/* ==========================================================================
   C++ & Algorithm 研习社 · 信息科技赛考校队
   明亮现代风格 —— 宽屏自适应（1400px）· 无外部依赖
   ========================================================================== */

/* ---------- 设计变量 ---------- */
:root {
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --bg-tint: #f4f8ff;
  --bg-tint-2: #f7fbff;

  --ink: #101c33;        /* 标题 */
  --ink-2: #3a4a63;      /* 正文 */
  --ink-3: #6b7c96;      /* 次要 */
  --ink-4: #9aa8bd;      /* 弱化 */

  --line: #e3e9f2;
  --line-2: #eef3f9;

  --brand: #2563eb;
  --brand-d: #1d4ed8;
  --brand-l: #3b82f6;
  --brand-soft: #eff4ff;
  --brand-line: #d6e3ff;

  --violet: #7c3aed;
  --violet-soft: #f4f0ff;
  --teal: #0d9488;
  --teal-soft: #e8faf7;
  --amber: #d97706;
  --amber-soft: #fff5e6;
  --rose: #e11d48;
  --rose-soft: #fff1f4;
  --green: #059669;
  --green-soft: #ecfdf5;

  --r-sm: 10px;
  --r: 14px;
  --r-lg: 20px;
  --r-xl: 26px;

  --sh-sm: 0 1px 2px rgba(16, 28, 51, .05), 0 1px 3px rgba(16, 28, 51, .05);
  --sh: 0 4px 18px rgba(16, 28, 51, .07), 0 1px 3px rgba(16, 28, 51, .04);
  --sh-lg: 0 16px 48px rgba(16, 28, 51, .12), 0 2px 8px rgba(16, 28, 51, .05);

  --wrap: 1400px;
  --wrap-mid: 1160px;
  --wrap-narrow: 820px;

  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "HarmonyOS Sans SC", "Hiragino Sans GB", "Source Han Sans SC",
    "Noto Sans CJK SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Cascadia Mono", Consolas, "Courier New", monospace;
}

/* ---------- 正文两端对齐 ----------
   中文按字间距调整（inter-ideograph），避免中英混排时词间出现大空隙 */
.prose > p,
.sec-head > p,
.qa__body > p,
.sw__body > p,
.course__for,
.cbox__n {
  text-align: justify;
  text-justify: inter-ideograph;
  overflow-wrap: break-word;
}

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--ink-2);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg { max-width: 100%; }
img { height: auto; display: block; }

a { color: var(--brand); text-decoration: none; transition: color .15s ease; }
a:hover { color: var(--brand-d); }

h1, h2, h3, h4 {
  margin: 0 0 .5em;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -.02em;
}
h1 { font-size: clamp(2rem, 3.4vw, 3.15rem); line-height: 1.22; }
h2 { font-size: clamp(1.55rem, 2.4vw, 2.15rem); }
h3 { font-size: clamp(1.08rem, 1.3vw, 1.24rem); }
h4 { font-size: 1rem; }

p { margin: 0 0 1.05em; }
p:last-child { margin-bottom: 0; }

ul, ol { margin: 0 0 1.05em; padding-left: 1.35em; }
li { margin-bottom: .4em; }
li:last-child { margin-bottom: 0; }

strong, b { font-weight: 650; color: var(--ink); }

code, kbd {
  font-family: var(--mono);
  font-size: .875em;
  background: var(--brand-soft);
  color: var(--brand-d);
  padding: .12em .42em;
  border-radius: 5px;
}

::selection { background: #cfe0ff; }

hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }

/* ---------- 容器 ---------- */
.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: 36px; }
.wrap--mid { max-width: var(--wrap-mid); }
.wrap--narrow { max-width: var(--wrap-narrow); }

.section { padding: 92px 0; }
.section--tight { padding: 62px 0; }
.section--soft { background: var(--bg-soft); }
.section--tint { background: linear-gradient(180deg, var(--bg-tint) 0%, #fff 100%); }

/* ---------- 区块标题 ---------- */
.sec-head { margin-bottom: 48px; }
.sec-head h2 { margin-bottom: .4em; }
/* 导语占满容器宽度，不再收窄；居中区块整体限宽以保持对称 */
.sec-head > p {
  color: var(--ink-3);
  font-size: 1.05rem;
  margin-bottom: 0;
}
.sec-head--center { max-width: 980px; margin: 0 auto 48px; text-align: center; }
/* 居中区块的导语必须显式覆盖上面的两端对齐规则：
   元素自身的 text-align 优先级高于从父级继承来的 center */
.sec-head--center > p { text-align: center; text-justify: auto; }

.sec-label {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--brand-d);
  background: var(--brand-soft);
  border: 1px solid var(--brand-line);
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 18px;
}
.sec-label .ico { width: 15px; height: 15px; }
.sec-label--teal { color: var(--teal); background: var(--teal-soft); border-color: #c4ece6; }
.sec-label--amber { color: var(--amber); background: var(--amber-soft); border-color: #fbe0b8; }
.sec-label--violet { color: var(--violet); background: var(--violet-soft); border-color: #e2d7ff; }

/* ---------- 图标 ---------- */
.sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.ico {
  width: 1em; height: 1em;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex: 0 0 auto;
  vertical-align: -0.13em;
}

/* ---------- 顶栏 ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.topbar__in {
  display: flex;
  align-items: center;
  gap: 30px;
  height: 74px;
}

.brand { display: flex; align-items: center; gap: 11px; color: var(--ink); }
.brand:hover { color: var(--ink); }
.brand__mark {
  width: 38px; height: 38px;
  border-radius: 11px;
  background: linear-gradient(140deg, var(--brand-l), var(--violet));
  color: #fff;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: -.02em;
  box-shadow: 0 4px 12px rgba(37, 99, 235, .28);
  flex: 0 0 auto;
}
.brand__txt { display: flex; flex-direction: column; line-height: 1.25; }
.brand__name { font-size: 1.06rem; font-weight: 700; color: var(--ink); letter-spacing: -.01em; }
.brand__sub { font-size: .73rem; color: var(--ink-4); font-weight: 500; }

.nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav a {
  padding: 9px 15px;
  font-size: .93rem;
  font-weight: 500;
  color: var(--ink-2);
  border-radius: 9px;
  white-space: nowrap;
}
.nav a:hover { background: var(--brand-soft); color: var(--brand-d); }
.nav a[aria-current="page"] { color: var(--brand-d); font-weight: 650; background: var(--brand-soft); }

.nav__cta {
  margin-left: 12px;
  padding: 10px 20px !important;
  background: var(--brand);
  color: #fff !important;
  font-weight: 600 !important;
  border-radius: 10px;
  box-shadow: 0 4px 14px rgba(37, 99, 235, .28);
}
.nav__cta:hover { background: var(--brand-d) !important; color: #fff !important; }

.nav-toggle {
  display: none;
  margin-left: auto;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 8px 13px;
  color: var(--ink-2);
  cursor: pointer;
}
.nav-toggle .ico { width: 20px; height: 20px; display: block; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  font-family: inherit;
  font-size: .96rem;
  font-weight: 650;
  border: 1px solid transparent;
  border-radius: 11px;
  cursor: pointer;
  transition: background .16s ease, border-color .16s ease, box-shadow .16s ease, transform .16s ease;
  white-space: nowrap;
}
.btn .ico { width: 17px; height: 17px; }

.btn--primary {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 5px 18px rgba(37, 99, 235, .3);
}
.btn--primary:hover { background: var(--brand-d); color: #fff; transform: translateY(-1px); box-shadow: 0 8px 24px rgba(37, 99, 235, .36); }

.btn--ghost {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
  box-shadow: var(--sh-sm);
}
.btn--ghost:hover { border-color: var(--brand-line); color: var(--brand-d); background: var(--brand-soft); }

.btn--soft {
  background: var(--brand-soft);
  border-color: var(--brand-line);
  color: var(--brand-d);
}
.btn--soft:hover { background: #e2ebff; color: var(--brand-d); }

