/* =========================================================
   跨界小吴哥 — 工程笔记蓝图 设计系统
   Color tokens
   ========================================================= */
:root {
    --paper: #F6F4EE;       /* 纸白底 */
    --paper-dim: #ECE8DD;   /* 区块底 */
    --ink: #14233A;         /* 深墨蓝 主文 */
    --ink-soft: #41506A;    /* 次要文字 */
    --signal: #2E7D5B;      /* 信号绿 强调 */
    --copper: #C2683A;      /* 铜橙 模块锚点 */
    --grid: #E4E0D6;        /* 方格线 */
    --rule: #C7CFD8;        /* 分隔线 */
    --paper-dark: #1B2A3F;  /* 深底区块 */

    --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Roboto Mono", Consolas, Menlo, monospace;
    --font-sans: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;

    --text-mono: clamp(0.8rem, 0.78rem + 0.1vw, 0.875rem);
    --text-body: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-h2: clamp(1.5rem, 1.2rem + 1.5vw, 2.25rem);
    --text-hero: clamp(2.75rem, 1rem + 6vw, 5.5rem);

    --space-section: clamp(1.75rem, 1.3rem + 2vw, 3rem);
    --content-max: 1080px;

    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

/* =========================================================
   Base
   ========================================================= */
*, *::before, *::after { box-sizing: border-box; }

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

body, html {
    margin: 0;
    padding: 0;
    width: 100%;
    min-height: 100%;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-sans);
    font-size: var(--text-body);
    line-height: 1.6;
    text-align: left;
    /* 方格纸背景：细网格点阵 */
    background-image:
        linear-gradient(var(--grid) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid) 1px, transparent 1px);
    background-size: 28px 28px;
    background-position: -1px -1px;
}

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

a {
    color: var(--signal);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s var(--ease-out);
}
a:hover { border-bottom-color: currentColor; }

/* =========================================================
   Layout container
   ========================================================= */
.main-container {
    min-height: calc(100vh - 56px - 80px);
    width: 100%;
    max-width: var(--content-max);
    margin: 0 auto;
    padding: 0 clamp(1.25rem, 1rem + 2vw, 3rem);
}

/* =========================================================
   Site nav (topnav include)
   ========================================================= */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    height: 56px;
    padding: 0 clamp(1.25rem, 1rem + 2vw, 3rem);
    background: rgba(246, 244, 238, 0.88);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--rule);
}
.site-nav .brand {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: 0.05em;
    color: var(--ink);
}
.site-nav .brand .brand-dot {
    color: var(--copper);
}
.site-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.75rem;
    align-items: center;
}
.site-nav li a {
    font-family: var(--font-mono);
    font-size: var(--text-mono);
    letter-spacing: 0.06em;
    color: var(--ink-soft);
    padding: 0.25rem 0;
}
.site-nav li a.is-active {
    color: var(--signal);
    border-bottom-color: var(--signal);
}

/* =========================================================
   Hero
   ========================================================= */
.hero {
    padding: clamp(2.75rem, 2.2rem + 3vw, 4.5rem) 0 clamp(1.5rem, 1.2rem + 1.5vw, 2.5rem);
    max-width: 980px;
}
.hero .hero-tag {
    font-family: var(--font-mono);
    font-size: var(--text-mono);
    color: var(--copper);
    letter-spacing: 0.12em;
    margin: 0 0 1.25rem;
}
.hero h1 {
    font-family: var(--font-mono);
    font-weight: 800;
    font-size: var(--text-hero);
    line-height: 1.02;
    letter-spacing: -0.01em;
    color: var(--ink);
    margin: 0 0 1rem;
}
.hero .hero-sub {
    font-size: clamp(1.05rem, 1rem + 0.5vw, 1.4rem);
    color: var(--ink-soft);
    max-width: 42ch;
    margin: 0;
    font-weight: 400;
}

/* 入场动效：仅 hero 一个 */
@keyframes hero-rise {
    from { opacity: 0; transform: translateY(14px); }
    to { opacity: 1; transform: translateY(0); }
}
.hero > * {
    opacity: 0;
    animation: hero-rise 0.7s var(--ease-out) forwards;
}
.hero > :nth-child(2) { animation-delay: 0.12s; }
.hero > :nth-child(3) { animation-delay: 0.24s; }

