:root {
  --bg: #090a0f;
  --bg-secondary: #101827;
  --panel: rgba(255, 255, 255, 0.06);
  --panel-strong: rgba(255, 255, 255, 0.1);
  --panel-line: rgba(255, 255, 255, 0.12);
  --accent: #67e8f9;
  --accent-2: #fbbf24;
  --text: #f7fafc;
  --muted: rgba(255, 255, 255, 0.72);
  --paper: #fbf8f1;
  --paper-ink: #1d2430;
  --paper-line: #d8d3c8;
  --paper-muted: #5b6472;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.28);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top, rgba(103, 232, 249, 0.08), transparent 30rem),
    radial-gradient(circle at 80% 20%, rgba(251, 191, 36, 0.08), transparent 22rem),
    linear-gradient(180deg, #111827 0%, #090a0f 48%, #06070b 100%);
}

a {
  color: var(--accent);
}

.site-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(9, 10, 15, 0.8);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-content {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.logo {
  color: #fff;
  text-decoration: none;
  font-weight: 800;
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.82);
  text-decoration: none;
  transition: color 0.25s ease, transform 0.25s ease;
}

.nav-links a:hover,
.nav-links a.is-active {
  color: var(--accent);
}

.hero {
  padding: 56px 0 26px;
}

.hero-panel,
.info-card,
.article-card,
.paper {
  border: 1px solid var(--panel-line);
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.hero-panel {
  padding: 32px;
  border-radius: 28px;
}

.eyebrow,
.article-kind {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  background: rgba(103, 232, 249, 0.12);
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero h1,
.article-header h1 {
  margin: 14px 0 10px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: clamp(2.4rem, 5vw, 4.5rem);
  line-height: 1.05;
}

.hero p,
.article-subtitle,
.intro {
  max-width: 54rem;
  color: var(--muted);
  font-size: 1.08rem;
  line-height: 1.7;
}

.grid {
  display: grid;
  gap: 24px;
}

.grid--split {
  grid-template-columns: minmax(0, 1.7fr) minmax(280px, 0.9fr);
  margin: 24px 0 60px;
}

.info-card,
.article-card {
  padding: 24px;
  border-radius: 24px;
}

.info-card h2,
.article-card h2,
.paper h2,
.paper h3,
.meta-card h2 {
  margin: 0 0 14px;
  color: #ffffff;
}

.article-list {
  display: grid;
  gap: 18px;
}

.article-card h3 {
  margin: 0 0 10px;
  font-family: "Playfair Display", Georgia, serif;
  font-size: 1.9rem;
}

.meta-line {
  color: rgba(255, 255, 255, 0.66);
  font-size: 0.92rem;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid rgba(103, 232, 249, 0.36);
  background: linear-gradient(45deg, #667eea, #764ba2);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  box-shadow: 0 10px 30px rgba(102, 126, 234, 0.24);
}

.button:hover {
  transform: translateY(-2px);
}

.button--ghost {
  background: transparent;
  box-shadow: none;
  color: var(--accent);
}

.paper-wrap {
  padding: 18px 0 70px;
}

.breadcrumbs {
  margin: 0 0 14px;
  color: rgba(255, 255, 255, 0.65);
  font-size: 0.95rem;
}

.breadcrumbs a {
  text-decoration: none;
}

.paper {
  border-radius: 30px;
  overflow: hidden;
}

.article-header {
  padding: 36px 38px 24px;
  border-bottom: 1px solid rgba(216, 211, 200, 0.45);
  color: var(--paper-ink);
  background:
    linear-gradient(180deg, rgba(251, 248, 241, 0.98), rgba(246, 241, 230, 0.98)),
    linear-gradient(135deg, rgba(103, 232, 249, 0.08), rgba(251, 191, 36, 0.08));
}

.article-header h1,
.article-header .article-subtitle,
.article-header .article-kind {
  color: var(--paper-ink);
}

.article-header .article-kind {
  background: rgba(31, 76, 112, 0.08);
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 2.1fr) minmax(260px, 0.92fr);
  gap: 24px;
  padding: 28px 38px 8px;
  background: var(--paper);
  color: var(--paper-ink);
}

