:root {
  --primary: #5b6ef5;
  --primary-dark: #4453d6;
  --primary-light: #8b9bff;
  --accent: #ffd166;
  --accent-soft: #ffe9a8;
  --pink: #ff8fb1;
  --mint: #6ee7d1;
  --bg: #f4f6ff;
  --bg-alt: #eef1fc;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --surface-border: rgba(91, 110, 245, 0.16);
  --text: #1e2340;
  --text-soft: #4a5170;
  --text-muted: #767d9c;
  --shadow-sm: 0 2px 10px rgba(38, 48, 110, 0.06);
  --shadow-md: 0 10px 30px rgba(38, 48, 110, 0.1);
  --shadow-lg: 0 22px 60px rgba(38, 48, 110, 0.16);
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 26px;
  --radius-xl: 34px;
  --gradient-hero: linear-gradient(135deg, #5b6ef5 0%, #7c5cf5 38%, #b06ef0 68%, #ff8fb1 100%);
  --gradient-soft: linear-gradient(135deg, rgba(91, 110, 245, 0.12), rgba(255, 143, 177, 0.12));
  --gradient-accent: linear-gradient(120deg, #ffd166, #ff8fb1);
  --glass-blur: saturate(180%) blur(18px);
  --transition: 0.32s cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 72px;
  --content-max: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1024;
    --bg-alt: #12162e;
    --surface: rgba(24, 29, 58, 0.66);
    --surface-solid: #191e3c;
    --surface-border: rgba(139, 155, 255, 0.18);
    --text: #eef1ff;
    --text-soft: #c2c8e8;
    --text-muted: #8b93b8;
    --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.35);
    --shadow-md: 0 12px 34px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 26px 70px rgba(0, 0, 0, 0.55);
    --gradient-hero: linear-gradient(135deg, #2a2f6b 0%, #3f2f7a 40%, #5c2f7d 70%, #7a3557 100%);
    --gradient-soft: linear-gradient(135deg, rgba(91, 110, 245, 0.18), rgba(255, 143, 177, 0.14));
    --primary-light: #a3b0ff;
  }
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.78;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 12% 8%, rgba(91, 110, 245, 0.16), transparent 42%),
    radial-gradient(circle at 88% 4%, rgba(255, 143, 177, 0.16), transparent 40%),
    radial-gradient(circle at 50% 100%, rgba(110, 231, 209, 0.12), transparent 46%);
  background-attachment: fixed;
  overflow-x: hidden;
  transition: background-color var(--transition), color var(--transition);
}

img,
svg {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition), opacity var(--transition);
}

a:hover,
a:focus-visible {
  color: var(--primary-dark);
}

@media (prefers-color-scheme: dark) {
  a:hover,
  a:focus-visible {
    color: var(--primary-light);
  }
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

h1, h2, h3, h4 {
  line-height: 1.32;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text);
}

h1 {
  font-size: clamp(1.7rem, 1.1rem + 2.4vw, 2.9rem);
  margin: 0 0 1rem;
}

h2 {
  font-size: clamp(1.4rem, 1.05rem + 1.4vw, 2.05rem);
  margin: 0 0 1rem;
  position: relative;
  padding-bottom: 0.55rem;
}

h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 58px;
  height: 4px;
  border-radius: 4px;
  background: var(--gradient-accent);
}

h3 {
  font-size: clamp(1.1rem, 0.95rem + 0.6vw, 1.32rem);
  margin: 1.6rem 0 0.6rem;
}

h4 {
  font-size: 1.03rem;
  margin: 1.2rem 0 0.4rem;
  color: var(--primary-dark);
}

@media (prefers-color-scheme: dark) {
  h4 {
    color: var(--primary-light);
  }
}

p {
  margin: 0 0 1rem;
}

ul, ol {
  margin: 0 0 1rem;
  padding-left: 1.3rem;
}

li {
  margin-bottom: 0.42rem;
}

::selection {
  background: rgba(91, 110, 245, 0.28);
}

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--surface-border);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), background var(--transition);
}

