/**
 * Global CSS - Design System & Common Styles
 * Purpose: Design Tokens + Base Styles + Universal Components
 */

/* ========== 1. CSS Reset ========== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #333;
    background: #fff;
    overflow-x: hidden;
}

/* ========== 2. Design Tokens - Color System ========== */
:root {
    --brand-primary: #DC2626;
    --brand-secondary: #1F2937;
    --brand-accent: #ffc107;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-light: #999999;
    --bg-white: #ffffff;
    --bg-light: #f8f9fa;
    --bg-dark: #2c3e50;
    --border-color: #e0e0e0;
    --success: #28a745;
    --error: #dc3545;
}

/* ========== 3. Typography System ========== */
h1 { font-size: 2.5rem; font-weight: 700; line-height: 1.2; margin-bottom: 1.5rem; color: var(--text-primary); }
h2 { font-size: 2rem; font-weight: 700; line-height: 1.3; margin-bottom: 1.25rem; color: var(--text-primary); }
h3 { font-size: 1.75rem; font-weight: 600; line-height: 1.3; margin-bottom: 1rem; color: var(--text-primary); }
h4 { font-size: 1.5rem; font-weight: 600; line-height: 1.4; margin-bottom: 0.875rem; color: var(--text-primary); }
h5 { font-size: 1.25rem; font-weight: 600; line-height: 1.4; margin-bottom: 0.75rem; color: var(--text-primary); }
h6 { font-size: 1.125rem; font-weight: 600; line-height: 1.4; margin-bottom: 0.5rem; color: var(--text-primary); }
p { font-size: 1rem; line-height: 1.6; margin-bottom: 1rem; color: var(--text-secondary); }
.lead { font-size: 1.125rem; font-weight: 300; line-height: 1.7; color: var(--text-secondary); }

/* ========== 4. Spacing Utilities ========== */
.container {
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
    margin-right: auto;
    margin-left: auto;
}
.section-padding { padding: 4rem 0; }
.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: 0.5rem !important; }
.mb-2 { margin-bottom: 1rem !important; }
.mb-3 { margin-bottom: 1.5rem !important; }
.mb-4 { margin-bottom: 2rem !important; }
.mb-5 { margin-bottom: 3rem !important; }
.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: 0.5rem !important; }
.mt-2 { margin-top: 1rem !important; }
.mt-3 { margin-top: 1.5rem !important; }
.mt-4 { margin-top: 2rem !important; }
.mt-5 { margin-top: 3rem !important; }

/* ========== 5. Layout Utilities ========== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.d-flex { display: flex; }
.justify-content-center { justify-content: center; }
.justify-content-between { justify-content: space-between; }
.align-items-center { align-items: center; }

/* ========== 6. Common Components ========== */
/* Buttons - 全站通用按钮 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    text-decoration: none;
    border-radius: 4px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    min-width: 48px;
    min-height: 48px;
}
.btn-primary {
    background-color: var(--brand-primary);
    color: #fff;
}
.btn-primary:hover {
    background-color: var(--brand-secondary);
    color: #fff;
    text-decoration: none;
}
.btn-secondary {
    background-color: var(--brand-secondary);
    color: #fff;
}
.btn-secondary:hover {
    background-color: var(--brand-primary);
    color: #fff;
    text-decoration: none;
}
.btn-accent {
    background-color: var(--brand-accent);
    color: #333;
}
.btn-accent:hover {
    background-color: #e6a800;
    color: #333;
    text-decoration: none;
}

/* Cards - 基础卡片样式 */
.card {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

/* ========== 7. Responsive Container ========== */
@media (min-width: 576px) { .container { max-width: 540px; } }
@media (min-width: 768px) { .container { max-width: 720px; } }
@media (min-width: 992px) { .container { max-width: 960px; } }
@media (min-width: 1200px) { .container { max-width: 1140px; } }

/* ========== 8. Accessibility ========== */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: #000;
    color: #fff;
    padding: 8px 12px;
    text-decoration: none;
    z-index: 10000;
}
.skip-link:focus { top: 0; }

/* ========== 9. Images ========== */
img, .img-fluid {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ========== 10. Links ========== */
a {
    color: var(--brand-primary);
    text-decoration: none;
    transition: color 0.3s ease;
}
a:hover {
    color: var(--brand-secondary);
    text-decoration: underline;
}

/* ========== 11. B2B service visual modules ========== */
.service-proof-panel {
    background: #ffffff;
    border-bottom: 1px solid rgba(15, 31, 30, 0.06);
    padding: clamp(48px, 7vw, 88px) 0;
}

.service-proof-panel--tint {
    background: #FAF7F2;
}

.service-proof-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(360px, 42%);
    gap: clamp(24px, 4vw, 56px);
    align-items: center;
}

