:root {
  --color-space: #0A1E3F;
  --color-ink: #16324F;
  --color-paper: #F7F2E9;
  --color-fire: #FF4D00;
  --color-fire-grad: #FF6B00;
  --color-silver: #C0C7D1;
  --color-silver-light: #E5E9EF;
  --color-white: #FFFFFF;
  --color-text: #1A1A1A;
  --color-night: #DBE4F0;

  --font-body: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans CJK SC', sans-serif;
  --font-display: 'Rajdhani', 'DIN Alternate', 'Arial Narrow', sans-serif;
  --font-mono: 'Roboto Mono', 'JetBrains Mono', 'SFMono-Regular', monospace;

  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --radius-pill: 999px;

  --container-w: 1240px;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: clamp(3rem, 7vw, 6rem);

  --shadow-card: 0 2px 12px rgba(10, 30, 63, 0.08);
  --shadow-lift: 0 8px 32px rgba(10, 30, 63, 0.16);
  --shadow-fire: 0 4px 20px rgba(255, 77, 0, 0.35);
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background:
    radial-gradient(closest-side at 12% -8%, rgba(10, 30, 63, 0.05), transparent 55%),
    var(--color-paper);
  min-height: 100vh;
  overflow-x: hidden;
}

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

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

input, select, textarea {
  font: inherit;
  color: inherit;
}

ul, ol {
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

:focus-visible {
  outline: 2px solid var(--color-fire);
  outline-offset: 3px;
  border-radius: 4px;
}

.container {
  width: min(100% - 2rem, var(--container-w));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.875em;
  letter-spacing: 0.02em;
}

.section {
  padding-block: var(--space-lg);
}

.section-head {
  margin-bottom: 2rem;
  max-width: 72ch;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-fire);
  margin-bottom: 0.5rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-space);
}

.section-desc {
  margin-top: 0.75rem;
  color: rgba(26, 26, 26, 0.72);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.625rem 1.5rem;
  border-radius: var(--radius-pill);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.2;
  text-align: center;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.btn-primary {
  background: var(--color-fire);
  color: #fff;
  box-shadow: var(--shadow-fire);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--color-fire-grad);
  box-shadow: 0 8px 28px rgba(255, 107, 0, 0.45);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(192, 199, 209, 0.6);
  color: var(--color-space);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--color-fire);
  color: var(--color-fire);
}

.btn-ghost-dark {
  background: transparent;
  border-color: rgba(219, 228, 240, 0.5);
  color: var(--color-night);
}

.btn-ghost-dark:hover,
.btn-ghost-dark:focus-visible {
  border-color: #fff;
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn-silver {
  background: var(--color-silver);
  color: var(--color-ink);
}

.btn-silver:hover,
.btn-silver:focus-visible {
  background: var(--color-white);
  box-shadow: var(--shadow-card);
}

.card {
  border-radius: var(--radius-lg);
  padding: clamp(1.25rem, 3vw, 2rem);
  position: relative;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card-paper {
  background: var(--color-white);
  border: 1px solid rgba(192, 199, 209, 0.35);
  box-shadow: var(--shadow-card);
}

.card-dark {
  background: var(--color-ink);
  color: var(--color-night);
}

.card-fire {
  background: linear-gradient(135deg, var(--color-fire), var(--color-fire-grad));
  color: #fff;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lift);
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: clamp(0.75rem, 2vw, 1.25rem);
}

.bento-cell {
  grid-column: 1 / -1;
}

@media (min-width: 640px) {
  .bento-cell--sm-6 {
    grid-column: span 6;
  }
  .bento-cell--sm-12 {
    grid-column: span 12;
  }
}

@media (min-width: 1024px) {
  .bento-cell--3 { grid-column: span 3; }
  .bento-cell--4 { grid-column: span 4; }
  .bento-cell--6 { grid-column: span 6; }
  .bento-cell--8 { grid-column: span 8; }
  .bento-cell--9 { grid-column: span 9; }
  .bento-cell--12 { grid-column: span 12; }
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.875rem;
  border-radius: var(--radius-pill);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.4;
  background: var(--color-silver-light);
  color: var(--color-ink);
  white-space: nowrap;
}

