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

:root {
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-modal-backdrop: 300;
  --z-modal: 400;
  --z-toast: 500;
  --z-tooltip: 600;
}

body.day {
  --page-bg-top: oklch(0.82 0.045 230);
  --page-bg-bottom: oklch(0.92 0.025 215);
  --card-bg: oklch(1 0 0);
  --card-shadow: oklch(0.3 0.02 250 / 0.1);
  --text-primary: oklch(0.15 0 0);
  --text-secondary: oklch(0.45 0.015 250);
  --text-tertiary: oklch(0.6 0.015 250);
  --text-inverse: oklch(1 0 0);
  --accent: oklch(0.55 0.18 250);
  --accent-hover: oklch(0.5 0.2 250);
  --accent-soft: oklch(0.88 0.05 250);
  --warm: oklch(0.65 0.18 50);
  --cool: oklch(0.55 0.15 220);
  --border: oklch(0.88 0.008 250);
  --error: oklch(0.55 0.2 25);
  --error-bg: oklch(0.92 0.06 25);
  --skeleton-bg: oklch(0.9 0.008 250);
  --skeleton-shine: oklch(0.96 0.005 250);
  --stat-icon-bg: oklch(0.92 0.04 230 / 0.3);
  --input-bg: oklch(0.97 0.005 250);
  --input-border: oklch(0.85 0.01 250);
  --placeholder: oklch(0.6 0.01 250);
  --logo-highlight: oklch(0.2 0.07 50);
}

body.night {
  --page-bg-top: oklch(0.1 0.025 260);
  --page-bg-bottom: oklch(0.16 0.02 250);
  --card-bg: oklch(0.19 0.018 260);
  --card-shadow: oklch(0 0 0 / 0.3);
  --text-primary: oklch(0.9 0 0);
  --text-secondary: oklch(0.6 0.015 260);
  --text-tertiary: oklch(0.48 0.015 260);
  --text-inverse: oklch(0.15 0 0);
  --accent: oklch(0.62 0.18 250);
  --accent-hover: oklch(0.57 0.2 250);
  --accent-soft: oklch(0.27 0.08 250);
  --warm: oklch(0.7 0.18 50);
  --cool: oklch(0.6 0.15 220);
  --border: oklch(0.27 0.012 260);
  --error: oklch(0.62 0.2 25);
  --error-bg: oklch(0.24 0.06 25);
  --skeleton-bg: oklch(0.24 0.012 260);
  --skeleton-shine: oklch(0.28 0.012 260);
  --stat-icon-bg: oklch(0.9 0.04 230 / 0.06);
  --input-bg: oklch(0.24 0.015 260);
  --input-border: oklch(0.3 0.015 260);
  --placeholder: oklch(0.48 0.015 260);
  --logo-highlight: oklch(0.88 0.13 55);
}

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

body {
  font-family: var(--font-sans);
  font-weight: 400;
  line-height: 1.5;
  color: var(--text-primary);
  background: linear-gradient(145deg, var(--page-bg-top), var(--page-bg-bottom));
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  transition: background var(--transition-base);
}

#app {
  width: 100%;
  max-width: 520px;
}

.hidden {
  display: none !important;
}

.app-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
  text-wrap: balance;
}

.logo-highlight {
  color: var(--logo-highlight);
}

.search-form {
  flex: 1;
  min-width: 200px;
  max-width: 280px;
}

.search-wrapper {
  display: flex;
  align-items: center;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: var(--radius-full);
  padding: 0.375rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.search-wrapper:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 0.875rem;
  padding: 0.375rem 0.75rem;
  color: var(--text-primary);
  min-width: 0;
}

.search-input::placeholder {
  color: var(--placeholder);
}

.search-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: none;
  background: var(--accent);
  color: var(--text-inverse);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: 0.8rem;
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.search-btn:hover {
  background: var(--accent-hover);
}

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

.weather-display {
  animation: fadeSlideUp 300ms ease-out;
}

@keyframes fadeSlideUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.weather-hero {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: 0 4px 24px var(--card-shadow);
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.weather-icon-wrapper {
  flex-shrink: 0;
  width: 120px;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--stat-icon-bg);
  border-radius: var(--radius-full);
}

