:root {
  --spring-green: #9BCF6B;
  --summer-blue: #2E8BC0;
  --autumn-orange: #E8A33D;
  --winter-silver: #E6ECF0;
  --deep-space: #0E1418;
  --ink-blue: #1B2A38;
  --sakura-pink: #F2A6A0;
  --grape-purple: #6E4B8A;
  --warm-white: #F5F1E8;
  --cement-gray: #8A9BA8;
  --c-primary: var(--spring-green);
  --c-secondary: var(--summer-blue);
  --c-accent: var(--autumn-orange);
  --c-bg: var(--warm-white);
  --c-text: var(--deep-space);
  --c-muted: var(--cement-gray);
  --c-line: rgba(14, 20, 24, 0.12);
  --c-line-light: rgba(230, 236, 240, 0.15);
  --font-display: "Oswald", "Arial Narrow", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;
  --space-10: 128px;
  --container-max: 1200px;
  --header-bg: var(--deep-space);
  --footer-bg: var(--deep-space);
  --ease-out: cubic-bezier(0.22, 0.61, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  border-radius: 0;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-text);
  background-color: var(--c-bg);
  -webkit-font-smoothing: antialiased;
}

body.is-nav-open {
  overflow: hidden;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: var(--c-secondary);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

button {
  font-family: inherit;
  cursor: pointer;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.3;
  color: var(--c-text);
}

h1 {
  font-size: clamp(32px, 5vw, 52px);
  letter-spacing: 0.02em;
  font-weight: 700;
}

h2 {
  font-size: clamp(24px, 3vw, 36px);
  letter-spacing: 0.01em;
}

h3 {
  font-size: clamp(20px, 2vw, 26px);
}

p {
  max-width: 45em;
}

ul,
ol {
  list-style-position: inside;
}

.container {
  width: min(var(--container-max), 100% - 48px);
  margin-inline: auto;
}

.section {
  padding: var(--space-8) 0;
}

.section--alt {
  background: var(--winter-silver);
}

.section--ink {
  background: var(--ink-blue);
}

.section--ink h1,
.section--ink h2,
.section--ink h3,
.section--ink h4 {
  color: var(--warm-white);
}

.section--ink .section-intro {
  color: rgba(230, 236, 240, 0.72);
}

.section-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-bottom: var(--space-5);
}

.section-index {
  font-family: var(--font-display);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.2em;
  color: var(--c-muted);
  text-transform: uppercase;
}

.section-title {
  font-weight: 500;
}

.section-intro {
  width: 100%;
  color: var(--c-muted);
  font-size: 15px;
  line-height: 1.7;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-5);
}

.span-1 { grid-column: span 1; }
.span-2 { grid-column: span 2; }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-10 { grid-column: span 10; }
.span-11 { grid-column: span 11; }
.span-12 { grid-column: span 12; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  font-size: 13px;
  color: var(--c-muted);
  margin-bottom: var(--space-5);
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb li + li::before {
  content: "/";
  color: var(--c-line);
  font-family: var(--font-display);
}

.breadcrumb a {
  color: var(--c-muted);
  text-decoration: none;
  transition: color 0.25s;
}

.breadcrumb a:hover {
  color: var(--c-secondary);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1;
  color: var(--c-text);
  background: transparent;
  border: 1px solid var(--c-line);
  text-decoration: none;
  transition: background 0.25s, color 0.25s, border-color 0.25s;
}

.btn-primary {
  background: var(--spring-green);
  border-color: var(--spring-green);
  color: var(--deep-space);
  font-weight: 600;
}

.btn-primary:hover {
  background: #87bb4f;
  border-color: #87bb4f;
}

.btn-outline {
  border-color: rgba(14, 20, 24, 0.35);
  color: var(--c-text);
}

.btn-outline:hover {
  border-color: var(--deep-space);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  background: var(--winter-silver);
  color: var(--deep-space);
  border: 1px solid var(--c-line);
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: all 0.25s;
}

.tag:hover,
.tag.is-active {
  background: var(--deep-space);
  border-color: var(--deep-space);
  color: var(--warm-white);
}

