/* Sidegloss 官网 —— 书卷 / 编辑风。设计原则见仓库根目录 .impeccable.md */
@font-face {
  font-family: "Newsreader";
  src: url("fonts/newsreader.woff2") format("woff2");
  font-weight: 200 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Newsreader";
  src: url("fonts/newsreader-italic.woff2") format("woff2");
  font-weight: 200 800;
  font-style: italic;
  font-display: swap;
}

:root {
  --paper: #f6f8f1;
  --paper-deep: #ecf0e4;
  --paper-edge: #e3e9da;
  --ink: #1b2e26;
  --ink-soft: #3d5047;
  --muted: #5f7167;
  --rule: #d3ddcd;
  --rule-soft: #e2e9dd;
  --accent: #1d7a5b;
  --accent-bright: #229470;
  --accent-wash: #d9eee0;
  --marker: #f0deb0;
  --marker-strong: #ebcf85;
  --star: #b87c0c;
  --danger: #a4452c;

  --serif-en: "Newsreader", "Iowan Old Style", Georgia, serif;
  --serif-zh: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "STSong", "Microsoft YaHei", serif;
  --sans: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  --step--1: clamp(0.8rem, 0.78rem + 0.1vw, 0.86rem);
  --step-0: clamp(0.95rem, 0.92rem + 0.15vw, 1.03rem);
  --step-1: clamp(1.15rem, 1.08rem + 0.35vw, 1.35rem);
  --step-2: clamp(1.4rem, 1.25rem + 0.75vw, 1.85rem);
  --step-3: clamp(1.9rem, 1.55rem + 1.7vw, 2.9rem);
  --step-4: clamp(2.4rem, 1.7rem + 3.4vw, 4.4rem);

  --space-xs: 0.5rem;
  --space-s: 0.85rem;
  --space-m: clamp(1.2rem, 1rem + 1vw, 1.8rem);
  --space-l: clamp(2rem, 1.5rem + 2.5vw, 3.6rem);
  --space-xl: clamp(3.4rem, 2.4rem + 5vw, 7rem);

  --measure: 38rem;
  --margin-col: 13.5rem;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

*,
*::before,
*::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; scroll-padding-top: 5rem; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 var(--step-0)/1.75 var(--sans);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--accent-bright); outline-offset: 3px; border-radius: 2px; }
::selection { background: var(--marker); color: var(--ink); }

h1, h2, h3 { font-family: var(--serif-zh); font-weight: 700; line-height: 1.25; margin: 0; letter-spacing: 0.01em; }
p { margin: 0; }
.en { font-family: var(--serif-en); }

.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}

/* 荧光笔：全站唯一的高饱和色，只用于"被划出/被收藏"的内容 */
.marker {
  background: linear-gradient(transparent 58%, var(--marker) 58%, var(--marker) 92%, transparent 92%) no-repeat;
  background-size: 100% 100%;
  padding: 0 0.08em;
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
}

/* ---------- 刊头 ---------- */
.masthead {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: saturate(1.2) blur(6px);
  border-bottom: 1px solid var(--rule);
}
.masthead-inner {
  max-width: 72rem; margin: 0 auto;
  padding: 0.7rem clamp(1rem, 4vw, 2.5rem);
  display: flex; align-items: center; gap: var(--space-m);
}
.wordmark {
  font: italic 600 1.45rem/1 var(--serif-en);
  color: var(--ink); text-decoration: none; letter-spacing: -0.01em;
  display: inline-flex; align-items: baseline; gap: 0.45rem;
}
.wordmark small {
  font: 500 0.7rem/1 var(--sans); font-style: normal; letter-spacing: 0.18em;
  color: var(--muted); text-transform: uppercase;
}
.masthead nav { margin-left: auto; display: flex; align-items: center; gap: clamp(0.6rem, 2vw, 1.6rem); font-size: var(--step--1); }
.masthead nav a:not(.button) { color: var(--ink-soft); text-decoration: none; }
.masthead nav a:not(.button):hover { color: var(--accent); }
.masthead nav a[aria-current="page"] { color: var(--ink); font-weight: 600; }
@media (max-width: 40rem) {
  .masthead nav a:not(.button):not(.user-chip) { display: none; }
  .wordmark small { display: none; }
}