.tag-live {
  background: var(--color-fire);
  color: #fff;
  box-shadow: var(--shadow-fire);
}

.breadcrumb {
  font-size: 0.8125rem;
  color: rgba(26, 26, 26, 0.58);
  margin-bottom: 2rem;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.375rem;
}

.breadcrumb-item {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}

.breadcrumb-link {
  color: var(--color-ink);
  transition: color 0.2s ease;
}

.breadcrumb-link:hover,
.breadcrumb-link:focus-visible {
  color: var(--color-fire);
}

.breadcrumb-sep {
  font-family: var(--font-mono);
  color: var(--color-silver);
  font-size: 0.6875rem;
}

.breadcrumb-current {
  color: var(--color-fire);
  font-weight: 600;
}

.img-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background: var(--color-ink);
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame--landscape { aspect-ratio: 16 / 9; }
.img-frame--portrait { aspect-ratio: 3 / 4; }
.img-frame--square { aspect-ratio: 1 / 1; }

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 9999;
  display: inline-block;
  padding: 0.5rem 1rem;
  background: var(--color-fire);
  color: #fff;
  font-size: 0.8125rem;
  font-weight: 600;
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-fire);
  transform: translateY(-300%);
  transition: transform 0.2s ease;
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid #fff;
  outline-offset: -2px;
}

.site-masthead {
  position: relative;
  z-index: 200;
  background: var(--color-space);
  color: var(--color-night);
  border-bottom: 2px solid var(--color-fire);
}

.masthead-top {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1.75rem 0 1rem;
  position: relative;
}

.masthead-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--color-white);
}

.masthead-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-fire), var(--color-fire-grad));
  box-shadow: 0 0 0 3px rgba(255, 77, 0, 0.2), var(--shadow-fire);
  font-size: 1.125rem;
  color: #fff;
  line-height: 1;
  flex-shrink: 0;
}

.masthead-brand-name {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.1;
  color: var(--color-white);
}

.masthead-tagline {
  margin-top: 0.25rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--color-night);
  opacity: 0.75;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  position: absolute;
  top: 50%;
  right: 0;
  transform: translateY(-50%);
  padding: 0.5rem 0.875rem;
  min-height: 40px;
  border: 1px solid rgba(192, 199, 209, 0.35);
  border-radius: var(--radius-pill);
  color: var(--color-night);
  font-size: 0.75rem;
  font-weight: 600;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  border-color: var(--color-fire);
  background: rgba(255, 77, 0, 0.12);
}

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: background-color 0.2s ease;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.2s ease, top 0.2s ease, bottom 0.2s ease;
}

.nav-toggle-bars::before {
  top: -6px;
}

.nav-toggle-bars::after {
  bottom: -6px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
  bottom: 0;
  transform: rotate(-45deg);
}

.nav-toggle-text {
  font-size: 0.75rem;
}

.masthead-status {
  border-top: 1px solid rgba(192, 199, 209, 0.15);
  border-bottom: 1px solid rgba(192, 199, 209, 0.15);
  background: linear-gradient(115deg, rgba(255, 77, 0, 0.14) -10%, transparent 45%);
}

.masthead-status-text {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.375rem 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--color-night);
  white-space: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}

.masthead-status-text::-webkit-scrollbar {
  display: none;
}

.status-pulse {
  flex-shrink: 0;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-fire);
  animation: pulse 2s ease-out infinite;
}

@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(255, 77, 0, 0.5);
  }
  70% {
    box-shadow: 0 0 0 8px rgba(255, 77, 0, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(255, 77, 0, 0);
  }
}

.masthead-nav {
  border-bottom: 2px solid var(--color-fire);
}

.masthead-nav-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.25rem;
  padding: 0.75rem 0;
}

.masthead-nav-link {
  position: relative;
  display: inline-block;
  padding: 0.625rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-night);
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.masthead-nav-link::after {
  content: '';
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 0.25rem;
  height: 2px;
  border-radius: 2px;
  background: var(--color-fire);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.masthead-nav-link:hover,
.masthead-nav-link:focus-visible {
  color: #fff;
}