.abstract-box,
.meta-card,
.download-panel,
.citation-box,
.note-box {
  border: 1px solid var(--paper-line);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.72);
}

.abstract-box {
  padding: 22px;
  background: linear-gradient(180deg, #eef2f8, #f6f9fc);
}

.abstract-label {
  margin-bottom: 10px;
  color: #214968;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.keyword-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.keyword-list span {
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(31, 76, 112, 0.08);
  color: #214968;
  font-size: 0.92rem;
}

.meta-card {
  padding: 22px;
  color: var(--paper-ink);
  background: linear-gradient(180deg, #f8fafc, #f2f5f7);
}

.meta-card dl {
  margin: 0;
}

.meta-card dt {
  margin-top: 16px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #214968;
}

.meta-card dt:first-child {
  margin-top: 0;
}

.meta-card dd {
  margin: 4px 0 0;
  color: var(--paper-ink);
}

.paper-body {
  padding: 0 38px 28px;
  background: var(--paper);
  color: var(--paper-ink);
}

.paper-body p {
  margin: 14px 0;
  line-height: 1.74;
  text-align: justify;
}

.paper-body h2 {
  margin-top: 34px;
  padding-bottom: 6px;
  font-size: 1.5rem;
  color: #17354e;
  border-bottom: 1px solid var(--paper-line);
}

.paper-body h3 {
  margin-top: 24px;
  font-size: 1.18rem;
  color: #17354e;
}

.formula-block {
  padding: 18px 20px;
  margin: 18px 0;
  text-align: center;
  overflow-x: auto;
  border-radius: 22px;
  background: #eef2f8;
  border: 1px solid #d9e2ec;
}

table {
  width: 100%;
  margin: 18px 0;
  border-collapse: collapse;
  background: rgba(255, 255, 255, 0.7);
}

th,
td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border: 1px solid var(--paper-line);
}

th {
  background: #eef2f8;
  color: #17354e;
}

.note {
  padding: 14px 16px;
  border-left: 4px solid #d6a440;
  border-radius: 0 16px 16px 0;
  background: #fff8e8;
  color: #6f5422;
}

.summary-list,
.contact-list,
.standard-list {
  padding-left: 20px;
}

.summary-list li,
.contact-list li,
.standard-list li {
  margin: 10px 0;
}

.paper-footer {
  padding: 0 38px 38px;
  background: var(--paper);
  color: var(--paper-ink);
}

.download-panel,
.citation-box,
.note-box {
  padding: 22px;
}

.citation-box {
  white-space: pre-wrap;
  word-break: break-word;
  font-family: "Courier New", Courier, monospace;
  font-size: 0.92rem;
  line-height: 1.65;
  background: #f2eee6;
}

.note-box {
  margin-top: 18px;
  background: linear-gradient(180deg, #fffdf8, #f8f1e3);
}

.paper-footer h2,
.paper-footer h3,
.meta-card h2 {
  color: #17354e;
}

.site-footer {
  padding: 0 0 54px;
}

.footer-panel {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 26px 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

.footer-links {
  display: flex;
  gap: 28px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.65);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--accent);
}

.copyright {
  color: rgba(255, 255, 255, 0.42);
}

@media (max-width: 900px) {
  .grid--split,
  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-header,
  .article-layout,
  .paper-body,
  .paper-footer {
    padding-left: 22px;
    padding-right: 22px;
  }
}

@media (max-width: 720px) {
  .site-shell,
  .nav-content,
  .footer-panel {
    width: min(100% - 20px, 1180px);
  }

  .hero {
    padding-top: 28px;
  }

  .hero-panel,
  .info-card,
  .article-card,
  .paper {
    border-radius: 22px;
  }

  .hero h1,
  .article-header h1 {
    font-size: 2.2rem;
  }

  .nav-content {
    padding: 12px 0;
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    gap: 12px;
  }

  body {
    font-size: 17px;
  }
}