.service-proof-grid--reverse {
    grid-template-columns: minmax(360px, 42%) minmax(0, 1fr);
}

.service-proof-copy {
    display: grid;
    gap: 16px;
}

.service-proof-kicker {
    color: #DC2626;
    font-size: 0.75rem;
    font-weight: 800;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.service-proof-title {
    color: #0F1F1E;
    font-family: 'Plus Jakarta Sans', 'Inter', system-ui, sans-serif;
    font-size: clamp(1.5rem, 2.6vw, 2.25rem);
    font-weight: 800;
    line-height: 1.14;
    letter-spacing: -0.02em;
    margin: 0;
}

.service-proof-text {
    color: #5b6473;
    font-size: clamp(0.9375rem, 1vw, 1.0625rem);
    line-height: 1.65;
    max-width: 68ch;
    margin: 0;
}

.service-proof-list {
    display: grid;
    gap: 10px;
    list-style: none;
    padding: 0;
    margin: 4px 0 0;
}

.service-proof-list li {
    display: flex;
    gap: 10px;
    color: #25302f;
    font-size: 0.9375rem;
    line-height: 1.55;
}

.service-proof-list i {
    color: #DC2626;
    flex: 0 0 auto;
    margin-top: 3px;
}

.service-proof-media {
    margin: 0;
    overflow: hidden;
    border-radius: 12px;
    background: #ffffff;
    border: 1px solid rgba(15, 31, 30, 0.08);
    box-shadow: 0 14px 32px rgba(15, 31, 30, 0.10);
}

.service-proof-media img {
    width: 100%;
    aspect-ratio: 16 / 10;
    object-fit: cover;
    display: block;
}

.service-proof-media figcaption {
    padding: 12px 14px 14px;
    color: #5b6473;
    font-size: 0.8125rem;
    line-height: 1.45;
}

.service-proof-stack {
    display: grid;
    gap: 14px;
}

.service-proof-stack .service-proof-media img {
    aspect-ratio: 16 / 7.5;
}

.service-evidence-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(14px, 2vw, 20px);
    margin-top: clamp(24px, 4vw, 40px);
}

.service-evidence-card {
    overflow: hidden;
    border-radius: 12px;
    background: #ffffff;
    border: 1px solid rgba(15, 31, 30, 0.08);
    box-shadow: 0 8px 22px rgba(15, 31, 30, 0.06);
}

.service-evidence-card img {
    display: block;
    width: 100%;
    aspect-ratio: 16 / 10;
    object-fit: cover;
}

.service-evidence-card__body {
    padding: 16px 18px 18px;
}

.service-evidence-card__body h3 {
    color: #0F1F1E;
    font-size: 1rem;
    font-weight: 800;
    line-height: 1.3;
    margin: 0 0 8px;
}

.service-evidence-card__body p {
    color: #5b6473;
    font-size: 0.875rem;
    line-height: 1.55;
    margin: 0;
}

@media (max-width: 991px) {
    .service-proof-grid,
    .service-proof-grid--reverse {
        grid-template-columns: 1fr;
    }
    .service-proof-grid--reverse .service-proof-media,
    .service-proof-grid--reverse .service-proof-stack {
        order: -1;
    }
    .service-evidence-grid {
        grid-template-columns: 1fr;
    }
}


/* B-opt shared: breadcrumb + page TOC */
.bcrumb{background:#FAF7F2;border-bottom:1px solid rgba(15,31,30,.08)}
.bcrumb__list{max-width:1320px;margin:0 auto;padding:10px clamp(16px,3vw,32px);list-style:none;display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-size:.8125rem}
.bcrumb__item{display:flex;align-items:center;gap:8px;color:#5b6473}
.bcrumb__item:not(:first-child)::before{content:"/";color:rgba(15,31,30,.3)}
.bcrumb__item a{color:#5b6473;text-decoration:none}
.bcrumb__item a:hover{color:#DC2626;text-decoration:underline}
.bcrumb__item--current{color:#1F2937;font-weight:600}
.pgtoc{max-width:1320px;margin:clamp(18px,2.5vw,28px) auto 0;padding:0 clamp(16px,3vw,32px)}
.pgtoc__box{background:#fff;border:1px solid rgba(15,31,30,.1);border-radius:12px;padding:14px 20px}
.pgtoc__t{font-weight:700;font-size:.78rem;letter-spacing:.08em;text-transform:uppercase;color:#5b6473;margin:0 0 10px}
.pgtoc__list{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:6px 18px}
.pgtoc__list a{color:#1F2937;text-decoration:none;font-size:.9rem;padding:3px 0;border-bottom:1px solid transparent}
.pgtoc__list a:hover{color:#DC2626;border-bottom-color:#DC2626}