/* ============================================================================
   焦点娱乐 · 教育直播 ｜ base.css
   设计系统：黑板焦点 Chalkboard Focus
   ----------------------------------------------------------------------------
   结构：tokens → reset → typography → layout → header → footer
         → buttons/chips → focus-bracket → panel → marquee → stats
         → faq → forms → reveal → responsive-base
   约定：类名统一 jd- 前缀；浅色纸张为全站底色，深色黑板为段落级反转
   ============================================================================ */

/* ---------- tokens ---------- */
:root {
  --jd-board: #1c3a31;        /* 黑板绿 */
  --jd-board-deep: #12291f;   /* 黑板深处 */
  --jd-board-frame: #8a6e3d;  /* 木质框 */
  --jd-paper: #f6f1e3;        /* 纸张底 */
  --jd-paper-2: #efe7d3;      /* 纸张深 */
  --jd-card: #fffdf6;         /* 教案卡 */
  --jd-ink: #24312b;          /* 钢笔墨 */
  --jd-ink-2: #5d6b62;        /* 次级 */
  --jd-ink-3: #8b968d;        /* 辅助 */
  --jd-chalk: #f7f4e8;        /* 粉笔白 */
  --jd-chalk-2: #c9d3c4;      /* 粉笔灰绿 */
  --jd-marker: #d95b3f;       /* 红笔批注 */
  --jd-hl: #f0c04a;           /* 荧光黄 */
  --jd-teal: #2e7d6b;         /* 教鞭青 */
  --jd-line: rgba(36, 49, 43, .14);
  --jd-line-chalk: rgba(247, 244, 232, .22);

  --jd-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", SimSun, serif;
  --jd-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --jd-kai: "Kaiti SC", KaiTi, "Noto Serif SC", serif;

  --jd-wrap: 1180px;
  --jd-radius: 4px;
  --jd-shadow: 0 18px 40px -24px rgba(18, 41, 31, .35);
  --jd-ease: cubic-bezier(.22, .7, .3, 1);
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  font-family: var(--jd-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--jd-ink);
  background: var(--jd-paper);
  background-image:
    radial-gradient(rgba(36, 49, 43, .045) 1px, transparent 1.5px);
  background-size: 26px 26px;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: 0; }
table { border-collapse: collapse; width: 100%; }

/* ---------- typography ---------- */
h1, h2, h3, h4 { font-family: var(--jd-serif); font-weight: 700; line-height: 1.25; }
h1 { font-size: clamp(2rem, 4.6vw, 3.1rem); }
.jd-h2 { font-size: clamp(1.5rem, 3vw, 2.15rem); letter-spacing: .01em; }
.jd-h2 em { font-style: normal; color: var(--jd-marker); }
.jd-h3 { font-size: 1.18rem; }
p { color: var(--jd-ink-2); }
.jd-kicker {
  display: flex; align-items: center; gap: 10px;
  font-size: .8rem; letter-spacing: .32em; text-transform: uppercase;
  color: var(--jd-teal); margin-bottom: 14px;
}
.jd-kicker::before { content: ""; width: 30px; height: 2px; background: var(--jd-marker); }
.jd-lead { font-size: 1.05rem; color: var(--jd-ink-2); max-width: 62ch; }
.jd-num { font-family: var(--jd-kai); color: var(--jd-hl); }

/* 粉笔标题（黑板区块内） */
.jd-board .jd-h2, .jd-board h1, .jd-board h3 { color: var(--jd-chalk); }
.jd-board p { color: var(--jd-chalk-2); }
.jd-chalkline {
  display: inline-block; padding-bottom: 6px;
  background-image: linear-gradient(100deg, rgba(247, 244, 232, .55), rgba(247, 244, 232, .18));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 100% 3px;
}

/* ---------- layout ---------- */
.jd-wrap { width: min(var(--jd-wrap), calc(100% - 48px)); margin-inline: auto; }
.jd-main { display: block; }
.jd-sec { padding: 92px 0; }
.jd-sec--tight { padding: 64px 0; }
.jd-sec__head { max-width: 720px; margin-bottom: 46px; }
.jd-sec__head--split {
  display: flex; align-items: flex-end; justify-content: space-between;
  gap: 32px; max-width: none;
}
.jd-grid { display: grid; gap: 22px; }
.jd-grid--2 { grid-template-columns: repeat(2, 1fr); }
.jd-grid--3 { grid-template-columns: repeat(3, 1fr); }
.jd-grid--4 { grid-template-columns: repeat(4, 1fr); }

