:root {
  color-scheme: light;
  --ink: #10233e;
  --muted: #536579;
  --surface: #ffffff;
  --page: #eff4f8;
  --accent: #e94743;
  --accent-hover: #cc3532;
  --line: #d6e0e9;
}

* { box-sizing: border-box; }

html { min-height: 100%; background: var(--page); }

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: linear-gradient(135deg, #f7fafc 0%, var(--page) 62%, #e8f0f8 100%);
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 2;
  padding: 10px 14px;
  color: #fff;
  background: var(--ink);
  transform: translateY(-160%);
}

.skip-link:focus { transform: translateY(0); }

.site-entry {
  display: grid;
  grid-template-columns: minmax(0, 1.06fr) minmax(280px, 0.94fr);
  align-items: stretch;
  width: min(1120px, calc(100% - 48px));
  min-height: min(660px, calc(100vh - 148px));
  margin: clamp(32px, 9vh, 108px) auto 44px;
  background: var(--surface);
  box-shadow: 0 8px 24px rgba(28, 55, 79, 0.12);
}

.intro {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(40px, 7vw, 96px);
}

.site-name {
  margin: 0 0 24px;
  color: var(--accent);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

h1 {
  max-width: 9em;
  margin: 0;
  font-size: clamp(40px, 5vw, 70px);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.15;
  text-wrap: balance;
}

.description {
  max-width: 34em;
  margin: 28px 0 32px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
  text-wrap: pretty;
}

.entry-button {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  width: fit-content;
  min-width: 244px;
  min-height: 52px;
  padding: 0 18px 0 22px;
  color: #fff;
  background: var(--accent);
  font-size: 16px;
  font-weight: 800;
  text-decoration: none;
  transition: background-color 180ms ease-out, transform 180ms ease-out;
}

.entry-button:hover { background: var(--accent-hover); transform: translateY(-2px); }
.entry-button:focus-visible { outline: 3px solid #14395f; outline-offset: 4px; }
.entry-button[aria-disabled="true"] { cursor: not-allowed; opacity: 0.55; }
.entry-button[aria-disabled="true"]:hover { background: var(--accent); transform: none; }
.entry-button span { font-size: 24px; font-weight: 400; line-height: 1; }

.entry-note { min-height: 1.6em; margin: 14px 0 0; color: var(--muted); font-size: 14px; }

.study-preview { position: relative; min-height: 360px; margin: 0; background: #dfe8ef; overflow: hidden; }
.study-preview::after { position: absolute; inset: 0; content: ""; background: linear-gradient(180deg, transparent 42%, rgba(6, 24, 44, 0.82)); }
.study-preview img { display: block; width: 100%; height: 100%; object-fit: cover; }

.preview-copy {
  position: absolute;
  right: clamp(24px, 4vw, 48px);
  bottom: clamp(24px, 4vw, 48px);
  left: clamp(24px, 4vw, 48px);
  z-index: 1;
  display: grid;
  gap: 8px;
  color: #fff;
}

.preview-copy strong { font-size: clamp(28px, 3vw, 42px); letter-spacing: -0.02em; }
.preview-copy span { font-size: 15px; font-weight: 700; }

footer {
  width: min(1120px, calc(100% - 48px));
  margin: 0 auto 32px;
  color: #5d6b7a;
  font-size: 13px;
  line-height: 1.7;
}

footer p { margin: 0; }
footer a { display: inline-flex; align-items: center; gap: 4px; color: inherit; text-decoration: none; }
footer a + a { margin-left: 12px; }
footer a:hover { color: var(--ink); text-decoration: underline; }
footer a:focus-visible { outline: 2px solid #14395f; outline-offset: 3px; }
.filing-icon { width: 18px; height: 18px; object-fit: contain; }

@media (max-width: 720px) {
  .site-entry { grid-template-columns: 1fr; width: min(100% - 32px, 560px); min-height: 0; margin-top: 24px; }
  .intro { padding: 48px 28px; }
  h1 { max-width: 100%; font-size: clamp(38px, 12vw, 56px); }
  .description { font-size: 16px; }
  .entry-button { width: 100%; }
  .study-preview { min-height: 310px; }
  footer { width: min(100% - 32px, 560px); }
}

@media (prefers-reduced-motion: reduce) {
  .entry-button { transition: none; }
}