/* ---------- 按钮 ---------- */
.button {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.45em;
  font: 600 var(--step--1)/1 var(--sans);
  padding: 0.62rem 1.05rem; border-radius: 999px; border: 1px solid transparent;
  background: var(--accent); color: var(--paper); text-decoration: none; cursor: pointer;
  transition: background-color 160ms var(--ease-out), transform 160ms var(--ease-out), border-color 160ms var(--ease-out);
}
.button:hover { background: #17664b; }
.button:active { transform: translateY(1px); }
.button.ghost { background: transparent; color: var(--ink); border-color: var(--rule); }
.button.ghost:hover { border-color: var(--ink-soft); background: var(--paper-deep); }
.button.quiet { background: transparent; color: var(--accent); padding-inline: 0.3rem; }
.button.quiet:hover { background: transparent; text-decoration: underline; }
.button.danger { background: transparent; color: var(--danger); border-color: color-mix(in srgb, var(--danger) 35%, transparent); }
.button.danger:hover { background: color-mix(in srgb, var(--danger) 8%, transparent); }
.button[disabled] { opacity: 0.55; cursor: not-allowed; }

.user-chip {
  display: inline-flex; align-items: center; gap: 0.5rem;
  text-decoration: none; color: var(--ink); font-size: var(--step--1);
}
.avatar {
  width: 1.9rem; height: 1.9rem; border-radius: 50%;
  display: grid; place-items: center; flex-shrink: 0;
  background: var(--accent-wash); color: var(--accent);
  font: 700 0.85rem/1 var(--sans);
}

/* ---------- 页脚 ---------- */
.colophon {
  border-top: 1px solid var(--rule);
  margin-top: var(--space-xl);
  padding: var(--space-l) clamp(1rem, 4vw, 2.5rem) var(--space-m);
  color: var(--muted); font-size: var(--step--1);
}
.colophon-inner { max-width: 72rem; margin: 0 auto; display: grid; gap: var(--space-s) var(--space-l); grid-template-columns: minmax(0, 1fr) auto; align-items: end; }
.colophon p { max-width: 36rem; }
.colophon nav { display: flex; gap: 1.2rem; flex-wrap: wrap; }
.colophon a { color: var(--ink-soft); }
@media (max-width: 40rem) { .colophon-inner { grid-template-columns: 1fr; } }

/* ---------- 表单控件 ---------- */
input[type="search"], input[type="text"] {
  font: inherit; color: var(--ink);
  background: color-mix(in srgb, var(--paper) 50%, #fff);
  border: 1px solid var(--rule); border-radius: 999px;
  padding: 0.5rem 1rem; min-width: 0;
}
input[type="search"]:focus { border-color: var(--accent); outline: none; box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-bright) 18%, transparent); }

.segmented { display: inline-flex; border: 1px solid var(--rule); border-radius: 999px; padding: 3px; gap: 2px; background: var(--paper); }
.segmented button, .segmented label {
  font: 500 var(--step--1)/1 var(--sans); color: var(--ink-soft);
  border: 0; background: transparent; border-radius: 999px; padding: 0.45rem 0.85rem; cursor: pointer;
}
.segmented input { position: absolute; opacity: 0; pointer-events: none; }
.segmented button[aria-pressed="true"], .segmented label:has(input:checked) { background: var(--ink); color: var(--paper); }
.segmented label:has(input:focus-visible) { outline: 2px solid var(--accent-bright); outline-offset: 2px; }

.toast {
  position: fixed; left: 50%; bottom: 1.5rem; z-index: 20;
  transform: translate(-50%, 0.8rem); opacity: 0; pointer-events: none;
  display: flex; align-items: center; gap: 1rem;
  background: var(--ink); color: var(--paper); border-radius: 999px;
  padding: 0.6rem 0.8rem 0.6rem 1.2rem; font-size: var(--step--1);
  box-shadow: 0 12px 30px rgb(27 46 38 / 0.25);
  transition: opacity 220ms var(--ease-out), transform 220ms var(--ease-out);
}
.toast[data-show] { opacity: 1; transform: translate(-50%, 0); pointer-events: auto; }
.toast button { font: 600 var(--step--1)/1 var(--sans); color: var(--marker); background: transparent; border: 0; cursor: pointer; padding: 0.35rem 0.5rem; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
}