/* ================================
   100 Envelopes Challenge - Design System
   ================================ */

/* CSS Custom Properties */
:root {
  /* Colors - Dark Theme */
  --color-bg-primary: #0a0a0f;
  --color-bg-secondary: #12121a;
  --color-bg-card: rgba(255, 255, 255, 0.03);
  --color-bg-card-hover: rgba(255, 255, 255, 0.06);

  /* Accent Gradient */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  --gradient-subtle: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);

  /* Text Colors */
  --color-text-primary: #ffffff;
  --color-text-secondary: rgba(255, 255, 255, 0.7);
  --color-text-muted: rgba(255, 255, 255, 0.4);

  /* Accent Colors */
  --color-accent: #667eea;
  --color-accent-light: #a78bfa;
  --color-success: #10b981;
  --color-warning: #f59e0b;

  /* Borders */
  --border-subtle: 1px solid rgba(255, 255, 255, 0.08);
  --border-glow: 1px solid rgba(102, 126, 234, 0.3);

  /* Shadows */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.15);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Reset & Base */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background Pattern */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(102, 126, 234, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(118, 75, 162, 0.08) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
}

h3 {
  font-size: clamp(1.25rem, 2vw, 1.5rem);
}

p {
  color: var(--color-text-secondary);
}

a {
  color: var(--color-accent-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}

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

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: var(--spacing-md) 0;
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: var(--border-subtle);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-text-primary);
}

.nav-logo .logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--gradient-primary);
  border-radius: 12px;
  font-size: 1.25rem;
  transform: rotate(-8deg);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
  -webkit-text-fill-color: initial;
  -webkit-background-clip: initial;
  background-clip: initial;
}

.nav-logo span:not(.logo-icon) {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Bounce Animation for Envelope Cards */
@keyframes bounce {

  0%,
  100% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.03);
  }
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text-primary);
}

/* Hero Section */
.hero {
  padding: calc(var(--spacing-2xl) * 2) 0 var(--spacing-2xl);
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--gradient-subtle);
  border: var(--border-glow);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  color: var(--color-accent-light);
  margin-bottom: var(--spacing-lg);
}

.hero h1 {
  margin-bottom: var(--spacing-md);
}

.hero h1 .gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  max-width: 600px;
  margin: 0 auto var(--spacing-xl);
  font-size: 1.125rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(102, 126, 234, 0.5);
}

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

.btn-secondary:hover {
  background: var(--color-bg-card-hover);
  border-color: rgba(255, 255, 255, 0.15);
}

/* Cards */
.card {
  background: var(--color-bg-card);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  backdrop-filter: blur(10px);
  transition: all var(--transition-normal);
}

.card:hover {
  background: var(--color-bg-card-hover);
  border-color: rgba(255, 255, 255, 0.12);
  box-shadow: var(--shadow-card);
}

/* Glass Card */
.glass-card {
  background: rgba(255, 255, 255, 0.02);
  border: var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-card);
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
}

.stat-card {
  text-align: center;
  padding: var(--spacing-lg);
}

.stat-value {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* Progress Bar */
.progress-section {
  margin-bottom: var(--spacing-xl);
}

.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-sm);
}

.progress-title {
  font-weight: 600;
}

.progress-percentage {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.progress-bar {
  height: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% {
    transform: translateX(-100%);
  }

  100% {
    transform: translateX(100%);
  }
}

/* This Week Section */
.current-week {
  margin-bottom: var(--spacing-xl);
}

.current-week-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.week-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
}

.envelope-display {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--spacing-md);
}

.envelope-card {
  background: var(--gradient-subtle);
  border: var(--border-glow);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
  animation: bounce 2s ease-in-out infinite;
}

.envelope-card:nth-child(2) {
  animation-delay: 0.3s;
}

.envelope-card::before {
  content: '✉️';
  position: absolute;
  top: var(--spacing-sm);
  right: var(--spacing-sm);
  font-size: 1.5rem;
  opacity: 0.5;
}

.envelope-number {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-xs);
}

.envelope-amount {
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.weekly-total {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.weekly-total .envelope-amount {
  background: linear-gradient(135deg, #10b981, #34d399);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.weekly-total::before {
  content: '✨';
}

/* History Table */
.history-section {
  margin-bottom: var(--spacing-xl);
}

.history-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: var(--spacing-md);
}

.history-table th,
.history-table td {
  padding: var(--spacing-sm) var(--spacing-md);
  text-align: left;
  border-bottom: var(--border-subtle);
}

.history-table th {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  font-weight: 600;
}

.history-table td {
  color: var(--color-text-secondary);
}

.history-table tr:hover td {
  background: var(--color-bg-card);
}

.history-table .amount {
  font-weight: 600;
  color: var(--color-accent-light);
}

.history-table .running-total {
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Envelopes Grid */
.envelopes-section h3 {
  margin-bottom: var(--spacing-md);
}

.envelopes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(48px, 1fr));
  gap: var(--spacing-xs);
}

.envelope-chip {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-card);
  border: var(--border-subtle);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.envelope-chip:hover {
  background: var(--color-bg-card-hover);
  transform: scale(1.05);
}

