/* ==================================
   CSS Variables & Design Tokens
   ================================== */
:root {
  /* Colors - Dark Theme */
  --bg-primary: #0a0a0f;
  --bg-secondary: #13131a;
  --bg-tertiary: #1a1a24;
  --bg-card: rgba(26, 26, 36, 0.8);

  /* Accent Colors */
  --accent-primary: #6366f1;
  --accent-secondary: #818cf8;
  --accent-gradient: linear-gradient(
    135deg,
    #6366f1 0%,
    #8b5cf6 50%,
    #a855f7 100%
  );
  --accent-success: #22c55e;
  --accent-warning: #f59e0b;
  --accent-danger: #ef4444;

  /* Text Colors */
  --text-primary: #ffffff;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;

  /* Glass Effect */
  --glass-bg: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms ease;

  /* Typography */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;

  /* Safe Areas */
  --safe-area-top: env(safe-area-inset-top, 0px);
  --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Background Gradient */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(
      ellipse at 20% 20%,
      rgba(99, 102, 241, 0.15) 0%,
      transparent 50%
    ),
    radial-gradient(
      ellipse at 80% 80%,
      rgba(139, 92, 246, 0.1) 0%,
      transparent 50%
    ),
    var(--bg-primary);
  z-index: -1;
}

.hidden {
  display: none !important;
}

/* ==================================
   Splash Screen
   ================================== */
.splash-screen {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition:
    opacity var(--transition-slow),
    visibility var(--transition-slow);
}

.splash-screen.fade-out {
  opacity: 0;
  visibility: hidden;
}

.splash-content {
  text-align: center;
  animation: pulse 1.5s ease-in-out infinite;
}

.splash-icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
}

.splash-content h1 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.splash-content p {
  color: var(--text-muted);
  margin-top: var(--spacing-sm);
}

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

/* ==================================
   App Container
   ================================== */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
  padding-top: var(--safe-area-top);
  padding-bottom: calc(70px + var(--safe-area-bottom));
}

/* ==================================
   Header
   ================================== */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: var(--spacing-md);
  padding-top: calc(var(--spacing-md) + var(--safe-area-top));
  background: rgba(10, 10, 15, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
}

.header-content {
  max-width: 600px;
  margin: 0 auto;
}

.header-title {
  font-size: var(--font-size-xl);
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-subtitle {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* ==================================
   Main Content
   ================================== */
.main-content {
  flex: 1;
  padding: var(--spacing-md);
  max-width: 600px;
  margin: 0 auto;
  width: 100%;
}

.view {
  display: none;
  animation: fadeIn var(--transition-normal);
}

.view.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==================================
   Glass Card
   ================================== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--glass-shadow);
  transition:
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
}

.glass-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

/* ==================================
   Dashboard
   ================================== */
.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-md);
}

.stat-card {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.stat-card.full-width {
  grid-column: 1 / -1;
}

.stat-icon {
  font-size: 1.5rem;
}

.stat-label {
  font-size: var(--font-size-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-value {
  font-size: var(--font-size-2xl);
  font-weight: 700;
}

.stat-unit {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.stat-trend {
  font-size: var(--font-size-sm);
}

.stat-trend.positive {
  color: var(--accent-success);
}

.stat-trend.negative {
  color: var(--accent-danger);
}

.protein-progress {
  width: 100%;
}

.progress-bar {
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--accent-gradient);
  border-radius: var(--radius-full);
  transition: width var(--transition-normal);
}

.activity-card h3 {
  font-size: var(--font-size-base);
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.chart-container {
  height: 200px;
  position: relative;
}

/* ==================================
   Bottom Navigation
   ================================== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-around;
  padding: var(--spacing-sm) var(--spacing-md);
  padding-bottom: calc(var(--spacing-sm) + var(--safe-area-bottom));
  background: rgba(10, 10, 15, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--glass-border);
  z-index: 100;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  transition:
    color var(--transition-fast),
    transform var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.nav-item:active {
  transform: scale(0.95);
}

.nav-item.active {
  color: var(--accent-primary);
}

.nav-item.active .nav-icon {
  transform: scale(1.1);
}

.nav-icon {
  font-size: 1.25rem;
  transition: transform var(--transition-fast);
}

.nav-label {
  font-size: var(--font-size-xs);
  font-weight: 500;
}

/* ==================================
   Buttons
   ================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
}

.btn-danger {
  background: rgba(239, 68, 68, 0.2);
  color: var(--accent-danger);
  border: 1px solid rgba(239, 68, 68, 0.3);
}

/* ==================================
   Modal
   ================================== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(5px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
  z-index: 1000;
  animation: fadeIn var(--transition-fast);
}

.modal-content {
  width: 100%;
  max-width: 400px;
  max-height: 80vh;
  overflow-y: auto;
  animation: slideUp var(--transition-normal);
}

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

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

.modal-header h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--spacing-xs);
}

.modal-body {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.modal-footer {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.modal-footer .btn {
  flex: 1;
}

/* ==================================
   Timer Overlay
   ================================== */
.timer-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1100;
}

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

.timer-content h2 {
  font-size: var(--font-size-xl);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
}

.timer-display {
  font-size: 5rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-xl);
  font-variant-numeric: tabular-nums;
}

.timer-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
}

/* ==================================
   Form Elements
   ================================== */
input[type="number"],
input[type="text"],
input[type="date"],
select {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  font-family: inherit;
  font-size: var(--font-size-base);
  background: var(--bg-tertiary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  transition:
    border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

input:focus,
select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

label {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.setting-item {
  margin-bottom: var(--spacing-md);
}

.setting-item:last-child {
  margin-bottom: 0;
}

/* ==================================
   Back Button
   ================================== */
.back-button {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--bg-tertiary);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  cursor: pointer;
  margin-bottom: var(--spacing-md);
  transition: all var(--transition-fast);
}

.back-button:hover {
  color: var(--text-primary);
  border-color: var(--accent-primary);
}

/* ==================================
   Settings
   ================================== */
.settings-section {
  margin-bottom: var(--spacing-md);
}

.settings-section h3 {
  font-size: var(--font-size-base);
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.settings-section .btn {
  width: 100%;
  margin-top: var(--spacing-sm);
}

/* ==================================
   Scrollbar
   ================================== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--glass-border);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ==================================
   Responsive
   ================================== */
@media (max-width: 380px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .stat-card.full-width {
    grid-column: 1;
  }
}