/* 章节标签（教案纸页眉） */
.jd-tabhead {
  display: flex; align-items: center; gap: 14px;
  border-bottom: 2px solid var(--jd-ink);
  padding-bottom: 12px; margin-bottom: 34px;
}
.jd-tabhead b {
  font-family: var(--jd-kai); font-size: 1.05rem;
  background: var(--jd-ink); color: var(--jd-chalk);
  padding: 3px 12px; border-radius: 2px 2px 0 0;
}
.jd-tabhead span { font-size: .82rem; letter-spacing: .22em; color: var(--jd-ink-3); }

/* ---------- header ---------- */
.jd-head {
  position: sticky; top: 0; z-index: 60;
  background: rgba(246, 241, 227, .92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--jd-line);
}
.jd-head__bar {
  display: flex; align-items: center; gap: 28px;
  padding: 14px 0;
}
.jd-logo { display: flex; align-items: center; gap: 12px; font-family: var(--jd-serif); font-weight: 700; font-size: 1.22rem; }
.jd-logo em {
  display: block; font-style: normal; font-family: var(--jd-sans);
  font-size: .62rem; letter-spacing: .3em; color: var(--jd-ink-3); font-weight: 400;
}
.jd-logo__mark {
  position: relative; width: 34px; height: 34px; flex: none;
  background: var(--jd-board);
}
.jd-logo__mark::before {
  content: ""; position: absolute; inset: 7px;
  border: 2px solid var(--jd-hl);
  clip-path: polygon(0 0, 34% 0, 34% 14%, 14% 14%, 14% 34%, 0 34%, 0 0,
    100% 0, 100% 34%, 86% 34%, 86% 14%, 66% 14%, 66% 0,
    100% 100%, 66% 100%, 66% 86%, 86% 86%, 86% 66%, 100% 66%,
    0 100%, 0 66%, 14% 66%, 14% 86%, 34% 86%, 34% 100%);
}
.jd-logo__mark::after {
  content: ""; position: absolute; inset: 0; margin: auto;
  width: 8px; height: 8px; border-radius: 50%; background: var(--jd-marker);
}
.jd-nav { display: flex; gap: 4px; margin-left: auto; }
.jd-nav a {
  position: relative; padding: 8px 13px; font-size: .95rem; border-radius: 2px;
  transition: color .25s var(--jd-ease);
}
.jd-nav a::after {
  content: ""; position: absolute; left: 13px; right: 13px; bottom: 4px;
  height: 6px; transform: scaleX(0); transform-origin: left;
  background: linear-gradient(90deg, rgba(240, 192, 74, .8), rgba(240, 192, 74, .2));
  transition: transform .3s var(--jd-ease);
}
.jd-nav a:hover::after, .jd-nav a[aria-current="page"]::after { transform: scaleX(1); }
.jd-nav a[aria-current="page"] { color: var(--jd-ink); font-weight: 600; }
.jd-head__cta { display: flex; gap: 10px; }
.jd-burger { display: none; width: 40px; height: 40px; position: relative; }
.jd-burger span, .jd-burger span::before, .jd-burger span::after {
  content: ""; position: absolute; left: 50%; top: 50%;
  width: 20px; height: 2px; background: var(--jd-ink); transform: translate(-50%, -50%);
}
.jd-burger span { position: absolute; }
.jd-burger span::before { top: -7px; left: 0; }
.jd-burger span::after { top: 7px; left: 0; }

/* 移动导航态 */
.jd-head.is-open .jd-nav { display: flex; }
.jd-head.is-open .jd-burger span { background: transparent; }
.jd-head.is-open .jd-burger span::before { transform: rotate(45deg); top: 0; }
.jd-head.is-open .jd-burger span::after { transform: rotate(-45deg); top: 0; }

/* ---------- buttons / chips ---------- */
.jd-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 2px; font-size: .95rem; font-weight: 600;
  border: 1px solid transparent;
  transition: transform .25s var(--jd-ease), box-shadow .25s var(--jd-ease);
}
.jd-btn:hover { transform: translateY(-2px); box-shadow: var(--jd-shadow); }
.jd-btn--ink { background: var(--jd-ink); color: var(--jd-chalk); }
.jd-btn--marker { background: var(--jd-marker); color: #fff; }
.jd-btn--ghost { border-color: var(--jd-ink); color: var(--jd-ink); }
.jd-btn--chalk { background: var(--jd-hl); color: var(--jd-board-deep); }
.jd-btn--outline-chalk { border-color: rgba(247, 244, 232, .5); color: var(--jd-chalk); }
.jd-btn--sm { padding: 8px 15px; font-size: .85rem; }
.jd-chip {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 4px 12px; border: 1px dashed var(--jd-ink-3); border-radius: 999px;
  font-size: .8rem; color: var(--jd-ink-2);
}
.jd-chip i { width: 7px; height: 7px; border-radius: 50%; background: var(--jd-teal); }
.jd-board .jd-chip { border-color: rgba(247, 244, 232, .35); color: var(--jd-chalk-2); }
.jd-chip--on i { background: var(--jd-marker); animation: jd-blink 1.4s infinite; }
@keyframes jd-blink { 50% { opacity: .25; } }

