/* ═══════════ PengOS · Apple-grade design system ═══════════ */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #000;
  --bg-soft: #0a0a0f;
  --card: rgba(255,255,255,.045);
  --card-border: rgba(255,255,255,.09);
  --text: #f5f5f7;
  --text-2: #a1a1a6;
  --text-3: #6e6e73;
  --blue: #2997ff;
  --purple: #bf5af2;
  --pink: #ff375f;
  --green: #30d158;
  --orange: #ff9f0a;
  --radius: 24px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
          "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", "JetBrains Mono", Consolas, "Courier New", monospace;
}

html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.hidden { display: none !important; }

/* ─── 导航 ─── */
#nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  background: rgba(0,0,0,.72);
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.nav-inner {
  max-width: 1024px; margin: 0 auto; height: 52px;
  display: flex; align-items: center; gap: 32px; padding: 0 22px;
}
.logo { font-weight: 700; font-size: 17px; color: var(--text); text-decoration: none; cursor: pointer; }
.nav-links { display: flex; gap: 28px; flex: 1; }
.nav-links a {
  color: var(--text-2); text-decoration: none; font-size: 13px;
  transition: color .25s; cursor: pointer;
}
.nav-links a:hover { color: var(--text); }
.nav-cta {
  background: var(--blue); color: #fff; border: none; border-radius: 980px;
  padding: 6px 16px; font-size: 13px; font-family: var(--font); cursor: pointer;
  transition: transform .2s, background .2s;
}
.nav-cta:hover { background: #3da2ff; transform: scale(1.04); }

/* ─── Hero ─── */
.hero {
  min-height: 100vh; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
  padding: 120px 22px 80px; position: relative;
}
.hero-glow {
  position: absolute; top: 10%; left: 50%; transform: translateX(-50%);
  width: 900px; height: 600px; pointer-events: none;
  background:
    radial-gradient(ellipse 400px 300px at 30% 40%, rgba(41,151,255,.22), transparent 70%),
    radial-gradient(ellipse 400px 300px at 70% 60%, rgba(191,90,242,.18), transparent 70%),
    radial-gradient(ellipse 300px 250px at 50% 30%, rgba(255,55,95,.12), transparent 70%);
  filter: blur(40px);
  animation: glowDrift 12s ease-in-out infinite alternate;
}
@keyframes glowDrift {
  from { transform: translateX(-50%) scale(1) rotate(0deg); }
  to   { transform: translateX(-50%) scale(1.15) rotate(5deg); }
}
.hero-eyebrow {
  color: var(--blue); font-size: 15px; font-weight: 600;
  letter-spacing: .08em; margin-bottom: 20px; position: relative;
}
.hero-title {
  font-size: clamp(48px, 9vw, 104px); font-weight: 700;
  line-height: 1.05; letter-spacing: -.02em; position: relative;
}
.grad-text {
  background: linear-gradient(95deg, #2997ff 0%, #bf5af2 45%, #ff375f 90%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-sub {
  margin-top: 26px; font-size: clamp(16px, 2.4vw, 21px);
  color: var(--text-2); line-height: 1.6; position: relative;
}
.hero-actions { margin-top: 40px; display: flex; gap: 24px; align-items: center; position: relative; }
.btn-primary {
  background: var(--blue); color: #fff; border: none; border-radius: 980px;
  padding: 14px 30px; font-size: 17px; font-weight: 600; font-family: var(--font);
  cursor: pointer; transition: transform .25s cubic-bezier(.2,.8,.3,1.2), box-shadow .25s;
}
.btn-primary:hover { transform: scale(1.05); box-shadow: 0 8px 30px rgba(41,151,255,.45); }
.btn-link {
  background: none; border: none; color: var(--blue); font-size: 17px;
  font-family: var(--font); cursor: pointer; transition: opacity .2s;
}
.btn-link:hover { opacity: .75; text-decoration: underline; }
.hero-stats {
  margin-top: 60px; display: flex; gap: 48px; position: relative;
  color: var(--text-3); font-size: 14px;
}
.hero-stats b { color: var(--text); font-size: 20px; display: block; margin-bottom: 2px; }

/* ─── 区块通用 ─── */
.section { max-width: 1024px; margin: 0 auto; padding: 100px 22px 40px; }
.sec-eyebrow {
  color: var(--blue); font-size: 14px; font-weight: 600;
  letter-spacing: .12em; text-transform: uppercase; margin-bottom: 12px;
}
.sec-title {
  font-size: clamp(36px, 6vw, 64px); font-weight: 700;
  letter-spacing: -.02em; line-height: 1.1;
}
.sec-sub { color: var(--text-2); font-size: 17px; margin-top: 16px; }

