/* ==========================================================================
   信号与像素 · Signal & Pixel
   设计系统：token → 基础 → 组件 → 页面
   字体优先使用系统字体（San Francisco / PingFang SC），
   贴合苹果「默认使用平台系统字体」的排版原则。
   ========================================================================== */

/* ---------- 1. Design tokens ---------- */
:root {
  color-scheme: dark;

  /* 中性色阶（暗色为默认，呼应深夜刷机 / 折腾设备的使用场景）*/
  --bg: #000000;
  --surface-0: #0a0a0c;
  --surface-1: rgba(255, 255, 255, 0.045);
  --surface-1-hover: rgba(255, 255, 255, 0.075);
  --surface-2: rgba(255, 255, 255, 0.065);
  --hairline: rgba(255, 255, 255, 0.10);
  --hairline-strong: rgba(255, 255, 255, 0.16);

  --text-primary: #f5f5f7;
  --text-secondary: #98989d;
  --text-tertiary: #6e6e73;

  /* 两条内容主线各自的信号色，克制地只用于标签 / 链接 / 光晕 */
  --accent-tech: #3ee6d8;      /* 折腾：拆机、越狱、底层调试 —— 呼应终端信号色，也是初音绿松石的邻近色 */
  --accent-tech-rgb: 62, 230, 216;
  --accent-music: #b18bff;     /* 音乐：Vocaloid / P主作品 —— 合成器紫 */
  --accent-music-rgb: 177, 139, 255;
  --accent-essay: #ff9f5a;     /* 随笔：随想与生活 —— 温暖的琥珀 */
  --accent-essay-rgb: 255, 159, 90;

  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "PingFang SC", "Helvetica Neue", "Segoe UI", sans-serif;
  --font-text: -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "PingFang SC", "Helvetica Neue", "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Menlo", "Consolas", monospace;

  --radius-s: 10px;
  --radius-m: 18px;
  --radius-l: 28px;
  --radius-pill: 999px;

  /* 缓动：以「临界阻尼」为默认，仅在有动量的交互上保留轻微回弹 */
  --ease-out-fluid: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-spring-soft: cubic-bezier(0.34, 1.32, 0.42, 1);
  --dur-fast: 180ms;
  --dur-base: 320ms;
  --dur-slow: 560ms;

  --max-width: 1080px;
  --edge: clamp(20px, 5vw, 64px);
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f5f5f7;
  --surface-0: #ffffff;
  --surface-1: rgba(0, 0, 0, 0.035);
  --surface-1-hover: rgba(0, 0, 0, 0.06);
  --surface-2: rgba(0, 0, 0, 0.05);
  --hairline: rgba(0, 0, 0, 0.09);
  --hairline-strong: rgba(0, 0, 0, 0.14);

  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;

  --accent-tech: #0aa89b;
  --accent-tech-rgb: 10, 168, 155;
  --accent-music: #7a4de0;
  --accent-music-rgb: 122, 77, 224;
  --accent-essay: #d97a2f;
  --accent-essay-rgb: 217, 122, 47;
}

/* ---------- 2. Reset & base ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-text);
  line-height: 1.5;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
  transition: background var(--dur-slow) var(--ease-out-fluid),
              color var(--dur-slow) var(--ease-out-fluid);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

::selection { background: rgba(var(--accent-tech-rgb), 0.28); }

/* 可见的键盘焦点样式 —— 保证质感的同时不牺牲可访问性 */
:focus-visible {
  outline: 2px solid rgba(var(--accent-tech-rgb), 0.9);
  outline-offset: 3px;
  border-radius: 6px;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding-left: var(--edge);
  padding-right: var(--edge);
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 650;
  margin: 0;
  color: var(--text-primary);
}

.display-1 {
  font-size: clamp(2.6rem, 6vw, 4.6rem);
  line-height: 1.04;
  letter-spacing: -0.03em;
  font-weight: 680;
}

.display-2 {
  font-size: clamp(2rem, 4.2vw, 3rem);
  line-height: 1.08;
  letter-spacing: -0.025em;
}

.title-1 {
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
}

.title-2 {
  font-size: 1.2rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}

.lede {
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  line-height: 1.55;
  color: var(--text-secondary);
  letter-spacing: -0.005em;
  max-width: 46em;
}

p { color: var(--text-secondary); }

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0;
}

/* ---------- 4. Nav ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 14px var(--edge);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: transparent;
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  transition: background var(--dur-base) var(--ease-out-fluid),
              border-color var(--dur-base) var(--ease-out-fluid),
              backdrop-filter var(--dur-base) var(--ease-out-fluid);
}

.site-nav.is-scrolled {
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  border-bottom: 1px solid var(--hairline);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
}

/* 液态玻璃折射：在支持 SVG backdrop 滤镜的浏览器里叠加轻微的表面扭曲，
   不支持的浏览器会静默忽略 url() 部分，保留后面的模糊 + 饱和度效果 */
.liquid-glass-ready .site-nav.is-scrolled {
  backdrop-filter: url(#liquid-distortion) blur(20px) saturate(180%);
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
}

