@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400&display=swap');

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --color-primary: #f54e00;
    --color-primary-active: #d04200;
    --color-canvas: #f7f7f4;
    --color-canvas-soft: #fafaf7;
    --color-surface-card: #ffffff;
    --color-surface-strong: #e6e5e0;
    --color-hairline: #e6e5e0;
    --color-hairline-soft: #efeee8;
    --color-hairline-strong: #cfcdc4;
    --color-ink: #26251e;
    --color-body: #5a5852;
    --color-body-strong: #26251e;
    --color-muted: #807d72;
    --color-muted-soft: #a09c92;
    --color-on-primary: #ffffff;
    --color-success: #1f8a65;
    --color-error: #cf2d56;
    --rounded-xs: 4px;
    --rounded-sm: 6px;
    --rounded-md: 8px;
    --rounded-lg: 12px;
    --rounded-xl: 16px;
    --rounded-pill: 9999px;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', system-ui, 'Helvetica Neue', Helvetica, Arial, sans-serif;
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-body);
    background-color: var(--color-canvas);
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-ink);
    text-decoration: none;
}

a:hover {
    color: var(--color-primary);
}

img {
    display: block;
    max-width: 100%;
    height: auto;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.site-nav {
    background-color: var(--color-canvas);
    border-bottom: 1px solid var(--color-hairline);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-ink);
    letter-spacing: -0.3px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-logo span {
    color: var(--color-primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-body);
    line-height: 1.4;
    transition: color 0.15s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-ink);
}

.nav-hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    flex-direction: column;
    gap: 5px;
}

.nav-hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--color-ink);
    border-radius: 2px;
    transition: all 0.2s ease;
}

.hero-band {
    padding: 80px 0;
    background-color: var(--color-canvas);
}

.hero-content {
    max-width: 720px;
}

.hero-label {
    display: inline-flex;
    align-items: center;
    font-size: 11px;
    font-weight: 600;
    line-height: 1.4;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    background-color: var(--color-surface-strong);
    border-radius: var(--rounded-pill);
    padding: 4px 10px;
    margin-bottom: 24px;
}

.hero-h1 {
    font-size: 72px;
    font-weight: 400;
    line-height: 1.1;
    letter-spacing: -2.16px;
    color: var(--color-ink);
    margin-bottom: 24px;
}

.hero-sub {
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-body);
    max-width: 540px;
    margin-bottom: 40px;
}

.hero-image-wrap {
    margin-top: 64px;
    border-radius: var(--rounded-lg);
    overflow: hidden;
    border: 1px solid var(--color-hairline);
}

.hero-image-wrap img {
    width: 100%;
    height: 420px;
    object-fit: cover;
}

.section {
    padding: 80px 0;
}

.section-label {
    font-size: 11px;
    font-weight: 600;
    line-height: 1.4;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    margin-bottom: 16px;
}

.section-title {
    font-size: 36px;
    font-weight: 400;
    line-height: 1.2;
    letter-spacing: -0.72px;
    color: var(--color-ink);
    margin-bottom: 16px;
}

.section-sub {
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-body);
    max-width: 600px;
    margin-bottom: 48px;
}

.divider {
    border: none;
    border-top: 1px solid var(--color-hairline);
}

.card-grid {
    display: grid;
    gap: 24px;
    grid-template-columns: repeat(3, 1fr);
}

.card-grid-2 {
    display: grid;
    gap: 24px;
    grid-template-columns: repeat(2, 1fr);
}

.feature-card {
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-radius: var(--rounded-lg);
    padding: 24px;
}

.feature-card-icon {
    width: 40px;
    height: 40px;
    background-color: var(--color-surface-strong);
    border-radius: var(--rounded-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    font-size: 18px;
}

.feature-card-title {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.4;
    color: var(--color-ink);
    margin-bottom: 8px;
}

.feature-card-text {
    font-size: 14px;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-body);
}

.article-card {
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-radius: var(--rounded-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.article-card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.article-card-body {
    padding: 24px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.article-card-category {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    margin-bottom: 8px;
}

