:root {
  --primary: #0f4c81;
  --primary-light: #1f7a8c;
  --primary-mid: #3a9d8f;
  --primary-soft: #5aa9a3;
  --accent: #ff7a59;
  --accent-2: #ffb347;
  --bg: #f6f9fc;
  --bg-alt: #eef4fb;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --text: #1a2733;
  --text-muted: #5a6b7b;
  --text-soft: #8194a5;
  --border: rgba(15, 76, 129, 0.12);
  --border-strong: rgba(15, 76, 129, 0.22);
  --shadow-sm: 0 2px 8px rgba(15, 76, 129, 0.06);
  --shadow-md: 0 8px 28px rgba(15, 76, 129, 0.1);
  --shadow-lg: 0 18px 48px rgba(15, 76, 129, 0.16);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --gradient-hero: linear-gradient(135deg, #0f4c81 0%, #1f7a8c 45%, #3a9d8f 75%, #5aa9a3 100%);
  --gradient-accent: linear-gradient(120deg, #ff7a59 0%, #ffb347 100%);
  --gradient-soft: linear-gradient(160deg, rgba(15, 76, 129, 0.06) 0%, rgba(90, 169, 163, 0.08) 100%);
  --glass-blur: 18px;
  --transition: 0.32s cubic-bezier(0.22, 0.61, 0.36, 1);
  --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #5aa9a3;
    --primary-light: #4cc2b5;
    --primary-mid: #3a9d8f;
    --primary-soft: #1f7a8c;
    --accent: #ff8f6b;
    --accent-2: #ffc266;
    --bg: #0b141c;
    --bg-alt: #0f1e2a;
    --surface: rgba(20, 36, 50, 0.62);
    --surface-solid: #142432;
    --text: #e6eef5;
    --text-muted: #a3b6c7;
    --text-soft: #7d93a6;
    --border: rgba(90, 169, 163, 0.18);
    --border-strong: rgba(90, 169, 163, 0.32);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 52px rgba(0, 0, 0, 0.5);
    --gradient-hero: linear-gradient(135deg, #0a2c47 0%, #124a55 45%, #1f6b62 75%, #2c8a80 100%);
    --gradient-soft: linear-gradient(160deg, rgba(90, 169, 163, 0.08) 0%, rgba(31, 122, 140, 0.12) 100%);
  }
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(circle at 12% 8%, rgba(90, 169, 163, 0.14), transparent 42%),
    radial-gradient(circle at 88% 4%, rgba(31, 122, 140, 0.12), transparent 38%),
    radial-gradient(circle at 50% 100%, rgba(15, 76, 129, 0.06), transparent 55%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color var(--transition), color var(--transition);
}

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

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

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

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

ul,
ol {
  padding-left: 1.4em;
  margin: 0 0 1em;
}

li {
  margin-bottom: 0.5em;
}

p {
  margin: 0 0 1.1em;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 0.6em;
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
}

h1 {
  font-size: clamp(1.75rem, 4.2vw, 2.85rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  position: relative;
  padding-bottom: 0.55em;
}

h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 64px;
  height: 4px;
  border-radius: 4px;
  background: var(--gradient-accent);
}

h3 {
  font-size: clamp(1.1rem, 2.2vw, 1.35rem);
  color: var(--primary-light);
}

blockquote {
  margin: 1.2em 0;
  padding: 1.1em 1.4em;
  border-left: 4px solid var(--primary-mid);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--gradient-soft);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  color: var(--text-muted);
  font-style: normal;
}

blockquote p {
  margin: 0;
}

time {
  font-variant-numeric: tabular-nums;
  color: var(--text-soft);
  font-size: 0.9em;
}

