/* ============================================================
   A5K's Blog — style.css
   已确认规格：柔和现代 · 微玻璃 / 空灵细雅 / 青色强调 / 轻微动效
   ============================================================ */

:root {
  color-scheme: dark;

  --bg: #0a1430;
  --bg-deep: #070d20;
  --ink: #f2f5fa;
  --ink-soft: rgba(242, 245, 250, 0.72);
  --ink-faint: rgba(242, 245, 250, 0.46);
  --accent: #4fc3f7;
  --accent-soft: rgba(79, 195, 247, 0.38);
  --hairline: rgba(255, 255, 255, 0.14);

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

  --ease-out: cubic-bezier(0.32, 0.72, 0, 1);
  --ease-soft: cubic-bezier(0.22, 0.61, 0.36, 1);

  --inset-x: clamp(24px, 8vw, 140px);
  --radius-card: 18px;
}

* { box-sizing: border-box; }

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: rgba(79, 195, 247, 0.35); color: #ffffff; }

a { -webkit-tap-highlight-color: transparent; }

:focus-visible { outline: 2px solid rgba(79, 195, 247, 0.85); outline-offset: 3px; }

/* ---------- hero ---------- */

.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  background: var(--bg) url("assets/background.webp") center / cover no-repeat;
  animation: bg-breathe 24s var(--ease-soft) infinite alternate;
  will-change: transform;
}

@keyframes bg-breathe {
  from { transform: scale(1); }
  to   { transform: scale(1.03); }
}

/* 遮罩（scrim）已移除：背景图直接作为背景，不改动原图观感 */

.hero__content {
  position: absolute;
  left: var(--inset-x);
  top: 50%;
  transform: translateY(-50%);
  max-width: min(36rem, 82vw);
  z-index: 1;
}

.hero__title {
  margin: 0 0 0.9rem;
  margin-right: -0.16em;
  font-size: clamp(2.5rem, 7vw, 4.8rem);
  font-weight: 300;
  line-height: 1.1;
  letter-spacing: 0.16em;
  text-shadow: 0 2px 28px rgba(3, 8, 20, 0.55);
}

.hero__subtitle {
  margin: 0 0 2.3rem;
  font-size: clamp(1rem, 2.2vw, 1.28rem);
  font-weight: 300;
  letter-spacing: 0.2em;
  color: var(--ink-soft);
  text-shadow: 0 1px 18px rgba(3, 8, 20, 0.5);
}

.hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.72rem 1.45rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.08);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.18), 0 10px 30px rgba(3, 8, 20, 0.35);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  backdrop-filter: blur(12px) saturate(140%);
  color: var(--ink);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-decoration: none;
  transition:
    transform 0.55s var(--ease-out),
    background-color 0.55s var(--ease-out),
    border-color 0.55s var(--ease-out),
    box-shadow 0.55s var(--ease-out);
}

.btn:hover {
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.45);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.25),
    0 14px 38px rgba(3, 8, 20, 0.45),
    0 0 24px rgba(79, 195, 247, 0.18);
}

.btn:active { transform: translateY(0) scale(0.98); }

.btn .icon { width: 16px; height: 16px; flex: none; opacity: 0.92; }

.scroll-cue {
  position: absolute;
  left: 0;
  right: 0;
  bottom: clamp(18px, 4vh, 36px);
  margin: 0 auto;
  width: max-content;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  color: var(--ink-faint);
  text-decoration: none;
  font-size: 0.76rem;
  letter-spacing: 0.34em;
  z-index: 1;
  transition: color 0.5s var(--ease-out);
}

.scroll-cue:hover { color: var(--accent); }

.scroll-cue svg {
  width: 18px;
  height: 18px;
  animation: cue-float 2.8s ease-in-out 1.2s infinite;
}

@keyframes cue-float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(6px); }
}

/* ---------- writing ---------- */

.writing { background: var(--bg); }

.writing__inner {
  padding: clamp(64px, 10vh, 112px) var(--inset-x) 0;
}

.writing__heading {
  display: flex;
  align-items: center;
  gap: 1.1rem;
  margin: 0 0 2.6rem;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.32em;
  color: var(--ink-faint);
}