.weather-icon-wrapper img {
  width: 100px;
  height: 100px;
  object-fit: contain;
  image-rendering: auto;
}

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

.temp-group {
  display: flex;
  align-items: baseline;
  gap: 0.125rem;
  line-height: 1;
}

.temp-value {
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--text-primary);
}

.temp-unit {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.feels-like {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.weather-description {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--accent);
  text-transform: capitalize;
  margin-top: 0.5rem;
}

.location-info {
  display: flex;
  align-items: center;
  gap: 0.375rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
}

.location-info .fa-location-dot {
  flex-shrink: 0;
}

.country-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.125rem 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
  margin-left: 0.125rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.5rem;
}

.stat-card {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  background: var(--card-bg);
  border-radius: var(--radius-md);
  padding: 0.75rem;
  box-shadow: 0 2px 8px var(--card-shadow);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.stat-card:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--card-shadow);
}

.stat-icon {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--stat-icon-bg);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  color: var(--accent);
}

.stat-body {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.stat-label {
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-tertiary);
  line-height: 1.2;
}

.stat-value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
  margin-top: 0.125rem;
}

.skeleton {
  animation: fadeIn 200ms ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.skeleton-hero {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: 0 4px 24px var(--card-shadow);
  display: flex;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.skeleton-circle {
  width: 120px;
  height: 120px;
  border-radius: var(--radius-full);
  background: var(--skeleton-bg);
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
}

.skeleton-lines {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.skeleton-line {
  height: 1rem;
  border-radius: var(--radius-sm);
  background: var(--skeleton-bg);
  position: relative;
  overflow: hidden;
}

.skeleton-line.w-40 { width: 40%; }
.skeleton-line.w-60 { width: 60%; }
.skeleton-line.w-30 { width: 30%; }

.skeleton-circle::after,
.skeleton-line::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent,
    var(--skeleton-shine) 50%,
    transparent
  );
  animation: shimmer 1.5s ease-in-out infinite;
}

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

.skeleton-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.5rem;
}

.skeleton-card {
  height: 64px;
  border-radius: var(--radius-md);
  background: var(--skeleton-bg);
  position: relative;
  overflow: hidden;
}

.skeleton-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent,
    var(--skeleton-shine) 50%,
    transparent
  );
  animation: shimmer 1.5s ease-in-out infinite;
}

.error-message {
  animation: fadeSlideUp 200ms ease;
}

.error-content {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--card-bg);
  border: 1px solid var(--error);
  border-radius: var(--radius-md);
  padding: 1rem;
  box-shadow: 0 2px 8px var(--card-shadow);
}

.error-content .fa-triangle-exclamation {
  font-size: 1.25rem;
  color: var(--error);
  flex-shrink: 0;
}

.error-content p {
  font-size: 0.875rem;
  color: var(--text-primary);
  line-height: 1.4;
}

.empty-state {
  animation: fadeIn 300ms ease;
}

.empty-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 3rem 1.5rem;
}

.empty-content .fa-cloud-sun {
  font-size: 3rem;
  color: var(--text-primary);
  opacity: 0.5;
  margin-bottom: 1rem;
}

.empty-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.375rem;
}

.empty-sub {
  font-size: 0.875rem;
  color: var(--text-primary);
  opacity: 0.6;
  max-width: 28ch;
}

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

  .weather-display {
    animation: none;
  }
}

@media (max-width: 480px) {
  body {
    padding: 0.75rem;
  }

  .app-header {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .search-form {
    max-width: none;
  }

  .weather-hero {
    flex-direction: column;
    text-align: center;
    padding: 1.5rem;
  }

  .weather-info {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .location-info {
    justify-content: center;
  }

  .temp-value {
    font-size: 2.75rem;
  }

  .weather-icon-wrapper {
    width: 96px;
    height: 96px;
  }

  .weather-icon-wrapper img {
    width: 80px;
    height: 80px;
  }

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

  .skeleton-hero {
    flex-direction: column;
    text-align: center;
    padding: 1.5rem;
  }

  .skeleton-lines {
    align-items: center;
  }

  .empty-content {
    padding: 2rem 1rem;
  }
}