:root {
  --color-red: #FF3B30;
  --color-black: #111111;
  --color-white: #FFFFFF;
  --color-blue: #0A84FF;
  --color-silver: #B0B4BD;
  --color-gray: #6E7278;
  --color-red-tint: #FFE3E1;
  --color-deep: #001D3D;
  --color-amber: #FFD60A;

  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;
  --font-ui: "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", sans-serif;

  --header-h: 72px;
  --content-max: 1440px;
  --content-pad: clamp(1rem, 3vw, 2.5rem);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: clamp(16px, 1vw + 14px, 18px);
  line-height: 1.75;
  color: #1A1A1A;
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
}

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

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

ul,
ol {
  list-style: none;
}

h1,
h2 {
  font-family: var(--font-serif);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

h3,
h4,
h5,
h6 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.3;
}

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

@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;
  }
}

.container {
  width: min(100% - calc(var(--content-pad) * 2), var(--content-max));
  margin-inline: auto;
}

.split-shell {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) 3fr;
  gap: 0;
}

.prose {
  max-width: 68ch;
  font-size: inherit;
}

.prose p + p {
  margin-top: 1.2em;
}

.prose a {
  color: var(--color-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose a:hover {
  color: var(--color-red);
  text-decoration-color: var(--color-red);
}

.section-heading {
  font-family: var(--font-serif);
  font-weight: 900;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--color-black);
  margin-bottom: 1rem;
}

.heading-mark {
  color: var(--color-red);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 0.875rem;
  line-height: 1;
  text-decoration: none;
  padding: 0.7rem 1.5rem 0.7rem 1.2rem;
  border: 0;
  cursor: pointer;
  background: transparent;
  color: inherit;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 50%, calc(100% - 12px) 100%, 0 100%);
  transition: background-color 0.25s ease, color 0.25s ease, transform 0.15s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn-accent {
  background: var(--color-red);
  color: var(--color-white);
}

.btn-accent:hover {
  background: #E6352A;
  color: var(--color-white);
}

.btn-sm {
  padding: 0.55rem 1.3rem 0.55rem 1rem;
  font-size: 0.8125rem;
}

.btn-symbol {
  font-size: 1.1em;
  line-height: 1;
  display: inline-block;
  transition: transform 0.2s ease;
}

.btn:hover .btn-symbol {
  transform: translateX(3px);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.6rem;
  background: var(--color-red-tint);
  color: #C52820;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 2px;
  line-height: 1.4;
  white-space: nowrap;
}

.tag-live::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-red);
  animation: tag-pulse 2s infinite ease-in-out;
}

@keyframes tag-pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.3;
  }
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8125rem;
  color: var(--color-gray);
  padding: 1rem 0;
}

.breadcrumb a {
  color: var(--color-gray);
  transition: color 0.2s ease;
}

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

.breadcrumb-sep {
  color: var(--color-silver);
  font-feature-settings: "tnum";
}

.media-frame {
  position: relative;
  overflow: hidden;
  background: var(--color-silver);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  border: 1px solid rgba(0, 0, 0, 0.06);
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.media-frame:hover img {
  transform: scale(1.03);
}

.media-ratio-4-3 {
  aspect-ratio: 4 / 3;
}

.media-ratio-16-9 {
  aspect-ratio: 16 / 9;
}

.media-ratio-square {
  aspect-ratio: 1 / 1;
}

.media-ratio-wide {
  aspect-ratio: 21 / 9;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 1rem;
  z-index: 2000;
  background: var(--color-black);
  color: var(--color-white);
  padding: 0.6rem 1.2rem;
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 0.875rem;
  border-radius: 0 0 8px 8px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-black);
  color: var(--color-white);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 5;
  pointer-events: none;
}

.scroll-progress::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(to right, var(--color-red) 0%, var(--color-red) 60%, var(--color-blue) 100%);
  transform: scaleX(var(--scroll, 0));
  transform-origin: 0 50%;
}

.header-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--content-pad);
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-white);
  flex-shrink: 0;
}

.brand-mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  background: var(--color-red);
  color: var(--color-white);
  font-family: var(--font-ui);
  font-size: 1.15rem;
  font-weight: 900;
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.brand-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
  line-height: 1;
}

.brand-name {
  font-size: 1.15rem;
  font-weight: 900;
  letter-spacing: 0.02em;
}

.brand-sub {
  font-size: 0.625rem;
  color: var(--color-silver);
  letter-spacing: 0.2em;
}