.article-card-title {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.4;
    color: var(--color-ink);
    margin-bottom: 12px;
}

.article-card-excerpt {
    font-size: 14px;
    line-height: 1.5;
    color: var(--color-body);
    flex: 1;
    margin-bottom: 20px;
}

.article-card-meta {
    font-size: 13px;
    color: var(--color-muted);
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-primary);
    color: var(--color-on-primary);
    font-size: 14px;
    font-weight: 500;
    line-height: 1;
    padding: 10px 18px;
    height: 40px;
    border-radius: var(--rounded-md);
    border: none;
    cursor: pointer;
    transition: background-color 0.15s ease;
    text-decoration: none;
}

.btn-primary:hover {
    background-color: var(--color-primary-active);
    color: var(--color-on-primary);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-surface-card);
    color: var(--color-ink);
    font-size: 14px;
    font-weight: 500;
    line-height: 1;
    padding: 10px 18px;
    height: 40px;
    border-radius: var(--rounded-md);
    border: 1px solid var(--color-hairline-strong);
    cursor: pointer;
    transition: border-color 0.15s ease;
    text-decoration: none;
}

.btn-secondary:hover {
    border-color: var(--color-ink);
    color: var(--color-ink);
}

.section-band {
    background-color: var(--color-surface-card);
    border-top: 1px solid var(--color-hairline);
    border-bottom: 1px solid var(--color-hairline);
}

.text-block {
    max-width: 720px;
}

.text-block h1,
.text-block h2,
.text-block h3 {
    color: var(--color-ink);
    font-weight: 400;
}

.text-block h1 {
    font-size: 48px;
    letter-spacing: -1.44px;
    line-height: 1.1;
    margin-bottom: 24px;
}

.text-block h2 {
    font-size: 26px;
    letter-spacing: -0.325px;
    line-height: 1.25;
    margin-top: 48px;
    margin-bottom: 16px;
}

.text-block h3 {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.4;
    margin-top: 32px;
    margin-bottom: 12px;
}

.text-block p {
    font-size: 16px;
    line-height: 1.5;
    color: var(--color-body);
    margin-bottom: 16px;
}

.text-block ul,
.text-block ol {
    padding-left: 24px;
    margin-bottom: 16px;
    color: var(--color-body);
}

.text-block li {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 6px;
}

.text-block a {
    color: var(--color-primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.text-block a:hover {
    color: var(--color-primary-active);
}

.text-block .code-inline {
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-radius: var(--rounded-xs);
    padding: 2px 6px;
    color: var(--color-ink);
}

.article-meta-bar {
    display: flex;
    align-items: center;
    gap: 24px;
    padding: 16px 0;
    border-bottom: 1px solid var(--color-hairline);
    margin-bottom: 40px;
    font-size: 13px;
    color: var(--color-muted);
}

.article-meta-bar .category-pill {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    background-color: var(--color-surface-strong);
    border-radius: var(--rounded-pill);
    padding: 4px 10px;
    color: var(--color-ink);
}

.info-box {
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-left: 3px solid var(--color-primary);
    border-radius: var(--rounded-md);
    padding: 20px 24px;
    margin: 24px 0;
}

.info-box p {
    font-size: 14px;
    line-height: 1.5;
    color: var(--color-body);
    margin: 0;
}

.info-box p + p {
    margin-top: 8px;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 24px 0;
    font-size: 14px;
}

.data-table th {
    text-align: left;
    font-weight: 600;
    font-size: 11px;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    padding: 10px 16px;
    border-bottom: 2px solid var(--color-hairline);
}

.data-table td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--color-hairline-soft);
    color: var(--color-body);
    line-height: 1.5;
}

.data-table tr:last-child td {
    border-bottom: none;
}

.image-caption {
    font-size: 13px;
    color: var(--color-muted);
    line-height: 1.4;
    margin-top: 8px;
}

.full-image {
    width: 100%;
    border-radius: var(--rounded-lg);
    border: 1px solid var(--color-hairline);
    overflow: hidden;
    margin: 32px 0;
}