/* ─── 仪表盘 ─── */
.dash-grid {
  display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; margin-top: 48px;
}
.dash-card {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: var(--radius); padding: 32px;
  backdrop-filter: blur(10px);
  transition: transform .35s cubic-bezier(.2,.8,.3,1), border-color .35s;
}
.dash-card:hover { transform: translateY(-4px); border-color: rgba(255,255,255,.2); }
.ring-card { display: flex; align-items: center; justify-content: center; position: relative; }
.ring { width: 170px; transform: rotate(-90deg); }
.ring-bg { fill: none; stroke: rgba(255,255,255,.08); stroke-width: 13; }
.ring-fg {
  fill: none; stroke: url(#ringGrad); stroke-width: 13; stroke-linecap: round;
  stroke-dasharray: 527.8; stroke-dashoffset: 527.8;
  transition: stroke-dashoffset 1.4s cubic-bezier(.3,.7,.3,1);
}
.ring-label { position: absolute; text-align: center; }
.ring-num { font-size: 34px; font-weight: 700; display: block; }
.ring-text { font-size: 13px; color: var(--text-2); }
.stat-big { font-size: 44px; font-weight: 700; line-height: 1; }
.stat-unit { font-size: 18px; color: var(--text-3); font-weight: 500; margin-left: 4px; }
.stat-label { color: var(--text-2); font-size: 14px; margin-top: 8px; margin-bottom: 24px; }
.streak { color: var(--orange); }
.mini-bars { display: flex; gap: 4px; height: 52px; align-items: flex-end; }
.mini-bar {
  flex: 1; border-radius: 4px 4px 2px 2px; min-height: 6px;
  background: rgba(255,255,255,.1);
  transition: height .8s cubic-bezier(.3,.7,.3,1), background .3s;
  cursor: pointer;
}
.mini-bar.done { background: linear-gradient(180deg, #2997ff, #bf5af2); }
.mini-bar.part { background: rgba(41,151,255,.45); }
.mini-bar:hover { filter: brightness(1.4); }

/* ─── 章节卡片 ─── */
.chapter-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px; margin-top: 48px;
}
.ch-card {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: var(--radius); padding: 30px; cursor: pointer;
  position: relative; overflow: hidden;
  transition: transform .35s cubic-bezier(.2,.8,.3,1), border-color .35s, box-shadow .35s;
}
.ch-card::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(500px circle at var(--mx,50%) var(--my,50%), rgba(255,255,255,.07), transparent 45%);
  opacity: 0; transition: opacity .3s; pointer-events: none;
}
.ch-card:hover::before { opacity: 1; }
.ch-card:hover { transform: translateY(-6px); border-color: rgba(255,255,255,.22); box-shadow: 0 20px 50px rgba(0,0,0,.5); }
.ch-head { display: flex; justify-content: space-between; align-items: flex-start; }
.ch-icon { font-size: 34px; }
.ch-num {
  font-size: 13px; font-weight: 700; letter-spacing: .15em;
  color: var(--text-3); font-family: var(--mono);
}
.ch-title { font-size: 21px; font-weight: 700; margin-top: 18px; }
.ch-sub { color: var(--text-2); font-size: 14px; margin-top: 6px; }
.ch-foot { display: flex; align-items: center; gap: 12px; margin-top: 22px; }
.ch-track { flex: 1; height: 5px; border-radius: 3px; background: rgba(255,255,255,.09); overflow: hidden; }
.ch-fill {
  height: 100%; border-radius: 3px; width: 0;
  background: linear-gradient(90deg, #2997ff, #bf5af2);
  transition: width .9s cubic-bezier(.3,.7,.3,1);
}
.ch-pct { font-size: 12px; color: var(--text-3); font-family: var(--mono); min-width: 36px; text-align: right; }
.ch-badge {
  position: absolute; top: 24px; right: 24px; font-size: 18px;
  opacity: 0; transform: scale(.4) rotate(-30deg);
  transition: all .5s cubic-bezier(.3,1.5,.5,1);
}
.ch-card.done .ch-badge { opacity: 1; transform: scale(1) rotate(0); }
.ch-card.done { border-color: rgba(48,209,88,.35); }

