:root {
    --bt-ink: #1c2a24;
    --bt-ink-soft: #3d4f46;
    --bt-paper: #f7f8f4;
    --bt-paper-edge: #e4e7df;
    --bt-brass: #b08a3c;
    --bt-brass-deep: #8a6a2a;
    --bt-moss: #1f3a32;
    --bt-moss-deep: #10221c;
    --bt-font-display: "Instrument Serif", "Songti SC", "SimSun", serif;
    --bt-font-body: "Source Sans 3", "PingFang SC", "Microsoft YaHei", sans-serif;
}

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

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

body.bt-announce {
    min-height: 100vh;
    color: var(--bt-ink);
    font-family: var(--bt-font-body);
    background: var(--bt-moss-deep);
    overflow-x: hidden;
}

.bt-announce__atmosphere {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    background:
        radial-gradient(ellipse 90% 60% at 50% -10%, rgba(176, 138, 60, 0.18), transparent 55%),
        radial-gradient(ellipse 70% 50% at 100% 100%, rgba(47, 90, 74, 0.45), transparent 50%),
        linear-gradient(165deg, #143028 0%, #0d1a16 48%, #152820 100%);
}

.bt-announce__atmosphere::after {
    content: "";
    position: absolute;
    inset: 0;
    opacity: 0.35;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 80% 70% at 50% 40%, #000 30%, transparent 85%);
}

.bt-announce__stage {
    position: relative;
    z-index: 1;
    width: min(720px, calc(100% - 2rem));
    margin: 0 auto;
    padding: clamp(2.5rem, 8vh, 4.5rem) 0 3rem;
}

.bt-announce__brand {
    text-align: center;
    margin-bottom: 1.75rem;
    animation: bt-fade-rise 0.7s ease both;
}

.bt-announce__brand-name {
    margin: 0;
    font-family: var(--bt-font-display);
    font-size: clamp(2.4rem, 7vw, 3.4rem);
    font-weight: 400;
    letter-spacing: 0.04em;
    line-height: 1.05;
    color: #f2ebe0;
    text-shadow: 0 2px 24px rgba(0, 0, 0, 0.35);
}

.bt-announce__brand-sub {
    margin: 0.45rem 0 0;
    font-size: 0.92rem;
    letter-spacing: 0.28em;
    text-indent: 0.28em;
    text-transform: none;
    color: rgba(212, 196, 150, 0.78);
}

.bt-announce__board {
    position: relative;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.55), transparent 28%),
        var(--bt-paper);
    border: 1px solid var(--bt-paper-edge);
    border-radius: 2px;
    padding: clamp(1.6rem, 4vw, 2.4rem) clamp(1.35rem, 4vw, 2.5rem) clamp(1.8rem, 4vw, 2.6rem);
    box-shadow:
        0 1px 0 rgba(255, 255, 255, 0.65) inset,
        0 18px 50px rgba(0, 0, 0, 0.35),
        0 2px 0 rgba(176, 138, 60, 0.25);
    animation: bt-fade-rise 0.85s 0.08s ease both;
}

.bt-announce__board::before {
    content: "";
    position: absolute;
    inset: 10px;
    border: 1px solid rgba(176, 138, 60, 0.28);
    pointer-events: none;
}

.bt-announce__meta {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.75rem 1rem;
    margin-bottom: 1rem;
}

.bt-announce__badge {
    display: inline-block;
    padding: 0.2rem 0.55rem;
    border-left: 3px solid var(--bt-brass);
    background: rgba(176, 138, 60, 0.1);
    color: var(--bt-brass-deep);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.16em;
}

.bt-announce__date {
    color: var(--bt-ink-soft);
    font-size: 0.88rem;
}

.bt-announce__headline {
    margin: 0;
    font-family: var(--bt-font-display);
    font-size: clamp(2rem, 6vw, 2.75rem);
    font-weight: 400;
    line-height: 1.15;
    color: var(--bt-ink);
    letter-spacing: 0.02em;
}

.bt-announce__ver-label {
    font-size: 0.62em;
    margin-right: 0.08em;
    color: var(--bt-brass-deep);
}

.bt-announce__lede {
    margin: 0.65rem 0 0;
    color: var(--bt-ink-soft);
    font-size: 1rem;
    line-height: 1.55;
    max-width: 36em;
}

.bt-announce__divider {
    height: 1px;
    margin: 1.35rem 0 1.2rem;
    background: linear-gradient(90deg, transparent, rgba(176, 138, 60, 0.55), transparent);
}

.bt-announce__body {
    color: var(--bt-ink);
    font-size: 1.02rem;
    line-height: 1.7;
}

.bt-announce__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.75rem;
    padding-top: 1.25rem;
    border-top: 1px dashed rgba(28, 42, 36, 0.15);
}