.brand .mark {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-tech), var(--accent-music));
  display: inline-block;
}

.brand .sub {
  color: var(--text-tertiary);
  font-weight: 400;
  font-size: 0.78rem;
  font-family: var(--font-mono);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  font-size: 0.88rem;
  color: var(--text-secondary);
  padding: 8px 13px;
  border-radius: var(--radius-pill);
  transition: color var(--dur-fast) var(--ease-out-fluid),
              background var(--dur-fast) var(--ease-out-fluid);
}

.nav-links a:hover { color: var(--text-primary); background: var(--surface-1); }
.nav-links a.active { color: var(--text-primary); background: var(--surface-2); }

.theme-toggle {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--hairline);
  background: var(--surface-1);
  display: grid;
  place-items: center;
  cursor: pointer;
  color: var(--text-primary);
  margin-left: 8px;
  transition: transform var(--dur-fast) var(--ease-spring-soft),
              background var(--dur-fast) var(--ease-out-fluid);
}
.theme-toggle:active { transform: scale(0.9); }
.theme-toggle svg { width: 16px; height: 16px; }

/* ---------- 5. Hero ---------- */
.hero {
  position: relative;
  padding: clamp(64px, 12vh, 128px) 0 clamp(48px, 8vh, 88px);
  overflow: hidden;
}

.hero-orb {
  position: absolute;
  top: -220px;
  right: -160px;
  width: 560px;
  height: 560px;
  border-radius: 50%;
  background:
    radial-gradient(circle at 35% 35%, rgba(var(--accent-tech-rgb), 0.32), transparent 60%),
    radial-gradient(circle at 65% 65%, rgba(var(--accent-music-rgb), 0.26), transparent 60%);
  filter: blur(60px);
  pointer-events: none;
  z-index: 0;
  animation: driftOrb 22s ease-in-out infinite;
}

@keyframes driftOrb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-24px, 30px) scale(1.05); }
}

.hero-inner { position: relative; z-index: 1; }

.hero .eyebrow { margin-bottom: 18px; }

.hero h1 { margin-bottom: 22px; max-width: 15ch; }

.hero .lede { margin-bottom: 34px; }

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.chip {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-secondary);
  border: 1px solid var(--hairline);
  background: var(--surface-1);
  padding: 7px 13px;
  border-radius: var(--radius-pill);
}

/* ---------- 6. Segmented filter (signature interactive element) ---------- */
.segmented {
  position: relative;
  display: inline-flex;
  gap: 2px;
  padding: 4px;
  border-radius: var(--radius-pill);
  background: var(--surface-1);
  border: 1px solid var(--hairline);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  margin: 44px 0 28px;
}

.liquid-glass-ready .segmented {
  backdrop-filter: url(#liquid-distortion) blur(16px);
}

.segmented .thumb {
  position: absolute;
  top: 4px;
  left: 4px;
  height: calc(100% - 8px);
  width: 0;
  border-radius: var(--radius-pill);
  background: var(--surface-0);
  border: 1px solid var(--hairline-strong);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.28), inset 0 1px 0 rgba(255, 255, 255, 0.16);
  will-change: transform, width;
  pointer-events: none;
}

/* 滑块本身也是一小块会移动的玻璃：加一点折射，让它更像被「拉伸」出来的液态高光，
   而不是一块纯色色块滑过去 */
.liquid-glass-ready .segmented .thumb {
  background: color-mix(in srgb, var(--surface-0) 78%, transparent);
  backdrop-filter: url(#liquid-distortion-soft) blur(6px) saturate(160%);
  -webkit-backdrop-filter: blur(6px) saturate(160%);
}

.segmented button {
  position: relative;
  z-index: 1;
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  font-family: var(--font-text);
  font-size: 0.86rem;
  color: var(--text-secondary);
  padding: 9px 18px;
  border-radius: var(--radius-pill);
  transition: color var(--dur-fast) var(--ease-out-fluid);
}

.segmented button:active { color: var(--text-primary); }
.segmented button.is-active { color: var(--text-primary); }
.segmented button .dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  margin-right: 7px;
  transform: translateY(-1px);
}

/* ---------- 7. Post grid & cards ---------- */
.post-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  padding-bottom: 40px;
}

@media (max-width: 720px) {
  .post-grid { grid-template-columns: 1fr; }
}

.post-card {
  position: relative;
  display: block;
  padding: 26px;
  border-radius: var(--radius-l);
  background: var(--surface-1);
  border: 1px solid var(--hairline);
  overflow: hidden;
  opacity: 0;
  transform: translateY(14px);
  transition: opacity var(--dur-slow) var(--ease-out-fluid),
              transform var(--dur-slow) var(--ease-out-fluid),
              background var(--dur-fast) var(--ease-out-fluid),
              border-color var(--dur-fast) var(--ease-out-fluid);
}

.post-card.is-visible { opacity: 1; transform: translateY(0); }

.post-card:hover {
  background: var(--surface-1-hover);
  border-color: var(--hairline-strong);
}

.post-card.is-filtered-out {
  display: none;
}

.post-card .cat {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.post-card .cat .dot {
  width: 6px; height: 6px; border-radius: 50%;
}

