/* =========================================================
   黄虎啸 · TA Portfolio — style.css
   现代简约：封面深色 + 正文浅色；响应式 + 打印
   ========================================================= */

:root {
  --c-bg: #f6f7f9;
  --c-surface: #ffffff;
  --c-text: #1d1f24;
  --c-muted: #6b7280;
  --c-border: #e5e7eb;
  --c-accent: #4f6df5;
  --c-accent-dark: #3b54c9;

  --cover-bg: #0e1117;
  --cover-text: #f3f4f6;
  --cover-muted: #9aa4b2;

  --radius: 10px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --shadow-md: 0 6px 18px rgba(16, 24, 40, .08), 0 2px 6px rgba(16, 24, 40, .06);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, .35);

  --container: 1080px;
  --nav-h: 60px;

  --font-cn: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans CJK SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-cn);
  color: var(--c-text);
  background: var(--c-bg);
  line-height: 1.65;
  font-size: 16px;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-accent); text-decoration: none; }
a:hover { text-decoration: underline; }
ul, ol { margin: 0; padding: 0; }
figure { margin: 0; }

.container { width: min(100% - 2.5rem, var(--container)); margin-inline: auto; }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 2000;
  background: var(--c-accent); color: #fff; padding: .5rem .8rem; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------- 顶部导航 ---------- */
.site-nav {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-border);
}
.nav-inner {
  width: min(100% - 2.5rem, var(--container));
  margin-inline: auto;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
}
.nav-brand { font-weight: 700; color: var(--c-text); letter-spacing: .02em; }
.nav-brand:hover { text-decoration: none; color: var(--c-accent); }
.nav-menu { display: flex; gap: .25rem; flex-wrap: wrap; }
.nav-menu a {
  color: var(--c-muted); padding: .45rem .7rem; border-radius: 8px;
  font-size: .92rem; transition: color .15s, background .15s;
}
.nav-menu a:hover { color: var(--c-text); background: rgba(0,0,0,.04); text-decoration: none; }
.nav-menu a.is-active { color: var(--c-accent); background: rgba(79, 109, 245, .08); }

.nav-toggle {
  display: none; width: 42px; height: 42px; border: 0; background: transparent; cursor: pointer;
  flex-direction: column; justify-content: center; gap: 5px; align-items: center;
}
.nav-toggle span { width: 22px; height: 2px; background: var(--c-text); border-radius: 2px; transition: .25s; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 封面 ---------- */
.cover {
  background: radial-gradient(1200px 600px at 70% -10%, #1b2538 0%, var(--cover-bg) 60%);
  color: var(--cover-text);
  min-height: calc(100vh - var(--nav-h));
  display: flex; align-items: center; text-align: center;
  padding: 4rem 1.25rem;
}
.cover-inner { width: 100%; max-width: 820px; margin-inline: auto; }
.cover-eyebrow {
  text-transform: uppercase; letter-spacing: .28em; font-size: .78rem;
  color: var(--cover-muted); margin: 0 0 1rem;
}
.cover-title { font-size: clamp(2.6rem, 7vw, 4.6rem); margin: 0 0 .6rem; letter-spacing: .02em; font-weight: 800; }
.cover-sub { font-size: clamp(1.05rem, 2.4vw, 1.4rem); color: #d7deea; margin: 0 0 .5rem; }
.cover-projects { color: var(--cover-muted); margin: 0 0 1.8rem; font-size: .98rem; }
.cover-tags {
  list-style: none; display: flex; flex-wrap: wrap; gap: .5rem; justify-content: center;
  padding: 0; margin: 0 0 2.2rem;
}
.cover-tags li {
  border: 1px solid rgba(255,255,255,.18); color: #cdd6e4;
  padding: .35rem .8rem; border-radius: 999px; font-size: .85rem; background: rgba(255,255,255,.03);
}
.cover-scroll { color: var(--cover-muted); font-size: .9rem; }
.cover-scroll:hover { color: #fff; text-decoration: none; }