.writing__heading::after {
  content: "";
  height: 1px;
  width: 72px;
  flex: none;
  background: linear-gradient(90deg, var(--accent-soft), transparent);
}

.card {
  display: block;
  max-width: 760px;
  padding: 1.55rem 1.7rem 1.7rem;
  border-radius: var(--radius-card);
  border: 1px solid var(--hairline);
  background: rgba(255, 255, 255, 0.05);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
  color: inherit;
  text-decoration: none;
  transition:
    transform 0.6s var(--ease-out),
    background-color 0.6s var(--ease-out),
    border-color 0.6s var(--ease-out),
    box-shadow 0.6s var(--ease-out);
}

.card:hover {
  transform: translateY(-3px);
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(79, 195, 247, 0.42);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    0 18px 44px rgba(3, 8, 20, 0.45);
}

.card__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.95rem;
}

.card__tag {
  font-size: 0.72rem;
  letter-spacing: 0.24em;
  color: var(--accent);
  border: 1px solid rgba(79, 195, 247, 0.45);
  border-radius: 999px;
  padding: 0.16rem 0.66rem 0.16rem 0.72rem;
}

.card__arrow {
  display: flex;
  color: var(--ink-faint);
  transition: transform 0.6s var(--ease-out), color 0.6s var(--ease-out);
}

.card__arrow svg { width: 18px; height: 18px; }

.card:hover .card__arrow {
  transform: translateX(4px);
  color: var(--accent);
}

.card__title {
  margin: 0 0 0.5rem;
  font-size: clamp(1.08rem, 2vw, 1.3rem);
  font-weight: 500;
  line-height: 1.5;
  letter-spacing: 0.05em;
}

.card__desc {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.85;
  letter-spacing: 0.02em;
  color: var(--ink-soft);
}

.writing__more {
  margin: 2.1rem 0 0;
  font-size: 0.88rem;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
}

/* ---------- footer ---------- */

.footer {
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  margin-top: clamp(56px, 9vh, 96px);
}

.footer p {
  margin: 0;
  padding: 1.5rem var(--inset-x) 2.1rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
}

/* 致谢行紧随版权行：收紧行距 */
.footer p.footer__thanks { padding-bottom: 0.4rem; }
.footer p + p { padding-top: 0.25rem; }

/* 致谢行里的小鲸鱼图标（随文字颜色、随字号缩放） */
.footer__whale {
  width: 1em;
  height: 1em;
  fill: currentColor;
  vertical-align: -0.12em;
  margin-right: 0.3em;
}

/* ---------- entry animations ---------- */

.hero__title,
.hero__subtitle,
.hero__links {
  animation: rise 0.9s var(--ease-out) both;
}

.hero__subtitle { animation-delay: 0.12s; }
.hero__links    { animation-delay: 0.24s; }

.scroll-cue { animation: rise 0.9s var(--ease-out) 0.5s both; }

@keyframes rise {
  from { opacity: 0; transform: translateY(22px); }
  to   { opacity: 1; transform: translateY(0); }
}

.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.9s var(--ease-out), transform 0.9s var(--ease-out);
}

.js .reveal.is-in {
  opacity: 1;
  transform: translateY(0);
}

.js .reveal--d1 { transition-delay: 0.08s; }
.js .reveal--d2 { transition-delay: 0.16s; }

/* ---------- mobile ---------- */

@media (max-width: 768px) {
  .hero__bg { background-position: 58% center; }

  .hero__content {
    top: clamp(78px, 15vh, 152px);
    top: clamp(78px, 15svh, 152px);
    transform: none;
    max-width: none;
    padding-right: var(--inset-x);
  }

  .hero__title {
    letter-spacing: 0.13em;
    margin-right: -0.13em;
  }

  .hero__subtitle { letter-spacing: 0.16em; }

  .writing__inner { padding-top: 76px; }
}

/* ---------- narrow phones: keep the card title on one line ---------- */

@media (max-width: 480px) {
  .card { padding: 1.5rem 1.2rem 1.55rem; }

  .card__title {
    font-size: 0.96rem;
    letter-spacing: 0.03em;
  }
}

/* ---------- reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  .hero__bg,
  .hero__title,
  .hero__subtitle,
  .hero__links,
  .scroll-cue,
  .scroll-cue svg { animation: none; }

