:root {
  --ink: #1c1410;
  --ink-soft: #3d2f26;
  --paper: #f3e2c2;
  --wood-deep: #8b5a2b;
  --wood-mid: #c48a3a;
  --wood-light: #e2b56a;
  --accent: #0f5c4c;
  --accent-soft: #1a7a66;
  --danger: #8b2e2e;
  --panel: rgba(255, 248, 235, 0.9);
  --panel-border: rgba(255, 245, 220, 0.55);
  --shadow: 0 24px 60px rgba(28, 20, 16, 0.28);
  --radius: 18px;
  --font-display: "ZCOOL XiaoWei", "Noto Serif SC", serif;
  --font-body: "Noto Serif SC", "Songti SC", serif;
  --cream: #f8ecd6;
}

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

html,
body {
  margin: 0;
  min-height: 100%;
}

body.theme-yi {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(255, 220, 160, 0.45), transparent 55%),
    radial-gradient(ellipse 70% 50% at 90% 80%, rgba(15, 92, 76, 0.18), transparent 50%),
    linear-gradient(160deg, #2a1c12 0%, #4a321f 38%, #6b4528 72%, #3a2618 100%);
  min-height: 100vh;
}

body.theme-yi::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.08;
  background-image: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(255, 255, 255, 0.35) 2px,
    rgba(255, 255, 255, 0.35) 3px
  );
  mix-blend-mode: soft-light;
}

.shell {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.25rem 0 2rem;
}

.topbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.25rem;
  animation: rise 700ms ease both;
}

.brand {
  display: grid;
  gap: 0.25rem;
}

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

.brand h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 400;
  letter-spacing: 0.12em;
  color: var(--cream);
  text-shadow: 0 2px 0 rgba(0, 0, 0, 0.25);
  line-height: 1;
}

.brand p,
.topbar-sub {
  margin: 0;
  color: rgba(248, 236, 214, 0.78);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
}

.topbar-actions {
  display: flex;
  gap: 0.55rem;
  flex-wrap: wrap;
}

.btn {
  appearance: none;
  border: none;
  border-radius: 12px;
  padding: 0.65rem 0.9rem;
  background: var(--accent);
  color: #f7fff9;
  font-family: inherit;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 160ms ease, background 160ms ease;
}

.btn:hover {
  background: var(--accent-soft);
  transform: translateY(-1px);
}

.btn.secondary {
  background: transparent;
  color: var(--cream);
  border: 1px solid rgba(248, 236, 214, 0.35);
}

.btn.secondary:hover {
  background: rgba(248, 236, 214, 0.08);
}

.panel {
  background: var(--panel);
  backdrop-filter: blur(8px);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
  box-shadow: 0 10px 28px rgba(20, 12, 8, 0.18);
  border: 1px solid var(--panel-border);
}

.footer-note {
  margin-top: 1.5rem;
  color: rgba(248, 236, 214, 0.65);
  font-size: 0.82rem;
  text-align: center;
  letter-spacing: 0.04em;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 720px) {
  .shell {
    width: min(100% - 1.25rem, 720px);
  }

  .topbar {
    flex-direction: column;
    align-items: start;
  }
}