.post-card h3 {
  font-size: 1.24rem;
  line-height: 1.28;
  letter-spacing: -0.015em;
  margin-bottom: 10px;
}

.post-card p {
  font-size: 0.92rem;
  line-height: 1.55;
  margin: 0 0 18px;
  color: var(--text-secondary);
}

.post-card .foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-tertiary);
}

.post-card.featured {
  grid-column: 1 / -1;
  padding: 40px;
  background: linear-gradient(150deg, var(--surface-2), var(--surface-1));
}

.post-card.featured h3 { font-size: clamp(1.5rem, 2.6vw, 2.1rem); max-width: 18ch; }

/* ---------- 8. Section headers ---------- */
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 4px;
}

section { padding: 24px 0 60px; }
section + section { border-top: 1px solid var(--hairline); }

/* ---------- 9. Footer ---------- */
footer {
  border-top: 1px solid var(--hairline);
  padding: 40px var(--edge) 64px;
  margin-top: 40px;
}

footer .foot-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: center;
  justify-content: space-between;
}

footer .foot-links {
  display: flex;
  gap: 18px;
  font-size: 0.86rem;
  color: var(--text-secondary);
}

footer .foot-links a:hover { color: var(--text-primary); }

footer .copyright {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-tertiary);
}

/* ---------- 10. Article page ---------- */
.article-head {
  padding-top: clamp(52px, 10vh, 96px);
  padding-bottom: 40px;
}

.article-head .cat { margin-bottom: 20px; }

.article-head h1 {
  max-width: 20ch;
  margin-bottom: 22px;
}

.article-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-tertiary);
  padding-top: 22px;
  border-top: 1px solid var(--hairline);
}

.article-body {
  max-width: 68ch;
  font-size: 1.08rem;
  line-height: 1.8;
  padding-bottom: 64px;
}

.article-body p { color: var(--text-primary); opacity: 0.92; margin: 0 0 26px; }
.article-body h2 {
  font-size: 1.5rem;
  letter-spacing: -0.015em;
  margin: 48px 0 18px;
}
.article-body h3 { font-size: 1.18rem; margin: 34px 0 14px; }
.article-body ul, .article-body ol { color: var(--text-primary); opacity: 0.92; line-height: 1.75; padding-left: 1.3em; }
.article-body li { margin-bottom: 8px; }
.article-body a {
  color: var(--accent-tech);
  text-decoration: underline;
  text-decoration-color: rgba(var(--accent-tech-rgb), 0.35);
  text-underline-offset: 3px;
}
.article-body strong { color: var(--text-primary); font-weight: 650; }

.article-body blockquote {
  margin: 32px 0;
  padding: 4px 0 4px 22px;
  border-left: 3px solid rgba(var(--accent-music-rgb), 0.55);
  color: var(--text-secondary);
  font-style: normal;
}

.article-body pre {
  background: var(--surface-0);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-m);
  padding: 20px 22px;
  overflow-x: auto;
  margin: 30px 0;
}

.article-body code {
  font-family: var(--font-mono);
  font-size: 0.86rem;
}

.article-body :not(pre) > code {
  background: var(--surface-2);
  padding: 2px 6px;
  border-radius: 6px;
  color: var(--accent-tech);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
  transition: color var(--dur-fast) var(--ease-out-fluid),
              transform var(--dur-fast) var(--ease-spring-soft);
}
.back-link:hover { color: var(--text-primary); transform: translateX(-2px); }

/* ---------- 11. Spec sheet (about page signature) ---------- */
.spec-table {
  display: grid;
  gap: 1px;
  background: var(--hairline);
  border: 1px solid var(--hairline);
  border-radius: var(--radius-m);
  overflow: hidden;
  margin: 20px 0 44px;
}

.spec-row {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 12px;
  padding: 18px 22px;
  background: var(--surface-0);
}

.spec-row .k {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-tertiary);
}

.spec-row .v {
  font-size: 0.94rem;
  color: var(--text-primary);
}

.spec-row .v small { color: var(--text-secondary); display: block; margin-top: 2px; font-size: 0.82rem; }

@media (max-width: 560px) {
  .spec-row { grid-template-columns: 1fr; gap: 4px; }
}

.tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 44px; }

/* ---------- 12. Reduced motion / transparency / contrast ---------- */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; }
  .post-card { transition: opacity 200ms ease !important; transform: none !important; }
  .hero-orb { animation: none; }
  .segmented .thumb { transition: opacity 150ms ease !important; }
  .back-link:hover { transform: none; }
}

@media (prefers-reduced-transparency: reduce) {
  .site-nav.is-scrolled { backdrop-filter: none; background: var(--surface-0); }
  .segmented { backdrop-filter: none; background: var(--surface-0); }
}

@media (prefers-contrast: more) {
  :root { --hairline: rgba(255,255,255,0.4); --hairline-strong: rgba(255,255,255,0.6); }
  :root[data-theme="light"] { --hairline: rgba(0,0,0,0.4); --hairline-strong: rgba(0,0,0,0.6); }
}