/* CSS Variables - Design System */
:root {
  --bg: #0f172a;
  --panel: #111827;
  --muted: #94a3b8;
  --text: #e5e7eb;
  --accent: #22d3ee;
  --accent-2: #60a5fa;
  --error: #f87171;
  --success: #34d399;
  --ring: rgba(96,165,250,0.35);
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 20px;
  --spacing-2xl: 24px;
  
  /* Border radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-xl: 12px;
  --radius-2xl: 16px;
  --radius-full: 999px;
  
  /* Typography */
  --font-size-xs: 11px;
  --font-size-sm: 12px;
  --font-size-base: 14px;
  --font-size-lg: 16px;
  --font-size-xl: 20px;
  --font-size-2xl: 22px;
}

/* Reset and Base Styles */
* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell,
    Noto Sans, Helvetica Neue, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  background: linear-gradient(135deg, #0b1220, var(--bg) 35%, #0b1220 100%);
  color: var(--text);
  display: block;
  padding: var(--spacing-2xl);
}

/* Content link styles for dark background */
.main-card a {
  color: var(--accent-2);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(96,165,250,0.6);
}

.main-card a:hover {
  color: var(--accent);
  text-decoration-color: rgba(34,211,238,0.85);
}

.main-card a:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 2px;
  border-radius: 4px;
}

/* Navigation Styles */
.main-nav {
  background: var(--panel);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  padding: var(--spacing-md) 0;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: var(--font-size-lg);
}

.nav-logo-img {
  height: 96px;
  width: auto;
}

.nav-links {
  display: flex;
  gap: var(--spacing-xl);
}

.nav-link {
  color: var(--muted);
  text-decoration: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--text);
  background: rgba(255,255,255,0.05);
}

.nav-link--active {
  color: var(--accent);
  background: rgba(34,211,238,0.1);
}

/* Adjust body padding for navigation */
body:has(.main-nav) {
  padding-top: calc(var(--spacing-2xl) + 120px);
}

/* Layout Components */
.main-card {
  width: 100%;
  max-width: 760px;
  background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-xl);
  box-shadow: 0 10px 30px rgba(0,0,0,0.35);
  backdrop-filter: blur(8px);
  margin: 0 auto;
}
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--spacing-xl);
}

/* Global blocks & cards */
.section {
  margin-top: var(--spacing-2xl);
}

.section--padded {
  padding: var(--spacing-xl);
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.07);
  border-radius: var(--radius-2xl);
}

.grid {
  display: grid;
  gap: var(--spacing-xl);
}

.grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

@media (max-width: 760px) {
  .grid--2, .grid--3 {
    grid-template-columns: 1fr;
  }
}

.card {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
}

.card--highlight {
  background: linear-gradient(180deg, rgba(34,211,238,0.08), rgba(255,255,255,0.03));
  border-color: rgba(34,211,238,0.25);
}

.card h3 { margin: 0 0 var(--spacing-sm); font-size: var(--font-size-lg); }
.card p { margin: 0; color: var(--muted); line-height: 1.5; }

.header {
  margin-bottom: var(--spacing-xl);
}

.header__title {
  margin: 0 0 var(--spacing-md);
  font-size: var(--font-size-2xl);
  line-height: 1.2;
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.header__title .spark {
  color: var(--accent);
  font-weight: 700;
}

.header-logo-img {
  height: 64px;
  width: auto;
  margin-right: var(--spacing-sm);
}

.header__subtitle {
  margin: 0 0 var(--spacing-xl);
  color: var(--muted);
}

/* Form Components */
.form-row {
  display: grid;
  gap: var(--spacing-md);
}

.form-row--two-cols {
  grid-template-columns: 1fr 1fr;
}

.form-field {
  background: var(--panel);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
  padding: var(--spacing-md);
}

.form-label {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--muted);
  margin-bottom: var(--spacing-sm);
}

.input-wrapper,
.select-wrapper {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  background: rgba(255,255,255,0.03);
  border: 1px solid rgba(255,255,255,0.08);
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-lg);
}

.form-select,
.form-input {
  width: 100%;
  background: transparent;
  color: var(--text);
  border: none;
  outline: none;
  font-size: var(--font-size-lg);
  appearance: none;
}

/* Button Components */
.btn {
  padding: var(--spacing-lg) var(--spacing-base);
  border-radius: var(--radius-lg);
  border: 1px solid transparent;
  cursor: pointer;
  font-weight: 600;
  font-size: var(--font-size-base);
  transition: all 0.2s ease;
}