.card {
  background: var(--warm-white);
  border: 1px solid var(--c-line);
  padding: var(--space-5);
}

.card-title {
  font-size: 22px;
  margin-bottom: var(--space-2);
}

.card-meta {
  font-size: 13px;
  color: var(--c-muted);
  letter-spacing: 0.04em;
}

.stat-card {
  background: var(--deep-space);
  color: var(--winter-silver);
  padding: var(--space-5);
  border: 1px solid rgba(230, 236, 240, 0.1);
}

.stat-card .stat-value {
  font-family: var(--font-display);
  font-size: 38px;
  font-weight: 600;
  line-height: 1.1;
  color: var(--spring-green);
}

.stat-card .stat-label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-muted);
  text-transform: uppercase;
  margin-top: var(--space-2);
}

.file-card {
  position: relative;
  background: var(--warm-white);
  border: 1px solid var(--c-line);
  padding: var(--space-6) var(--space-5) var(--space-5);
  margin-top: 26px;
}

.file-card .file-label {
  position: absolute;
  top: -13px;
  left: 16px;
  height: 26px;
  display: inline-flex;
  align-items: center;
  padding: 0 14px;
  background: var(--ink-blue);
  color: var(--winter-silver);
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: capitalize;
}

.data-strip {
  display: flex;
  align-items: center;
  gap: 12px;
}

.data-strip .strip-track {
  flex: 1;
  height: 10px;
  background: rgba(14, 20, 24, 0.1);
  border: 1px solid rgba(14, 20, 24, 0.05);
  overflow: hidden;
}

.data-strip .strip-fill {
  display: block;
  height: 100%;
  width: var(--fill, 60%);
  background: linear-gradient(90deg, var(--spring-green), var(--summer-blue));
}

.toc {
  list-style: none;
  background: var(--winter-silver);
  border: 1px solid var(--c-line);
}

.toc li {
  border-bottom: 1px solid var(--c-line);
}

.toc li:last-child {
  border-bottom: 0;
}

.toc a {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 18px;
  color: var(--c-text);
  text-decoration: none;
  transition: background 0.25s, color 0.25s;
}

.toc a:hover {
  background: var(--spring-green);
  color: var(--deep-space);
}

.toc .toc-index {
  font-family: var(--font-display);
  font-size: 11px;
  color: var(--c-muted);
  letter-spacing: 0.08em;
  min-width: 2em;
}

.statement {
  font-size: clamp(20px, 2.5vw, 28px);
  font-weight: 300;
  line-height: 1.55;
  max-width: 22em;
  padding-left: 20px;
  border-left: 2px solid var(--c-accent);
  color: var(--c-text);
}

.img-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
  background: linear-gradient(135deg, rgba(46, 139, 192, 0.18), rgba(155, 207, 107, 0.12)), var(--winter-silver);
  border: 1px solid var(--c-line);
}

.img-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(45deg, rgba(14, 20, 24, 0.05) 25%, transparent 25%, transparent 75%, rgba(14, 20, 24, 0.05) 75%),
    linear-gradient(45deg, rgba(14, 20, 24, 0.05) 25%, transparent 25%, transparent 75%, rgba(14, 20, 24, 0.05) 75%);
  background-size: 16px 16px;
  background-position: 0 0, 8px 8px;
}

.img-frame::after {
  content: attr(data-caption);
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 6px 12px;
  font-size: 12px;
  color: var(--warm-white);
  background: rgba(14, 20, 24, 0.65);
  opacity: 0;
  transition: opacity 0.3s;
}

.img-frame:hover::after,
.img-frame:focus-within::after {
  opacity: 1;
}

.img-frame--wide {
  aspect-ratio: 16 / 9;
}

.img-frame--tall {
  aspect-ratio: 3 / 4;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 2000;
  padding: 10px 18px;
  background: var(--summer-blue);
  color: #fff;
  font-size: 14px;
  text-decoration: none;
  transition: top 0.25s ease;
}

.skip-link:focus {
  top: 12px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--header-bg);
  border-bottom: 1px solid var(--c-line-light);
}