.btn--onDark { background: #fff; color: var(--brand-d); }
.btn--onDark:hover { background: #eef4ff; color: var(--brand-d); }

.btn--ghostDark {
  background: rgba(255, 255, 255, .12);
  border-color: rgba(255, 255, 255, .34);
  color: #fff;
}
.btn--ghostDark:hover { background: rgba(255, 255, 255, .24); color: #fff; }

.btn--sm { padding: 10px 19px; font-size: .9rem; border-radius: 10px; }
.btn--block { width: 100%; }

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, #f2f7ff 0%, #fbfdff 52%, #fff 100%);
  padding: 68px 0 64px;
}
.hero::before {
  content: "";
  position: absolute;
  top: -220px; right: -140px;
  width: 760px; height: 760px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(99, 132, 255, .20), rgba(124, 58, 237, .08) 45%, transparent 70%);
  pointer-events: none;
}
.hero::after {
  content: "";
  position: absolute;
  bottom: -260px; left: -180px;
  width: 640px; height: 640px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(13, 148, 136, .13), transparent 68%);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 1; }

.hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(0, .96fr);
  gap: 34px 64px;
  align-items: center;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: .82rem;
  font-weight: 650;
  color: var(--brand-d);
  background: #fff;
  border: 1px solid var(--brand-line);
  padding: 6px 15px;
  border-radius: 999px;
  box-shadow: var(--sh-sm);
  margin-bottom: 22px;
}
.pill i {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 0 3px rgba(5, 150, 105, .16);
  flex: 0 0 auto;
}

.hero h1 { margin-bottom: 20px; }
.hero h1 em {
  font-style: normal;
  background: linear-gradient(100deg, var(--brand) 10%, var(--violet) 90%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__lead {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--ink-2);
  max-width: 40em;
  margin-bottom: 26px;
}
.hero__acts { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 22px; }
.hero__note {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  font-size: .88rem;
  color: var(--ink-3);
  list-style: none;
  padding: 0;
  margin: 0;
}
.hero__note li { display: flex; align-items: center; gap: 6px; margin: 0; }
.hero__note .ico { width: 15px; height: 15px; color: var(--green); }

/* ---------- 首屏代码窗口：暗色执行台 ----------
   左栏代码 + 右栏执行状态（变量 / dp 表 / 调用栈），或下方数组条；
   顶部进度条，底部滑出运行结果。脚本每次刷新随机换一套「算法 + 配色」，
   配色用 --cw-* 局部变量收在 .codewin 里（见下方的 .codewin--<主题>）。
   脚本不跑（窄屏 / 减少动态效果）时，它就是一张静态代码图。 */
.codewin {
  /* 默认主题（青）也是无脚本时的兜底配色 */
  --cw-bg: #0b1120;
  --cw-bar: #131f38;
  --cw-fg: #c7d2e0;
  --cw-line: rgba(148, 163, 184, .16);
  --cw-accent: #38bdf8;
  --cw-glow-1: rgba(56, 189, 248, .18);
  --cw-glow-2: rgba(56, 189, 248, .12);
  --cw-kw: #c084fc;
  --cw-fn: #60a5fa;
  --cw-num: #fbbf24;
  --cw-cm: #6b7c96;
  --cw-ok: #34d399;

  position: relative;
  background: var(--cw-bg);
  border: 1px solid rgba(148, 163, 184, .22);
  border-radius: var(--r-lg);
  box-shadow: 0 26px 60px rgba(10, 20, 40, .34), 0 2px 10px rgba(10, 20, 40, .18);
  overflow: hidden;
}
/* 主题：只换强调色与语法色，结构完全一致 */
.codewin--violet { --cw-accent: #a78bfa; --cw-glow-1: rgba(167, 139, 250, .2); --cw-glow-2: rgba(167, 139, 250, .12);
                   --cw-kw: #f0abfc; --cw-fn: #a78bfa; --cw-num: #fbbf24; --cw-cm: #7b7f9e; }
.codewin--amber { --cw-accent: #f59e0b; --cw-glow-1: rgba(245, 158, 11, .2); --cw-glow-2: rgba(245, 158, 11, .12);
                  --cw-kw: #f472b6; --cw-fn: #fbbf24; --cw-num: #4ade80; --cw-cm: #8b8578; }
.codewin--emerald { --cw-accent: #34d399; --cw-glow-1: rgba(52, 211, 153, .2); --cw-glow-2: rgba(52, 211, 153, .12);
                    --cw-kw: #5eead4; --cw-fn: #34d399; --cw-num: #fbbf24; --cw-cm: #6b8578; }
.codewin--rose { --cw-accent: #fb7185; --cw-glow-1: rgba(251, 113, 133, .2); --cw-glow-2: rgba(251, 113, 133, .12);
                 --cw-kw: #f0abfc; --cw-fn: #fb7185; --cw-num: #fbbf24; --cw-cm: #8a7480; }

/* 标题栏：红黄绿 + 文件名 + 运行状态灯 */
.codewin__bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 12px 16px;
  background: var(--cw-bar);
  border-bottom: 1px solid var(--cw-line);
}
/* 只作用于标题栏自己的三个圆点：用 > 以免命中状态灯的 <i> */
.codewin__bar > i { width: 11px; height: 11px; border-radius: 50%; background: #2b3b57; }
.codewin__bar > i:nth-child(1) { background: #ff5f57; }
.codewin__bar > i:nth-child(2) { background: #febc2e; }
.codewin__bar > i:nth-child(3) { background: #28c840; }
.codewin__bar em {
  margin-left: 8px;
  font-family: var(--mono);
  font-size: .76rem;
  font-style: normal;
  color: #7f8ea8;
}

.codewin__stat {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
  font-size: .72rem;
  font-weight: 650;
  color: #8494ad;
  white-space: nowrap;
}
.codewin__stat i {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #46536b;
  flex: 0 0 auto;
}
.codewin__stat.is-run { color: var(--cw-accent); }
.codewin__stat.is-run i { background: var(--cw-accent); animation: cw-pulse 1.3s ease-in-out infinite; }
.codewin__stat.is-done { color: var(--cw-ok); }
.codewin__stat.is-done i { background: var(--cw-ok); }
@keyframes cw-pulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--cw-glow-1); }
  55% { box-shadow: 0 0 0 5px rgba(0, 0, 0, 0); }
}

/* 执行进度条 */
.codewin__prog { height: 2px; background: rgba(148, 163, 184, .12); }
.codewin__prog i {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--cw-accent), var(--cw-fn));
  box-shadow: 0 0 10px var(--cw-glow-1);
  transition: width .32s linear;
}

/* 主体：左代码、右执行状态 */
.codewin__body { display: grid; grid-template-columns: minmax(0, 1fr) 172px; }
/* 数组类算法：右栏收起，代码占满整宽，数组条放到下方 */
.codewin.is-strip .codewin__body { grid-template-columns: minmax(0, 1fr); }
.codewin.is-strip .codewin__state { display: none; }

.codewin__code {
  position: relative;
  margin: 0;
  padding: 16px 16px 18px;
  font-family: var(--mono);
  font-size: .84rem;
  line-height: 1.85;
  color: var(--cw-fg);
  overflow-x: auto;
  /* 行是块级元素，行与行之间的源码空白必须折叠掉，否则代码里会多出空行 */
  white-space: normal;
}
.codewin__code code { display: block; background: none; padding: 0; font-size: inherit; color: inherit; }
.codewin__code .ln { display: block; white-space: pre; transition: opacity .35s ease; }
/* 行号 */
.codewin__code .no {
  display: inline-block;
  width: 1.9ch;
  margin-right: 13px;
  text-align: right;
  font-style: normal;
  font-size: .92em;
  color: #3f4d66;
  user-select: none;
}
/* 执行时：还没跑到的行压暗，跑过的行点亮 */
.codewin.is-run .ln { opacity: .4; }
.codewin.is-run .ln.is-lit { opacity: 1; }