.full-image img {
    width: 100%;
    height: 360px;
    object-fit: cover;
}

.contact-form-wrap {
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-radius: var(--rounded-lg);
    padding: 40px;
    max-width: 560px;
}

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--color-ink);
    margin-bottom: 6px;
}

.form-input {
    width: 100%;
    background-color: var(--color-surface-card);
    color: var(--color-ink);
    font-family: inherit;
    font-size: 16px;
    border: 1px solid var(--color-hairline-strong);
    border-radius: var(--rounded-md);
    padding: 12px 16px;
    height: 44px;
    transition: border-color 0.15s ease;
    outline: none;
}

.form-input:focus {
    border-color: var(--color-ink);
}

.form-input.error {
    border-color: var(--color-error);
}

.form-error {
    font-size: 13px;
    color: var(--color-error);
    margin-top: 4px;
    display: none;
}

.form-error.visible {
    display: block;
}

.form-message {
    font-size: 14px;
    padding: 12px 16px;
    border-radius: var(--rounded-md);
    margin-top: 16px;
    display: none;
}

.form-message.success {
    background-color: #d4f0e8;
    color: var(--color-success);
    border: 1px solid #b3e0d0;
    display: block;
}

.form-message.loading {
    background-color: var(--color-surface-strong);
    color: var(--color-muted);
    border: 1px solid var(--color-hairline);
    display: block;
}

.site-footer {
    background-color: var(--color-canvas);
    border-top: 1px solid var(--color-hairline);
    padding: 64px 0 48px;
}

.footer-inner {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-brand-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-ink);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-brand-name span {
    color: var(--color-primary);
}

.footer-brand-desc {
    font-size: 14px;
    line-height: 1.5;
    color: var(--color-body);
    max-width: 240px;
}

.footer-col-title {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    margin-bottom: 16px;
}

.footer-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: 14px;
    color: var(--color-body);
    transition: color 0.15s ease;
}

.footer-links a:hover {
    color: var(--color-ink);
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 24px;
    border-top: 1px solid var(--color-hairline);
    font-size: 13px;
    color: var(--color-muted);
    flex-wrap: wrap;
    gap: 12px;
}

.cookie-banner {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--color-ink);
    color: var(--color-canvas);
    border-radius: var(--rounded-lg);
    padding: 20px 28px;
    max-width: 640px;
    width: calc(100% - 48px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    z-index: 1000;
    box-shadow: 0 4px 24px rgba(38, 37, 30, 0.15);
}

.cookie-text {
    font-size: 14px;
    line-height: 1.5;
    flex: 1;
}

.cookie-text a {
    color: var(--color-canvas);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.cookie-actions {
    display: flex;
    gap: 10px;
    flex-shrink: 0;
}

.cookie-accept {
    background-color: var(--color-primary);
    color: var(--color-on-primary);
    font-size: 14px;
    font-weight: 500;
    border: none;
    border-radius: var(--rounded-md);
    padding: 8px 16px;
    height: 36px;
    cursor: pointer;
    transition: background-color 0.15s ease;
}

.cookie-accept:hover {
    background-color: var(--color-primary-active);
}

.cookie-reject {
    background-color: transparent;
    color: var(--color-canvas);
    font-size: 14px;
    font-weight: 500;
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: var(--rounded-md);
    padding: 8px 16px;
    height: 36px;
    cursor: pointer;
    transition: border-color 0.15s ease;
}

.cookie-reject:hover {
    border-color: rgba(255,255,255,0.7);
}

.breadcrumb {
    font-size: 13px;
    color: var(--color-muted);
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.breadcrumb a {
    color: var(--color-muted);
}

.breadcrumb a:hover {
    color: var(--color-ink);
}

.breadcrumb span {
    color: var(--color-muted-soft);
}

.page-hero {
    padding: 64px 0 48px;
    background-color: var(--color-canvas);
}

.page-hero-label {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    margin-bottom: 16px;
}