#site-header:hover {
  box-shadow: var(--shadow-md);
}

.header-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  min-height: var(--header-h);
  padding: 0.6rem clamp(1rem, 3vw, 2rem);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.18rem;
  color: var(--text);
  letter-spacing: 0.02em;
}

.brand:hover {
  color: var(--primary);
}

.brand-logo {
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  filter: drop-shadow(0 4px 12px rgba(91, 110, 245, 0.4));
  transition: transform var(--transition), filter var(--transition);
}

.brand:hover .brand-logo {
  transform: rotate(-8deg) scale(1.08);
  filter: drop-shadow(0 6px 18px rgba(255, 143, 177, 0.55));
}

.brand-name {
  background: linear-gradient(120deg, var(--primary), var(--pink));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}

.main-nav li {
  margin: 0;
}

.main-nav a {
  display: inline-block;
  padding: 0.42rem 0.78rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-soft);
  position: relative;
  transition: color var(--transition), background var(--transition), transform var(--transition);
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: #fff;
  background: var(--gradient-hero);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(91, 110, 245, 0.32);
}

/* ============ Main & Sections ============ */
main {
  display: block;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: clamp(1rem, 2.5vw, 2rem) clamp(1rem, 3vw, 2rem) 2rem;
}

section {
  margin: clamp(1.6rem, 4vw, 3rem) 0;
  padding: clamp(1.2rem, 3vw, 2.2rem);
  background: var(--surface);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
  animation: fadeUp 0.7s cubic-bezier(0.22, 1, 0.36, 1) both;
}

section:hover {
  box-shadow: var(--shadow-md);
  border-color: rgba(91, 110, 245, 0.3);
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(26px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@supports (animation-timeline: view()) {
  section {
    animation: fadeUp linear both;
    animation-timeline: view();
    animation-range: entry 0% cover 22%;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

/* ============ Hero ============ */
.hero {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 5vw, 4rem) clamp(1.2rem, 4vw, 3rem);
  border-radius: var(--radius-xl);
  background: var(--gradient-hero);
  background-size: 180% 180%;
  animation: heroShift 16s ease-in-out infinite, fadeUp 0.8s cubic-bezier(0.22, 1, 0.36, 1) both;
  color: #fff;
  border: none;
  box-shadow: var(--shadow-lg);
  isolation: isolate;
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  z-index: -1;
}

.hero::before {
  width: 420px;
  height: 420px;
  top: -160px;
  right: -120px;
  background: radial-gradient(circle, rgba(255, 209, 102, 0.55), transparent 68%);
  filter: blur(6px);
  animation: floatBlob 14s ease-in-out infinite;
}

.hero::after {
  width: 360px;
  height: 360px;
  bottom: -180px;
  left: -100px;
  background: radial-gradient(circle, rgba(110, 231, 209, 0.5), transparent 70%);
  filter: blur(8px);
  animation: floatBlob 18s ease-in-out infinite reverse;
}

@keyframes heroShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

@keyframes floatBlob {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-24px, 26px) scale(1.12); }
}

.hero-inner {
  position: relative;
  max-width: 880px;
}

.hero h1 {
  color: #fff;
  text-shadow: 0 4px 26px rgba(20, 22, 60, 0.35);
}

.hero-lead {
  font-size: clamp(0.96rem, 0.9rem + 0.35vw, 1.08rem);
  color: rgba(255, 255, 255, 0.94);
  line-height: 1.85;
  max-width: 78ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  margin-top: 1.6rem;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.72rem 1.6rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.96rem;
  letter-spacing: 0.02em;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
  will-change: transform;
}

.btn-primary {
  background: #fff;
  color: var(--primary-dark);
  box-shadow: 0 10px 26px rgba(16, 20, 60, 0.28);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  color: var(--primary-dark);
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 16px 36px rgba(16, 20, 60, 0.36);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.7);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  color: #fff;
  background: rgba(255, 255, 255, 0.26);
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 14px 32px rgba(16, 20, 60, 0.3);
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  margin: 1.2rem 0 0;
  padding: 0.6rem 1rem;
  background: var(--surface);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
}