/* ============ HEADER / NAV ============ */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), box-shadow var(--transition);
}

header nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.65rem 1.5rem;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
}

header nav > a[aria-label] {
  font-size: 1.2rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--primary);
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
  flex-shrink: 0;
  transition: transform var(--transition), filter var(--transition);
}

header nav > a[aria-label]:hover {
  transform: translateY(-1px);
  filter: brightness(1.15);
}

header nav ul {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.15rem 0.35rem;
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1 1 auto;
}

header nav ul li {
  margin: 0;
}

header nav ul li a {
  display: inline-block;
  padding: 0.4rem 0.78rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  transition: color var(--transition), background var(--transition), transform var(--transition);
}

header nav ul li a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--gradient-accent);
  transform: translateX(-50%);
  transition: width var(--transition);
}

header nav ul li a:hover,
header nav ul li a:focus-visible {
  color: var(--primary);
  background: rgba(90, 169, 163, 0.12);
  transform: translateY(-1px);
}

header nav ul li a:hover::after {
  width: 55%;
}

header nav form[role="search"] {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-shrink: 0;
}

header nav form[role="search"] label {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

header nav form[role="search"] input[type="search"] {
  width: 180px;
  padding: 0.5rem 0.9rem;
  font-size: 0.9rem;
  font-family: inherit;
  color: var(--text);
  background: var(--surface-solid);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  transition: width var(--transition), border-color var(--transition), box-shadow var(--transition);
}

header nav form[role="search"] input[type="search"]::placeholder {
  color: var(--text-soft);
}

header nav form[role="search"] input[type="search"]:focus {
  width: 220px;
  border-color: var(--primary-mid);
  box-shadow: 0 0 0 3px rgba(58, 157, 143, 0.18);
  outline: none;
}

header nav form[role="search"] button {
  padding: 0.5rem 1.1rem;
  font-size: 0.9rem;
  font-family: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-hero);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
}

header nav form[role="search"] button:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
  filter: brightness(1.08);
}

header nav form[role="search"] button:active {
  transform: translateY(0) scale(0.97);
}

/* ============ MAIN LAYOUT ============ */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem 3rem;
}

main > section {
  margin: 2.2rem 0;
  padding: 2rem clamp(1.2rem, 3vw, 2.4rem);
  background: var(--surface);
  backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(160%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  animation: fadeUp 0.7s cubic-bezier(0.22, 0.61, 0.36, 1) both;
  animation-timeline: view();
  animation-range: entry 0% cover 28%;
}

main > section:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--border-strong);
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@supports not (animation-timeline: view()) {
  main > section {
    animation: none;
  }
}

/* ============ HERO ============ */
#hero {
  position: relative;
  margin-top: 1.8rem;
  padding: clamp(2rem, 5vw, 3.6rem) clamp(1.4rem, 4vw, 3rem);
  background: var(--gradient-hero);
  border: none;
  border-radius: var(--radius-xl);
  overflow: hidden;
  color: #eaf6f4;
  box-shadow: var(--shadow-lg);
}

#hero::before {
  content: "";
  position: absolute;
  inset: -40%;
  background:
    radial-gradient(circle at 20% 30%, rgba(255, 179, 71, 0.28), transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(90, 169, 163, 0.35), transparent 50%);
  animation: heroGlow 14s ease-in-out infinite alternate;
  pointer-events: none;
}

@keyframes heroGlow {
  from {
    transform: rotate(0deg) scale(1);
  }
  to {
    transform: rotate(8deg) scale(1.12);
  }
}

#hero > * {
  position: relative;
  z-index: 1;
}

#hero h1 {
  color: #ffffff;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.25);
  max-width: 22ch;
}

#hero h1::after {
  content: "";
  display: block;
  width: 90px;
  height: 5px;
  margin-top: 0.7rem;
  border-radius: 5px;
  background: var(--gradient-accent);
}

#hero > p {
  max-width: 68ch;
  color: rgba(234, 246, 244, 0.92);
  font-size: clamp(0.98rem, 1.6vw, 1.08rem);
  line-height: 1.85;
}

#hero figure {
  margin: 2rem 0 0;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.22);
  transition: transform var(--transition), box-shadow var(--transition);
}

#hero figure:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 56px rgba(0, 0, 0, 0.3);
}

#hero figure svg {
  width: 100%;
  height: auto;
  border-radius: var(--radius-md);
}

