* { box-sizing: border-box; }
body {
    background: #f7f4ed;
    color: #1c1c1c;
    font-family: ui-sans-serif, system-ui, -apple-system, sans-serif;
    line-height: 1.5;
    margin: 0;
}
a { color: #1c1c1c; text-decoration: underline; }
a.oi-related-card, a.oi-logo, .oi-nav-desktop a, .oi-nav-mobile a { text-decoration: none; }

.oi-header {
    background: #f7f4ed;
    border-bottom: 1px solid #eceae4;
    position: sticky;
    top: 0;
    z-index: 50;
}
.oi-header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
}
.oi-logo { font-weight: 600; font-size: 18px; letter-spacing: -0.5px; color: #1c1c1c; }
.oi-logo span { color: #5f5f5d; font-weight: 400; }
.oi-nav-desktop { display: flex; gap: 28px; }
.oi-nav-desktop a { color: #1c1c1c; font-size: 15px; }
.oi-nav-desktop a:hover { color: #5f5f5d; }
.oi-menu-toggle { display: none; flex-direction: column; gap: 4px; background: none; border: none; cursor: pointer; padding: 8px; border-radius: 6px; }
.oi-menu-toggle span { width: 20px; height: 2px; background: #1c1c1c; }
.oi-nav-mobile { display: none; flex-direction: column; padding: 8px 24px 20px; border-top: 1px solid #eceae4; }
.oi-nav-mobile a { padding: 10px 0; color: #1c1c1c; font-size: 15px; }
.oi-nav-mobile.open { display: flex; }
@media (max-width: 768px) {
    .oi-nav-desktop { display: none; }
    .oi-menu-toggle { display: flex; }
}

.oi-breadcrumb { font-size: 14px; color: #5f5f5d; margin-bottom: 24px; }
.oi-breadcrumb a { color: #5f5f5d; text-decoration: underline; }
.oi-breadcrumb-sep { margin: 0 8px; }
.oi-breadcrumb-current { color: #1c1c1c; }

.oi-tag { display: inline-block; background: #eceae4; color: #1c1c1c; font-size: 13px; padding: 4px 12px; border-radius: 9999px; }

.oi-btn-primary {
    display: inline-block;
    background: #1c1c1c;
    color: #fcfbf8;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 16px;
    border: none;
    cursor: pointer;
    box-shadow: rgba(255,255,255,0.2) 0px 0.5px 0px 0px inset, rgba(0,0,0,0.2) 0px 0px 0px 0.5px inset, rgba(0,0,0,0.05) 0px 1px 2px 0px;
    text-decoration: none;
}
.oi-btn-primary:active { opacity: 0.8; }
.oi-btn-ghost {
    display: inline-block;
    background: transparent;
    color: #1c1c1c;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 16px;
    border: 1px solid rgba(28,28,28,0.4);
    cursor: pointer;
    text-decoration: none;
}

.oi-hero { max-width: 1200px; margin: 0 auto; padding: 96px 24px 64px; text-align: center; }
.oi-hero h1 { font-size: 48px; font-weight: 600; letter-spacing: -1.2px; line-height: 1.1; margin: 0 0 20px; }
.oi-hero p { font-size: 18px; color: #5f5f5d; line-height: 1.38; max-width: 640px; margin: 0 auto 32px; }
@media (max-width: 640px) {
    .oi-hero h1 { font-size: 32px; letter-spacing: -0.9px; }
}

.oi-section { max-width: 1200px; margin: 0 auto; padding: 48px 24px; }
.oi-section-title { font-size: 32px; font-weight: 600; letter-spacing: -0.9px; margin-bottom: 32px; }

.oi-card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
@media (max-width: 900px) { .oi-card-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .oi-card-grid { grid-template-columns: 1fr; } }

.oi-card { background: #f7f4ed; border: 1px solid #eceae4; border-radius: 12px; overflow: hidden; text-decoration: none; color: #1c1c1c; display: block; }
.oi-card img { width: 100%; height: 180px; object-fit: cover; display: block; }
.oi-card-body { padding: 20px; }
.oi-card-body h3 { font-size: 20px; font-weight: 400; margin: 12px 0 8px; line-height: 1.25; }
.oi-card-body p { font-size: 14px; color: #5f5f5d; margin: 0; }

.oi-layout { max-width: 1200px; margin: 0 auto; padding: 48px 24px; display: grid; grid-template-columns: 240px 1fr; gap: 40px; }
@media (max-width: 900px) { .oi-layout { grid-template-columns: 1fr; } }

.oi-sidebar-title { font-weight: 600; font-size: 14px; text-transform: uppercase; letter-spacing: 0.5px; color: #5f5f5d; margin-bottom: 12px; }
.oi-sidebar-list { list-style: none; padding: 0; margin: 0 0 24px; }
.oi-sidebar-list li a { display: block; padding: 8px 12px; border-radius: 6px; color: #1c1c1c; font-size: 15px; }
.oi-sidebar-list li a.active, .oi-sidebar-list li a:hover { background: rgba(28,28,28,0.04); }
.oi-sidebar-note { border: 1px solid #eceae4; border-radius: 12px; padding: 16px; font-size: 13px; color: #5f5f5d; }

