0 var(--spacing-lg);
  }
}

/* ===================================
   UTILITY CLASSES
   =================================== */
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }
.pt-xl { padding-top: var(--spacing-xl); }

.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }
.pb-xl { padding-bottom: var(--spacing-xl); }

.hidden {
  display: none !important;
}

.visible {
  display: block !important;
}

/* ===================================
   LOADING & SKELETON STATES
   =================================== */
.skeleton {
  background: linear-gradient(90deg, var(--light-gray) 25%, var(--off-white) 50%, var(--light-gray) 75%);
  background-size: 200% 100%;
  animation: loading 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

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