.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
}

.breadcrumb li {
  margin: 0;
  color: var(--text-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.4rem;
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumb [aria-current="page"] {
  color: var(--text-soft);
  font-weight: 600;
}

/* ============ TOC ============ */
.toc {
  margin: 1.4rem 0;
  padding: clamp(1rem, 2.5vw, 1.6rem);
  background: var(--gradient-soft);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.toc h2 {
  font-size: 1.1rem;
  margin-bottom: 0.9rem;
}

.toc h2::after {
  width: 40px;
  height: 3px;
}

.toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.toc li {
  margin: 0;
}

.toc a {
  display: inline-block;
  padding: 0.34rem 0.86rem;
  border-radius: 999px;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-soft);
  background: var(--surface);
  border: 1px solid var(--surface-border);
  transition: all var(--transition);
}

.toc a:hover,
.toc a:focus-visible {
  color: #fff;
  background: var(--gradient-hero);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(91, 110, 245, 0.3);
}

/* ============ Cards: articles / news / testimonials ============ */
#news article,
#articles article {
  padding: clamp(1rem, 2.5vw, 1.5rem);
  margin: 0 0 1.1rem;
  background: var(--surface-solid);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#news article::before,
#articles article::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition);
}

#news article:hover,
#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(91, 110, 245, 0.34);
}

#news article:hover::before,
#articles article:hover::before {
  opacity: 1;
}

#news article h3,
#articles article h3 {
  margin-top: 0;
}

#news time,
#articles time {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--primary-dark);
  background: rgba(91, 110, 245, 0.1);
  padding: 0.12rem 0.62rem;
  border-radius: 999px;
  margin-bottom: 0.5rem;
}

@media (prefers-color-scheme: dark) {
  #news time,
  #articles time {
    color: var(--primary-light);
    background: rgba(139, 155, 255, 0.16);
  }
}

#news article a,
#articles article a {
  font-weight: 700;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

#news article a::after,
#articles article a::after {
  content: "→";
  transition: transform var(--transition);
}

#news article a:hover::after,
#articles article a:hover::after {
  transform: translateX(4px);
}

/* ============ Testimonials ============ */
#testimonials blockquote {
  margin: 0 0 1.1rem;
  padding: 1.1rem 1.3rem 1.1rem 1.5rem;
  background: var(--surface-solid);
  border: 1px solid var(--surface-border);
  border-left: 5px solid var(--primary);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#testimonials blockquote::before {
  content: "\201C";
  position: absolute;
  top: -0.4rem;
  right: 1rem;
  font-size: 3.4rem;
  line-height: 1;
  color: var(--primary);
  opacity: 0.16;
  font-family: Georgia, serif;
}

#testimonials blockquote:hover {
  transform: translateY(-4px) rotate(-0.4deg);
  box-shadow: var(--shadow-md);
  border-left-color: var(--pink);
}

#testimonials blockquote p {
  margin: 0 0 0.6rem;
  color: var(--text-soft);
  font-style: italic;
}

#testimonials blockquote footer {
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-muted);
  font-style: normal;
}

/* ============ FAQ ============ */
#faq details {
  margin: 0 0 0.8rem;
  padding: 0.9rem 1.1rem;
  background: var(--surface-solid);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), border-color var(--transition), background var(--transition);
}

#faq details:hover {
  border-color: rgba(91, 110, 245, 0.34);
  box-shadow: var(--shadow-md);
}

#faq details[open] {
  border-color: rgba(91, 110, 245, 0.42);
  background: var(--gradient-soft);
}

#faq summary {
  cursor: pointer;
  font-weight: 700;
  font-size: 1rem;
  color: var(--text);
  list-style: none;
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  transition: color var(--transition);
}