/* ---------- focus-bracket（取景框组件） ---------- */
.jd-focus { position: relative; }
.jd-focus::before {
  content: ""; position: absolute; inset: 10px; pointer-events: none;
  background:
    linear-gradient(var(--jd-hl), var(--jd-hl)) 0 0 / 20px 2px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 0 0 / 2px 20px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 100% 0 / 20px 2px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 100% 0 / 2px 20px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 0 100% / 20px 2px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 0 100% / 2px 20px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 100% 100% / 20px 2px no-repeat,
    linear-gradient(var(--jd-hl), var(--jd-hl)) 100% 100% / 2px 20px no-repeat;
  opacity: 0; transition: opacity .35s var(--jd-ease);
}
.jd-focus:hover::before { opacity: 1; }
.jd-focus--on::before { opacity: 1; }

/* ---------- panel（教案卡片） ---------- */
.jd-panel {
  position: relative; background: var(--jd-card);
  border: 1px solid var(--jd-line); border-radius: var(--jd-radius);
  padding: 30px 26px;
  transition: transform .3s var(--jd-ease), box-shadow .3s var(--jd-ease);
}
.jd-panel:hover { transform: translateY(-4px); box-shadow: var(--jd-shadow); }
.jd-panel::after { /* 红笔角批 */
  content: ""; position: absolute; right: -1px; top: -1px;
  width: 34px; height: 34px;
  background: linear-gradient(225deg, var(--jd-marker) 0 50%, transparent 50%);
  border-radius: 0 var(--jd-radius) 0 0;
  opacity: .85;
}
.jd-panel__no {
  font-family: var(--jd-kai); font-size: .95rem; color: var(--jd-marker);
  letter-spacing: .12em; margin-bottom: 10px;
}
.jd-panel p { font-size: .92rem; }
.jd-panel .jd-h3 { margin-bottom: 10px; }

/* 黑板上的粉笔卡 */
.jd-panel--chalk {
  background: rgba(247, 244, 232, .05);
  border: 1px dashed rgba(247, 244, 232, .35);
}
.jd-panel--chalk:hover { background: rgba(247, 244, 232, .09); }
.jd-panel--chalk .jd-h3 { color: var(--jd-chalk); }

/* ---------- board（黑板区块） ---------- */
.jd-board {
  background:
    radial-gradient(120% 90% at 50% 0%, rgba(247, 244, 232, .06), transparent 60%),
    repeating-linear-gradient(3deg, rgba(255, 255, 255, .012) 0 2px, transparent 2px 7px),
    linear-gradient(160deg, var(--jd-board) 0%, var(--jd-board-deep) 100%);
  border-block: 10px solid var(--jd-board-frame);
  position: relative;
}
.jd-board::before { /* 粉笔灰槽 */
  content: ""; position: absolute; left: 0; right: 0; bottom: 12px; height: 4px;
  background: linear-gradient(90deg, transparent, rgba(247, 244, 232, .25), transparent);
}
.jd-board .jd-kicker { color: var(--jd-hl); }
.jd-board .jd-kicker::before { background: var(--jd-hl); }

/* ---------- marquee（课表走马灯） ---------- */
.jd-marquee {
  overflow: hidden; border-block: 1px solid var(--jd-line);
  background: var(--jd-paper-2); padding: 13px 0;
}
.jd-marquee__track {
  display: flex; gap: 48px; width: max-content;
  animation: jd-slide 32s linear infinite;
}
.jd-marquee:hover .jd-marquee__track { animation-play-state: paused; }
.jd-marquee__item { display: flex; align-items: baseline; gap: 10px; font-size: .88rem; white-space: nowrap; }
.jd-marquee__item span { font-family: var(--jd-kai); color: var(--jd-marker); letter-spacing: .1em; }
.jd-marquee__item b { font-weight: 600; }
.jd-marquee__item::before { content: "▸"; color: var(--jd-teal); }
@keyframes jd-slide { to { transform: translateX(-50%); } }

/* ---------- stats ---------- */
.jd-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.jd-stats > div { text-align: center; padding: 22px 10px; border: 1px dashed var(--jd-line-chalk); border-radius: var(--jd-radius); }
.jd-stats b {
  display: block; font-family: var(--jd-serif); font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  color: var(--jd-hl); line-height: 1.1;
}
.jd-stats b::after { content: ""; }
.jd-stats span { font-size: .85rem; color: var(--jd-chalk-2); }

