/* ============================================
   bill Template — 账单工作室
   Design: Soft UI Evolution + Warm ledger paper
   Color: Ink #292524 + Copper #C2410C on Cream
   Distinct from liushui: zigzag services, timeline, split CTA
   ============================================ */

:root {
    --bl-ink: #292524;
    --bl-ink-soft: #44403C;
    --bl-muted: #57534E;
    --bl-copper: #C2410C;
    --bl-copper-hover: #9A3412;
    --bl-copper-soft: #FFEDD5;
    --bl-paper: #FAF6F0;
    --bl-paper-2: #F3EDE4;
    --bl-card: #FFFCF8;
    --bl-line: #E7E0D6;
    --bl-on-dark: #FFF7ED;
    --bl-radius: 12px;
    --bl-shadow: 0 10px 30px rgba(41, 37, 36, 0.08);
    --bl-font: "Songti SC", "Noto Serif SC", Georgia, "Times New Roman", "Microsoft YaHei", serif;
    --bl-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
    --bl-t: 0.22s ease;
    --bl-z-nav: 40;
    --bl-z-overlay: 70;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
@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;
    }
}

body {
    font-family: var(--bl-sans);
    font-size: 16px;
    line-height: 1.7;
    color: var(--bl-ink);
    background: var(--bl-paper);
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a { color: inherit; text-decoration: none; cursor: pointer; transition: color var(--bl-t), background var(--bl-t), border-color var(--bl-t), transform var(--bl-t); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; }
h1, h2, h3, h4 { font-family: var(--bl-font); font-weight: 700; line-height: 1.25; color: var(--bl-ink); }

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

.bl-container { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 24px; }

/* === Topbar + Nav === */
.bl-topbar {
    background: var(--bl-ink);
    color: #E7E5E4;
    font-size: 0.78rem;
    letter-spacing: 0.04em;
}
.bl-topbar-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    min-height: 36px;
    gap: 12px;
}
.bl-topbar a { color: #FDBA74; min-height: 32px; display: inline-flex; align-items: center; }
.bl-topbar a:hover { color: #fff; }

.bl-nav {
    position: sticky;
    top: 0;
    z-index: var(--bl-z-nav);
    background: rgba(250, 246, 240, 0.94);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--bl-line);
}
.bl-nav.scrolled { box-shadow: 0 4px 16px rgba(41, 37, 36, 0.06); }
.bl-nav-inner {
    max-width: 1120px;
    margin: 0 auto;
    padding: 10px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.bl-logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    min-height: 44px;
    font-family: var(--bl-font);
    font-size: 1.1rem;
    font-weight: 700;
}
.bl-logo-img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    background: #F6E7C9;
    flex-shrink: 0;
}
.bl-nav-links { display: flex; gap: 4px; }
.bl-nav-links a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 8px 14px;
    color: var(--bl-ink-soft);
    font-size: 0.92rem;
    border-bottom: 2px solid transparent;
}
.bl-nav-links a:hover { color: var(--bl-copper); border-bottom-color: var(--bl-copper); }
.bl-nav-cta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 8px 18px;
    background: var(--bl-copper);
    color: #fff;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.88rem;
}
.bl-nav-cta:hover { background: var(--bl-copper-hover); }
.bl-mobile-btn {
    display: none;
    width: 44px;
    height: 44px;
    border: none;
    background: none;
    color: var(--bl-ink);
}

/* === Hero === */
.bl-hero { padding: 48px 0 40px; }
.bl-hero-split {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 48px;
    align-items: center;
}
.bl-kicker {
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--bl-copper);
    margin-bottom: 12px;
}
.bl-hero h1 {
    font-size: clamp(2rem, 4.6vw, 3.2rem);
    margin-bottom: 16px;
}
.bl-hero h1 span {
    display: block;
    margin-top: 10px;
    font-size: 0.48em;
    font-weight: 600;
    color: var(--bl-muted);
    letter-spacing: 0.02em;
}
.bl-hero-desc { color: var(--bl-ink-soft); max-width: 440px; margin-bottom: 28px; }
.bl-hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }

.bl-btn-primary,
.bl-btn-line,
.bl-btn-on-dark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 26px;
    border-radius: 4px;
    font-weight: 700;
    font-size: 0.95rem;
}
.bl-btn-primary { background: var(--bl-copper); color: #fff; }
.bl-btn-primary:hover { background: var(--bl-copper-hover); }
.bl-btn-line { border: 1px solid var(--bl-ink); color: var(--bl-ink); background: transparent; }
.bl-btn-line:hover { background: var(--bl-ink); color: #fff; }
.bl-btn-on-dark { background: #fff; color: var(--bl-copper-hover); }
.bl-btn-on-dark:hover { transform: translateY(-1px); }

.bl-hero-frame {
    position: relative;
    background: var(--bl-card);
    border: 1px solid var(--bl-line);
    padding: 12px 12px 40px;
    box-shadow: var(--bl-shadow);
    transform: rotate(1.4deg);
}
.bl-hero-frame img { width: 100%; height: 340px; object-fit: cover; }
.bl-hero-frame figcaption {
    position: absolute;
    left: 20px;
    bottom: 12px;
    font-size: 0.78rem;
    color: var(--bl-muted);
}