#faq summary::-webkit-details-marker {
  display: none;
}

#faq summary::before {
  content: "+";
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  margin-top: 0.18rem;
  border-radius: 50%;
  background: var(--gradient-hero);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1;
  transition: transform var(--transition), background var(--transition);
}

#faq details[open] summary::before {
  content: "−";
  transform: rotate(180deg);
}

#faq summary:hover {
  color: var(--primary);
}

#faq details p {
  margin: 0.7rem 0 0.2rem;
  color: var(--text-soft);
  padding-left: 2.1rem;
  animation: fadeIn 0.4s ease both;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ Contact ============ */
#contact ul {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.7rem;
}

#contact li {
  margin: 0;
  padding: 0.7rem 1rem;
  background: var(--surface-solid);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  color: var(--text-soft);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  word-break: break-word;
}

#contact li:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
  border-color: rgba(91, 110, 245, 0.34);
}

#contact a {
  font-weight: 700;
  word-break: break-all;
}

/* ============ Sitemap & Links ============ */
#sitemap ul,
#links ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

#sitemap li,
#links li {
  margin: 0;
}

#sitemap a,
#links a {
  display: inline-block;
  padding: 0.34rem 0.86rem;
  border-radius: 999px;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-soft);
  background: var(--surface-solid);
  border: 1px solid var(--surface-border);
  transition: all var(--transition);
}

#sitemap a:hover,
#links a:hover,
#sitemap a:focus-visible,
#links a:focus-visible {
  color: #fff;
  background: var(--gradient-hero);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(91, 110, 245, 0.3);
}

/* ============ Legal ============ */
#legal {
  font-size: 0.94rem;
}

#legal h3 {
  color: var(--primary-dark);
}

@media (prefers-color-scheme: dark) {
  #legal h3 {
    color: var(--primary-light);
  }
}

/* ============ Footer ============ */
footer[role="contentinfo"] {
  max-width: var(--content-max);
  margin: 0 auto 2rem;
  padding: clamp(1.2rem, 3vw, 2rem);
  background: var(--surface);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  font-size: 0.88rem;
  color: var(--text-muted);
  text-align: center;
}

footer[role="contentinfo"] p {
  margin: 0 0 0.5rem;
}

footer[role="contentinfo"] a {
  display: inline-block;
  margin-top: 0.4rem;
  padding: 0.44rem 1.2rem;
  border-radius: 999px;
  font-weight: 700;
  color: #fff;
  background: var(--gradient-hero);
  transition: transform var(--transition), box-shadow var(--transition);
}

footer[role="contentinfo"] a:hover,
footer[role="contentinfo"] a:focus-visible {
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 12px 26px rgba(91, 110, 245, 0.36);
}

/* ============ Responsive ============ */
@media (max-width: 900px) {
  :root {
    --header-h: 64px;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .main-nav {
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .main-nav::-webkit-scrollbar {
    display: none;
  }

  .main-nav ul {
    flex-wrap: nowrap;
    padding-bottom: 0.2rem;
  }

  .main-nav a {
    white-space: nowrap;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
  }
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
    line-height: 1.72;
  }

  section {
    border-radius: var(--radius-md);
    padding: 1.1rem;
  }

  .hero {
    border-radius: var(--radius-lg);
    padding: 1.6rem 1.2rem;
  }

  .toc ul,
  #sitemap ul,
  #links ul {
    gap: 0.4rem;
  }

  .toc a,
  #sitemap a,
  #links a {
    font-size: 0.82rem;
    padding: 0.3rem 0.72rem;
  }

  #contact ul {
    grid-template-columns: 1fr;
  }

  #faq details p {
    padding-left: 0;
  }

  footer[role="contentinfo"] {
    margin: 0 1rem 1.4rem;
    border-radius: var(--radius-md);
  }
}

@media (hover: none) {
  .main-nav a:hover,
  .toc a:hover,
  #sitemap a:hover,
  #links a:hover {
    transform: none;
  }
}