/* ─── 资源 ─── */
.res-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 48px; }
.res-item {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: 18px; padding: 22px 26px; display: flex; gap: 18px; align-items: flex-start;
  transition: border-color .3s, transform .3s;
}
.res-item:hover { border-color: rgba(255,255,255,.2); transform: translateY(-2px); }
.res-tag {
  flex-shrink: 0; font-size: 12px; font-weight: 700; padding: 4px 12px;
  border-radius: 980px; background: rgba(41,151,255,.15); color: var(--blue);
}
.res-name { font-weight: 600; font-size: 15px; }
.res-desc { color: var(--text-2); font-size: 13px; margin-top: 5px; line-height: 1.5; }

footer {
  text-align: center; color: var(--text-3); font-size: 13px;
  padding: 60px 22px 40px; border-top: 1px solid rgba(255,255,255,.06); margin-top: 80px;
}

/* ─── 滚动显现 ─── */
.reveal { opacity: 0; transform: translateY(36px); transition: opacity .9s ease, transform .9s cubic-bezier(.2,.7,.3,1); }
.reveal.in { opacity: 1; transform: none; }

/* ═══════════ 章节详情页 ═══════════ */
.cv-hero {
  padding: 150px 22px 70px; text-align: center; position: relative; overflow: hidden;
  background: radial-gradient(ellipse 800px 400px at 50% -10%, rgba(41,151,255,.13), transparent 70%);
}
.back-btn {
  position: absolute; top: 80px; left: max(22px, calc(50% - 500px));
  background: var(--card); border: 1px solid var(--card-border); color: var(--text-2);
  border-radius: 980px; padding: 8px 18px; font-size: 13px; font-family: var(--font);
  cursor: pointer; transition: color .2s, border-color .2s;
}
.back-btn:hover { color: var(--text); border-color: rgba(255,255,255,.3); }
.cv-num {
  font-family: var(--mono); font-size: 15px; font-weight: 700;
  letter-spacing: .3em; color: var(--blue);
}
.cv-title {
  font-size: clamp(38px, 7vw, 72px); font-weight: 700;
  letter-spacing: -.02em; margin-top: 12px;
}
.cv-sub { font-size: 20px; color: var(--text-2); margin-top: 10px; }
.cv-intro { max-width: 640px; margin: 22px auto 0; color: var(--text-2); line-height: 1.7; font-size: 16px; }
.cv-progress {
  max-width: 420px; height: 6px; margin: 34px auto 0; border-radius: 3px;
  background: rgba(255,255,255,.09); overflow: hidden;
}
.cv-progress-bar {
  height: 100%; width: 0; border-radius: 3px;
  background: linear-gradient(90deg, #2997ff, #bf5af2, #ff375f);
  transition: width .8s cubic-bezier(.3,.7,.3,1);
}
.cv-body { max-width: 780px; margin: 0 auto; padding: 20px 22px 100px; }

/* 理论区 */
.theory { margin-bottom: 44px; }
.theory h3 {
  font-size: 26px; font-weight: 700; margin-bottom: 18px;
  display: flex; align-items: center; gap: 12px;
}
.theory h3::before {
  content: ""; width: 5px; height: 24px; border-radius: 3px;
  background: linear-gradient(180deg, #2997ff, #bf5af2);
}
.theory p { color: #d1d1d6; line-height: 1.85; font-size: 16px; margin-bottom: 14px; }
.theory ul { margin: 0 0 14px 22px; }
.theory li { color: #d1d1d6; line-height: 1.85; font-size: 16px; margin-bottom: 6px; }
.theory b { color: var(--text); }
.theory code {
  font-family: var(--mono); font-size: .9em;
  background: rgba(41,151,255,.13); color: #7dc4ff;
  padding: 2px 7px; border-radius: 6px;
}
pre.code {
  font-family: var(--mono); font-size: 14px; line-height: 1.75;
  background: #111116; border: 1px solid rgba(255,255,255,.08);
  border-radius: 14px; padding: 20px 24px; margin: 14px 0;
  overflow-x: auto; color: #c8e6c9;
}
.tip, .warn {
  border-radius: 14px; padding: 14px 18px; font-size: 14px !important; line-height: 1.7 !important;
}
.tip { background: rgba(48,209,88,.09); border: 1px solid rgba(48,209,88,.25); }
.warn { background: rgba(255,159,10,.09); border: 1px solid rgba(255,159,10,.3); }