/* 语法着色（暗色） */
.c-kw { color: var(--cw-kw, var(--violet)); font-weight: 600; }
.c-fn { color: var(--cw-fn, var(--brand)); }
.c-num { color: var(--cw-num, var(--amber)); }
.c-cm { color: var(--cw-cm, var(--ink-4)); font-style: italic; }
.c-str { color: var(--cw-ok, var(--teal)); }

/* 打字机：每个字符一个 .ch，逐字点亮（.is-typing 由脚本加上，无脚本时全部可见） */
.codewin__code.is-typing .ch { opacity: 0; }
.codewin__code.is-typing .ch.is-in { opacity: 1; }

/* 打字光标 */
.codewin__cursor {
  position: absolute;
  left: 0; top: 0;
  width: 8px;
  height: 1.02em;
  margin-top: .1em;
  border-radius: 1.5px;
  background: var(--cw-accent);
  box-shadow: 0 0 12px var(--cw-accent);
  opacity: 0;
  pointer-events: none;
}
.codewin__cursor.is-on { animation: cw-blink .95s steps(1, end) infinite; }
@keyframes cw-blink {
  0%, 58% { opacity: 1; }
  59%, 100% { opacity: 0; }
}

/* 当前执行行：一条带发光左边界的高亮带，位置由脚本写入 transform */
.codewin__hl {
  position: absolute;
  left: 0; right: 0; top: 0;
  height: 24px;                  /* 兜底值，脚本会按真实行高覆盖 */
  background: linear-gradient(90deg, var(--cw-glow-1), var(--cw-glow-2) 58%, rgba(0, 0, 0, 0));
  box-shadow:
    inset 3px 0 0 var(--cw-accent),
    inset 0 1px 0 var(--cw-glow-2),
    inset 0 -1px 0 var(--cw-glow-2);
  opacity: 0;
  transition: transform .2s cubic-bezier(.33, 1, .68, 1), opacity .22s ease;
  pointer-events: none;
}
.codewin__hl.is-jump { transition: none; }   /* 首次落位不做补间 */

/* 右栏：执行状态 */
.codewin__state {
  padding: 15px 13px;
  border-left: 1px solid var(--cw-line);
  background: rgba(255, 255, 255, .022);
}
.cw-hd {
  margin: 0 0 9px;
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .08em;
  color: #64748b;
}
.cw-panel { display: flex; flex-direction: column; gap: 5px; }
.cw-hd--log { margin-top: 15px; }

/* 变量行（数论 / 递推类） */
.cw-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  margin: 0;
  padding: 5px 10px 6px;
  border-radius: 9px;
  background: rgba(148, 163, 184, .08);
}
.cw-k { font-family: var(--mono); font-size: .72rem; color: #7f8ea8; }
.cw-v {
  font-family: var(--mono);
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.1;
  color: #dbe4f0;
}
/* 值变化时弹一下，让「哪一步改了哪个变量」看得见 */
.cw-v.is-hit {
  color: var(--cw-accent);
  text-shadow: 0 0 16px var(--cw-accent);
  animation: cw-pop .45s cubic-bezier(.33, 1, .68, 1) both;
}
@keyframes cw-pop {
  0% { transform: scale(.72); opacity: .25; }
  55% { transform: scale(1.09); }
  100% { transform: scale(1); opacity: 1; }
}

/* 递推表（动态规划）：一行一行填出来 */
.cw-li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px;
  margin: 0;
  padding: 4px 9px 5px;
  border-radius: 7px;
  background: rgba(148, 163, 184, .08);
  font-family: var(--mono);
  font-size: .72rem;
  color: #8fa0b8;
  animation: cw-slide .28s ease both;
}
.cw-li b { color: #dbe4f0; font-weight: 700; }
.cw-li.is-new { background: var(--cw-glow-2); color: #cbd5e1; }
.cw-li.is-new b { color: var(--cw-accent); text-shadow: 0 0 12px var(--cw-accent); }

/* 调用栈（递归）：一层层压上去，再一层层弹回来 */
.cw-fr {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 6px;
  margin: 0;
  padding: 5px 9px;
  border-radius: 7px;
  border-left: 2px solid var(--cw-accent);
  background: rgba(148, 163, 184, .1);
  font-family: var(--mono);
  font-size: .72rem;
  color: #cbd5e1;
  animation: cw-slide .26s ease both;
}
.cw-fr b { color: var(--cw-accent); font-weight: 700; }
.cw-fr.is-out { opacity: 0; transform: translateY(8px); transition: opacity .32s ease, transform .32s ease; }

/* 执行日志 */
.cw-log { display: flex; flex-direction: column; gap: 4px; margin-top: 4px; }
.cw-log p {
  display: flex;
  align-items: baseline;
  /* 值与标签相邻而不是顶到右边缘：右下角的悬浮卡会盖住面板右侧 */
  justify-content: flex-start;
  gap: 8px;
  margin: 0;
  font-family: var(--mono);
  font-size: .68rem;
  color: #64748b;
  animation: cw-slide .28s ease both;
}
.cw-log p b { font-weight: 700; }
.cw-log p.is-new { color: #b6c2d6; }
.cw-log p.is-new b { color: var(--cw-accent); }
@keyframes cw-slide {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

/* 数组条（查找 / 排序类）：代码下方横跨整宽 */
.cw-strip {
  padding: 22px 16px 15px;
  border-top: 1px solid var(--cw-line);
  background: rgba(255, 255, 255, .022);
}
.cw-strip[hidden] { display: none; }
.cw-arr-hd {
  margin: 0 0 10px;
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .06em;
  color: #64748b;
}
.cw-cells { display: flex; gap: 7px; }
.cw-cell {
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  padding: 10px 4px 9px;
  border-radius: 9px;
  border: 1px solid transparent;
  background: rgba(148, 163, 184, .1);
  color: #c7d2e0;
  font-family: var(--mono);
  font-size: .95rem;
  font-weight: 700;
  text-align: center;
  transition: background .25s ease, border-color .25s ease, color .25s ease,
              transform .25s ease, opacity .25s ease;
}
.cw-cell.is-dim { opacity: .3; }                                  /* 二分：落在区间外 */
.cw-cell.is-cmp {                                                 /* 冒泡：正在比较 */
  background: rgba(245, 158, 11, .2);
  border-color: rgba(245, 158, 11, .55);
  color: #fcd34d;
  transform: translateY(-3px);
}
.cw-cell.is-mid, .cw-cell.is-swap {                               /* 命中的 mid / 正在交换 */
  background: var(--cw-glow-1);
  border-color: var(--cw-accent);
  color: #fff;
  transform: translateY(-3px);
}
.cw-cell.is-hit { background: rgba(52, 211, 153, .2); border-color: rgba(52, 211, 153, .6); color: #a7f3d0; }
.cw-cell.is-done { background: rgba(52, 211, 153, .12); color: #6ee7b7; }   /* 已排好 */
.cw-cell-p {
  position: absolute;
  left: -6px; right: -6px;
  top: -16px;
  font-family: var(--mono);
  font-size: .6rem;
  font-weight: 700;
  font-style: normal;
  letter-spacing: .04em;
  color: var(--cw-accent);
  text-align: center;
  white-space: nowrap;
}

/* 运行结果：贴住窗口底边，不占高度、不推挤首屏排版 */
.codewin__out {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 13px 18px;
  background: rgba(52, 211, 153, .12);
  border-top: 1px solid rgba(52, 211, 153, .3);
  font-family: var(--mono);
  font-size: .88rem;
  color: #6ee7b7;
  transform: translateY(101%);
  opacity: 0;
  transition: transform .36s cubic-bezier(.33, 1, .68, 1), opacity .3s ease;
  pointer-events: none;
}
.codewin__out.is-on { transform: none; opacity: 1; }
.codewin__out-c { color: var(--cw-ok); font-weight: 700; }
.codewin__out-v {
  font-weight: 700;
  color: #a7f3d0;
  text-shadow: 0 0 14px rgba(52, 211, 153, .55);
}

/* 窄屏：不跑动画，右栏收起，代码占满整宽 */
@media (max-width: 860px) {
  .codewin__body { grid-template-columns: minmax(0, 1fr); }
  .codewin__state { display: none; }
}