.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-item {
  list-style: none;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 0.9rem;
  color: rgba(255, 255, 255, 0.72);
  font-family: var(--font-ui);
  font-size: 0.8125rem;
  font-weight: 500;
  line-height: 1.2;
  border-radius: 2px;
  position: relative;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-index {
  color: var(--color-red);
  font-size: 0.625rem;
  font-weight: 700;
  font-feature-settings: "tnum";
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0.9rem;
  right: 0.9rem;
  bottom: 0;
  height: 2px;
  background: var(--color-red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s ease;
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  background: rgba(255, 255, 255, 0.06);
  color: var(--color-white);
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: transparent;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  cursor: pointer;
  padding: 0;
}

.nav-toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-white);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(7px) 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(-7px) rotate(-45deg);
}

.site-footer {
  background: var(--color-deep);
  color: rgba(255, 255, 255, 0.78);
  margin-top: auto;
}

.site-footer::before {
  content: "";
  display: block;
  height: 4px;
  background: linear-gradient(to right, var(--color-red) 0%, var(--color-red) 60%, var(--color-blue) 60%, var(--color-blue) 100%);
}

.footer-grid {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 3.5rem var(--content-pad) 2.5rem;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.4fr;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-white);
  margin-bottom: 1.25rem;
}

.footer-logo-mark {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  background: var(--color-red);
  color: var(--color-white);
  font-family: var(--font-ui);
  font-weight: 900;
  font-size: 1.25rem;
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}

.footer-logo-text {
  font-family: var(--font-ui);
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: 0.02em;
}

.footer-logo-dot {
  color: var(--color-red);
}

.footer-about {
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.66);
  max-width: 28em;
}

.footer-trust {
  margin-top: 1rem;
  font-size: 0.75rem;
  color: var(--color-amber);
  opacity: 0.92;
  padding: 0.5rem 0.75rem;
  background: rgba(255, 214, 10, 0.08);
  border-left: 3px solid var(--color-amber);
  line-height: 1.5;
}

.footer-col {
  min-width: 0;
}

.footer-title {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-white);
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  margin-bottom: 1.1rem;
}

.footer-index {
  color: var(--color-red);
  font-size: 0.625rem;
  margin-right: 0.4rem;
  font-feature-settings: "tnum";
}

.footer-links li + li {
  margin-top: 0.5rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.68);
  font-size: 0.875rem;
  position: relative;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.footer-links a:hover {
  color: var(--color-white);
  padding-left: 0.5rem;
}

.footer-links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 2px;
  background: var(--color-blue);
  transform: translateY(-50%);
  transition: width 0.2s ease;
}

.footer-links a:hover::before {
  width: 0.35rem;
}

.footer-col-legal .footer-links a::before {
  background: var(--color-blue);
}

.footer-contact li {
  font-size: 0.875rem;
  line-height: 1.6;
  padding: 0.35rem 0;
  color: rgba(255, 255, 255, 0.7);
  overflow-wrap: break-word;
}

.contact-key {
  color: var(--color-silver);
  font-weight: 500;
  margin-right: 0.5rem;
}

.footer-note {
  margin-top: 0.75rem;
  font-size: 0.75rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.42);
  border-left: 2px solid var(--color-gray);
  padding-left: 0.6rem;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(0, 0, 0, 0.22);
}

.footer-bottom-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 1.2rem var(--content-pad);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.footer-copy {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.46);
  font-feature-settings: "tnum";
}

.footer-slogan {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.32);
  letter-spacing: 0.1em;
}

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
  }

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

  .footer-about {
    max-width: 40em;
  }
}

@media (max-width: 900px) {
  :root {
    --header-h: 64px;
  }

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

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-black);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    border-bottom: 4px solid var(--color-red);
    padding: 1rem var(--content-pad) 1.5rem;
    margin-left: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease;
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0.125rem;
  }

  .nav-link {
    width: 100%;
    justify-content: space-between;
    padding: 0.75rem 0.5rem;
  }

  .nav-link::after {
    left: 0.5rem;
    right: 0.5rem;
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr;
    padding: 2.5rem var(--content-pad) 2rem;
    gap: 2rem;
  }

  .footer-brand {
    grid-column: auto;
  }

  .header-inner {
    gap: 0.5rem;
  }

  .btn-sm {
    padding: 0.5rem 1.1rem 0.5rem 0.9rem;
    font-size: 0.75rem;
  }

  .brand-name {
    font-size: 1rem;
  }

  .brand-sub {
    font-size: 0.5625rem;
  }

  .brand-mark {
    width: 32px;
    height: 32px;
    font-size: 1rem;
  }
}