.site-header::before {
  content: "";
  display: block;
  height: 4px;
  background: linear-gradient(90deg, var(--spring-green) 0%, var(--summer-blue) 30%, var(--autumn-orange) 68%, var(--winter-silver) 100%);
}

.site-header.is-scrolled {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.28);
}

.header-shell {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 14px 24px 0;
}

.header-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--warm-white);
  text-decoration: none;
}

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

.brand-mark {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2px;
  width: 30px;
  height: 30px;
  transform: rotate(45deg);
  flex: none;
}

.brand-dot {
  display: block;
  width: 14px;
  height: 14px;
}

.brand-dot--spring { background: var(--spring-green); }
.brand-dot--summer { background: var(--summer-blue); }
.brand-dot--autumn { background: var(--autumn-orange); }
.brand-dot--winter { background: var(--winter-silver); }

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--warm-white);
}

.brand-tagline {
  font-size: 10px;
  letter-spacing: 0.24em;
  color: var(--c-muted);
  text-transform: uppercase;
  margin-top: 2px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.search-shell {
  position: relative;
  display: flex;
  align-items: center;
}

.search-input {
  width: 190px;
  padding: 9px 38px 9px 12px;
  background: rgba(230, 236, 240, 0.08);
  border: 1px solid rgba(230, 236, 240, 0.18);
  color: var(--winter-silver);
  font-family: var(--font-body);
  font-size: 14px;
  transition: border-color 0.25s, background 0.25s;
}

.search-input::placeholder {
  color: rgba(230, 236, 240, 0.38);
}

.search-input:focus {
  outline: none;
  border-color: var(--spring-green);
  background: rgba(230, 236, 240, 0.13);
}

.search-shell::after {
  content: "";
  position: absolute;
  right: 13px;
  width: 11px;
  height: 11px;
  border: 2px solid var(--c-muted);
  border-radius: 50%;
  pointer-events: none;
}

.search-shell::before {
  content: "";
  position: absolute;
  right: 9px;
  bottom: 12px;
  width: 6px;
  height: 2px;
  background: var(--c-muted);
  transform: rotate(45deg);
  pointer-events: none;
}

.search-shell:focus-within::after,
.search-shell:focus-within::before {
  border-color: var(--spring-green);
  background: var(--spring-green);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 9px 16px;
  background: var(--autumn-orange);
  color: var(--deep-space);
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-decoration: none;
  border: 1px solid var(--autumn-orange);
  transition: background 0.25s, color 0.25s;
}

.header-cta:hover {
  background: transparent;
  color: var(--autumn-orange);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 1px solid rgba(230, 236, 240, 0.22);
  padding: 9px 12px;
  color: var(--winter-silver);
  font-size: 13px;
  line-height: 1;
  transition: border-color 0.25s, color 0.25s;
}

.nav-toggle:hover {
  border-color: var(--spring-green);
  color: var(--spring-green);
}

.nav-toggle-box {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
  flex: none;
}

.nav-toggle-line {
  height: 2px;
  background: currentColor;
  transition: transform 0.25s, opacity 0.25s;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.site-nav {
  border-top: 1px solid rgba(230, 236, 240, 0.1);
  margin-top: 12px;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 18px 10px;
  color: var(--winter-silver);
  font-size: 15px;
  font-weight: 400;
  letter-spacing: 0.02em;
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.25s;
}

.nav-index {
  font-family: var(--font-display);
  font-size: 10px;
  font-weight: 600;
  color: var(--c-muted);
  letter-spacing: 0.08em;
  margin-top: 2px;
}

.nav-link:hover {
  color: var(--spring-green);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 18px;
  right: 18px;
  bottom: 0;
  height: 2px;
  background: var(--spring-green);
  transform: scaleX(0);
  transition: transform 0.3s var(--ease-out);
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.nav-link[aria-current="page"] {
  color: var(--spring-green);
}

.site-footer {
  position: relative;
  background: var(--footer-bg);
  color: var(--winter-silver);
}