.masthead-nav-link:hover::after,
.masthead-nav-link:focus-visible::after {
  transform: scaleX(1);
}

.masthead-nav-link[aria-current="page"] {
  color: #fff;
}

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

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 10000;
  pointer-events: none;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.08);
}

.reading-progress-track {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: 0 3px 3px 0;
  background: linear-gradient(90deg, var(--color-fire), var(--color-fire-grad));
}

.site-footer {
  position: relative;
  background: var(--color-space);
  color: var(--color-night);
  overflow: hidden;
  margin-top: var(--space-lg);
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-fire), var(--color-fire-grad) 35%, transparent 90%);
}

.site-footer::after {
  content: '';
  position: absolute;
  width: 320px;
  height: 320px;
  right: -100px;
  top: -140px;
  border-radius: 50%;
  background: radial-gradient(closest-side, rgba(255, 77, 0, 0.07), transparent 100%);
  pointer-events: none;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  padding: 3rem 0 2rem;
  position: relative;
  z-index: 1;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.footer-brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-fire), var(--color-fire-grad));
  box-shadow: var(--shadow-fire);
  font-size: 1rem;
  color: #fff;
  flex-shrink: 0;
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #fff;
}

.footer-desc {
  margin-top: 1rem;
  max-width: 32ch;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--color-silver);
}

.footer-heading {
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 1.25rem;
}

.footer-contact-list {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.footer-contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.footer-contact-label {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-silver);
  opacity: 0.7;
}

.footer-contact-value {
  font-size: 0.875rem;
  color: var(--color-night);
  word-break: break-all;
  line-height: 1.5;
}

.footer-contact-note {
  margin-top: 1rem;
  font-size: 0.6875rem;
  line-height: 1.6;
  color: var(--color-silver);
  opacity: 0.7;
}

.footer-links-list {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--color-night);
  transition: color 0.2s ease;
}

.footer-link::before {
  content: '→';
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-fire);
  transition: transform 0.2s ease;
}

.footer-link:hover,
.footer-link:focus-visible {
  color: #fff;
}

.footer-link:hover::before,
.footer-link:focus-visible::before {
  transform: translateX(3px);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-items: center;
  justify-content: space-between;
  padding: 1.75rem 0;
  border-top: 1px solid rgba(192, 199, 209, 0.15);
  position: relative;
  z-index: 1;
}

.footer-copy {
  font-size: 0.8125rem;
  color: var(--color-silver);
}

.footer-copy [data-year] {
  font-variant-numeric: tabular-nums;
}

.footer-icp {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--color-silver);
  opacity: 0.8;
}

.back-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 900;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-fire);
  color: #fff;
  font-size: 1.125rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-fire);
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease, background-color 0.2s ease;
}

.back-top[data-top-shown] {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-top:hover,
.back-top:focus-visible {
  background: var(--color-fire-grad);
}

[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-reveal][data-revealed] {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 899px) {
  .masthead-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-ink);
    box-shadow: 0 24px 40px rgba(10, 30, 63, 0.45);
    border-bottom: 2px solid var(--color-fire);
  }

  .masthead-nav[data-open] {
    display: block;
  }

  .masthead-nav-list {
    flex-direction: column;
    padding: 0.75rem 1rem 1.25rem;
    gap: 0.125rem;
  }

  .masthead-nav-link {
    display: block;
    padding: 0.875rem 1rem;
    border-radius: var(--radius-sm);
  }

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

  .masthead-nav-link[aria-current="page"] {
    background: rgba(255, 77, 0, 0.18);
    color: #fff;
  }
}

@media (min-width: 640px) {
  .footer-bottom {
    flex-direction: row;
  }
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
    gap: 3rem;
  }
}

@media (min-width: 900px) {
  .nav-toggle {
    display: none;
  }

  .masthead-nav {
    display: block;
  }

  .masthead-nav-list {
    flex-direction: row;
  }
}

@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;
  }

  .status-pulse {
    animation: none;
    box-shadow: none;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }
}