/* ---------- faq ---------- */
.jd-faq { border: 1px solid var(--jd-line); border-radius: var(--jd-radius); background: var(--jd-card); }
.jd-faq details { border-bottom: 1px dashed var(--jd-line); }
.jd-faq details:last-child { border-bottom: 0; }
.jd-faq summary {
  cursor: pointer; list-style: none; display: flex; gap: 12px; align-items: center;
  padding: 18px 22px; font-weight: 600; font-family: var(--jd-serif);
}
.jd-faq summary::-webkit-details-marker { display: none; }
.jd-faq summary::before {
  content: "问"; flex: none; width: 24px; height: 24px; display: grid; place-items: center;
  background: var(--jd-marker); color: #fff; font-size: .78rem; font-family: var(--jd-kai); border-radius: 2px;
}
.jd-faq details[open] summary::before { content: "答"; background: var(--jd-teal); }
.jd-faq p { padding: 0 22px 20px 58px; font-size: .92rem; }

/* ---------- forms ---------- */
.jd-form { display: grid; gap: 16px; }
.jd-form--2 { grid-template-columns: 1fr 1fr; }
.jd-field label { display: block; font-size: .85rem; font-weight: 600; margin-bottom: 6px; }
.jd-field label small { color: var(--jd-marker); font-weight: 400; }
.jd-field input, .jd-field select, .jd-field textarea {
  width: 100%; padding: 12px 14px;
  background: var(--jd-card); color: var(--jd-ink);
  border: 1px solid var(--jd-line); border-radius: 2px;
  transition: border-color .2s, box-shadow .2s;
}
.jd-field input:focus, .jd-field select:focus, .jd-field textarea:focus {
  outline: 0; border-color: var(--jd-teal);
  box-shadow: 0 0 0 3px rgba(46, 125, 107, .16);
}
.jd-form__note { font-size: .8rem; color: var(--jd-ink-3); }
.jd-form__ok {
  display: none; padding: 14px 18px; border: 1px dashed var(--jd-teal);
  border-radius: 2px; color: var(--jd-teal); background: rgba(46, 125, 107, .07); font-size: .9rem;
}
.jd-form.is-sent .jd-form__ok { display: block; }
.jd-board .jd-field input, .jd-board .jd-field select, .jd-board .jd-field textarea {
  background: rgba(247, 244, 232, .92); border-color: transparent;
}

/* ---------- reveal ---------- */
.jd-reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--jd-ease), transform .7s var(--jd-ease); }
.jd-reveal.is-in { opacity: 1; transform: none; }
.jd-reveal[data-delay="1"] { transition-delay: .1s; }
.jd-reveal[data-delay="2"] { transition-delay: .2s; }
.jd-reveal[data-delay="3"] { transition-delay: .3s; }
.jd-reveal[data-delay="4"] { transition-delay: .4s; }

/* ---------- footer ---------- */
.jd-foot { background: var(--jd-board-deep); color: var(--jd-chalk-2); padding: 70px 0 30px; }
.jd-foot__grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; }
.jd-foot h4 { color: var(--jd-chalk); font-size: 1rem; margin-bottom: 16px; }
.jd-foot a { font-size: .9rem; color: var(--jd-chalk-2); transition: color .2s; }
.jd-foot a:hover { color: var(--jd-hl); }
.jd-foot ul { display: grid; gap: 9px; }
.jd-foot__brand p { font-size: .88rem; max-width: 34ch; margin-top: 10px; }
.jd-foot__legal {
  margin-top: 46px; padding-top: 22px; border-top: 1px dashed rgba(247, 244, 232, .2);
  font-size: .78rem; display: grid; gap: 8px; color: rgba(201, 211, 196, .75);
}
.jd-foot__legal .jd-foot__warn { color: var(--jd-hl); }

/* ---------- responsive base ---------- */
@media (max-width: 1024px) {
  .jd-grid--4 { grid-template-columns: repeat(2, 1fr); }
  .jd-grid--3 { grid-template-columns: repeat(2, 1fr); }
  .jd-foot__grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 860px) {
  .jd-nav {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; background: var(--jd-paper);
    border-bottom: 2px solid var(--jd-ink); padding: 14px 24px 20px;
  }
  .jd-head__cta { margin-left: auto; }
  .jd-burger { display: block; }
  .jd-sec { padding: 64px 0; }
}
@media (max-width: 640px) {
  .jd-grid--2, .jd-grid--3, .jd-grid--4 { grid-template-columns: 1fr; }
  .jd-stats { grid-template-columns: repeat(2, 1fr); }
  .jd-form--2 { grid-template-columns: 1fr; }
  .jd-head__cta .jd-btn--ghost { display: none; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .jd-reveal { opacity: 1; transform: none; transition: none; }
  .jd-marquee__track { animation: none; }
  * { animation-duration: .01ms !important; }
}