  .js .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .btn,
  .card,
  .card__arrow { transition: none; }
}

/* ============================================================
   Jekyll 增补：文章列表卡片（日期）与文章页
   ============================================================ */

.card__top {
  justify-content: flex-start;
  gap: 0.9rem;
}

.card__arrow { margin-left: auto; }

.card__date {
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--ink-faint);
}

.card + .card { margin-top: 16px; }

/* 从文章返回时短暂高亮对应卡片 */
.card.is-highlight {
  border-color: rgba(79, 195, 247, 0.55);
  background: rgba(255, 255, 255, 0.09);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 0 0 1px rgba(79, 195, 247, 0.2),
    0 14px 38px rgba(3, 8, 20, 0.5);
}

/* ---------- post page ---------- */

.post {
  padding: clamp(36px, 7vh, 80px) var(--inset-x) 0;
}

.post__nav {
  max-width: 760px;
  margin: 0 auto clamp(26px, 5vh, 48px);   /* 水平居中 */
}

.post__nav a {
  color: var(--ink-faint);
  text-decoration: none;
  font-size: 0.84rem;
  letter-spacing: 0.14em;
  transition: color 0.5s var(--ease-out);
}

.post__nav a:hover { color: var(--accent); }

.post__header {
  max-width: 760px;
  margin: 0 auto 2.4rem;                   /* 水平居中 */
}

.post__date {
  margin: 0 0 0.7rem;
  font-size: 0.78rem;
  letter-spacing: 0.24em;
  color: var(--ink-faint);
}

.post__title {
  margin: 0;
  font-size: clamp(1.7rem, 4vw, 2.5rem);
  font-weight: 300;
  line-height: 1.35;
  letter-spacing: 0.06em;
  text-shadow: 0 2px 24px rgba(3, 8, 20, 0.5);
}

.post__body {
  max-width: 760px;
  margin: 0 auto;                          /* 水平居中 */
  font-size: 1.02rem;
  line-height: 1.95;
  letter-spacing: 0.01em;
  color: var(--ink);
}

.post__body > :first-child { margin-top: 0; }

.post__body h2 {
  margin: 2.3em 0 0.7em;
  font-size: 1.24rem;
  font-weight: 500;
  line-height: 1.5;
  letter-spacing: 0.04em;
}

.post__body h3 {
  margin: 2em 0 0.6em;
  font-size: 1.08rem;
  font-weight: 500;
  line-height: 1.5;
}

.post__body p { margin: 0 0 1.35em; }

.post__body a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 195, 247, 0.35);
  transition: border-color 0.4s var(--ease-out);
}

.post__body a:hover { border-bottom-color: var(--accent); }

.post__body ul,
.post__body ol {
  margin: 0 0 1.35em;
  padding-left: 1.4em;
}

.post__body li { margin: 0.35em 0; }

.post__body blockquote {
  margin: 1.5em 0;
  padding: 0.15em 0 0.15em 1.1em;
  border-left: 2px solid rgba(79, 195, 247, 0.42);
  color: var(--ink-soft);
}

.post__body code {
  font-family: ui-monospace, SFMono-Regular, Consolas, "Courier New", monospace;
  font-size: 0.9em;
  background: rgba(255, 255, 255, 0.07);
  border-radius: 6px;
  padding: 0.14em 0.42em;
}

.post__body pre {
  margin: 1.5em 0;
  padding: 1rem 1.15rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--hairline);
  border-radius: 12px;
  overflow: auto;
  line-height: 1.7;
}

.post__body pre code {
  background: none;
  padding: 0;
  font-size: 0.88rem;
}

.post__body img {
  display: block;
  width: 100%;
  height: auto;
  margin: 1.7em 0;
  border-radius: 14px;
  border: 1px solid var(--hairline);
  box-shadow: 0 14px 38px rgba(3, 8, 20, 0.45);
}

.post__body hr {
  margin: 2.4em 0;
  border: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* （此前的遮罩色阶衔接方案已随遮罩移除一并撤销） */

