:root {
  --bg: #f5f7fa;
  --bg-alt: #ffffff;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --border: rgba(15, 43, 70, 0.12);
  --text: #1a2733;
  --text-soft: #4a5a6a;
  --text-mute: #7a8896;
  --primary: #0f2b46;
  --primary-soft: #1c4a72;
  --accent: #e8b04b;
  --accent-soft: #f2c96f;
  --teal: #2f6f8f;
  --gradient-hero: linear-gradient(135deg, #0f2b46 0%, #1c4a72 45%, #2f6f8f 100%);
  --gradient-accent: linear-gradient(135deg, #e8b04b 0%, #f2c96f 100%);
  --shadow-sm: 0 2px 8px rgba(15, 43, 70, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 43, 70, 0.1);
  --shadow-lg: 0 16px 48px rgba(15, 43, 70, 0.16);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --header-h: 64px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a1620;
    --bg-alt: #0f1f2d;
    --surface: rgba(23, 42, 60, 0.68);
    --surface-solid: #142534;
    --border: rgba(232, 176, 75, 0.16);
    --text: #e8eef4;
    --text-soft: #b4c2ce;
    --text-mute: #8494a2;
    --primary: #2f6f8f;
    --primary-soft: #1c4a72;
    --accent: #f2c96f;
    --accent-soft: #e8b04b;
    --teal: #4a90b0;
    --gradient-hero: linear-gradient(135deg, #0a1620 0%, #142534 45%, #1c4a72 100%);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
  }
}

*,
*::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: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  background-image:
    radial-gradient(circle at 12% 8%, rgba(232, 176, 75, 0.08) 0, transparent 32%),
    radial-gradient(circle at 88% 18%, rgba(47, 111, 143, 0.1) 0, transparent 36%),
    radial-gradient(circle at 50% 92%, rgba(232, 176, 75, 0.06) 0, transparent 30%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ---------- Header / Nav ---------- */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  backdrop-filter: blur(16px) saturate(160%);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

header nav {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 4px;
  height: var(--header-h);
  overflow-x: auto;
  overflow-y: hidden;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

header nav::-webkit-scrollbar {
  display: none;
}

header nav a {
  flex: 0 0 auto;
  display: inline-block;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition), background var(--transition), transform var(--transition);
}

header nav a:hover,
header nav a:focus-visible {
  color: var(--primary);
  background: rgba(232, 176, 75, 0.16);
  transform: translateY(-1px);
  outline: none;
}

header nav a:first-child {
  color: var(--accent);
  font-weight: 700;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ---------- Main layout ---------- */
main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px 64px;
}

main > article {
  display: block;
}

/* ---------- Hero ---------- */
#hero {
  position: relative;
  margin: 32px 0 48px;
  padding: 56px 40px 48px;
  border-radius: var(--radius-lg);
  background: var(--gradient-hero);
  color: #ffffff;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  animation: fadeUp 0.7s ease both;
}

#hero::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -10%;
  width: 60%;
  height: 180%;
  background: radial-gradient(circle, rgba(232, 176, 75, 0.28) 0, transparent 62%);
  pointer-events: none;
}

#hero::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -8%;
  width: 50%;
  height: 140%;
  background: radial-gradient(circle, rgba(47, 111, 143, 0.4) 0, transparent 60%);
  pointer-events: none;
}

#hero h1 {
  position: relative;
  z-index: 1;
  margin: 0 0 20px;
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: 0.01em;
  background: linear-gradient(120deg, #ffffff 0%, #f2c96f 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

#hero > p {
  position: relative;
  z-index: 1;
  max-width: 780px;
  margin: 0 0 36px;
  font-size: 1.02rem;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.86);
}

#hero figure {
  position: relative;
  z-index: 1;
  margin: 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--surface);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition), box-shadow var(--transition);
}