#hero figcaption {
  margin-top: 0.8rem;
  text-align: center;
  font-size: 0.9rem;
  color: rgba(234, 246, 244, 0.82);
  letter-spacing: 0.04em;
}

/* ============ PRODUCTS / LISTS ============ */
#products ul,
#howto ul,
#howto ol,
#sitemap ul,
#links ul,
#news ul {
  list-style: none;
  padding-left: 0;
}

#products ul li {
  position: relative;
  padding: 0.7rem 1rem 0.7rem 2.6rem;
  margin-bottom: 0.6rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#products ul li::before {
  content: "✓";
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.15rem;
  height: 1.15rem;
  display: grid;
  place-items: center;
  font-size: 0.72rem;
  font-weight: 700;
  color: #fff;
  background: var(--gradient-hero);
  border-radius: 50%;
  line-height: 1;
}

#products ul li:hover {
  transform: translateX(6px);
  border-color: var(--primary-mid);
  box-shadow: var(--shadow-sm);
}

#howto ol {
  counter-reset: step;
}

#howto ol li {
  position: relative;
  padding: 0.75rem 1rem 0.75rem 3rem;
  margin-bottom: 0.6rem;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  counter-increment: step;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.6rem;
  height: 1.6rem;
  display: grid;
  place-items: center;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  background: var(--gradient-accent);
  border-radius: 50%;
  line-height: 1;
}

#howto ol li:hover {
  transform: translateX(6px);
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
}

#howto ul li {
  position: relative;
  padding-left: 1.5rem;
}

#howto ul li::before {
  content: "";
  position: absolute;
  left: 0.2rem;
  top: 0.72em;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--primary-mid);
}

/* ============ CASES / NEWS / ARTICLES ============ */
#news ul li {
  position: relative;
  padding: 0.85rem 1rem 0.85rem 2.4rem;
  margin-bottom: 0.6rem;
  background: var(--surface-solid);
  border-left: 3px solid var(--primary-mid);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: background var(--transition), transform var(--transition), border-color var(--transition);
}

#news ul li::before {
  content: "●";
  position: absolute;
  left: 0.95rem;
  top: 0.85rem;
  color: var(--accent);
  font-size: 0.7rem;
}

#news ul li:hover {
  background: var(--gradient-soft);
  transform: translateX(5px);
  border-left-color: var(--accent);
}

#news time {
  margin-right: 0.5rem;
  font-weight: 600;
  color: var(--primary-light);
}

#articles article {
  padding: 1.3rem 1.5rem;
  margin-bottom: 1rem;
  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);
}

#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-mid);
}

#articles article h3 {
  margin-bottom: 0.35rem;
  color: var(--text);
  transition: color var(--transition);
}

#articles article:hover h3 {
  color: var(--primary-light);
}

#articles article p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

#articles article a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  background: var(--gradient-soft);
  border: 1px solid var(--border-strong);
  transition: background var(--transition), color var(--transition), transform var(--transition), box-shadow var(--transition);
}

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

#articles article a:hover {
  background: var(--gradient-hero);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

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

/* ============ FAQ ============ */
#faq dl {
  margin: 0;
}

#faq dt {
  position: relative;
  padding: 0.85rem 1rem 0.85rem 2.4rem;
  margin-top: 0.75rem;
  font-weight: 700;
  color: var(--primary-light);
  background: var(--gradient-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

#faq dt::before {
  content: "?";
  position: absolute;
  left: 0.85rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.25rem;
  height: 1.25rem;
  display: grid;
  place-items: center;
  font-size: 0.78rem;
  font-weight: 800;
  color: #fff;
  background: var(--gradient-hero);
  border-radius: 50%;
  line-height: 1;
}

#faq dt:hover {
  background: rgba(90, 169, 163, 0.18);
}

#faq dd {
  margin: 0 0 0.4rem;
  padding: 0.9rem 1.1rem 0.9rem 2.4rem;
  color: var(--text-muted);
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  transition: background var(--transition), border-color var(--transition);
}