/* ---------- Part 分隔 ---------- */
.part-header {
  background: linear-gradient(180deg, #11151d 0%, #161b25 100%);
  color: var(--cover-text);
  padding: 3.4rem 0 2.6rem;
  border-top: 1px solid rgba(255,255,255,.05);
}
.part-kicker {
  text-transform: uppercase; letter-spacing: .3em; font-size: .78rem;
  color: var(--c-accent); margin: 0 0 .4rem; font-weight: 600;
}
.part-title { font-size: clamp(1.7rem, 4vw, 2.5rem); margin: 0 0 .5rem; }
.part-desc { color: var(--cover-muted); margin: 0; max-width: 60ch; }

/* ---------- Slide ---------- */
.slide { padding: 3rem 0; }
.slide.alt { background: var(--c-surface); border-block: 1px solid var(--c-border); }
.slide-title {
  font-size: clamp(1.35rem, 2.6vw, 1.7rem); margin: 0 0 .9rem;
  padding-bottom: .5rem; border-bottom: 2px solid var(--c-border);
}
.slide-lead { color: #3a3f47; margin: 0 0 1.1rem; max-width: 72ch; }

.muted { color: var(--c-muted); }

.tech-points, .plain-list, .overview-list { list-style: none; }
.overview-list { counter-reset: ov; display: grid; gap: .7rem; }
.overview-list li {
  counter-increment: ov; font-size: 1.05rem; padding: .8rem 1rem .8rem 3rem;
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius);
  position: relative;
}
.overview-list li::before {
  content: counter(ov); position: absolute; left: 1rem; top: 50%; transform: translateY(-50%);
  width: 1.6rem; height: 1.6rem; border-radius: 50%;
  background: var(--c-accent); color: #fff; display: grid; place-items: center;
  font-size: .85rem; font-weight: 700;
}
.tech-points { display: grid; gap: .5rem; margin-bottom: 1.4rem; }
.tech-points li {
  position: relative; padding-left: 1.5rem; color: #2c3138;
}
.tech-points li::before {
  content: ""; position: absolute; left: .2rem; top: .62em;
  width: 7px; height: 7px; border-radius: 2px; background: var(--c-accent); transform: rotate(45deg);
}
.plain-list { display: grid; gap: .55rem; }
.plain-list li { padding-left: 1.3rem; position: relative; }
.plain-list li::before { content: "—"; position: absolute; left: 0; color: var(--c-accent); }

/* ---------- 图廊 ---------- */
.gallery {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; margin-top: .4rem;
}
.gallery .frame:only-child { grid-column: 1 / -1; max-width: 820px; }
.frame {
  background: var(--c-surface); border: 1px solid var(--c-border); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-sm); transition: box-shadow .2s, transform .2s;
}
.frame:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.frame img { width: 100%; cursor: zoom-in; background: #0e1117; }
.frame figcaption {
  padding: .55rem .8rem; font-size: .82rem; color: var(--c-muted);
  border-top: 1px solid var(--c-border);
}

/* ---------- 视频 ---------- */
.video-embed { margin-top: 1.3rem; }
.ratio {
  position: relative; width: 100%; padding-top: 56.25%;
  border-radius: var(--radius); overflow: hidden; background: #0e1117;
  box-shadow: var(--shadow-sm); border: 1px solid var(--c-border);
}
.ratio iframe, .ratio video {
  position: absolute; inset: 0; width: 100%; height: 100%; border: 0; background: #000;
}
.video-caption { margin: .55rem 0 0; font-size: .85rem; color: var(--c-muted); }

/* ---------- Footer ---------- */
.site-footer { background: #0e1117; color: var(--cover-muted); padding: 1.6rem 0; text-align: center; font-size: .85rem; }