/* 表格 */
.tbl {
  border: 1px solid rgba(255,255,255,.1); border-radius: 14px;
  overflow: hidden; margin: 14px 0; font-size: 14px;
}
.tr { display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; }
.tr span { padding: 11px 16px; color: #d1d1d6; border-bottom: 1px solid rgba(255,255,255,.06); }
.tr:last-child span { border-bottom: none; }
.tr.th span { background: rgba(255,255,255,.06); font-weight: 700; color: var(--text); font-size: 13px; }

/* 练习 */
.cv-ex-title { font-size: 30px; font-weight: 700; margin: 70px 0 6px; }
.cv-ex-sub { color: var(--text-2); font-size: 15px; margin-bottom: 28px; }
.ex-card {
  background: var(--card); border: 1px solid var(--card-border);
  border-radius: 20px; padding: 26px 28px; margin-bottom: 18px;
  transition: border-color .3s;
}
.ex-card.correct { border-color: rgba(48,209,88,.5); }
.ex-card.wrong { border-color: rgba(255,55,95,.5); animation: shake .4s; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  25% { transform: translateX(-7px); } 75% { transform: translateX(7px); }
}
.ex-head { display: flex; gap: 12px; align-items: flex-start; margin-bottom: 16px; }
.ex-tag {
  flex-shrink: 0; font-size: 11px; font-weight: 700; padding: 3px 10px;
  border-radius: 980px; margin-top: 2px;
}
.ex-tag.choice { background: rgba(41,151,255,.15); color: var(--blue); }
.ex-tag.fill { background: rgba(191,90,242,.15); color: var(--purple); }
.ex-tag.cmd { background: rgba(48,209,88,.15); color: var(--green); }
.ex-q { font-size: 16px; font-weight: 600; line-height: 1.6; }
.ex-opts { display: flex; flex-direction: column; gap: 10px; }
.ex-opt {
  text-align: left; background: rgba(255,255,255,.04);
  border: 1px solid rgba(255,255,255,.1); border-radius: 12px;
  padding: 13px 18px; color: var(--text); font-size: 15px; font-family: var(--font);
  cursor: pointer; transition: all .2s;
}
.ex-opt:hover { background: rgba(255,255,255,.08); border-color: rgba(255,255,255,.25); }
.ex-opt.picked-right { background: rgba(48,209,88,.13); border-color: var(--green); }
.ex-opt.picked-wrong { background: rgba(255,55,95,.13); border-color: var(--pink); }
.ex-opt:disabled { cursor: default; opacity: .85; }
.ex-input-row { display: flex; gap: 10px; }
.ex-input {
  flex: 1; background: rgba(255,255,255,.05);
  border: 1px solid rgba(255,255,255,.14); border-radius: 12px;
  padding: 13px 18px; color: var(--text); font-size: 15px; font-family: var(--font);
  outline: none; transition: border-color .2s;
}
.ex-input.cmd-input { font-family: var(--mono); color: #7dc4ff; }
.ex-input:focus { border-color: var(--blue); }
.ex-submit {
  background: var(--blue); color: #fff; border: none; border-radius: 12px;
  padding: 0 22px; font-size: 15px; font-weight: 600; font-family: var(--font);
  cursor: pointer; transition: background .2s;
}
.ex-submit:hover { background: #3da2ff; }
.ex-submit:disabled { background: rgba(255,255,255,.12); color: var(--text-3); cursor: default; }
.ex-explain {
  margin-top: 16px; border-radius: 12px; padding: 14px 18px; font-size: 14px;
  line-height: 1.7; display: none;
}
.ex-explain.show { display: block; animation: fadeUp .4s ease; }
.ex-explain.ok { background: rgba(48,209,88,.09); border: 1px solid rgba(48,209,88,.25); color: #b9f6ca; }
.ex-explain.no { background: rgba(255,55,95,.08); border: 1px solid rgba(255,55,95,.25); color: #ffcdd2; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.cv-complete { text-align: center; padding: 70px 20px; }
.cv-complete-icon { font-size: 64px; animation: pop .7s cubic-bezier(.3,1.6,.4,1); }
@keyframes pop { from { transform: scale(0) rotate(-20deg); } to { transform: scale(1) rotate(0); } }
.cv-complete h3 { font-size: 30px; font-weight: 700; margin: 18px 0 8px; }
.cv-complete p { color: var(--text-2); margin-bottom: 28px; }

/* ─── 响应式 ─── */
@media (max-width: 860px) {
  .dash-grid { grid-template-columns: 1fr; }
  .res-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .back-btn { left: 22px; top: 70px; }
}