/* 《死亡回忆录》：书封墨蓝、绛红与雾白。交互沿用原站。 */
:root {
    --book-ink: #142435;
    --book-paper: #f3f5f6;
    --book-muted: #5e7080;
    --book-line: #dce2e7;
    --book-surface: #ffffff;
    --book-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
}
body { background: var(--book-paper); }
main { min-height: 100vh; background: var(--book-paper); }
.invite-intro-section { padding-top: 3rem; }
.invite-intro-card {
    padding: 0 1rem;
    border: 0;
    border-radius: 0;
    background: none;
    box-shadow: none;
    text-align: center;
}
.book-eyebrow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: .75rem;
    margin-bottom: 1.2rem;
    color: var(--main-accent);
    font-size: .75rem;
    font-weight: 600;
    letter-spacing: .22em;
}
.book-eyebrow::before, .book-eyebrow::after {
    content: "";
    width: 1.8rem;
    height: 1px;
    background: var(--border-accent);
}
.invite-intro-title {
    margin-bottom: .7rem;
    font-family: var(--book-serif);
    font-size: clamp(2rem, 5vw, 3.35rem);
    font-weight: 600;
    letter-spacing: .1em;
    line-height: 1.4;
    color: var(--book-ink);
}
.invite-intro-title span { display: inline; color: inherit; }
.book-subtitle {
    margin: 0 0 1.25rem;
    color: var(--book-muted);
    font-family: var(--book-serif);
    font-size: 1.1rem;
    letter-spacing: .08em;
    line-height: 1.8;
}
.invite-intro-text {
    max-width: 42rem;
    margin: 0 auto;
    font-size: .9rem;
    line-height: 1.95;
    color: var(--book-muted);
}
.invite-intro-text + .invite-intro-text { margin-top: .35rem; }
.carousel-section { padding-top: 1.8rem; padding-bottom: 2.5rem; }
.carousel {
    border-radius: .75rem;
    background: #0e1e2e;
    box-shadow: 0 18px 45px -25px rgba(20, 36, 53, .5);
}
.carousel-slide {
    position: relative;
    isolation: isolate;
    height: 25rem;
    display: flex;
    align-items: center;
    padding: 3rem 4rem;
    gap: 2rem;
    overflow: hidden;
    background: radial-gradient(ellipse at 80% 70%, #334456 0%, #142435 45%, #0e1e2e 90%);
}
.carousel-slide::after {
    content: "";
    position: absolute;
    bottom: 2rem;
    left: 4rem;
    width: 2rem;
    height: 2px;
    background: #bd7e89;
}
.carousel-slide .book-slide-image {
    width: 42%;
    height: 100%;
    max-height: 21rem;
    object-fit: contain;
    margin-left: auto;
    filter: drop-shadow(0 15px 18px rgba(0, 0, 0, .4));
}
.book-slide-copy { flex: 1; min-width: 0; }
.book-slide-label { color: #d0a8af; font-size: .7rem; letter-spacing: .2em; }
.book-slide-copy h2 {
    margin: 1.15rem 0;
    color: #f4f1ed;
    font-family: var(--book-serif);
    font-size: 2rem;
    font-weight: 500;
    line-height: 1.6;
    letter-spacing: .04em;
}
.book-slide-copy p { color: #bcc8d3; font-size: .85rem; line-height: 1.9; }
.carousel-btn { opacity: .8; color: #fff; }
.carousel-dots { bottom: .8rem; }
.steps-heading {
    margin-bottom: 1.35rem;
    color: var(--book-ink);
    font-family: var(--book-serif);
    font-size: 1.6rem;
    font-weight: 600;
    letter-spacing: .12em;
}
.steps-list { gap: 1rem; }
.step-card {
    padding: 1.75rem 2rem;
    border-color: var(--book-line);
    border-radius: .65rem;
    background: var(--book-surface);
    box-shadow: 0 3px 15px rgba(20, 36, 53, .025);
}
.step-title { color: var(--book-ink); font-size: 1.05rem; }
.step-intro, .step-note { line-height: 1.9; }
.step-note { color: var(--book-muted); font-size: .8rem; }