.oi-toc { border: 1px solid #eceae4; border-radius: 12px; padding: 20px 24px; margin: 32px 0; background: #f7f4ed; }
.oi-toc-title { font-weight: 600; margin: 0 0 12px; font-size: 15px; }
.oi-toc a { display: block; padding: 4px 0; color: #5f5f5d; font-size: 15px; text-decoration: none; }
.oi-toc a:hover { color: #1c1c1c; }

.oi-prose h2 { font-size: 28px; font-weight: 600; letter-spacing: -0.7px; margin: 40px 0 16px; }
.oi-prose h3 { font-size: 20px; font-weight: 600; margin: 28px 0 12px; }
.oi-prose p { font-size: 16px; color: #1c1c1c; margin: 0 0 16px; }
.oi-prose img { width: 100%; border-radius: 12px; border: 1px solid #eceae4; margin: 24px 0; }

.oi-faq-item { border-bottom: 1px solid #eceae4; padding: 16px 0; }
.oi-faq-item summary { cursor: pointer; font-weight: 600; font-size: 16px; list-style: none; }
.oi-faq-item summary::-webkit-details-marker { display: none; }
.oi-faq-item summary::after { content: '+'; float: right; font-weight: 400; }
.oi-faq-item[open] summary::after { content: '−'; }
.oi-faq-item p { margin: 12px 0 0; color: #5f5f5d; }

.oi-related { max-width: 1200px; margin: 48px auto 0; padding: 0 24px; }
.oi-related-title { font-size: 24px; font-weight: 600; margin-bottom: 20px; }
.oi-related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 768px) { .oi-related-grid { grid-template-columns: 1fr; } }
.oi-related-card { border: 1px solid #eceae4; border-radius: 12px; overflow: hidden; text-decoration: none; color: #1c1c1c; }
.oi-related-card img { width: 100%; height: 140px; object-fit: cover; display: block; }
.oi-related-body { padding: 16px; }
.oi-related-body h3 { font-size: 15px; font-weight: 400; margin: 8px 0 0; }

.oi-footer { background: #f7f4ed; border-top: 1px solid #eceae4; margin-top: 64px; }
.oi-footer-grid { max-width: 1200px; margin: 0 auto; padding: 48px 24px 24px; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; }
@media (max-width: 768px) { .oi-footer-grid { grid-template-columns: 1fr; } }
.oi-footer-desc { color: #5f5f5d; font-size: 14px; margin: 12px 0; }
.oi-footer-disclaimer { color: #5f5f5d; font-size: 12px; }
.oi-footer-title { font-weight: 600; font-size: 14px; margin: 0 0 12px; }
.oi-footer-col ul { list-style: none; padding: 0; margin: 0; }
.oi-footer-col ul li { margin-bottom: 8px; }
.oi-footer-col ul li a, .oi-footer-col p a { font-size: 14px; color: #5f5f5d; text-decoration: none; }
.oi-footer-bottom { max-width: 1200px; margin: 0 auto; padding: 24px; border-top: 1px solid #eceae4; font-size: 12px; color: #5f5f5d; }
.oi-footer-bottom p { margin: 4px 0; }

.oi-form { max-width: 560px; }
.oi-form-group { margin-bottom: 20px; }
.oi-form-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.oi-form-group input, .oi-form-group textarea {
    width: 100%;
    background: #f7f4ed;
    border: 1px solid #eceae4;
    border-radius: 6px;
    padding: 10px 12px;
    font-size: 15px;
    color: #1c1c1c;
    font-family: inherit;
}
.oi-form-group input:focus, .oi-form-group textarea:focus {
    outline: none;
    box-shadow: rgba(59,130,246,0.5) 0px 0px 0px 2px;
}
.oi-confirm-msg { color: #1c1c1c; margin-top: 16px; font-size: 15px; }
.hidden { display: none; }

.oi-cookie-banner {
    position: fixed;
    bottom: 16px;
    left: 16px;
    right: 16px;
    max-width: 560px;
    margin: 0 auto;
    background: #1c1c1c;
    color: #fcfbf8;
    border-radius: 16px;
    padding: 20px 24px;
    box-shadow: rgba(0,0,0,0.2) 0px 8px 24px;
    z-index: 100;
}
.oi-cookie-banner p { font-size: 14px; margin: 0 0 16px; }
.oi-cookie-actions { display: flex; gap: 12px; }
.oi-cookie-actions button { border-radius: 9999px; padding: 8px 20px; font-size: 14px; cursor: pointer; border: none; }
.oi-cookie-accept { background: #fcfbf8; color: #1c1c1c; }
.oi-cookie-reject { background: transparent; color: #fcfbf8; border: 1px solid rgba(255,255,255,0.4) !important; }

.oi-legal { max-width: 760px; margin: 0 auto; padding: 48px 24px; }
.oi-legal h1 { font-size: 36px; font-weight: 600; letter-spacing: -0.9px; margin-bottom: 24px; }
.oi-legal h2 { font-size: 22px; font-weight: 600; margin: 32px 0 12px; }
.oi-legal p { font-size: 16px; color: #1c1c1c; margin: 0 0 14px; }