/* =========================================================
   技术标注分隔线
   ========================================================= */
.blueprint-rule {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 0 0 var(--space-section);
    color: var(--ink-soft);
}
.blueprint-rule::before,
.blueprint-rule::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--rule);
}
.blueprint-rule span {
    font-family: var(--font-mono);
    font-size: var(--text-mono);
    letter-spacing: 0.1em;
    white-space: nowrap;
}

/* =========================================================
   Section modules (编程 / 硬件 / AI)
   ========================================================= */
.mod {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(1.5rem, 1.2rem + 1vw, 2.75rem);
    align-items: center;
    padding: clamp(1.75rem, 1.4rem + 1.5vw, 3rem) 0;
    border-top: 1px solid var(--rule);
}
/* 图文左右交替 */
.mod:nth-child(even) .mod-media { order: -1; }

.mod-index {
    font-family: var(--font-mono);
    font-size: var(--text-mono);
    color: var(--copper);
    letter-spacing: 0.08em;
    margin: 0 0 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
.mod-index::before {
    content: "";
    width: 1.5rem;
    height: 2px;
    background: var(--copper);
}
.mod h2 {
    font-family: var(--font-mono);
    font-weight: 700;
    font-size: var(--text-h2);
    line-height: 1.15;
    color: var(--ink);
    margin: 0 0 1rem;
}
.mod .mod-desc {
    color: var(--ink-soft);
    font-size: var(--text-body);
    margin: 0;
}
.mod .mod-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
    margin: 1.25rem 0 0;
    padding: 0;
    list-style: none;
}
.mod .mod-tags li {
    font-family: var(--font-mono);
    font-size: var(--text-mono);
    color: var(--ink-soft);
    padding: 0.2rem 0.6rem;
    border: 1px solid var(--rule);
    background: var(--paper);
}

/* 媒体区 */
.mod-media {
    display: grid;
    gap: 0.5rem;
}
.mod-media figure {
    margin: 0;
    position: relative;
}
.mod-media img {
    width: 100%;
    border-radius: 3px;
    border: 1px solid var(--rule);
}
/* 多图时的并排网格 */
.mod-media .pair {
    grid-template-columns: 1fr 1fr;
}
.mod-media figcaption {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--ink-soft);
    margin-top: 0.35rem;
    letter-spacing: 0.04em;
}

/* =========================================================
   Project page compatibility (.main-p / .author)
   ========================================================= */
.main-p {
    font-size: var(--text-body);
    text-align: left;
    padding: clamp(3rem, 2.5rem + 3vw, 5rem) 0;
    line-height: 2.1;
    max-width: 680px;
    color: var(--ink);
}
.author {
    font-family: var(--font-mono);
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--copper);
    float: right;
    margin: 1.5rem 0 0;
}

/* =========================================================
   Footer (备案)
   ========================================================= */
footer {
    background: var(--paper-dark);
    color: #C9D4E3;
    border-top: 3px solid var(--copper);
    padding: 1rem clamp(1.25rem, 1rem + 2vw, 3rem);
    font-size: 0.75rem;
    text-align: center;
    width: 100%;
    margin: 0 auto;
    overflow: auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 0.5rem 1rem;
    line-height: 1.6;
}
footer a {
    color: #E8EEF6;
    border-bottom: none;
}
footer img {
    height: 20px;
    width: 20px;
    display: inline-block;
    vertical-align: middle;
}

/* =========================================================
   Responsive
   ========================================================= */
@media (max-width: 760px) {
    .mod {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }
    .mod:nth-child(even) .mod-media { order: 0; }
    .mod-media .pair {
        grid-template-columns: 1fr 1fr;
    }
    .hero .hero-sub { max-width: none; }
}

@media (max-width: 420px) {
    .mod-media .pair { grid-template-columns: 1fr; }
}

/* =========================================================
   Reduced motion
   ========================================================= */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .hero > * { opacity: 1; }
}