:root {
  --bg: #f4f4f4;
  --surface: #fafafa;
  --text-main: #1c1c1c;
  --text-sub: #707070;
  --accent-green: #6d8c78;
  --accent-purple: #7f758c;
  --accent-red: #b27474;
  --accent-yellow: #b5a27b;
  --action-bg: #f7f8f4;
  --action-bg-hover: #eef2ea;
  --action-border: #d7dfd4;
  --action-text: #1f2a22;
  --border: #e0e0e0;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: #161616;
    --surface: #222222;
    --text-main: #e5e5e5;
    --text-sub: #8c8c8c;
    --accent-green: #4b6a56;
    --accent-purple: #5a5266;
    --accent-red: #8c4f4f;
    --accent-yellow: #8c7a53;
    --action-bg: #e9ece4;
    --action-bg-hover: #dde3d8;
    --action-border: #cad2c5;
    --action-text: #1c1c1c;
    --border: #333333;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #161616;
  --surface: #222222;
  --text-main: #e5e5e5;
  --text-sub: #8c8c8c;
  --accent-green: #4b6a56;
  --accent-purple: #5a5266;
  --accent-red: #8c4f4f;
  --accent-yellow: #8c7a53;
  --action-bg: #e9ece4;
  --action-bg-hover: #dde3d8;
  --action-border: #cad2c5;
  --action-text: #1c1c1c;
  --border: #333333;
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f4f4f4;
  --surface: #fafafa;
  --text-main: #1c1c1c;
  --text-sub: #707070;
  --accent-green: #6d8c78;
  --accent-purple: #7f758c;
  --accent-red: #b27474;
  --accent-yellow: #b5a27b;
  --action-bg: #f7f8f4;
  --action-bg-hover: #eef2ea;
  --action-border: #d7dfd4;
  --action-text: #1f2a22;
  --border: #e0e0e0;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light dark;
}

body {
  margin: 0;
  padding: 80px 20px 40px;
  display: flex;
  justify-content: center;
  background-color: var(--bg);
  color: var(--text-main);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  line-height: 1.6;
}

button {
  font-family: inherit;
}

main {
  width: 100%;
  max-width: 620px;
}

.site-controls {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: calc(100vw - 36px);
}

.language-select,
.theme-selector {
  display: inline-flex;
  padding: 3px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.language-select {
  min-height: 40px;
  max-width: 132px;
  padding: 0 28px 0 10px;
  color: var(--text-main);
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}

.language-select:focus-visible {
  outline: 2px solid var(--accent-green);
  outline-offset: 2px;
}

.theme-selector {
  gap: 2px;
}

.theme-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  padding: 0;
  color: var(--text-sub);
  background-color: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  cursor: pointer;
}

.theme-button:hover {
  color: var(--text-main);
  border-color: var(--border);
}

.theme-button[aria-pressed="true"] {
  color: var(--text-main);
  background-color: var(--bg);
  border-color: var(--border);
}

.theme-button:focus-visible {
  outline: 2px solid var(--accent-green);
  outline-offset: 2px;
}

.theme-button svg {
  width: 18px;
  height: 18px;
  pointer-events: none;
}

header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

h1,
h2,
h3,
p,
ul {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
}

h2 {
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
  font-size: 1.3rem;
  line-height: 1.3;
}

section + section h2,
.support-callout h2 {
  margin-top: 36px;
}

.support-callout h2:first-child {
  margin-top: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.05rem;
  line-height: 1.35;
}

p {
  margin-bottom: 16px;
}

ul {
  margin-bottom: 24px;
  padding-left: 20px;
}

li {
  margin-bottom: 12px;
}

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

.tagline {
  margin-top: 6px;
  margin-bottom: 0;
  color: var(--text-sub);
  font-size: 1.05rem;
  font-style: italic;
}

.back-link {
  display: inline-block;
  margin-bottom: 16px;
  color: var(--text-sub);
  font-size: 0.9rem;
  text-decoration: none;
}

