:root {
  --bg: #eef3f6;
  --bg-elevated: #ffffff;
  --ink: #14202b;
  --ink-soft: #5b6b7c;
  --ink-faint: #8a9aab;
  --line: #d9e2ea;
  --accent: #0e7c7b;
  --accent-deep: #0a5c5b;
  --accent-soft: rgba(14, 124, 123, 0.12);
  --accent-mid: rgba(14, 124, 123, 0.22);
  --warm: #c9783c;
  --shadow: 0 1px 2px rgba(20, 32, 43, 0.04), 0 10px 28px rgba(20, 32, 43, 0.07);
  --shadow-lg: 0 8px 30px rgba(14, 124, 123, 0.12);
  --radius: 16px;
  --radius-sm: 12px;
  --font-display: "Sora", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --header-h: 68px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --max: 1120px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.page-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 45% at 15% -5%, rgba(14, 124, 123, 0.18), transparent 55%),
    radial-gradient(ellipse 55% 40% at 95% 8%, rgba(201, 120, 60, 0.1), transparent 50%),
    radial-gradient(ellipse 50% 35% at 50% 100%, rgba(45, 90, 120, 0.08), transparent 55%),
    linear-gradient(180deg, #e8f0f3 0%, var(--bg) 35%, #f5f8fa 100%);
}

a {
  color: inherit;
  text-decoration: none;
}

/* —— Header —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  backdrop-filter: blur(16px) saturate(1.2);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  background: rgba(238, 243, 246, 0.82);
  border-bottom: 1px solid rgba(217, 226, 234, 0.9);
}

.header-inner {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  flex-shrink: 0;
}

.brand-mark {
  width: 36px;
  height: 36px;
  line-height: 0;
  filter: drop-shadow(0 4px 10px rgba(14, 124, 123, 0.28));
}

.brand-mark svg {
  display: block;
  border-radius: 10px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 0.05rem;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.brand-tag {
  font-size: 0.68rem;
  color: var(--ink-faint);
}

.header-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.header-links a {
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  font-size: 0.88rem;
  color: var(--ink-soft);
  transition: background 0.2s, color 0.2s;
}

.header-links a:hover {
  color: var(--accent-deep);
  background: var(--accent-soft);
}

.lang-switch {
  display: inline-flex;
  gap: 0.2rem;
  margin-left: 0.35rem;
  padding: 0.2rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.85);
}

.lang-switch button {
  appearance: none;
  border: 0;
  padding: 0.35rem 0.7rem;
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  font-family: var(--font-display);
  color: var(--ink-soft);
  background: transparent;
  cursor: pointer;
  transition: color 0.2s, background 0.2s;
}

.lang-switch button.is-active,
.lang-switch button:hover {
  color: var(--accent-deep);
  background: var(--accent-soft);
}

/* —— Hero —— */
.hero {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 1.75rem auto 1.75rem;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  align-items: center;
  gap: 1.5rem 2rem;
  min-height: min(52vh, 380px);
  animation: rise 0.7s var(--ease) both;
}

.hero-main {
  display: flex;
  flex-direction: column;
  gap: 1.35rem;
  min-width: 0;
}

.hero-copy {
  max-width: 34rem;
}

.hero-brand {
  margin: 0 0 0.7rem;
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 6.5vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 1;
  color: var(--ink);
}

.hero h1 {
  margin: 0 0 0.7rem;
  font-family: var(--font-body);
  font-size: clamp(1.2rem, 2.5vw, 1.45rem);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.4;
  color: var(--accent-deep);
}

.hero-lead {
  margin: 0;
  max-width: 26rem;
  color: var(--ink-soft);
  font-size: 1rem;
  line-height: 1.65;
}

.hero-stats {
  margin: 0.85rem 0 0;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-deep);
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.4;
}

.hero-stats[hidden] {
  display: none;
}

.hero-search {
  position: relative;
  width: 100%;
  max-width: 480px;
}

.hero-search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--ink-faint);
  pointer-events: none;
}

#searchInput {
  width: 100%;
  height: 52px;
  padding: 0 3.4rem 0 2.75rem;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--bg-elevated);
  box-shadow: var(--shadow);
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--ink);
  outline: none;
  transition: border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

#searchInput::placeholder {
  color: var(--ink-faint);
}

#searchInput:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft), var(--shadow);
}

.search-clear {
  position: absolute;
  right: 2.5rem;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--ink-faint);
  cursor: pointer;
  display: none;
  place-items: center;
  padding: 0;
}

.search-clear.is-visible {
  display: grid;
}

.search-clear:hover {
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.search-hint {
  position: absolute;
  right: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  min-width: 1.35rem;
  padding: 0.12rem 0.35rem;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: #f4f7f9;
  color: var(--ink-faint);
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 600;
  line-height: 1.2;
}

.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 280px;
}

.hero-art {
  width: min(100%, 420px);
  height: auto;
  display: block;
}

.art-panel-back {
  transform-origin: center;
  animation: floatA 6.5s var(--ease) infinite;
}

.art-panel-mid {
  transform-origin: center;
  animation: floatB 5.5s var(--ease) 0.4s infinite;
}

.art-panel-front {
  transform-origin: center;
  animation: floatC 7s var(--ease) 0.2s infinite;
}

@keyframes floatA {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@keyframes floatB {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

@keyframes floatC {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

/* —— Tools shell + category nav —— */
.tools-shell {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 0 auto 2.5rem;
}

.tools-toolbar {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--line);
  animation: rise 0.7s var(--ease) 0.05s both;
}