#hero figure:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

#hero figure svg {
  display: block;
  width: 100%;
  height: auto;
}

#hero figcaption {
  padding: 12px 18px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.7);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

/* ---------- Sections ---------- */
main section {
  margin: 0 0 40px;
  padding: 36px 32px;
  background: var(--surface);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  animation: fadeUp 0.6s ease both;
}

main section:nth-of-type(odd) {
  background: var(--surface);
}

main section:hover {
  box-shadow: var(--shadow-md);
  transition: box-shadow var(--transition);
}

/* ---------- Headings ---------- */
main h2 {
  position: relative;
  margin: 0 0 24px;
  padding-left: 18px;
  font-size: clamp(1.3rem, 2.6vw, 1.75rem);
  font-weight: 800;
  line-height: 1.35;
  color: var(--text);
}

main h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
}

main h3 {
  margin: 28px 0 12px;
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--primary-soft);
}

main h3:first-of-type {
  margin-top: 0;
}

main h4 {
  margin: 20px 0 8px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--teal);
}

main p {
  margin: 0 0 14px;
  color: var(--text-soft);
}

main section > p:last-child,
main section > ul:last-child {
  margin-bottom: 0;
}

/* ---------- Links ---------- */
main a {
  color: var(--primary-soft);
  text-decoration: none;
  background-image: linear-gradient(var(--accent), var(--accent));
  background-size: 0% 2px;
  background-position: 0 100%;
  background-repeat: no-repeat;
  transition: color var(--transition), background-size var(--transition);
}

main a:hover,
main a:focus-visible {
  color: var(--accent);
  background-size: 100% 2px;
  outline: none;
}

/* ---------- Article cards ---------- */
#articles {
  display: block;
}

#articles > article {
  position: relative;
  margin: 0 0 16px;
  padding: 22px 24px;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  animation: fadeUp 0.6s ease both;
}

#articles > article:last-of-type {
  margin-bottom: 0;
}

#articles > article::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 4px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition);
}

#articles > article:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: rgba(232, 176, 75, 0.4);
}

#articles > article:hover::before {
  opacity: 1;
}

#articles > article h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--text);
}

#articles > article p {
  margin: 0 0 8px;
  font-size: 0.92rem;
}

#articles > article p:first-of-type {
  display: inline-block;
  padding: 2px 10px;
  margin-bottom: 10px;
  font-size: 0.78rem;
  color: var(--teal);
  background: rgba(47, 111, 143, 0.1);
  border-radius: var(--radius-pill);
}

#articles > article p:last-child {
  margin: 0;
}

#articles > article a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
}

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

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

/* ---------- FAQ ---------- */
#faq h3 {
  position: relative;
  padding: 14px 18px 14px 44px;
  margin: 12px 0 0;
  font-size: 1rem;
  color: var(--text);
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: default;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#faq h3::before {
  content: "Q";
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.78rem;
  font-weight: 800;
  color: #ffffff;
  background: var(--gradient-hero);
  border-radius: 50%;
}

#faq h3:hover {
  border-color: rgba(232, 176, 75, 0.5);
  box-shadow: var(--shadow-sm);
}

#faq h3 + p {
  margin: 0 0 4px;
  padding: 14px 18px 14px 44px;
  font-size: 0.92rem;
  color: var(--text-soft);
  background: rgba(47, 111, 143, 0.05);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* ---------- HowTo ---------- */
#howto h4 {
  position: relative;
  padding-left: 30px;
  margin: 22px 0 6px;
  color: var(--text);
}

#howto h4::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 18px;
  height: 18px;
  transform: translateY(-50%);
  border-radius: 50%;
  background: var(--gradient-accent);
  box-shadow: 0 0 0 4px rgba(232, 176, 75, 0.18);
}

#howto h4 + p {
  margin-left: 30px;
  padding-left: 14px;
  border-left: 2px solid var(--border);
}