/* 首屏数据条 */
.statbar {
  margin-top: 68px;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}
.statbar > div {
  background: #fff;
  padding: 26px 24px;
  transition: background .18s ease;
}
.statbar > div:hover { background: var(--bg-tint-2); }
.statbar b {
  display: flex;
  align-items: baseline;
  gap: 4px;
  font-size: 2rem;
  font-weight: 750;
  letter-spacing: -.03em;
  line-height: 1.1;
  color: var(--brand);
}
.statbar b em { font-style: normal; font-size: .42em; font-weight: 600; color: var(--ink-4); letter-spacing: 0; }
.statbar span { font-size: .87rem; color: var(--ink-3); }
.statbar > div:nth-child(2) b { color: var(--violet); }
.statbar > div:nth-child(3) b { color: var(--teal); }
.statbar > div:nth-child(4) b { color: var(--amber); }
.statbar > div:nth-child(5) b { color: var(--rose); }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(400px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 30px;
  box-shadow: var(--sh-sm);
  transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}
.card:hover { border-color: var(--brand-line); box-shadow: var(--sh); transform: translateY(-3px); }
.card h3 { margin-bottom: .5em; }
.card > p:last-child { margin-bottom: 0; }

.card__ic {
  width: 50px; height: 50px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
}
.card__ic .ico { width: 24px; height: 24px; }
.ic-brand { background: var(--brand-soft); color: var(--brand); }
.ic-violet { background: var(--violet-soft); color: var(--violet); }
.ic-teal { background: var(--teal-soft); color: var(--teal); }
.ic-amber { background: var(--amber-soft); color: var(--amber); }
.ic-rose { background: var(--rose-soft); color: var(--rose); }
.ic-green { background: var(--green-soft); color: var(--green); }

/* 勾选列表 */
.ticks { list-style: none; padding: 0; margin: 0; }
.ticks li {
  position: relative;
  padding-left: 27px;
  margin-bottom: .6em;
  color: var(--ink-2);
  font-size: .96rem;
}
.ticks li:last-child { margin-bottom: 0; }
.ticks li::before {
  content: "";
  position: absolute;
  left: 0; top: .38em;
  width: 17px; height: 17px;
  border-radius: 50%;
  background: var(--green-soft) url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23059669' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12.5 4.5 4.5L19 7'/%3E%3C/svg%3E") center / 11px 11px no-repeat;
}
.ticks--brand li::before {
  background-color: var(--brand-soft);
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%232563eb' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m5 12.5 4.5 4.5L19 7'/%3E%3C/svg%3E");
}

/* ---------- 主栏 + 侧栏 ----------
   正文列填满整列，右边缘与侧栏左边缘严格对齐 */
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 400px;
  gap: 72px;
  align-items: start;
}
.prose { max-width: none; }
.prose > p { color: var(--ink-2); }
.prose h3 { margin-top: 1.9em; margin-bottom: .7em; }
.prose h3:first-child { margin-top: 0; }
.prose > ul { margin-top: 0; }
.prose > p + ul, .prose > p + ol { margin-top: -.2em; }

.aside { position: sticky; top: 100px; }
/* 侧栏内容高过正文栏时取消吸顶：否则吸顶后底部会被视口裁掉，看不全 */
.aside--static { position: static; }

/* 快速入口：首屏直达入口带
   6 个入口做成实心彩色胶囊（各带自己的色相，白字白图标），是首屏里最跳的一块；
   带子本身留白底 + 蓝边 + 投影，并每隔几秒扫过一道高光，让它在静态首屏里「活着」。
   颜色都取白字对比度达标的深色值。 */
.quick-wrap { position: relative; grid-column: 1 / -1; }
.quick {       /* 作为首屏网格的一行，横跨整宽 */
  position: relative;
  overflow: hidden;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 20px;
  padding: 14px 18px;
  background: linear-gradient(120deg, #ffffff 0%, #f2f7ff 56%, #f6f2ff 100%);
  border: 1px solid var(--brand-line);
  border-radius: var(--r-lg);
  box-shadow: 0 14px 38px rgba(37, 99, 235, .14), 0 1px 2px rgba(16, 28, 51, .05);
}
/* 高光扫过：7 秒一趟，pointer-events 关掉，不影响点击 */
.quick::after {
  content: "";
  position: absolute;
  top: -60%;
  bottom: -60%;
  left: -180px;
  width: 140px;
  background: linear-gradient(100deg, rgba(255, 255, 255, 0), rgba(255, 255, 255, .8), rgba(255, 255, 255, 0));
  transform: skewX(-18deg);
  animation: quick-sheen 7s cubic-bezier(.5, 0, .5, 1) infinite;
  pointer-events: none;
}
@keyframes quick-sheen {
  0% { left: -180px; }
  60%, 100% { left: 108%; }
}
@media (prefers-reduced-motion: reduce) {
  .quick::after { display: none; }
}

.quick__title {
  display: flex;
  align-items: center;
  gap: 9px;
  flex: 0 0 auto;
  margin: 0;
  padding-right: 20px;
  border-right: 1px solid var(--brand-line);
  font-size: .95rem;
  font-weight: 800;
  letter-spacing: .08em;
  color: var(--brand-d);
  white-space: nowrap;
}
.quick__title .ico { width: 18px; height: 18px; }
/* 标签前一道渐变竖条，给整条入口带一个起手式 */
.quick__title::before {
  content: "";
  width: 5px;
  height: 20px;
  border-radius: 3px;
  background: linear-gradient(180deg, var(--brand), var(--violet));
}

/* 入口胶囊：实心彩色 + 白字 + 白圆图标，等宽铺满入口带 */
.tiles {
  display: flex;
  flex: 1 1 auto;
  flex-wrap: wrap;
  gap: 10px;
  min-width: 0;
}
.tile {
  --tone: #2563eb;
  --tone-d: #1d4ed8;
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 9px 16px 9px 9px;
  background: linear-gradient(135deg, var(--tone), var(--tone-d));
  border-radius: 999px;
  box-shadow: 0 4px 12px rgba(16, 28, 51, .16);
  font-size: .95rem;
  font-weight: 750;
  line-height: 1.3;
  color: #fff;
  white-space: nowrap;
  transition: filter .16s ease, box-shadow .16s ease, transform .16s ease;
}
/* 六个入口各自的色相（色值都按白字 ≥ 4.5:1 挑的） */
.tile--amber { --tone: #d97706; --tone-d: #b45309; }
.tile--brand { --tone: #3b82f6; --tone-d: #2563eb; }
.tile--teal { --tone: #14b8a6; --tone-d: #0f766e; }
.tile--violet { --tone: #8b5cf6; --tone-d: #7c3aed; }
.tile--green { --tone: #10b981; --tone-d: #047857; }
.tile--rose { --tone: #f43f5e; --tone-d: #e11d48; }

/* 悬停：整体提亮 + 浮起 + 更重的投影；箭头常驻不占位移 */
.tile::after {
  content: "→";
  font-weight: 700;
  color: #fff;
  opacity: .6;
  transition: opacity .18s ease, transform .18s ease;
}
.tile:hover {
  filter: brightness(1.07) saturate(1.05);
  box-shadow: 0 10px 24px rgba(16, 28, 51, .26);
  transform: translateY(-2px);
  text-decoration: none;
}
.tile:hover::after { opacity: 1; transform: translateX(2px); }

.tile .tile__ic {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: #fff;
  color: var(--tone-d);
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  transition: transform .18s ease;
}
.tile:hover .tile__ic { transform: scale(1.08) rotate(-4deg); }
.tile .tile__ic .ico { width: 19px; height: 19px; }
/* 胶囊文字：继承 .tile 的字号与字重，仅做换行控制 */
.tile__t { display: block; }
.tile:hover {color:#ffffff}