.bt-announce__btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.5rem;
    padding: 0.45rem 1.1rem;
    border: 1px solid rgba(28, 42, 36, 0.22);
    border-radius: 2px;
    background: transparent;
    color: var(--bt-ink);
    font-family: var(--bt-font-body);
    font-size: 0.92rem;
    font-weight: 600;
    text-decoration: none;
    transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.bt-announce__btn:hover {
    border-color: var(--bt-brass);
    color: var(--bt-brass-deep);
    transform: translateY(-1px);
}

.bt-announce__btn--primary {
    background: linear-gradient(180deg, #c49a45, var(--bt-brass-deep));
    border-color: transparent;
    color: #fff8ea;
    box-shadow: 0 8px 18px rgba(138, 106, 42, 0.28);
}

.bt-announce__btn--primary:hover {
    color: #fff;
    filter: brightness(1.05);
}

.bt-announce__foot {
    margin: 1.35rem 0 0;
    text-align: center;
    color: rgba(212, 196, 150, 0.45);
    font-size: 0.75rem;
    letter-spacing: 0.04em;
    animation: bt-fade-rise 0.9s 0.18s ease both;
}

/* Markdown body */
.bt-changelog-md .unity-rt-markdown,
.bt-changelog-md {
    color: inherit;
}

.bt-changelog-md h1,
.bt-changelog-md h2,
.bt-changelog-md h3,
.bt-changelog-md h4 {
    font-family: var(--bt-font-display);
    font-weight: 400;
    line-height: 1.25;
    color: var(--bt-ink);
    margin: 1.35em 0 0.55em;
}

.bt-changelog-md h1 { font-size: 1.55rem; }
.bt-changelog-md h2 { font-size: 1.32rem; }
.bt-changelog-md h3 { font-size: 1.15rem; }
.bt-changelog-md h4 { font-size: 1.05rem; }

.bt-changelog-md h1:first-child,
.bt-changelog-md h2:first-child,
.bt-changelog-md h3:first-child,
.bt-changelog-md > .unity-rt-markdown > :first-child {
    margin-top: 0;
}

.bt-changelog-md p {
    margin: 0.7em 0;
}

.bt-changelog-md ul,
.bt-changelog-md ol {
    margin: 0.55em 0 0.9em;
    padding-left: 1.35em;
}

.bt-changelog-md li + li {
    margin-top: 0.28em;
}

.bt-changelog-md strong {
    font-weight: 700;
    color: var(--bt-moss);
}

.bt-changelog-md a {
    color: var(--bt-brass-deep);
    text-decoration-thickness: 1px;
    text-underline-offset: 2px;
}

.bt-changelog-md code {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 0.9em;
    padding: 0.1em 0.35em;
    background: rgba(31, 58, 50, 0.08);
    border-radius: 3px;
}

.bt-changelog-md pre {
    overflow-x: auto;
    margin: 1em 0;
    padding: 0.9rem 1rem;
    background: rgba(31, 58, 50, 0.06);
    border: 1px solid rgba(28, 42, 36, 0.08);
    border-radius: 4px;
    font-size: 0.88rem;
}

.bt-changelog-md pre code {
    padding: 0;
    background: none;
}

.bt-changelog-md blockquote {
    margin: 1em 0;
    padding: 0.15rem 0 0.15rem 1rem;
    border-left: 3px solid var(--bt-brass);
    color: var(--bt-ink-soft);
}

.bt-changelog-md hr {
    border: 0;
    height: 1px;
    margin: 1.4em 0;
    background: linear-gradient(90deg, transparent, rgba(28, 42, 36, 0.18), transparent);
}

.bt-changelog-md table {
    width: 100%;
    border-collapse: collapse;
    margin: 1em 0;
    font-size: 0.95rem;
}

.bt-changelog-md th,
.bt-changelog-md td {
    border: 1px solid rgba(28, 42, 36, 0.12);
    padding: 0.45rem 0.65rem;
    text-align: left;
}

.bt-changelog-md th {
    background: rgba(176, 138, 60, 0.1);
}

.bt-changelog-md .text-muted {
    color: var(--bt-ink-soft);
}

.bt-changelog-md .unity-rt-color {
    font-weight: 700;
}

.bt-changelog-md .unity-rt-color--accent,
.bt-changelog-md .unity-rt-color--default {
    color: #b45309;
    background: rgba(180, 83, 9, 0.1);
    border-bottom: 1px solid rgba(180, 83, 9, 0.35);
    padding: 0 0.15em;
    border-radius: 2px;
}

@keyframes bt-fade-rise {
    from {
        opacity: 0;
        transform: translateY(14px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 560px) {
    .bt-announce__actions {
        flex-direction: column;
    }

    .bt-announce__btn {
        width: 100%;
    }
}