.bl-hero-metrics {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    margin-top: 36px;
    border-top: 1px solid var(--bl-line);
}
.bl-hero-metrics li {
    padding: 20px 8px 4px;
    text-align: center;
    border-right: 1px solid var(--bl-line);
}
.bl-hero-metrics li:last-child { border-right: none; }
.bl-hero-metrics strong {
    display: block;
    font-family: var(--bl-font);
    font-size: 1.6rem;
    color: var(--bl-copper);
}
.bl-hero-metrics span { font-size: 0.8rem; color: var(--bl-muted); }

/* === Sections === */
.bl-section { padding: 80px 0; }
.bl-section-paper { background: var(--bl-paper-2); }
.bl-sec-head { margin-bottom: 40px; }
.bl-sec-head-left { text-align: left; max-width: 520px; }
.bl-sec-head h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); margin-bottom: 8px; }
.bl-sec-head p { color: var(--bl-muted); }

/* === Zigzag services === */
.bl-zig { display: flex; flex-direction: column; gap: 56px; }
.bl-zig-row {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 40px;
    align-items: center;
}
.bl-zig-row:nth-child(even) .bl-zig-media { order: 2; }
.bl-zig-media {
    display: block;
    overflow: hidden;
    border-radius: var(--bl-radius);
    border: 1px solid var(--bl-line);
    box-shadow: var(--bl-shadow);
}
.bl-zig-media img {
    width: 100%;
    height: 280px;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.bl-zig-row:hover .bl-zig-media img { transform: scale(1.04); }
.bl-idx {
    display: block;
    font-family: var(--bl-font);
    font-size: 2rem;
    color: var(--bl-copper);
    margin-bottom: 8px;
    line-height: 1;
}
.bl-zig-body h3 { font-size: 1.35rem; margin-bottom: 10px; }
.bl-zig-body p { color: var(--bl-ink-soft); margin-bottom: 16px; }
.bl-text-link {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    font-weight: 700;
    color: var(--bl-copper);
    border-bottom: 1px solid var(--bl-copper);
}
.bl-text-link:hover { color: var(--bl-copper-hover); }

/* === Timeline === */
.bl-process-layout {
    display: grid;
    grid-template-columns: 0.8fr 1.2fr;
    gap: 48px;
    align-items: start;
}
.bl-timeline { position: relative; }
.bl-timeline::before {
    content: "";
    position: absolute;
    left: 18px;
    top: 8px;
    bottom: 8px;
    width: 2px;
    background: var(--bl-line);
}
.bl-timeline li {
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: 16px;
    padding-bottom: 28px;
    position: relative;
}
.bl-timeline li span {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bl-copper);
    color: #fff;
    font-size: 0.78rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 1;
}
.bl-timeline h3 { font-size: 1.05rem; margin-bottom: 4px; }
.bl-timeline p { color: var(--bl-muted); font-size: 0.9rem; }

/* === About band === */
.bl-band {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    min-height: 420px;
}
.bl-band-media img { width: 100%; height: 100%; min-height: 420px; object-fit: cover; }
.bl-band-copy {
    background: var(--bl-ink);
    color: #E7E5E4;
    padding: 64px 48px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.bl-band-copy h2 { color: #fff; margin-bottom: 14px; }
.bl-band-copy p { margin-bottom: 12px; color: #D6D3D1; }
.bl-band-copy .bl-kicker { color: #FDBA74; }
.bl-band-copy .bl-btn-primary { align-self: flex-start; margin-top: 12px; }

/* === Quotes === */
.bl-quotes {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    grid-template-rows: auto auto;
    gap: 16px;
}
.bl-quote-lead {
    grid-row: span 2;
    background: var(--bl-ink);
    color: #FFF7ED;
    padding: 36px 32px;
    border-radius: var(--bl-radius);
}
.bl-quote-lead p { font-family: var(--bl-font); font-size: 1.35rem; line-height: 1.6; }
.bl-quotes blockquote:not(.bl-quote-lead) {
    background: var(--bl-card);
    border: 1px solid var(--bl-line);
    border-radius: var(--bl-radius);
    padding: 22px 20px;
}
.bl-quotes footer { margin-top: 14px; font-size: 0.8rem; color: var(--bl-muted); }
.bl-quote-lead footer { color: #FDBA74; }

/* === FAQ === */
.bl-faq-item { border-bottom: 1px solid var(--bl-line); }
.bl-faq-q {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 16px;
    min-height: 64px;
    padding: 16px 0;
    background: none;
    border: none;
    text-align: left;
    font-size: 1.02rem;
    font-weight: 600;
    color: var(--bl-ink);
}
.bl-faq-q em {
    font-family: var(--bl-font);
    font-style: normal;
    color: var(--bl-copper);
    min-width: 32px;
}
.bl-faq-q svg { margin-left: auto; stroke: var(--bl-copper); flex-shrink: 0; transition: transform var(--bl-t); }
.bl-faq-item.active .bl-faq-q svg { transform: rotate(45deg); }
.bl-faq-a {
    max-height: 0;
    overflow: hidden;
    padding: 0 0 0 48px;
    color: var(--bl-ink-soft);
    font-size: 0.92rem;
    transition: max-height 0.28s ease, padding 0.28s ease;
}
.bl-faq-item.active .bl-faq-a { max-height: 220px; padding: 0 0 18px 48px; }