/* 入口带并入首屏网格后，网格与数据条之间无需再留大间距 */
.hero__grid + .statbar { margin-top: 30px; }

/* 窄屏：胶囊按内容宽度靠左流式排布，避免换行后最后一行被拉伸成整条 */
@media (max-width: 1000px) {
  .tile { flex: 0 1 auto; justify-content: flex-start; }
}
@media (max-width: 860px) {
  .quick { gap: 10px; padding: 13px 15px; }
  .quick__title { flex: 1 1 100%; padding: 0; border-right: 0; }
  .tile { font-size: .88rem; padding: 7px 13px 7px 7px; }
  .tile .tile__ic { width: 30px; height: 30px; }
  .tile .tile__ic .ico { width: 16px; height: 16px; }
}
.panel {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 28px;
  box-shadow: var(--sh-sm);
}
.panel + .panel { margin-top: 20px; }
.panel__title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--brand-d);
  margin-bottom: 18px;
}
.panel__title .ico { width: 16px; height: 16px; }

.deflist { margin: 0; font-size: .93rem; }
.deflist dt {
  font-size: .78rem;
  font-weight: 650;
  color: var(--ink-4);
  letter-spacing: .03em;
  margin-top: 15px;
}
.deflist dt:first-child { margin-top: 0; }
.deflist dd {
  margin: 3px 0 0;
  color: var(--ink-2);
  line-height: 1.7;
}

/* 内页侧栏：未用 .panel 包裹时的独立样式 */
.aside > .aside__title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--brand-d);
  margin-bottom: 16px;
}
.aside > .deflist {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 24px 26px;
  box-shadow: var(--sh-sm);
}

/* ---------- 表格 ---------- */
.tbl-wrap {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: var(--sh-sm);
}
.tbl-scroll { overflow-x: auto; }

.tbl { width: 100%; border-collapse: collapse; font-size: .95rem; font-variant-numeric: tabular-nums; }
.tbl caption {
  caption-side: top;
  text-align: left;
  padding: 20px 26px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
  letter-spacing: -.01em;
}
.tbl thead th {
  text-align: left;
  padding: 13px 20px;
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--ink-3);
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
.tbl tbody th, .tbl tbody td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--line-2);
  text-align: left;
  vertical-align: top;
  font-weight: 400;
  color: var(--ink-2);
}
.tbl tbody tr:last-child th, .tbl tbody tr:last-child td { border-bottom: 0; }
.tbl tbody tr:hover { background: var(--bg-tint-2); }
.tbl tbody th { font-weight: 650; color: var(--ink); white-space: nowrap; }
.tbl .num {
  text-align: right;
  white-space: nowrap;
  font-family: var(--mono);
  font-size: .9rem;
  font-weight: 600;
  color: var(--brand);
  padding-right: 26px;
}
.tbl thead th.num { color: var(--ink-3); font-family: var(--sans); font-size: .78rem; }
.tbl .num--dim { color: var(--ink-3); }

/* 表格分组小标题 */
.treegroup + .treegroup { margin-top: 44px; }
.treegroup__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 16px;
}
.treegroup__head h3 { margin: 0; }
.treegroup__head span {
  font-size: .85rem;
  color: var(--ink-3);
  background: var(--brand-soft);
  border: 1px solid var(--brand-line);
  padding: 3px 11px;
  border-radius: 999px;
  font-weight: 600;
}

/* ---------- 赵老师 · 讲师卡 ---------- */
.teacher {
  display: grid;
  grid-template-columns: 340px minmax(0, 1fr);
  gap: 34px;
  align-items: start;
}

.tcard {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-xl);
  padding: 34px 30px;
  text-align: center;
  box-shadow: var(--sh);
  position: sticky;
  top: 100px;
}
.tcard__ava {
  width: 116px; height: 116px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: linear-gradient(140deg, var(--brand-l), var(--violet));
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 2.6rem;
  font-weight: 700;
  letter-spacing: -.02em;
  box-shadow: 0 12px 30px rgba(37, 99, 235, .3);
  overflow: hidden;
}
.tcard__ava img { width: 100%; height: 100%; object-fit: cover; }
.tcard h3 { margin-bottom: .2em; font-size: 1.35rem; }
.tcard__role {
  font-size: .92rem;
  color: var(--brand-d);
  font-weight: 600;
  margin-bottom: 18px;
}
.tcard__bio {
  font-size: .93rem;
  color: var(--ink-2);
  text-align: left;
  padding-top: 20px;
  border-top: 1px solid var(--line-2);
  margin-bottom: 0;
}
.tcard__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  list-style: none;
  padding: 0;
  margin: 20px 0 0;
}
.tcard__tags li {
  font-size: .79rem;
  font-weight: 600;
  color: var(--ink-3);
  background: var(--bg-soft);
  border: 1px solid var(--line);
  padding: 4px 11px;
  border-radius: 999px;
  margin: 0;
}

/* 课程卡 */
.course {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 28px;
  box-shadow: var(--sh-sm);
  transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
  display: flex;
  flex-direction: column;
}
.course:hover { border-color: var(--brand-line); box-shadow: var(--sh); transform: translateY(-3px); }
.course__top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 16px;
}
.course__ic {
  width: 46px; height: 46px;
  border-radius: 13px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
}
.course__ic .ico { width: 22px; height: 22px; }
.course__lvl {
  font-size: .75rem;
  font-weight: 700;
  padding: 4px 11px;
  border-radius: 999px;
  white-space: nowrap;
}
.course h3 { margin-bottom: .35em; }
.course__for { font-size: .87rem; color: var(--ink-3); margin-bottom: 14px; }
.course__list {
  list-style: none;
  padding: 0;
  margin: 0 0 20px;
  font-size: .92rem;
  flex: 1 1 auto;
}
.course__list li {
  position: relative;
  padding-left: 18px;
  color: var(--ink-2);
  margin-bottom: .38em;
}
.course__list li::before {
  content: "";
  position: absolute;
  left: 0; top: .68em;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--brand-l);
}
.course__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 18px;
  border-top: 1px solid var(--line-2);
  font-size: .85rem;
  color: var(--ink-3);
}

/* 课程：一行四列
   卡片宽度有限（约 315px），要点内容已配平为等长的 5 条，
   避免各卡高度悬殊、被最高的那张拉齐后出现大片留白 */
.grid--courses { grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 26px; }
.grid--courses .course { padding: 26px 22px; }
.grid--courses .course__top { margin-bottom: 13px; }
.grid--courses .course__ic { width: 38px; height: 38px; border-radius: 11px; }
.grid--courses .course__ic .ico { width: 19px; height: 19px; }
.grid--courses .course__lvl { font-size: .72rem; padding: 3px 9px; }
.grid--courses .course h3 { font-size: 1.04rem; margin-bottom: .32em; }
.grid--courses .course__for { font-size: .85rem; margin-bottom: 15px; }
.grid--courses .course__list { font-size: .89rem; line-height: 1.68; }
.grid--courses .course__list li { margin-bottom: .32em; padding-left: 16px; }
/* foot 里是「上课形式 + 咨询报名」，列宽只有约 315px，
   放宽换行并压缩按钮内边距，避免窄屏下挤成一行 */
.grid--courses .course__foot {
  padding-top: 14px;
  font-size: .82rem;
  flex-wrap: wrap;
  gap: 8px 10px;
}
.grid--courses .course__foot .btn { padding: 7px 14px; font-size: .84rem; }

/* 课程：横跨整宽的次级强调卡（首页用） */
.course--wide {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 200px;
  gap: 38px;
  align-items: center;
  padding: 32px 34px;
  background: var(--brand-soft);
  border-color: var(--brand-line);
}
.course--wide .course__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .2em 30px;
  margin-bottom: 0;
}
.course--wide .course__act { display: grid; gap: 10px; }

