/* === 食来运转 Tutorial — Clean Layout === */
:root {
  --w-side: 260px;
  --w-content: 820px;
  --c-bg: #F8F6FF;
  --c-surface: #FFFFFF;
  --c-text: #1E1B2E;
  --c-text2: #555566;
  --c-muted: #999AAA;
  --c-border: #E8E4F0;
  --c-accent: #7B68D0;
  --c-accent2: #6BA3D6;
  --c-code-bg: #1E1B2E;
  --c-code-text: #E0DCF0;
  --shadow: 0 2px 12px rgba(99,66,200,0.08);
  --radius: 12px;
  --font: system-ui,-apple-system,'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;
  --font-mono: 'JetBrains Mono','Fira Code',Consolas,monospace;
}

[data-theme="dark"] {
  --c-bg: #0F0B1A;
  --c-surface: #1A1530;
  --c-text: #F0ECFF;
  --c-text2: #B0A8CC;
  --c-muted: #6B6488;
  --c-border: #2A2540;
  --c-code-bg: #0D0B16;
  --c-code-text: #D8D0F0;
  --shadow: 0 2px 12px rgba(0,0,0,0.3);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:24px;font-size:16px}
body{font-family:var(--font);color:var(--c-text);background:var(--c-bg);line-height:1.7}
a{color:var(--c-accent);text-decoration:none}
img,svg{max-width:100%;height:auto}
pre,code{font-family:var(--font-mono)}

/* ===== Layout Grid ===== */
.layout{display:grid;grid-template-columns:var(--w-side) minmax(0,var(--w-content)) 1fr;min-height:100vh}
.main{grid-column:2}
@media(max-width:900px){.layout{grid-template-columns:1fr}.main{grid-column:1}}

/* ===== Sidebar ===== */
.sidebar{
  position:sticky;top:0;height:100vh;overflow-y:auto;
  background:var(--c-surface);border-right:1px solid var(--c-border);
  display:flex;flex-direction:column;z-index:10;
  transition:transform .3s;
}
@media(max-width:900px){
  .sidebar{
    position:fixed;left:0;top:0;width:var(--w-side);z-index:200;
    transform:translateX(-100%);box-shadow:4px 0 20px rgba(0,0,0,.15);
  }
  .sidebar.open{transform:translateX(0)}
}
.sidebar-header{
  padding:24px 20px 16px;
  display:flex;align-items:center;gap:10px;
  border-bottom:1px solid var(--c-border);
}
.sidebar-header .logo-text{font-size:1.15rem;font-weight:700;color:var(--c-accent)}
.sidebar-header .logo-sub{font-size:.75rem;color:var(--c-muted)}
.sidebar-nav{flex:1;padding:12px 0;overflow-y:auto}
.sidebar-nav .nav-group{margin-bottom:8px}
.sidebar-nav .nav-group-title{
  padding:8px 20px 4px;font-size:.7rem;font-weight:700;
  text-transform:uppercase;letter-spacing:.05em;color:var(--c-muted);
}
.sidebar-nav a{
  display:flex;align-items:center;gap:8px;padding:7px 20px;
  font-size:.88rem;color:var(--c-text2);border-radius:0;
  transition:background .15s,color .15s;
}
.sidebar-nav a:hover{background:rgba(123,104,208,.08);color:var(--c-accent)}
.sidebar-nav a.active{background:rgba(123,104,208,.12);color:var(--c-accent);font-weight:600}
.sidebar-nav a svg{width:18px;height:18px;flex-shrink:0;stroke:currentColor;fill:none;stroke-width:2}
.sidebar-footer{
  padding:12px 20px;border-top:1px solid var(--c-border);
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  font-size:.75rem;color:var(--c-muted);
}

/* Theme toggle */
.theme-btn{
  background:none;border:1px solid var(--c-border);border-radius:8px;
  padding:6px 12px;cursor:pointer;font-size:.8rem;color:var(--c-text2);
  display:flex;align-items:center;gap:6px;
}
.theme-btn:hover{background:rgba(123,104,208,.08)}
.theme-btn svg{width:16px;height:16px;stroke:currentColor;fill:none;stroke-width:2}

/* Mobile menu button */
.menu-btn{
  display:none;position:fixed;top:12px;left:12px;z-index:300;
  width:40px;height:40px;border-radius:10px;background:var(--c-surface);
  border:1px solid var(--c-border);cursor:pointer;align-items:center;justify-content:center;
  box-shadow:var(--shadow);
}
.menu-btn svg{width:22px;height:22px;stroke:var(--c-text);fill:none;stroke-width:2}
@media(max-width:900px){.menu-btn{display:flex}}
.overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:150}
.overlay.show{display:block}