.envelope-chip.used {
  background: var(--gradient-primary);
  border-color: transparent;
  color: white;
  opacity: 0.6;
}

/* Features Grid */
.features {
  padding: var(--spacing-2xl) 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.feature-card {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-lg);
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-md);
}

.feature-card h3 {
  margin-bottom: var(--spacing-sm);
}

/* About the Challenge Section */
.about-challenge {
  padding: var(--spacing-xl) 0 var(--spacing-2xl);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  max-width: 800px;
  margin: 0 auto;
}

.about-card {
  padding: var(--spacing-lg);
}

.about-card-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.about-card h3 {
  font-size: 1.35rem;
  margin: 0;
}

.about-card p {
  font-size: 1.125rem;
  line-height: 1.8;
}

.about-icon {
  font-size: 1.75rem;
  flex-shrink: 0;
}

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

/* How It Works */
.how-it-works {
  padding: var(--spacing-2xl) 0;
}

.steps-list {
  display: grid;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.step {
  display: flex;
  gap: var(--spacing-lg);
  align-items: flex-start;
}

.step-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 1.25rem;
}

.step-content h3 {
  margin-bottom: var(--spacing-xs);
}

/* Footer */
.footer {
  padding: var(--spacing-xl) 0;
  border-top: var(--border-subtle);
  text-align: center;
}

.footer p {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* Page Header */
.page-header {
  padding: calc(var(--spacing-2xl) + 60px) 0 var(--spacing-xl);
  text-align: center;
}

.page-header h1 {
  margin-bottom: var(--spacing-sm);
}

/* Section */
.section {
  margin-bottom: var(--spacing-xl);
}

.section-title {
  margin-bottom: var(--spacing-md);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.section-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--gradient-primary);
  opacity: 0.3;
}

/* Awaiting State */
.awaiting-state {
  text-align: center;
  padding: var(--spacing-2xl);
  color: var(--color-text-muted);
}

.awaiting-state .icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
  opacity: 0.5;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    gap: var(--spacing-md);
  }

  .hero {
    padding: calc(var(--spacing-2xl) + 40px) 0 var(--spacing-xl);
  }

  .stat-value {
    font-size: 2rem;
  }

  .envelope-amount {
    font-size: 2rem;
  }

  .step {
    flex-direction: column;
    text-align: center;
  }

  .step-number {
    margin: 0 auto;
  }

  .history-table {
    font-size: 0.875rem;
  }

  .history-table th,
  .history-table td {
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }

  .envelope-display {
    grid-template-columns: 1fr;
  }

  .envelopes-grid {
    grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
  }
}


/* ================================
   Share Button
   ================================ */
.share-btn {
  margin-top: var(--spacing-md);
}

.share-btn.copied {
  background: var(--color-success);
  border-color: var(--color-success);
  color: white;
}

/* ================================
   Theme Toggle
   ================================ */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--color-bg-card);
  border: var(--border-subtle);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  transition: all var(--transition-normal);
}

.theme-toggle:hover {
  background: var(--color-bg-card-hover);
  transform: scale(1.1);
}

/* ================================
   Light Theme
   ================================ */
[data-theme="light"] {
  --color-bg-primary: #f8fafc;
  --color-bg-secondary: #ffffff;
  --color-bg-card: rgba(0, 0, 0, 0.03);
  --color-bg-card-hover: rgba(0, 0, 0, 0.06);
  --color-text-primary: #1e293b;
  --color-text-secondary: rgba(30, 41, 59, 0.7);
  --color-text-muted: rgba(30, 41, 59, 0.5);
  --border-subtle: 1px solid rgba(0, 0, 0, 0.08);
  --border-glow: 1px solid rgba(102, 126, 234, 0.3);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.1);
}

[data-theme="light"] body::before {
  background:
    radial-gradient(ellipse at 20% 20%, rgba(102, 126, 234, 0.05) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(118, 75, 162, 0.05) 0%, transparent 50%);
}

[data-theme="light"] .nav {
  background: rgba(248, 250, 252, 0.9);
}

[data-theme="light"] .progress-bar {
  background: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .envelope-chip {
  background: rgba(0, 0, 0, 0.05);
}

/* ================================
   Confetti Animation
   ================================ */
.confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
  overflow: hidden;
}

.confetti {
  position: absolute;
  width: 10px;
  height: 10px;
  opacity: 0;
  animation: confetti-fall 3s ease-out forwards;
}

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

/* Milestone celebration banner */
.milestone-banner {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  background: var(--gradient-primary);
  padding: var(--spacing-lg) var(--spacing-xl);
  border-radius: var(--radius-lg);
  text-align: center;
  z-index: 1001;
  animation: milestone-pop 0.5s ease-out forwards;
  box-shadow: 0 20px 60px rgba(102, 126, 234, 0.5);
}

.milestone-banner h2 {
  color: white;
  margin-bottom: var(--spacing-xs);
  font-size: 2rem;
}

.milestone-banner p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1.125rem;
}

@keyframes milestone-pop {
  0% {
    transform: translate(-50%, -50%) scale(0);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.1);
  }
  100% {
    transform: translate(-50%, -50%) scale(1);
  }
}