/* 主推课程卡：横跨整宽的强调样式 */
.course--feature {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 48px;
  align-items: center;
  padding: 44px 48px;
  border: 0;
  border-radius: var(--r-xl);
  background: linear-gradient(135deg, #1e50e6 0%, #3b5bf5 46%, #7c3aed 100%);
  box-shadow: 0 20px 54px rgba(37, 99, 235, .26);
  color: #d5e0ff;
}
.course--feature:hover { transform: none; border: 0; box-shadow: 0 22px 58px rgba(37, 99, 235, .3); }
.course--feature h3 {
  color: #fff;
  font-size: clamp(1.35rem, 2vw, 1.72rem);
  margin-bottom: .4em;
}
.course--feature .course__lvl {
  color: #fff;
  background: rgba(255, 255, 255, .18);
  border: 1px solid rgba(255, 255, 255, .32);
}
.course--feature .course__for { color: #bfd0ff; font-size: .95rem; margin-bottom: 20px; }
.course--feature .course__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .2em 34px;
  margin-bottom: 0;
  font-size: .93rem;
}
.course--feature .course__list li { color: #dbe4ff; }
.course--feature .course__list li::before { background: #9db6ff; }
.course--feature .course__act { display: grid; gap: 12px; }

@media (max-width: 1240px) {
  .grid--courses { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 1080px) {
  .course--feature { grid-template-columns: 1fr; gap: 30px; padding: 34px 30px; }
  .course--feature .course__list { grid-template-columns: 1fr; }
  .course--wide { grid-template-columns: 1fr; gap: 26px; padding: 28px 26px; }
  .course--wide .course__list { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  .grid--courses { grid-template-columns: 1fr; }
}

/* ---------- 联系区 ---------- */
.contact {
  background: linear-gradient(135deg, #1e50e6 0%, #3b5bf5 42%, #7c3aed 100%);
  border-radius: var(--r-xl);
  padding: 54px 56px;
  color: #dbe4ff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 22px 60px rgba(37, 99, 235, .28);
}
.contact::before {
  content: "";
  position: absolute;
  top: -160px; right: -80px;
  width: 520px; height: 520px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, .18), transparent 66%);
  pointer-events: none;
}
.contact > * { position: relative; z-index: 1; }
.contact h2 { color: #fff; margin-bottom: .4em; }
.contact > p { color: #cbd8ff; /*max-width: 62ch;*/ font-size: 1.02rem; }

.contact__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 20px;
  margin-top: 34px;
}
.cbox {
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: var(--r);
  padding: 20px 22px;
  backdrop-filter: blur(4px);
}
.cbox__k {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: .78rem;
  font-weight: 650;
  letter-spacing: .06em;
  color: #b9caff;
  margin-bottom: 8px;
}
.cbox__k .ico { width: 15px; height: 15px; }
.cbox__v { font-size: 1.22rem; font-weight: 700; color: #fff; letter-spacing: -.01em; word-break: break-all; }
.cbox__v a { color: #fff; }
.cbox__v a:hover { color: #fff; text-decoration: underline; text-underline-offset: 3px; }
.cbox__n { font-size: .82rem; color: #b9caff; margin: 6px 0 0; }

.contact__acts { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }

/* ---------- 下载清单 ---------- */
.sw { display: grid; gap: 22px; }
.sw__row {
  display: grid;
  grid-template-columns: minmax(0, 300px) minmax(0, 1fr) 160px;
  gap: 40px;
  align-items: start;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 30px 34px;
  box-shadow: var(--sh-sm);
  transition: border-color .2s ease, box-shadow .2s ease;
}
.sw__row:hover { border-color: var(--brand-line); box-shadow: var(--sh); }
.sw__name { display: flex; gap: 15px; align-items: flex-start; }
.sw__ic {
  width: 50px; height: 50px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
}
.sw__ic .ico { width: 24px; height: 24px; }
.sw__name h3 { margin-bottom: .28em; font-size: 1.1rem; }
.sw__meta { font-size: .83rem; color: var(--ink-3); margin: 0; }
.sw__tag {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .05em;
  color: var(--amber);
  background: var(--amber-soft);
  border: 1px solid #fbe0b8;
  padding: 2px 9px;
  border-radius: 999px;
  margin-left: 7px;
  vertical-align: 2px;
}
.sw__body { color: var(--ink-2); font-size: .95rem; }
.sw__body > p { margin-bottom: .8em; }
.sw__notes { list-style: none; padding: 0; margin: 0; font-size: .9rem; }
.sw__notes li {
  position: relative;
  padding-left: 19px;
  color: var(--ink-3);
  margin-bottom: .32em;
}
.sw__notes li::before {
  content: "";
  position: absolute;
  left: 2px; top: .66em;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--brand-line);
}
.sw__act { text-align: right; }
.sw__act .btn { width: 100%; }

/* ---------- 团队 / 校队 ---------- */
.teamgrid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.teamcol {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 30px;
  box-shadow: var(--sh-sm);
}
.teamcol h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 16px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line-2);
  font-size: 1.06rem;
}
.teamcol h3 .ico { width: 19px; height: 19px; color: var(--brand); }
.teamcol ul { list-style: none; padding: 0; margin: 0; }
.teamcol li {
  position: relative;
  padding-left: 20px;
  font-size: .94rem;
  color: var(--ink-2);
  margin-bottom: .55em;
}
.teamcol li:last-child { margin-bottom: 0; }
.teamcol li::before {
  content: "";
  position: absolute;
  left: 0; top: .7em;
  width: 5px; height: 5px;
  border-radius: 50%;
  background: var(--brand-l);
}

/* ---------- 侧栏 + 内容（问答分栏） ---------- */
.rail {
  display: grid;
  grid-template-columns: 400px minmax(0, 1fr);
  gap: 72px;
  align-items: start;
}
.rail__side { position: sticky; top: 100px; }
.rail__side h2 { margin-bottom: .55em; }
.rail__side > p { color: var(--ink-3); font-size: 1.02rem; margin-bottom: 24px; }

/* ---------- 问答 ---------- */
.qa { display: grid; gap: 14px; align-content: start; }

.qa__item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  box-shadow: var(--sh-sm);
  overflow: hidden;
  transition: border-color .18s ease, box-shadow .18s ease;
}
.qa__item:hover { border-color: var(--brand-line); }
.qa__item[open] { border-color: var(--brand-line); box-shadow: var(--sh); }

.qa__q {
  list-style: none;
  cursor: pointer;
  padding: 20px 60px 20px 24px;
  position: relative;
  font-weight: 650;
  font-size: 1.03rem;
  color: var(--ink);
  line-height: 1.6;
  transition: background .15s ease;
}
.qa__q::-webkit-details-marker { display: none; }
.qa__q:hover { background: var(--bg-tint-2); }
.qa__q::after {
  content: "";
  position: absolute;
  right: 24px; top: 50%;
  width: 9px; height: 9px;
  margin-top: -6px;
  border-right: 2px solid var(--ink-4);
  border-bottom: 2px solid var(--ink-4);
  transform: rotate(45deg);
  transition: transform .22s ease, border-color .22s ease;
}
.qa__item[open] .qa__q::after { transform: rotate(-135deg); margin-top: -2px; border-color: var(--brand); }
.qa__item[open] .qa__q { background: var(--brand-soft); }

.qa__num {
  display: inline-block;
  font-family: var(--mono);
  font-size: .78rem;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-soft);
  border: 1px solid var(--brand-line);
  padding: 2px 8px;
  border-radius: 6px;
  margin-right: 11px;
  vertical-align: 2px;
}
.qa__item[open] .qa__num { background: #fff; }

.qa__body { padding: 22px 24px 26px; border-top: 1px solid var(--line-2); }
.qa__answer {
  font-size: 1rem;
  line-height: 1.82;
  color: var(--ink);
  font-weight: 550;
  background: var(--teal-soft);
  border-left: 3px solid var(--teal);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  padding: 15px 20px;
  margin: 0 0 18px;
}
.qa__answer b {
  display: inline-block;
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--teal);
  background: #fff;
  border: 1px solid #c4ece6;
  padding: 2px 8px;
  border-radius: 5px;
  margin-right: 9px;
  vertical-align: 2px;
}
.qa__body > p { color: var(--ink-2); font-size: .96rem; }
.qa__meta {
  margin-top: 18px !important;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: .8rem !important;
  color: var(--ink-4) !important;
}