.tools-heading {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--ink);
  white-space: nowrap;
}

.cat-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.15rem 0.1rem;
}

.cat-link {
  padding: 0.35rem 0.7rem;
  border-radius: 8px;
  font-size: 0.88rem;
  color: var(--ink-soft);
  transition: color 0.2s, background 0.2s;
}

.cat-link:hover {
  color: var(--accent-deep);
  background: var(--accent-soft);
}

/* —— Tools —— */
.main {
  width: 100%;
}

.category {
  margin-bottom: 2rem;
  padding: 1.35rem 1.35rem 1.45rem;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid rgba(217, 226, 234, 0.85);
  border-radius: 20px;
  box-shadow: 0 1px 2px rgba(20, 32, 43, 0.03);
  scroll-margin-top: calc(var(--header-h) + 1rem);
  animation: rise 0.65s var(--ease) both;
}

.category[hidden] {
  display: none;
}

.category-head {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1.1rem;
}

.category-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  border-radius: 12px;
  background: linear-gradient(145deg, rgba(14, 124, 123, 0.16), rgba(21, 111, 138, 0.1));
  color: var(--accent-deep);
  border: 1px solid var(--accent-mid);
}

.category-icon svg {
  width: 20px;
  height: 20px;
}

.category-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.category-head p {
  margin: 0.15rem 0 0;
  font-size: 0.84rem;
  color: var(--ink-faint);
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 0.85rem;
}

.tool-grid > article {
  margin: 0;
  min-width: 0;
}

.tool-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  height: 100%;
  padding: 1.1rem 1.15rem 1.15rem;
  background: var(--bg-elevated);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.28s var(--ease), border-color 0.28s var(--ease), box-shadow 0.28s var(--ease);
}

.tool-card[hidden] {
  display: none;
}

.tool-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-mid);
  box-shadow: var(--shadow-lg);
}

.tool-card:hover .tool-arrow {
  opacity: 1;
  transform: translate(0, 0);
  color: var(--accent);
}

.tool-card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.tool-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.25rem;
}

.tool-avatar {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--accent-deep);
  background: linear-gradient(160deg, #e7f4f4, #d8ecec);
}

.tool-arrow {
  opacity: 0;
  transform: translate(-4px, 4px);
  color: var(--ink-faint);
  transition: opacity 0.25s, transform 0.25s, color 0.25s;
}

.tool-card h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.tool-card p {
  margin: 0;
  flex: 1;
  font-size: 0.86rem;
  color: var(--ink-soft);
  line-height: 1.5;
}

.tool-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.45rem;
}

.tool-meta span {
  font-size: 0.68rem;
  color: var(--accent-deep);
  background: var(--accent-soft);
  padding: 0.18rem 0.45rem;
  border-radius: 6px;
}

.status {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.status.error {
  color: #b42318;
}

.empty-state {
  display: none;
  text-align: center;
  padding: 2.5rem 1rem;
  color: var(--ink-soft);
  background: rgba(255, 255, 255, 0.6);
  border: 1px dashed var(--line);
  border-radius: var(--radius);
}

.empty-state.is-visible {
  display: block;
}

.empty-state strong {
  display: block;
  margin-bottom: 0.35rem;
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: var(--ink);
}

/* —— SEO panels —— */
.seo-panel {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 0 auto 1.5rem;
}

.seo-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.seo-card,
.faq-panel {
  padding: 1.35rem 1.4rem;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 1px 2px rgba(20, 32, 43, 0.03);
}

.seo-card h2,
.faq-panel > h2 {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.seo-card p,
.seo-card li,
.faq-item p {
  margin: 0 0 0.55rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
  line-height: 1.7;
}

.seo-card ol {
  margin: 0;
  padding-left: 1.15rem;
}

.faq-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.faq-item {
  margin: 0;
  padding: 1rem;
  background: #f7fafb;
  border-radius: 12px;
  border: 1px solid transparent;
}

.faq-item h3 {
  margin: 0 0 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink);
}

.faq-item p {
  margin: 0;
}

.site-footer {
  width: min(var(--max), calc(100% - 2.5rem));
  margin: 1rem auto 0;
  padding: 1.5rem 0 2.5rem;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  font-size: 0.8rem;
  color: var(--ink-faint);
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 860px) {
  .seo-grid,
  .faq-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  :root {
    --header-h: 60px;
  }

  .header-inner,
  .hero,
  .tools-shell,
  .seo-panel,
  .site-footer {
    width: calc(100% - 1.5rem);
  }

  .header-links .nav-faq {
    display: none;
  }

  .hero {
    margin-top: 1.2rem;
    min-height: 0;
    grid-template-columns: 1fr;
    gap: 1.1rem;
  }

  .hero-visual {
    order: -1;
    min-height: 0;
    max-width: 300px;
    margin: 0 auto;
  }

  .hero-art {
    width: 100%;
  }

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

  .art-panel-back,
  .art-panel-mid,
  .art-panel-front {
    animation: none;
  }

  .tools-toolbar {
    flex-direction: column;
    align-items: stretch;
    gap: 0.65rem;
  }

  .cat-nav {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.2rem;
    -webkit-overflow-scrolling: touch;
  }

  .cat-link {
    flex-shrink: 0;
  }

  .category {
    padding: 1rem;
  }

  .brand-tag {
    display: none;
  }

  .search-hint {
    display: none;
  }

  #searchInput {
    padding-right: 2.8rem;
  }

  .search-clear {
    right: 0.7rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}