.btn--primary {
  color: #0b1220;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 6px 20px rgba(34,211,238,0.25);
}

.btn--secondary {
  background: transparent;
  color: var(--text);
  border-color: rgba(255,255,255,0.12);
}

.btn--swap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn--swap:hover {
  background: rgba(255,255,255,0.12);
  border-color: rgba(255,255,255,0.2);
}

.btn--swap:active {
  transform: scale(0.96) rotate(180deg);
}

.actions {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

/* Quick Amount Chips */
.quick-amounts {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-sm);
}

.chip {
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  cursor: pointer;
  border: 1px solid rgba(255,255,255,0.16);
  color: var(--text);
  background: rgba(255,255,255,0.05);
  transition: background 0.2s ease;
}

.chip:hover {
  background: rgba(255,255,255,0.1);
}

/* Result Display */
.result {
  margin-top: var(--spacing-base);
  padding: var(--spacing-base);
  border-radius: var(--radius-xl);
  background: rgba(2,6,23,0.65);
  border: 1px solid rgba(255,255,255,0.08);
}

.result__amount {
  font-size: var(--font-size-xl);
}

.result__meta {
  color: var(--muted);
  font-size: var(--font-size-sm);
  margin-top: var(--spacing-sm);
}

.result--error {
  color: var(--error);
}

/* Loading State */
.loading {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: var(--muted);
}

.loading__dot {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 1s infinite ease-in-out;
}

.loading__dot:nth-child(2) {
  animation-delay: .15s;
}

.loading__dot:nth-child(3) {
  animation-delay: .3s;
}

@keyframes pulse {
  0%, 80%, 100% {
    opacity: .2;
    transform: scale(.8);
  }
  40% {
    opacity: 1;
    transform: scale(1);
  }
}

/* Chart Components */
.chart-section {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-xl);
  background: var(--panel);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
}

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

.chart-header__title {
  margin: 0;
  font-size: var(--font-size-lg);
}

.chart-header__currency-pair {
  color: var(--accent);
  font-weight: 600;
  font-size: var(--font-size-base);
}

.chart-controls__select {
  background: rgba(255,255,255,0.05);
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: var(--font-size-sm);
}

.chart-container {
  position: relative;
  height: 200px;
  background: rgba(255,255,255,0.02);
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
}

.chart-canvas {
  width: 100%;
  height: 100%;
}

.chart-loader {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
  z-index: 2;
}

.chart-loader__dots {
  display: flex;
  gap: var(--spacing-xs);
}

.chart-loader__dot {
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 1s infinite ease-in-out;
}

.chart-loader__dot:nth-child(2) {
  animation-delay: .15s;
}

.chart-loader__dot:nth-child(3) {
  animation-delay: .3s;
}

.chart-loader__text {
  color: var(--muted);
  font-size: var(--font-size-sm);
}

/* Chart Tooltip */
.chart-tooltip {
  position: absolute;
  background: rgba(0, 0, 0, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: var(--font-size-sm);
  color: var(--text);
  pointer-events: none;
  z-index: 10;
  display: none;
  white-space: nowrap;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.chart-tooltip__date {
  color: var(--muted);
  font-size: var(--font-size-xs);
}

.chart-tooltip__rate {
  color: var(--accent);
  font-weight: 600;
  margin-top: 2px;
}

/* Popular Pairs Section */
.popular-section {
  margin-top: var(--spacing-xl);
  padding: var(--spacing-xl);
  background: var(--panel);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-xl);
}

.popular-section__title {
  margin: 0 0 var(--spacing-md);
  font-size: var(--font-size-lg);
}

.popular-pairs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--spacing-sm);
}

.popular-pair {
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.1);
  cursor: pointer;
  transition: background 0.2s ease;
}

.popular-pair:hover {
  background: rgba(255,255,255,0.1);
}

.popular-pair__name {
  font-weight: 600;
  font-size: var(--font-size-base);
}

/* Responsive Design */
@media (min-width: 720px) {
  .form-row--two-cols {
    grid-template-columns: 1fr auto 1fr;
    align-items: end;
  }
  
  .btn--swap {
    margin: 0 var(--spacing-sm) var(--spacing-base);
  }
}

/* Utility Classes */
.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;
}

.hidden {
  display: none;
}