.qa-cat + .qa-cat { margin-top: 64px; }
.qa-cat__head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
}
.qa-cat__head h2 { margin: 0; font-size: 1.3rem; }
.qa-cat__head span {
  font-family: var(--mono);
  font-size: .78rem;
  font-weight: 700;
  color: var(--brand-d);
  background: var(--brand-soft);
  border: 1px solid var(--brand-line);
  padding: 3px 11px;
  border-radius: 999px;
}

/* ---------- 文档目录 ---------- */
.doc { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 56px; align-items: start; }
.toc { position: sticky; top: 100px; }
.toc__title {
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink-4);
  margin-bottom: 14px;
}
.toc ol { list-style: none; padding: 0; margin: 0; }
.toc li { margin-bottom: 4px; }
.toc a {
  display: block;
  padding: 9px 14px;
  font-size: .9rem;
  color: var(--ink-2);
  border-radius: 9px;
  border-left: 2px solid transparent;
}
.toc a:hover { background: var(--brand-soft); color: var(--brand-d); border-left-color: var(--brand); text-decoration: none; }
.toc-tools { margin-top: 18px; }
.toc-tools button {
  width: 100%;
  font-family: inherit;
  font-size: .87rem;
  font-weight: 600;
  color: var(--brand-d);
  background: var(--brand-soft);
  border: 1px solid var(--brand-line);
  border-radius: 10px;
  padding: 10px 14px;
  cursor: pointer;
  transition: background .15s ease;
}
.toc-tools button:hover { background: #e2ebff; }

/* ---------- 行动区 ---------- */
.cta {
  background: linear-gradient(135deg, #f0f5ff 0%, #f6f2ff 100%);
  border: 1px solid var(--brand-line);
  border-radius: var(--r-xl);
  padding: 46px 52px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
}
.cta h2 { margin-bottom: .3em; font-size: 1.5rem; }
.cta p { color: var(--ink-2); margin-bottom: 0; max-width: 58em; font-size: .98rem; }
.cta__act { display: flex; flex-wrap: wrap; gap: 12px; }

/* ---------- 内页页头 ---------- */
.pagehead {
  background: linear-gradient(180deg, var(--bg-tint) 0%, #fff 100%);
  border-bottom: 1px solid var(--line);
  padding: 46px 0 54px;
}
.crumb { font-size: .85rem; color: var(--ink-4); margin-bottom: 20px; }
.crumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; padding: 0; margin: 0; }
.crumb li { margin: 0; }
.crumb li + li::before { content: "/"; margin-right: 8px; color: var(--ink-4); }
.crumb a { color: var(--ink-3); }
.crumb a:hover { color: var(--brand); }
.pagehead h1 { margin-bottom: 16px; }
.pagehead > .wrap > p { color: var(--ink-2); /*max-width: 78ch;*/ font-size: 1.05rem; margin-bottom: 0; }

/* ---------- 相关链接 ---------- */
.also { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; list-style: none; padding: 0; margin: 0; }
.also li { margin: 0; }
.also a {
  display: block;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 22px 24px;
  color: var(--ink);
  box-shadow: var(--sh-sm);
  transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease;
  height: 100%;
}
.also a:hover { border-color: var(--brand-line); box-shadow: var(--sh); transform: translateY(-2px); text-decoration: none; color: var(--brand-d); }
.also b { display: block; margin-bottom: .3em; font-size: 1rem; }
.also span { font-size: .88rem; color: var(--ink-3); }

/* ---------- 提示条 ---------- */
.note {
  display: flex;
  gap: 12px;
  background: var(--amber-soft);
  border: 1px solid #fbe0b8;
  border-radius: var(--r);
  padding: 18px 22px;
  font-size: .91rem;
  color: #7a4a06;
  margin: 0;
}
.note .ico { width: 19px; height: 19px; color: var(--amber); margin-top: 3px; }
.note strong { color: #7a4a06; }
.note p:last-child { margin-bottom: 0; }
.note--brand { background: var(--brand-soft); border-color: var(--brand-line); color: var(--brand-d); }
.note--brand .ico { color: var(--brand); }
.note--brand strong { color: var(--brand-d); }

/* ---------- 步骤 ---------- */
.steps { list-style: none; padding: 0; margin: 0; counter-reset: s; }
.steps li {
  position: relative;
  padding: 0 0 30px 60px;
  counter-increment: s;
}
.steps li::before {
  content: counter(s);
  position: absolute;
  left: 0; top: 0;
  width: 38px; height: 38px;
  background: var(--brand);
  color: #fff;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: .95rem;
  font-weight: 700;
  box-shadow: 0 5px 14px rgba(37, 99, 235, .3);
}
.steps li::after {
  content: "";
  position: absolute;
  left: 19px; top: 46px; bottom: 6px;
  width: 1px;
  background: var(--line);
}
.steps li:last-child { padding-bottom: 0; }
.steps li:last-child::after { display: none; }
.steps h3 { font-size: 1.05rem; margin-bottom: .3em; }
.steps p { font-size: .94rem; color: var(--ink-2); margin-bottom: 0; }

/* ---------- 页脚 ---------- */
.footer {
  background: var(--bg-soft);
  border-top: 1px solid var(--line);
  padding: 68px 0 0;
  font-size: .92rem;
}
.footer__grid {
  display: grid;
  grid-template-columns: 1.7fr repeat(3, 1fr);
  gap: 52px;
  padding-bottom: 48px;
}
.footer__brand .brand { margin-bottom: 18px; }
.footer__brand p { font-size: .89rem; color: var(--ink-3); max-width: 40em; }
.footer__note {
  margin-top: 18px;
  font-size: .84rem;
  color: var(--ink-4);
  padding-top: 16px;
  border-top: 1px solid var(--line);
}
.footer__note a { color: var(--ink-3); }
.footer__note a:hover { color: var(--brand); }

.footer__col h3 {
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink-4);
  margin-bottom: 16px;
}
.footer__col ul { list-style: none; padding: 0; margin: 0; }
.footer__col li { margin-bottom: .62em; }
.footer__col a { color: var(--ink-2); font-size: .9rem; }
.footer__col a:hover { color: var(--brand); }

.footer__bot {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
  padding: 24px 0 28px;
  border-top: 1px solid var(--line);
  font-size: .85rem;
  color: var(--ink-3);
}
.footer__bot p { margin: 0; }
.footer__bot a { color: var(--ink-3); }
.footer__bot a:hover { color: var(--brand); }

/* ---------- 浮动的联系方式按钮 ---------- */
.contact-fab {
  position: fixed;
  right: 26px;
  bottom: 26px;
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 13px 22px;
  background: var(--brand);
  color: #fff;
  font-size: .93rem;
  font-weight: 650;
  border-radius: 999px;
  box-shadow: 0 10px 30px rgba(37, 99, 235, .38);
  transition: background .18s ease, transform .18s ease;
}
.contact-fab:hover { background: var(--brand-d); color: #fff; transform: translateY(-2px); text-decoration: none; }
.contact-fab .ico { width: 18px; height: 18px; }

/* ---------- 工具类 ---------- */
.txt-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.75rem; }
.mt-4 { margin-top: 2.75rem; }
.mt-5 { margin-top: 4rem; }

.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--brand); color: #fff;
  padding: 13px 22px; z-index: 300; font-weight: 650;
  border-radius: 0 0 10px 0;
}
.skip:focus { left: 0; }

.vh {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1420px) {
}

@media (max-width: 1240px) {
  .wrap { padding-inline: 30px; }
  .hero__grid { gap: 44px; }
  .teacher { grid-template-columns: 300px minmax(0, 1fr); gap: 28px; }
  .split { grid-template-columns: minmax(0, 1fr) 330px; gap: 48px; }
}