/* ---------- Lightbox ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 2000; display: none;
  background: rgba(8, 10, 14, .92); backdrop-filter: blur(4px);
  align-items: center; justify-content: center; padding: 4rem 4.5rem 3rem;
}
.lightbox.is-open { display: flex; }
.lb-figure { margin: 0; max-width: 100%; max-height: 100%; text-align: center; }
.lb-figure img {
  max-width: 100%; max-height: calc(100vh - 7rem); margin: 0 auto;
  border-radius: 6px; box-shadow: var(--shadow-lg); object-fit: contain;
}
.lb-figure figcaption { color: #cdd6e4; margin-top: .8rem; font-size: .9rem; }
.lb-close, .lb-prev, .lb-next {
  position: absolute; background: rgba(255,255,255,.08); color: #fff;
  border: 1px solid rgba(255,255,255,.15); cursor: pointer;
  display: grid; place-items: center; border-radius: 50%;
  transition: background .15s; font-family: inherit;
}
.lb-close:hover, .lb-prev:hover, .lb-next:hover { background: rgba(255,255,255,.2); }
.lb-close { top: 1.2rem; right: 1.2rem; width: 46px; height: 46px; font-size: 1.7rem; line-height: 1; }
.lb-prev, .lb-next { top: 50%; transform: translateY(-50%); width: 50px; height: 50px; font-size: 2rem; }
.lb-prev { left: 1rem; } .lb-next { right: 1rem; }

/* =========================================================
   响应式断点
   ========================================================= */
/* 平板（≤1024） */
@media (max-width: 1024px) {
  .container { width: min(100% - 2rem, var(--container)); }
}

/* 768：移动端菜单 + 单列图廊 */
@media (max-width: 768px) {
  :root { --nav-h: 54px; }
  .nav-toggle { display: flex; }
  .nav-menu {
    position: absolute; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column; gap: 0; background: #fff;
    border-bottom: 1px solid var(--c-border);
    box-shadow: var(--shadow-md);
    max-height: 0; overflow: hidden; transition: max-height .25s ease;
  }
  .nav-menu.is-open { max-height: 360px; }
  .nav-menu a { padding: .85rem 1.2rem; border-radius: 0; border-top: 1px solid var(--c-border); }
  .gallery { grid-template-columns: 1fr; }
  .slide { padding: 2.2rem 0; }
  .part-header { padding: 2.6rem 0 2rem; }
  .lightbox { padding: 3rem 3.5rem 2rem; }
  .lb-prev { left: .4rem; } .lb-next { right: .4rem; }
  .lb-close { top: .8rem; right: .8rem; }
}

/* 375 小屏 */
@media (max-width: 375px) {
  body { font-size: 15px; }
  .cover-title { font-size: 2.3rem; }
  .lightbox { padding: 2.5rem 2.8rem 1.5rem; }
  .lb-prev, .lb-next { width: 42px; height: 42px; font-size: 1.7rem; }
}

/* 减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* =========================================================
   打印样式：隐藏导航/视频/lightbox，保留图文
   ========================================================= */
@media print {
  :root { --nav-h: 0; }
  .site-nav, .site-footer, .nav-toggle, .lightbox, .skip-link,
  .video-embed, .cover-scroll { display: none !important; }
  body { background: #fff; color: #000; font-size: 11pt; line-height: 1.5; }
  .container { width: 100%; margin: 0; }
  .cover {
    background: #fff; color: #000; min-height: auto; text-align: left;
    padding: 0 0 1rem; border-bottom: 2px solid #000;
  }
  .cover-eyebrow, .cover-sub, .cover-projects, .cover-tags li { color: #333; }
  .cover-tags li { border-color: #999; }
  .part-header { background: #fff; color: #000; border-bottom: 1px solid #999; padding: 1rem 0 .6rem; }
  .part-kicker { color: #333; }
  .part-desc { color: #444; }
  .slide { padding: .8rem 0; page-break-inside: avoid; }
  .slide.alt { background: #fff; border: 0; }
  .slide-title { border-bottom: 1px solid #999; }
  .slide-lead, .tech-points li { color: #1a1a1a; }
  .gallery { grid-template-columns: 1fr 1fr; gap: 6pt; }
  .frame { box-shadow: none; border: 1px solid #ccc; page-break-inside: avoid; }
  .frame img { cursor: default; }
  .frame figcaption { color: #444; border-top: 1px solid #ccc; }
  a { color: #000; text-decoration: underline; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 8pt; color: #555; }
  .thanks { page-break-before: always; }
}