/* ============================================================
   首页：整页翻页（hero ⊷ 文章页，滚动贴合 + 文章页内滚）
   ============================================================ */

html.home {
  scroll-snap-type: y mandatory;
}

.home .hero {
  height: 100svh;
  height: 100lvh;
  scroll-snap-align: start;
  scroll-snap-stop: always;   /* 惯性甩动也必须逐屏停靠：大力划不会跳过中间屏 */
}

.home .scroll-cue { bottom: calc(100lvh - 100svh + 24px); }

.home .hero__bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
}

.home .writing {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  height: 100svh;
  height: 100lvh;
  scroll-snap-align: start;
  scroll-snap-stop: always;   /* 惯性甩动也必须逐屏停靠（反向同理） */
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  background: rgba(10, 20, 48, 0);
  -webkit-backdrop-filter: blur(0px) saturate(110%);
  backdrop-filter: blur(0px) saturate(110%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
  transition:
    background-color 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94),   /* 退雾：快速清透，避免拖泥带水 */
    -webkit-backdrop-filter 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94),
    backdrop-filter 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* 纸面区雾化（全局，hero↔纸面之间切换；文章↔项目保持不散） */
.home.sheets-frosted .writing {
  background: rgba(10, 20, 48, 0.5);
  -webkit-backdrop-filter: blur(26px) saturate(140%);
  backdrop-filter: blur(26px) saturate(140%);
  transition:
    background-color 0.8s cubic-bezier(0.33, 0, 0.67, 1),
    -webkit-backdrop-filter 0.8s cubic-bezier(0.33, 0, 0.67, 1),
    backdrop-filter 0.8s cubic-bezier(0.33, 0, 0.67, 1);
}

/* 无 JS 时直接呈现毛玻璃（不依赖脚本） */
html:not(.js) .home .writing {
  background: rgba(10, 20, 48, 0.5);
  -webkit-backdrop-filter: blur(26px) saturate(140%);
  backdrop-filter: blur(26px) saturate(140%);
}

@media (prefers-reduced-motion: reduce) {
  .home .writing { transition: none; }
}

.home .writing__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex: none;
  padding: 48px var(--inset-x) 0;
}

.writing__nav {
  font-size: 0.82rem;
  letter-spacing: 0.18em;
  color: var(--ink-faint);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.4s var(--ease-out);
}

.writing__nav:hover { color: var(--accent); }

.home .writing__inner {
  flex: 1 1 auto;
  overflow-y: auto;
  overscroll-behavior-y: contain;          /* 列表到端点后不再把滚动“链”给整页（翻屏交给 JS 的 800ms 动画） */
  padding: 0 var(--inset-x) 0;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.22) transparent;
}

.home .writing__inner::-webkit-scrollbar { width: 8px; }
.home .writing__inner::-webkit-scrollbar-track { background: transparent; }
.home .writing__inner::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.18); border-radius: 999px; }
.home .writing__inner::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.32); }

.home .writing__heading { margin-bottom: 1.8rem; }
.home .footer { margin-top: 40px; }
.home .footer p { padding: 1.3rem 0 1.8rem; }
.home .footer p.footer__thanks { padding-bottom: 0.4rem; }
.home .footer p + p { padding-top: 0.25rem; }

@media (prefers-reduced-motion: reduce) {
  html.home { scroll-snap-type: none; }
}

/* ---------- 细节：标题句点收紧 + 隐藏首页页面滚动条 ---------- */

.hero__dot { margin-left: -0.15em; }

html.home { scrollbar-width: none; }
html.home::-webkit-scrollbar { display: none; }

/* ---------- 移动端适配：底部栏动态与安全区（PC 端 env()=0、svh==lvh，不受影响） ---------- */

html.home {
  overscroll-behavior-y: contain;          /* 翻页时不触发下拉刷新 */
}

.home .scroll-cue {
  bottom: calc(100lvh - 100svh + 24px + env(safe-area-inset-bottom, 0px));
}

.home .writing__inner {
  max-height: 100svh;                      /* 内容区以“最小视口”为上限：底部栏弹出时也能完整阅读 */
  padding-bottom: calc(0.5rem + env(safe-area-inset-bottom, 0px));
}

.home .footer p {
  padding-bottom: calc(1.8rem + env(safe-area-inset-bottom, 0px));
}

.footer p {
  padding-bottom: calc(2.1rem + env(safe-area-inset-bottom, 0px));
}