:root {
  --font-family: "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --mono-font: "SF Mono", Consolas, "Courier New", monospace;
}

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

html,
body {
  height: 100%;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}

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

a:hover {
  text-decoration: underline;
}

/* Layout */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--header-bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.nav {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1px;
    text-decoration: none;
    padding: 5px;
}

.logo-code {
    color: var(--logo-code);
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.logo-json {
    color: var(--logo-json);
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.logo-domain {
    color: var(--logo-domain);
    font-size: 1rem;
    letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 14px;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  text-decoration: none;
}

/* Theme switcher */
.theme-switcher {
  display: flex;
  align-items: center;
  gap: 4px;
  background-color: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3px;
}

.theme-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 12px;
  padding: 5px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.2s, color 0.2s;
}

.theme-btn:hover {
  color: var(--text);
}

.theme-btn.active {
  background-color: var(--accent);
  color: #ffffff;
}

/* Container */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px;
}

/* Hero */
.hero {
  text-align: center;
  padding: 48px 0 40px;
}

.hero h1 {
  font-size: 34px;
  font-weight: 800;
  margin-bottom: 12px;
}

.hero h1 .accent {
  color: var(--accent);
}

.hero p {
  color: var(--text-secondary);
  font-size: 16px;
  max-width: 520px;
  margin: 0 auto;
}

/* Tool grid */
.section-title {
  font-size: 20px;
  font-weight: 700;
  margin: 40px 0 16px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

/* Search bar */
.search-bar {
  position: relative;
  margin-bottom: 20px;
}
.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
}
.search-input {
  width: 100%;
  padding: 10px 12px 10px 40px;
  font-size: 14px;
  font-family: var(--font-family);
  color: var(--text);
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.15s;
}
.search-input:focus {
  border-color: var(--accent);
}
.search-input::placeholder {
  color: var(--text-secondary);
}

.tool-card {
  background-color: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.tool-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--shadow);
  border-color: var(--accent);
}

.tool-card h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.tool-card p {
  font-size: 13px;
  color: var(--text-secondary);
}

/* Tool page */
.tool-page h1 {
  font-size: 26px;
  margin-bottom: 8px;
}

.tool-page .tool-desc {
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.panel {
  background-color: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  margin-bottom: 20px;
}

.panel h2 {
  font-size: 16px;
  margin-bottom: 12px;
}

button {
  font-family: var(--font-family);
}

.btn {
  background-color: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 14px;
  cursor: pointer;
  transition: opacity 0.2s;
}

.btn:hover {
  opacity: 0.85;
}

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

.btn-secondary:hover {
  border-color: var(--accent);
}

textarea,
input[type="text"] {
  width: 100%;
  background-color: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  font-family: var(--mono-font);
  font-size: 14px;
  resize: vertical;
}

textarea:focus,
input[type="text"]:focus {
  outline: none;
  border-color: var(--accent);
}

select {
  background-color: var(--input-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 14px;
  font-family: var(--font-family);
}

select:focus {
  outline: none;
  border-color: var(--accent);
}

.code-block {
  background-color: var(--code-bg);
  color: var(--code-text);
  border-radius: 8px;
  padding: 16px;
  font-family: var(--mono-font);
  font-size: 13px;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-all;
  min-height: 60px;
}

/* Footer */
.footer {
  margin-top: 48px;
  border-top: 1px solid var(--border);
  padding: 24px 0;
  color: var(--text-secondary);
  font-size: 13px;
}

.footer__container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer__left {
  flex: 1;
  min-width: 260px;
}

.footer__copyright {
  margin: 0;
}

.footer__icp {
  cursor: pointer;
}

.footer__right {
  flex-shrink: 0;
}

.footer__links {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}

.footer__link {
  color: var(--text-secondary);
  font-size: 13px;
  white-space: nowrap;
}

.footer__link:hover {
  color: var(--accent);
  text-decoration: none;
}

.footer__link.active {
  color: var(--accent);
  font-weight: 600;
}

@media (max-width: 640px) {
  .footer__container {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* Static content pages (about / privacy / terms / contact / copyright) */
.content-page {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px 0;
  line-height: 1.8;
  color: var(--text);
}

.content-page .page-header {
  margin: 24px 0 40px;
  text-align: center;
}

.content-page .page-header h1 {
  color: var(--text);
  font-size: 28px;
  margin-bottom: 12px;
}

.content-page .page-header p {
  color: var(--text-secondary);
  font-size: 14px;
}

.content-page h2 {
  color: var(--text);
  font-size: 20px;
  margin: 32px 0 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.content-page h3 {
  color: var(--text);
  font-size: 17px;
  margin: 24px 0 12px;
}

.content-page p {
  margin: 12px 0;
  font-size: 15px;
}

.content-page ul {
  padding-left: 25px;
}

.content-page li {
  margin: 10px 0;
  font-size: 15px;
}

.content-page a {
  color: var(--accent);
}

.content-page .highlight {
  color: var(--accent);
  font-weight: 500;
}

/* Contact page cards */
.contact-container {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  justify-content: center;
  margin-bottom: 40px;
}

.contact-card {
  width: 320px;
  max-width: 100%;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 2px 10px var(--shadow);
  background: var(--panel-bg);
  border: 1px solid var(--border);
  transition: box-shadow 0.3s ease;
}

.contact-card:hover {
  box-shadow: 0 4px 18px var(--shadow);
}

.contact-card h2 {
  color: var(--accent);
  font-size: 20px;
  margin-bottom: 20px;
  text-align: center;
  border-bottom: none;
  padding-bottom: 0;
}

.contact-icon {
  text-align: center;
  margin-bottom: 20px;
}

.contact-icon svg {
  width: 50px;
  height: 50px;
  fill: var(--accent);
}

.contact-info {
  text-align: center;
}

.contact-info p {
  margin: 10px 0;
  font-size: 15px;
}

.contact-info a {
  color: var(--accent);
  text-decoration: none;
}

.contact-info a:hover {
  text-decoration: underline;
}

.tips {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px 24px;
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text-secondary);
  font-size: 15px;
}

.tips h3 {
  color: var(--text);
  font-size: 16px;
  margin-bottom: 10px;
}

/* Responsive */
@media (max-width: 640px) {
  .nav-links {
    gap: 12px;
  }

  .nav-links .nav-item:nth-child(n + 3) {
    display: none;
  }

  .hero h1 {
    font-size: 26px;
  }

  .theme-btn {
    padding: 4px 7px;
  }
}