/* ---------- Lists (sitemap / links) ---------- */
main ul {
  margin: 0 0 14px;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

main ul li {
  flex: 0 0 auto;
}

main ul li a {
  display: inline-block;
  padding: 8px 16px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-soft);
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  background-image: none;
  transition: color var(--transition), background var(--transition), border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

main ul li a:hover,
main ul li a:focus-visible {
  color: #ffffff;
  background: var(--gradient-hero);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  outline: none;
}

/* ---------- Contact ---------- */
#contact h3 {
  display: inline-block;
  margin: 22px 0 6px;
  padding: 3px 14px;
  font-size: 0.92rem;
  color: var(--primary-soft);
  background: rgba(232, 176, 75, 0.14);
  border-radius: var(--radius-pill);
}

#contact h3:first-of-type {
  margin-top: 0;
}

#contact h3 + p {
  padding-left: 4px;
  font-size: 0.94rem;
}

/* ---------- Legal ---------- */
#legal h3 {
  padding-bottom: 6px;
  border-bottom: 1px dashed var(--border);
}

/* ---------- Footer ---------- */
footer {
  position: relative;
  padding: 40px 20px 48px;
  text-align: center;
  background: var(--gradient-hero);
  color: rgba(255, 255, 255, 0.8);
  border-top: 1px solid var(--border);
}

footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 3px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
}

footer p {
  max-width: 720px;
  margin: 0 auto 8px;
  font-size: 0.86rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.72);
}

footer p:first-child {
  font-size: 0.94rem;
  font-weight: 600;
  color: #ffffff;
}

footer p:last-child {
  margin-bottom: 0;
}

/* ---------- Focus visibility ---------- */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Selection ---------- */
::selection {
  background: rgba(232, 176, 75, 0.35);
  color: var(--text);
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(47, 111, 143, 0.4);
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(232, 176, 75, 0.6);
  background-clip: content-box;
}

/* ---------- Animations ---------- */
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  #hero {
    padding: 44px 28px 36px;
  }
  main section {
    padding: 28px 24px;
  }
}

@media (max-width: 640px) {
  :root {
    --header-h: 56px;
  }

  body {
    font-size: 15px;
  }

  header nav {
    padding: 0 12px;
    gap: 2px;
  }

  header nav a {
    padding: 6px 10px;
    font-size: 0.82rem;
  }

  main {
    padding: 0 14px 48px;
  }

  #hero {
    margin: 18px 0 28px;
    padding: 32px 20px 24px;
    border-radius: var(--radius-md);
  }

  #hero > p {
    font-size: 0.94rem;
    line-height: 1.8;
    margin-bottom: 24px;
  }

  main section {
    margin-bottom: 24px;
    padding: 22px 18px;
    border-radius: var(--radius-md);
  }

  main h2 {
    padding-left: 14px;
    margin-bottom: 18px;
  }

  main h2::before {
    width: 4px;
  }

  main h3 {
    margin-top: 22px;
    font-size: 1.04rem;
  }

  #articles > article {
    padding: 18px 16px;
  }

  #faq h3 {
    padding: 12px 14px 12px 40px;
    font-size: 0.94rem;
  }

  #faq h3 + p {
    padding: 12px 14px 12px 40px;
  }

  main ul {
    gap: 8px;
  }

  main ul li a {
    padding: 6px 12px;
    font-size: 0.82rem;
  }

  footer {
    padding: 32px 16px 40px;
  }
}

@media (max-width: 380px) {
  #hero {
    padding: 26px 16px 20px;
  }
  main section {
    padding: 18px 14px;
  }
}

/* ---------- Print ---------- */
@media print {
  header,
  footer,
  #hero figure {
    display: none;
  }
  body {
    background: #ffffff;
    color: #000000;
  }
  main section {
    box-shadow: none;
    border: 1px solid #cccccc;
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
    background: #ffffff;
    animation: none;
  }
  main a {
    color: #000000;
    text-decoration: underline;
  }
}