.poster-wrap { max-width: 19rem; margin-top: 1.3rem; }
#poster-save-btn {
    position: static;
    transform: none;
    align-items: center;
    gap: .65rem;
    margin: 1rem auto 0;
    padding: .85rem 2rem;
    border-radius: .4rem;
    animation: none;
    box-shadow: 0 4px 12px rgba(156, 77, 90, .15);
}
#poster-save-btn:hover { transform: translateY(-1px); }
#poster-save-btn:disabled { transform: none; }
.platform-btn-large { font-family: inherit; color: var(--book-ink); }
.platform-btn-large:hover { background: var(--bg-accent); }
.platform-btn-large .name { color: inherit; }
.bot-header { background: var(--book-ink); }
.bot-bubble { box-shadow: 0 6px 24px rgba(20, 36, 53, .2); }
.bot-panel { border: 1px solid var(--book-line); }
.bot-messages { background: var(--book-paper); }
.bot-msg.from-bot { background: var(--book-surface); color: var(--book-ink); border-color: var(--book-line); }
.bot-footer { background: var(--book-surface); border-color: var(--book-line); }
.bot-download-link { overflow-wrap: anywhere; }
footer { color: var(--book-muted); border-color: var(--book-line); }
button:focus-visible, a:focus-visible {
    outline: 3px solid #bd7e89;
    outline-offset: 4px;
}
@media (max-width: 639px) {
    .invite-intro-section { padding-top: 2rem; }
    .invite-intro-card { padding: 0 .25rem; }
    .book-eyebrow { margin-bottom: .75rem; }
    .book-subtitle { font-size: .95rem; }
    .invite-intro-text { font-size: .84rem; text-align: left; }
    .carousel-section { padding-top: 1.25rem; padding-bottom: 2rem; }
    .carousel-slide { height: 20rem; padding: 2rem 1.3rem; gap: .6rem; }
    .carousel-slide::after { left: 1.3rem; bottom: 1.8rem; }
    .carousel-slide .book-slide-image { width: 44%; max-height: 16rem; }
    .book-slide-copy h2 { font-size: clamp(1.15rem, 4.8vw, 1.7rem); margin: .85rem 0; }
    .book-slide-label { font-size: .6rem; letter-spacing: .08em; }
    .book-slide-copy p { font-size: .72rem; }
    .carousel-btn { width: 1.75rem; height: 1.75rem; top: auto; bottom: .15rem; }
    .step-card { padding: 1.25rem; }
    .platforms-container { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .25rem; }
    .platform-btn-large { padding: .75rem 0; min-width: 0; font-size: .75rem; }
    .platform-btn-large .icon { width: clamp(2.75rem, 14vw, 3.5rem); height: clamp(2.75rem, 14vw, 3.5rem); }
    .bot-bubble { bottom: max(1rem, env(safe-area-inset-bottom)); }
    .bot-panel { bottom: calc(5rem + env(safe-area-inset-bottom)); }
}
@media (prefers-color-scheme: dark) {
    :root {
        --book-paper: #0e1925;
        --book-ink: #e7edf2;
        --book-muted: #a5b4c2;
        --book-line: #2c3b4a;
        --book-surface: #182736;
        --main-accent: #cf8e9b;
        --dark-accent: #ad6c79;
        --light-accent: #e4b4be;
        --bg-accent: #2b2430;
        --border-accent: #61404b;
        --text-normal: #e7edf2;
        --text-gray: #a5b4c2;
    }
    .invite-intro-card { background: none; border: 0; box-shadow: none; }
    .invite-intro-text { color: var(--book-muted); }
    .bot-header { background: #223649; }
    .bot-bubble, .bot-upload-btn, .bot-msg.from-user, .bot-msg a.bot-download-link,
    #poster-save-btn { background: #9c4d5a; }
    .platform-btn-large:hover { background: #263747; }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation: none !important; transition: none !important; }
}