@font-face {
    font-family: "Yehack Sans";
    src: url("../font/zh-CN.ttf") format("truetype");
    font-display: swap;
}

@font-face {
    font-family: "Yehack Display";
    src: url("../font/OBT.ttf") format("truetype");
    font-display: swap;
}

:root {
    --paper: #f2efe8;
    --paper-deep: #e6e1d7;
    --ink: #18201f;
    --muted: #69726d;
    --line: #c9c9bd;
    --accent: #e45b3f;
    --accent-dark: #ae3b29;
    --olive: #65735b;
    --white: #fbfaf6;
    --display: "Yehack Display", Georgia, serif;
    --sans: "Yehack Sans", "Microsoft YaHei", sans-serif;
    --content: min(1180px, calc(100% - 48px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    min-width: 320px;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--sans);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}
body::before {
    position: fixed;
    inset: 0;
    z-index: -2;
    content: "";
    background: linear-gradient(115deg, rgba(255,255,255,.38), transparent 42%), url("../image/bg-base.svg") center / cover;
    opacity: .12;
    pointer-events: none;
}
.site-noise {
    position: fixed;
    inset: 0;
    z-index: -1;
    opacity: .18;
    pointer-events: none;
    background-image: radial-gradient(#18201f 0.55px, transparent 0.55px);
    background-size: 7px 7px;
    mask-image: linear-gradient(to bottom, black, transparent 80%);
}
a { color: inherit; text-decoration: none; }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
img { display: block; max-width: 100%; }

.site-header {
    width: var(--content);
    min-height: 88px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    border-bottom: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: 12px; flex-shrink: 0; }
.brand-mark {
    width: 42px;
    height: 42px;
    display: grid;
    place-items: center;
    border: 1px solid var(--ink);
    background: var(--ink);
    overflow: hidden;
}
.brand-mark img { width: 30px; height: 30px; object-fit: contain; filter: grayscale(1) brightness(0) invert(1); }
.brand-copy { display: grid; gap: 1px; }
.brand-copy strong { font: 700 1.05rem/1 var(--display); letter-spacing: .08em; }
.brand-copy small { color: var(--muted); font: .6rem/1 var(--sans); letter-spacing: .16em; }
.main-nav { display: flex; align-items: center; gap: 28px; }
.main-nav a, .header-link { position: relative; color: var(--muted); font-size: .82rem; }
.main-nav a::after { position: absolute; right: 0; bottom: -8px; left: 0; height: 2px; content: ""; background: var(--accent); transform: scaleX(0); transform-origin: left; transition: transform .25s ease; }
.main-nav a:hover, .main-nav a.is-active { color: var(--ink); }
.main-nav a.is-active::after, .main-nav a:hover::after { transform: scaleX(1); }
.header-link { color: var(--ink); white-space: nowrap; }
.header-link span { color: var(--accent); font-size: 1.1rem; }

.site-main { width: var(--content); min-height: calc(100vh - 152px); margin: 0 auto; padding: 70px 0 100px; }
.view { animation: rise .45s ease both; }
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: translateY(0); } }
.eyebrow { margin: 0 0 18px; color: var(--accent-dark); font-size: .7rem; letter-spacing: .18em; text-transform: uppercase; }
.display-title { max-width: 760px; margin: 0; font: 400 clamp(3.4rem, 8vw, 7.2rem)/.92 var(--display); letter-spacing: -.04em; }
.display-title em { color: var(--accent); font-style: normal; }
.lead { max-width: 600px; margin: 28px 0 0; color: var(--muted); font-size: 1.05rem; }

.home-layout { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(260px, .65fr); gap: 80px; align-items: end; }
.home-note { padding-top: 24px; border-top: 1px solid var(--ink); }
.home-note p { margin: 0; font-size: .92rem; }
.home-note strong { display: block; margin-top: 20px; color: var(--accent); font: 700 2.6rem/.9 var(--display); }
.home-note small { color: var(--muted); }
.home-image { margin-top: 80px; aspect-ratio: 16 / 7; overflow: hidden; background: var(--ink); }
.home-image img { width: 100%; height: 100%; object-fit: cover; object-position: center 35%; filter: saturate(.7) contrast(1.05); }
.home-sections { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 1px; background: var(--line); }
.home-section-link { min-height: 180px; padding: 24px; background: var(--paper); transition: background .25s ease, color .25s ease; }
.home-section-link:hover { color: var(--white); background: var(--ink); }
.home-section-link span { display: block; color: var(--accent); font-size: .75rem; }
.home-section-link h2 { margin: 35px 0 8px; font: 400 1.65rem/1 var(--display); }
.home-section-link p { margin: 0; color: var(--muted); font-size: .8rem; }
.home-section-link:hover p { color: #c3cbc4; }