@media (max-width: 1080px) {
  .section { padding: 74px 0; }
  .hero { padding: 62px 0 58px; }
  .hero__grid { grid-template-columns: 1fr; gap: 30px; }
  /* 单列时快速入口提到代码窗口之前，避免要翻过整块代码才看到入口 */
  .quick-wrap { order: 2; }
  .hero__visual { order: 3; max-width: 620px; }
  .statbar { grid-template-columns: repeat(3, 1fr); margin-top: 34px; }
  .teacher { grid-template-columns: 1fr; }
  .tcard { position: static; max-width: 460px; margin-inline: auto; }
  .split { grid-template-columns: 1fr; gap: 40px; }
  .aside { position: static; }
  .rail { grid-template-columns: 1fr; gap: 36px; }
  .rail__side { position: static; }
  .doc { grid-template-columns: 1fr; gap: 32px; }
  .toc { position: static; }
  .toc ol { display: flex; flex-wrap: wrap; gap: 8px; }
  .toc li { margin: 0; }
  .toc a { border: 1px solid var(--line); border-radius: 999px; padding: 7px 15px; font-size: .86rem; background: #fff; }
  .toc a:hover { border-color: var(--brand-line); }
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 38px; }
  .sw__row { grid-template-columns: 1fr; gap: 20px; padding: 26px 26px; }
  .sw__act { text-align: left; }
  .sw__act .btn { width: auto; }
  .contact { padding: 44px 38px; }
}

@media (max-width: 860px) {
  body { font-size: 16px; }
  .nav-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    left: 0; right: 0; top: 74px;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 12px 24px 20px;
    box-shadow: var(--sh-lg);
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 13px 14px; border-radius: 10px; }
  .nav__cta { margin: 12px 0 0; text-align: center; }

  .wrap { padding-inline: 22px; }
  .section { padding: 62px 0; }
  .section--tight { padding: 48px 0; }
  .sec-head { margin-bottom: 34px; }
  .hero { padding: 48px 0 52px; }
  .hero__lead { font-size: 1.02rem; }
  .statbar { grid-template-columns: repeat(2, 1fr); }
  .statbar > div { padding: 20px 18px; }
  .statbar b { font-size: 1.6rem; }
  .grid { gap: 18px; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .card, .teamcol, .course { padding: 24px; }
  .tcard { padding: 28px 24px; }
  .contact { padding: 34px 24px; border-radius: var(--r-lg); }
  .contact__grid { grid-template-columns: 1fr; }
  .cta { padding: 32px 24px; border-radius: var(--r-lg); }
  .cta h2 { font-size: 1.28rem; }
  .footer { padding-top: 48px; }
  .footer__grid { grid-template-columns: 1fr; gap: 30px; }
  .qa__q { padding: 17px 48px 17px 18px; font-size: .99rem; }
  .qa__q::after { right: 20px; }
  .qa__body { padding: 18px 18px 22px; }
  .qa__answer { padding: 13px 16px; }
  .contact-fab { right: 16px; bottom: 16px; padding: 12px 18px; font-size: .88rem; }
  .tbl tbody th, .tbl tbody td, .tbl thead th { padding: 13px 16px; }
  .tbl .num { padding-right: 18px; }
}

@media (max-width: 480px) {
  .brand__sub { display: none; }
  .hero__acts .btn { width: 100%; }
  .statbar { grid-template-columns: 1fr; }
  .steps li { padding-left: 50px; }
}

/* ---------- 打印 ---------- */
@media print {
  .topbar, .footer, .nav-toggle, .toc-tools, .contact-fab, .hero__visual { display: none; }
  body { font-size: 11pt; background: #fff; color: #000; }
  .hero, .pagehead, .section--soft, .section--tint { background: #fff; padding: 12px 0; }
  .contact { background: #fff; color: #000; border: 1px solid #999; box-shadow: none; }
  .contact h2, .contact > p, .cbox__v, .cbox__k, .cbox__n { color: #000; }
  .cbox { border-color: #ccc; background: #f5f5f5; }
  .card, .qa__item, .sw__row, .tcard { break-inside: avoid; box-shadow: none; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: .82em; color: #555; }
}

/* ---------- 快速入口：编程学习（弹出平台选择） ---------- */
.tile-pop { position: relative; display: flex; flex: 1 1 auto; min-width: 0; }
.tile.is-primary {
  --tone: #fff;
  background: linear-gradient(120deg, #38bdf8, #6366f1 55%, #a855f7);
  border-color: transparent;
  color: #fff;
  font-weight: 750;
  box-shadow: 0 10px 26px rgba(56, 189, 248, .34);
}
.tile.is-primary .tile__ic { background: rgba(255, 255, 255, .22); color: #fff; }
.tile.is-primary:hover {
  background: linear-gradient(120deg, #38bdf8, #6366f1 55%, #a855f7);
  border-color: transparent;
  color: #fff;
  filter: brightness(1.06);
  box-shadow: 0 14px 32px rgba(99, 102, 241, .42);
}
.tile.is-primary::after { color: #fff; opacity: .85; }
.tile__caret { font-size: .78em; opacity: .85; line-height: 1; margin-left: -2px; }

.learnmenu {
  /* 用 fixed：首屏那段 overflow:hidden（裁装饰光晕用的）会把绝对定位的弹层切掉，
     所以位置由脚本按按钮的实际坐标计算，并随滚动/缩放重算 */
  position: fixed;
  z-index: 200;
  top: 0;
  left: 0;
  width: 400px;
  max-width: calc(100vw - 32px);
  padding: 16px;
  background: #fff;
  border: 1px solid var(--line, #e2ecf9);
  border-radius: var(--r-lg, 22px);
  box-shadow: 0 26px 60px rgba(16, 28, 51, .2), 0 4px 12px rgba(16, 28, 51, .06);
  text-align: left;
}
.learnmenu[hidden] { display: none; }
.learnmenu__title {
  margin: 0 0 10px;
  font-family: var(--mono, monospace);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--ink-4, #9fb0c9);
  text-transform: uppercase;
}
.learnmenu__item {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  padding: 11px 12px;
  border: 0;
  border-radius: 13px;
  background: none;
  color: var(--ink, #16233a);
  font-family: inherit;
  text-align: left;
  cursor: pointer;
  transition: background .16s ease;
}
.learnmenu__item:hover { background: var(--brand-soft, #eaf2ff); }
.learnmenu__ic {
  width: 38px; height: 38px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
}
.learnmenu__ic .ico { width: 19px; height: 19px; }
.learnmenu__text { flex: 1 1 auto; min-width: 0; }
.learnmenu__text b { display: block; font-size: .95rem; font-weight: 700; }
.learnmenu__text i {
  display: block;
  margin-top: 2px;
  font-style: normal;
  font-size: .8rem;
  color: var(--ink-3, #6f84a6);
}
.learnmenu__go { color: var(--brand-d, #0284c7); font-weight: 700; }
.learnmenu__badge {
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--amber-soft, #fff4dc);
  color: #b45309;
  font-family: var(--mono, monospace);
  font-size: .66rem;
  font-weight: 700;
  white-space: nowrap;
}
.learnmenu__item.is-soon { cursor: default; }
.learnmenu__item.is-soon:hover { background: #fff8ea; }
.learnmenu__notice {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin: 12px 0 0;
  padding: 12px 14px;
  border: 1px solid #fde3b0;
  border-radius: 13px;
  background: var(--amber-soft, #fff4dc);
  color: #7c5310;
  font-size: .86rem;
  line-height: 1.65;
}
.learnmenu__notice[hidden] { display: none; }
.learnmenu__notice .ico { width: 16px; height: 16px; color: #d97706; margin-top: 3px; flex: 0 0 auto; }
@keyframes learn-shake {
  0%, 100% { transform: none; }
  25% { transform: translateX(-3px); }
  75% { transform: translateX(3px); }
}
.learnmenu__item.is-shake { animation: learn-shake .4s ease; }

@media (prefers-reduced-motion: reduce) {
  .learnmenu__item.is-shake { animation: none; }
}

/* 首位的「编程学习」再突出一点：更宽 + 白色描边光环 */
.tile.is-primary { flex: 1.4 1 auto; box-shadow: 0 0 0 2px rgba(255, 255, 255, .55), 0 12px 28px rgba(99, 102, 241, .38); }
.tile.is-primary:hover { box-shadow: 0 0 0 2px rgba(255, 255, 255, .7), 0 16px 34px rgba(99, 102, 241, .46); }
@media (max-width: 1000px) { .tile.is-primary { flex: 0 1 auto; } }