.site-footer::before {
  content: "";
  display: block;
  height: 4px;
  background: linear-gradient(90deg, var(--spring-green) 0%, var(--summer-blue) 30%, var(--autumn-orange) 68%, var(--winter-silver) 100%);
}

.footer-shell {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-7) 24px var(--space-5);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: var(--space-6);
}

.footer-brand .brand,
.footer-brand .brand-name {
  color: var(--warm-white);
}

.footer-trust {
  color: var(--c-muted);
  font-size: 14px;
  line-height: 1.75;
  max-width: 34em;
  margin-top: var(--space-4);
}

.footer-col--contact {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(230, 236, 240, 0.08);
  padding: var(--space-4);
}

.footer-title {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--autumn-orange);
  margin-bottom: var(--space-4);
}

.footer-list {
  list-style: none;
}

.footer-list li {
  margin-bottom: var(--space-2);
  font-size: 14px;
  line-height: 1.6;
  color: var(--winter-silver);
}

.footer-list a {
  color: var(--winter-silver);
  text-decoration: none;
  transition: color 0.25s, padding-left 0.25s;
}

.footer-list a:hover {
  color: var(--spring-green);
  padding-left: 4px;
}

.footer-contact-list li {
  color: var(--winter-silver);
}

.footer-note {
  font-size: 12px;
  color: var(--c-muted);
  margin-top: var(--space-3);
  line-height: 1.6;
  max-width: 24em;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px 16px;
  padding-top: var(--space-4);
  margin-top: var(--space-6);
  border-top: 1px solid rgba(230, 236, 240, 0.14);
  color: var(--c-muted);
  font-size: 13px;
}

.footer-bottom span {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

[data-reveal] {
  opacity: 1;
}

.js [data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
  will-change: opacity, transform;
}

.js [data-reveal="left"] {
  transform: translateX(-24px);
}

.js [data-reveal="right"] {
  transform: translateX(24px);
}

.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

[data-filter-item].is-hidden {
  display: none;
}

[data-search-item].is-search-hidden {
  display: none;
}

:focus-visible {
  outline: 2px solid var(--summer-blue);
  outline-offset: 3px;
}

@media (max-width: 1023px) and (min-width: 769px) {
  .header-shell {
    padding-left: 20px;
    padding-right: 20px;
  }

  .brand-tagline {
    display: none;
  }

  .search-input {
    width: 150px;
  }

  .nav-link {
    padding-left: 12px;
    padding-right: 12px;
    font-size: 14px;
  }

  .nav-link::after {
    left: 12px;
    right: 12px;
  }

  .grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid > [class*="span-"] {
    grid-column: span 1;
  }

  .grid > .span-12 {
    grid-column: span 2;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand {
    grid-column: span 2;
  }
}

@media (max-width: 768px) {
  .header-shell {
    padding-left: 16px;
    padding-right: 16px;
    padding-top: 10px;
  }

  .header-bar {
    gap: 8px;
  }

  .brand-name {
    font-size: 20px;
  }

  .brand-tagline {
    display: none;
  }

  .header-actions {
    width: 100%;
    justify-content: flex-end;
  }

  .search-input {
    width: 100%;
    min-width: 140px;
  }

  .search-shell {
    flex: 1;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav[data-open="true"] {
    display: block;
  }

  .site-nav:not([data-open="true"]) {
    display: none;
  }

  .nav-list {
    flex-direction: column;
    padding-bottom: 8px;
  }

  .nav-link {
    padding: 14px 8px;
    border-bottom: 1px solid rgba(230, 236, 240, 0.08);
    font-size: 16px;
  }

  .nav-link::after {
    display: none;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .grid > [class*="span-"] {
    grid-column: span 1;
  }

  .section {
    padding: var(--space-7) 0;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-5);
  }

  .footer-brand {
    grid-column: span 1;
  }

  .footer-bottom {
    flex-direction: column;
    justify-content: center;
    text-align: center;
  }

  .container {
    width: min(100% - 32px, var(--container-max));
  }
}

@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;
    transition-delay: 0ms !important;
  }

  .js [data-reveal],
  .js [data-reveal="left"],
  .js [data-reveal="right"],
  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}