.page-hero-title {
    font-size: 48px;
    font-weight: 400;
    letter-spacing: -1.44px;
    line-height: 1.1;
    color: var(--color-ink);
    margin-bottom: 16px;
}

.page-hero-sub {
    font-size: 16px;
    line-height: 1.5;
    color: var(--color-body);
    max-width: 560px;
}

.article-page-hero {
    padding: 64px 0 0;
}

.article-page-title {
    font-size: 48px;
    font-weight: 400;
    letter-spacing: -1.44px;
    line-height: 1.1;
    color: var(--color-ink);
    margin-bottom: 24px;
    max-width: 800px;
}

.article-page-image {
    margin-top: 48px;
    border-radius: var(--rounded-lg);
    overflow: hidden;
    border: 1px solid var(--color-hairline);
}

.article-page-image img {
    width: 100%;
    height: 460px;
    object-fit: cover;
}

.article-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 64px;
    padding: 64px 0 80px;
    align-items: start;
}

.article-sidebar {
    position: sticky;
    top: 88px;
}

.sidebar-card {
    background-color: var(--color-surface-card);
    border: 1px solid var(--color-hairline);
    border-radius: var(--rounded-lg);
    padding: 24px;
    margin-bottom: 24px;
}

.sidebar-card-title {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.88px;
    text-transform: uppercase;
    color: var(--color-muted);
    margin-bottom: 16px;
}

.sidebar-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.sidebar-links a {
    font-size: 14px;
    color: var(--color-body);
    line-height: 1.4;
}

.sidebar-links a:hover {
    color: var(--color-ink);
}

.toc-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
    counter-reset: toc;
}

.toc-list li {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 13px;
    line-height: 1.4;
    color: var(--color-body);
}

.toc-list li::before {
    counter-increment: toc;
    content: counter(toc);
    font-size: 11px;
    font-weight: 600;
    color: var(--color-muted);
    min-width: 16px;
    margin-top: 2px;
}

.toc-list a {
    color: var(--color-body);
    font-size: 13px;
}

.toc-list a:hover {
    color: var(--color-ink);
}

.related-articles-section {
    padding: 64px 0 80px;
    border-top: 1px solid var(--color-hairline);
    background-color: var(--color-canvas);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
    padding: 80px 0;
}

.about-image {
    border-radius: var(--rounded-lg);
    overflow: hidden;
    border: 1px solid var(--color-hairline);
}

.about-image img {
    width: 100%;
    height: 400px;
    object-fit: cover;
}

@media (max-width: 1024px) {
    .hero-h1 { font-size: 56px; letter-spacing: -1.68px; }
    .card-grid { grid-template-columns: repeat(2, 1fr); }
    .article-layout { grid-template-columns: 1fr; }
    .article-sidebar { position: static; }
    .footer-inner { grid-template-columns: 1fr 1fr; }
    .about-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background-color: var(--color-canvas);
        border-bottom: 1px solid var(--color-hairline);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
    }
    .nav-links.open { display: flex; }
    .nav-hamburger { display: flex; }
    .site-nav { position: relative; }
    .hero-h1 { font-size: 36px; letter-spacing: -0.72px; }
    .section-title { font-size: 26px; letter-spacing: -0.325px; }
    .page-hero-title { font-size: 32px; letter-spacing: -0.5px; }
    .article-page-title { font-size: 32px; letter-spacing: -0.5px; }
    .card-grid { grid-template-columns: 1fr; }
    .card-grid-2 { grid-template-columns: 1fr; }
    .footer-inner { grid-template-columns: 1fr 1fr; gap: 32px; }
    .contact-form-wrap { padding: 24px; }
    .cookie-banner { flex-direction: column; align-items: flex-start; gap: 16px; bottom: 16px; }
    .about-grid { padding: 48px 0; }
}

@media (max-width: 480px) {
    .container { padding: 0 16px; }
    .hero-h1 { font-size: 28px; }
    .footer-inner { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; text-align: center; }
    .article-page-image img { height: 240px; }
}