.page-heading { display: flex; align-items: end; justify-content: space-between; gap: 30px; padding-bottom: 28px; border-bottom: 1px solid var(--ink); }
.page-heading h1 { max-width: 700px; margin: 0; font: 400 clamp(2.8rem, 6vw, 5.5rem)/.95 var(--display); letter-spacing: -.04em; }
.page-heading p { max-width: 280px; margin: 0; color: var(--muted); font-size: .9rem; }
.article-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 42px; }
.article-item { display: grid; grid-template-columns: 52px 1fr; gap: 18px; padding: 28px 0; border-bottom: 1px solid var(--line); }
.article-number { color: var(--accent); font-size: .75rem; }
.article-item h2 { margin: 0 0 9px; font: 400 1.6rem/1.1 var(--display); }
.article-item p { margin: 0 0 18px; color: var(--muted); font-size: .86rem; }
.article-meta { display: flex; flex-wrap: wrap; gap: 12px; color: var(--olive); font-size: .7rem; }
.tag { padding: 3px 8px; color: var(--accent-dark); border: 1px solid rgba(228,91,63,.45); }
.article-item:hover h2 { color: var(--accent-dark); }

.about-layout { display: grid; grid-template-columns: 1fr .85fr; gap: 90px; }
.about-layout h1 { margin: 0; font: 400 clamp(3rem, 6vw, 6rem)/.95 var(--display); }
.about-layout h1 em { color: var(--accent); font-style: normal; }
.about-copy > p { max-width: 540px; margin: 30px 0; color: var(--muted); font-size: 1rem; }
.about-photo { width: min(100%, 300px); aspect-ratio: 4 / 5; margin-left: auto; background: var(--ink); }
.about-photo img { width: 100%; height: 100%; object-fit: cover; filter: grayscale(1); opacity: .9; }
.about-facts { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--line); }
.fact { padding: 18px; background: var(--paper); }
.fact b { display: block; margin-bottom: 6px; font: 400 1.15rem var(--display); }
.fact span { color: var(--muted); font-size: .75rem; }
.about-list { margin-top: 62px; border-top: 1px solid var(--ink); }
.about-list-row { display: grid; grid-template-columns: 120px 1fr; gap: 20px; padding: 20px 0; border-bottom: 1px solid var(--line); }
.about-list-row strong { color: var(--accent-dark); font-size: .78rem; }
.about-list-row p { margin: 0; font-size: .9rem; }

.tool-intro { max-width: 610px; }
.tool-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; margin-top: 48px; background: var(--line); }
.tool-card { min-height: 300px; padding: 25px; background: var(--paper); }
.tool-card h2 { margin: 0 0 8px; font: 400 1.7rem var(--display); }
.tool-card p { min-height: 48px; margin: 0 0 18px; color: var(--muted); font-size: .82rem; }
.tool-area { display: grid; gap: 10px; }
.tool-input, .tool-output { width: 100%; min-height: 86px; padding: 12px; border: 1px solid var(--line); border-radius: 0; background: rgba(255,255,255,.35); color: var(--ink); resize: vertical; }
.tool-output { min-height: 48px; margin: 0; white-space: pre-wrap; font: .76rem/1.5 monospace; }
.tool-buttons { display: flex; flex-wrap: wrap; gap: 8px; }
.tool-button { padding: 8px 14px; border: 1px solid var(--ink); background: transparent; color: var(--ink); font-size: .75rem; }
.tool-button:hover, .tool-button.primary { background: var(--ink); color: var(--white); }

.site-footer { width: var(--content); display: flex; justify-content: space-between; gap: 20px; margin: 0 auto; padding: 22px 0; border-top: 1px solid var(--line); color: var(--muted); font-size: .65rem; letter-spacing: .08em; }
.toast { position: fixed; right: 24px; bottom: 24px; padding: 12px 16px; color: var(--white); background: var(--ink); opacity: 0; transform: translateY(10px); transition: opacity .2s ease, transform .2s ease; pointer-events: none; }
.toast.is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 720px) {
    :root { --content: min(100% - 32px, 560px); }
    .site-header { min-height: 76px; flex-wrap: wrap; gap: 15px; padding: 15px 0; }
    .main-nav { order: 3; width: 100%; justify-content: space-between; gap: 10px; }
    .header-link { display: none; }
    .site-main { padding-top: 48px; }
    .home-layout, .about-layout { grid-template-columns: 1fr; gap: 42px; }
    .display-title { font-size: clamp(3.2rem, 16vw, 5.5rem); }
    .home-image { margin-top: 48px; aspect-ratio: 4 / 3; }
    .home-sections, .article-list, .tool-grid { grid-template-columns: 1fr; }
    .page-heading { display: block; }
    .page-heading p { margin-top: 20px; }
    .about-photo { margin: 0; }
    .site-footer { display: block; }
    .site-footer span { display: block; margin: 5px 0; }
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; transition-duration: .01ms !important; }
}