.back-link:hover {
  color: var(--text-main);
}

.app-card,
.platform-card,
.feature-card,
.support-callout {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 18px;
}

.app-card,
.platform-card {
  margin-bottom: 20px;
}

.app-title,
.phase-title {
  margin: 0 0 8px;
  font-weight: 600;
  line-height: 1.35;
}

.app-title {
  font-size: 1.2rem;
}

.phase-title {
  font-size: 1.15rem;
}

.app-link,
.section-link {
  color: var(--accent-green);
  font-weight: 600;
  text-decoration: none;
}

.app-link {
  display: inline-block;
  margin-top: 8px;
}

.app-link:hover,
.section-link:hover,
.qr-toggle:hover {
  text-decoration: underline;
}

.crypto-instruction {
  margin: 4px 0 12px;
  color: var(--text-sub);
  font-size: 0.9rem;
}

.network-row {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.network-row:first-of-type {
  padding-top: 0;
  border-top: 0;
}

.network-tag {
  display: block;
  margin-bottom: 6px;
  color: var(--text-sub);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
}

.crypto-address,
.crypto-box {
  margin-bottom: 6px;
  padding: 12px;
  overflow-wrap: anywhere;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-main);
  font-family: monospace;
  font-size: 0.85rem;
}

.copy-field {
  display: flex;
  align-items: stretch;
  gap: 8px;
  margin-bottom: 6px;
}

.copy-field .crypto-address {
  flex: 1;
  min-width: 0;
  margin-bottom: 0;
}

.copy-button {
  min-width: 62px;
  padding: 0 10px;
  color: var(--accent-green);
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  white-space: nowrap;
}

.copy-button:hover {
  border-color: var(--accent-green);
}

.copy-button:focus-visible {
  outline: 2px solid var(--accent-green);
  outline-offset: 2px;
}

.qr-toggle {
  display: inline-block;
  margin-top: 4px;
  color: var(--accent-green);
  cursor: pointer;
  font-size: 0.82rem;
  font-weight: 600;
}

.qr-image {
  display: block;
  width: 100%;
  max-width: 170px;
  margin-top: 10px;
  background-color: var(--surface);
  border: 4px solid var(--surface);
  border-radius: 4px;
}

.binance-qr {
  margin-right: auto;
  margin-left: auto;
}

.fiat-button-container {
  display: flex;
  margin-top: 12px;
}

.paypal-action-button {
  display: inline-block;
  padding: 12px 24px;
  color: var(--action-text);
  background-color: var(--action-bg);
  border: 1px solid var(--action-border);
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color 0.15s ease,
    border-color 0.15s ease,
    transform 0.1s ease;
}

.paypal-action-button:hover {
  background-color: var(--action-bg-hover);
  border-color: var(--accent-green);
  text-decoration: none;
}

.paypal-action-button:active {
  transform: scale(0.98);
}

.timeline-item {
  position: relative;
  margin-bottom: 24px;
  padding-left: 16px;
  border-left: 3px solid var(--accent-green);
}

.timeline-item.overtime {
  border-left-color: var(--accent-purple);
}

.feature-grid {
  display: grid;
  gap: 16px;
  margin: 20px 0 8px;
}

.feature-card.accent {
  border-left: 3px solid var(--accent-yellow);
}

.support-callout {
  margin-top: 0;
  margin-bottom: 40px;
  border-color: var(--accent-green);
  border-left: 5px solid var(--accent-green);
}

.time-badge {
  color: var(--text-sub);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.privacy-policy {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

footer {
  margin-top: 60px;
  color: var(--text-sub);
  font-size: 0.85rem;
  text-align: center;
}

footer p {
  margin-bottom: 0;
}

@media (max-width: 520px) {
  body {
    padding-right: 16px;
    padding-left: 16px;
  }

  .site-controls {
    top: 14px;
    right: 14px;
  }

  h1 {
    font-size: 1.8rem;
  }
}