/* === Chips / CTA / Footer === */
.bl-chips { display: flex; flex-wrap: wrap; gap: 10px; }
.bl-chips a {
    display: inline-flex;
    align-items: center;
    min-height: 40px;
    padding: 8px 16px;
    border: 1px solid var(--bl-line);
    background: var(--bl-card);
    border-radius: 4px;
    font-size: 0.86rem;
    color: var(--bl-ink-soft);
}
.bl-chips a:hover { border-color: var(--bl-copper); color: var(--bl-copper); }
.bl-more { margin-top: 18px; }
.bl-more a { color: var(--bl-copper); font-weight: 700; }

.bl-cta { background: var(--bl-copper); color: #fff; padding: 48px 0; }
.bl-cta-split {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}
.bl-cta h2 { color: #fff; font-size: clamp(1.4rem, 3vw, 1.9rem); margin-bottom: 8px; }
.bl-cta p { color: #FFEDD5; max-width: 520px; }

.bl-footer { background: #1C1917; color: #A8A29E; padding: 48px 0 0; }
.bl-logo-on-dark { color: #fff; margin-bottom: 12px; }
.bl-footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 32px;
    padding-bottom: 32px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.bl-footer h4 { color: #fff; font-size: 0.88rem; margin-bottom: 12px; }
.bl-footer p { font-size: 0.86rem; line-height: 1.8; max-width: 360px; }
.bl-footer a {
    display: inline-flex;
    align-items: center;
    min-height: 36px;
    font-size: 0.86rem;
    color: #A8A29E;
}
.bl-footer a:hover { color: #FDBA74; }
.bl-footer-base {
    padding: 18px 0;
    display: flex;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
    font-size: 0.76rem;
    color: #78716C;
}

/* === Inner pages === */
.bl-page-hero {
    padding: 48px 0 32px;
    border-bottom: 1px solid var(--bl-line);
}
.bl-page-hero h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); margin-bottom: 8px; }
.bl-page-hero p { color: var(--bl-muted); max-width: 560px; }

.bl-empty {
    min-height: 58vh;
    display: flex;
    align-items: center;
    text-align: center;
    padding: 80px 0;
}
.bl-empty strong {
    display: block;
    font-family: var(--bl-font);
    font-size: 6rem;
    color: var(--bl-line);
    line-height: 1;
    margin-bottom: 8px;
}

/* === Lightbox === */
.bl-lightbox {
    display: none;
    position: fixed;
    inset: 0;
    z-index: var(--bl-z-overlay);
    background: rgba(28, 25, 23, 0.82);
    align-items: center;
    justify-content: center;
    padding: 32px;
    cursor: zoom-out;
}
.bl-lightbox.active { display: flex; }
.bl-lightbox img { max-width: 90%; max-height: 88vh; object-fit: contain; }
.bl-lightbox-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: rgba(255,255,255,0.12);
    color: #fff;
    font-size: 1.6rem;
}

/* === Responsive === */
@media (max-width: 1024px) {
    .bl-hero-split,
    .bl-zig-row,
    .bl-process-layout,
    .bl-band,
    .bl-quotes,
    .bl-cta-split,
    .bl-footer-grid { grid-template-columns: 1fr; }
    .bl-zig-row:nth-child(even) .bl-zig-media { order: 0; }
    .bl-quote-lead { grid-row: auto; }
    .bl-hero-metrics { grid-template-columns: repeat(2, 1fr); }
    .bl-hero-metrics li:nth-child(2) { border-right: none; }
    .bl-band-media img { min-height: 280px; }
    .bl-band-copy { padding: 40px 28px; }
}

@media (max-width: 768px) {
    .bl-nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 12px;
        right: 12px;
        flex-direction: column;
        background: var(--bl-card);
        border: 1px solid var(--bl-line);
        box-shadow: var(--bl-shadow);
        padding: 8px;
    }
    .bl-nav-links.active { display: flex; }
    .bl-nav-cta { display: none; }
    .bl-mobile-btn { display: inline-flex; align-items: center; justify-content: center; }
    .bl-hero-actions { flex-direction: column; }
    .bl-btn-primary, .bl-btn-line { width: 100%; }
    .bl-hero-frame img, .bl-zig-media img { height: 220px; }
    .bl-section { padding: 56px 0; }
    .bl-faq-a, .bl-faq-item.active .bl-faq-a { padding-left: 0; }
    .bl-topbar span { display: none; }
}

@media (max-width: 480px) {
    .bl-container, .bl-nav-inner { padding-left: 16px; padding-right: 16px; }
    .bl-hero-metrics { grid-template-columns: 1fr 1fr; }
}