#faq dd:hover {
  background: var(--gradient-soft);
  border-color: var(--border-strong);
}

/* ============ CONTACT ============ */
#contact p {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem 0.6rem;
  padding: 0.6rem 0.9rem;
  margin-bottom: 0.5rem;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#contact p:hover {
  transform: translateX(5px);
  border-color: var(--primary-mid);
  box-shadow: var(--shadow-sm);
}

#contact a {
  font-weight: 600;
  word-break: break-all;
}

/* ============ SITEMAP / LINKS ============ */
#sitemap ul,
#links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

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

#sitemap ul li a,
#links ul li a {
  display: inline-block;
  padding: 0.45rem 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition: transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#sitemap ul li a:hover,
#links ul li a:hover {
  color: #fff;
  background: var(--gradient-hero);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* ============ NOTICE / LEGAL ============ */
#notice p,
#legal p {
  color: var(--text-muted);
}

#notice {
  background: var(--gradient-soft);
}

/* ============ FOOTER ============ */
footer {
  max-width: 1200px;
  margin: 0 auto 2rem;
  padding: 1.8rem clamp(1.2rem, 3vw, 2.4rem);
  text-align: center;
  color: var(--text-muted);
  background: var(--surface);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

footer p {
  margin: 0.35rem 0;
  font-size: 0.9rem;
}

footer a {
  font-weight: 600;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 980px) {
  header nav {
    padding: 0.6rem 1.1rem;
    gap: 0.6rem 1rem;
  }

  header nav ul {
    order: 3;
    flex-basis: 100%;
    justify-content: center;
    padding-top: 0.35rem;
    border-top: 1px solid var(--border);
  }

  header nav form[role="search"] {
    margin-left: auto;
  }

  header nav form[role="search"] input[type="search"] {
    width: 150px;
  }

  header nav form[role="search"] input[type="search"]:focus {
    width: 170px;
  }
}

@media (max-width: 720px) {
  body {
    font-size: 15px;
    background-attachment: scroll;
  }

  main {
    padding: 0 0.9rem 2rem;
  }

  main > section {
    margin: 1.4rem 0;
    padding: 1.4rem 1.1rem;
    border-radius: var(--radius-md);
  }

  #hero {
    margin-top: 1.2rem;
    padding: 1.8rem 1.2rem;
    border-radius: var(--radius-lg);
  }

  #hero h1 {
    max-width: none;
  }

  #hero figure {
    margin-top: 1.4rem;
    padding: 0.6rem;
  }

  header nav {
    padding: 0.55rem 0.9rem;
  }

  header nav > a[aria-label] {
    font-size: 1.05rem;
  }

  header nav ul {
    gap: 0.1rem 0.2rem;
  }

  header nav ul li a {
    padding: 0.32rem 0.6rem;
    font-size: 0.84rem;
  }

  header nav form[role="search"] {
    flex-basis: 100%;
    order: 2;
  }

  header nav form[role="search"] input[type="search"],
  header nav form[role="search"] input[type="search"]:focus {
    width: 100%;
    flex: 1 1 auto;
  }

  #articles article {
    padding: 1.1rem 1.1rem;
  }

  #faq dt,
  #faq dd {
    padding-left: 2.2rem;
  }

  blockquote {
    padding: 0.9rem 1rem;
  }

  footer {
    padding: 1.4rem 1rem;
    border-radius: var(--radius-md);
  }
}

@media (max-width: 420px) {
  header nav ul li a {
    font-size: 0.8rem;
    padding: 0.3rem 0.5rem;
  }

  #hero h1 {
    font-size: 1.5rem;
  }

  #contact p {
    flex-direction: column;
    gap: 0.15rem;
  }
}

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

  main > section {
    animation: none;
    opacity: 1;
    transform: none;
  }
}

@media print {
  header,
  footer,
  #hero figure {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
  }

  main > section {
    box-shadow: none;
    border: 1px solid #ccc;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    animation: none;
  }
}