/* ===== Main Content ===== */
.main{padding:40px 48px 80px;max-width:var(--w-content);width:100%;margin:0 auto}
@media(max-width:900px){.main{padding:72px 20px 60px;max-width:100%}}
@media(max-width:480px){.main{padding:64px 14px 48px}}

/* ===== Sections ===== */
.sec{margin-bottom:64px;scroll-margin-top:24px}
.sec-title{font-size:1.8rem;font-weight:800;color:var(--c-text);margin-bottom:8px;line-height:1.25}
.sec-desc{font-size:1rem;color:var(--c-text2);margin-bottom:24px;max-width:640px}
.sec-divider{border:none;border-top:1px solid var(--c-border);margin:32px 0}

/* ===== Cards ===== */
.card{
  background:var(--c-surface);border:1px solid var(--c-border);
  border-radius:var(--radius);padding:20px 24px;margin-bottom:16px;
  box-shadow:var(--shadow);
}
.card h3{font-size:1.1rem;margin-bottom:8px;color:var(--c-accent)}
.card p{font-size:.9rem;color:var(--c-text2)}
.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin-bottom:24px}
@media(max-width:600px){.card-grid{grid-template-columns:1fr}}

/* Feature cards with colored left accent */
.card.accent{padding-left:20px;box-shadow:inset 3px 0 0 0 var(--c-accent)}

/* ===== Code Blocks ===== */
.code-block{
  background:var(--c-code-bg);border-radius:var(--radius);
  margin:20px 0 24px;overflow:hidden;box-shadow:var(--shadow);
}
.code-block-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:10px 16px;background:rgba(255,255,255,.04);
  border-bottom:1px solid rgba(255,255,255,.06);
}
.code-dots{display:flex;gap:6px}
.code-dots span{width:10px;height:10px;border-radius:50%}
.code-dots .r{background:#FF5F57}
.code-dots .y{background:#FEBC2E}
.code-dots .g{background:#28C840}
.code-lang{font-size:.75rem;color:rgba(255,255,255,.4)}
.copy-btn{
  background:none;border:1px solid rgba(255,255,255,.15);
  color:rgba(255,255,255,.5);padding:4px 10px;border-radius:6px;
  cursor:pointer;font-size:.75rem;transition:all .15s;
}
.copy-btn:hover{background:rgba(255,255,255,.1);color:#fff}
.code-block pre{
  margin:0;padding:18px 20px;overflow-x:auto;
  font-size:.84rem;line-height:1.65;color:var(--c-code-text);
  white-space:pre;tab-size:2;
}
.code-block pre code{background:none!important;padding:0!important;font-size:inherit}
.code-block pre::-webkit-scrollbar{height:4px}
.code-block pre::-webkit-scrollbar-thumb{background:rgba(255,255,255,.15);border-radius:2px}

/* Inline code */
:not(pre)>code{
  background:rgba(123,104,208,.1);color:var(--c-accent);
  padding:1px 6px;border-radius:4px;font-size:.9em;
}

/* ===== Tables ===== */
.tbl{width:100%;border-collapse:collapse;margin:16px 0 24px;font-size:.9rem}
.tbl th,.tbl td{padding:10px 14px;text-align:left;border-bottom:1px solid var(--c-border)}
.tbl th{font-weight:700;color:var(--c-accent);background:rgba(123,104,208,.04)}
.tbl tr:hover td{background:rgba(123,104,208,.03)}

/* ===== Tip/Warning/Success boxes ===== */
.callout{
  display:flex;gap:10px;align-items:flex-start;padding:14px 18px;
  border-radius:var(--radius);margin:16px 0;font-size:.9rem;line-height:1.6;
}
.callout svg{width:20px;height:20px;flex-shrink:0;margin-top:2px;stroke:currentColor;fill:none;stroke-width:2}
.callout.tip{background:rgba(123,104,208,.07);border:1px solid rgba(123,104,208,.15);color:var(--c-text2)}
.callout.warn{background:rgba(245,158,11,.07);border:1px solid rgba(245,158,11,.15);color:var(--c-text2)}
.callout.ok{background:rgba(16,185,129,.07);border:1px solid rgba(16,185,129,.15);color:var(--c-text2)}

/* ===== Back to Top ===== */
.btt{
  position:fixed;bottom:24px;right:24px;z-index:100;
  width:44px;height:44px;border-radius:50%;background:var(--c-accent);
  border:none;cursor:pointer;box-shadow:0 4px 16px rgba(123,104,208,.3);
  display:flex;align-items:center;justify-content:center;
  opacity:0;transform:translateY(20px);transition:all .3s;pointer-events:none;
}
.btt.show{opacity:1;transform:translateY(0);pointer-events:auto}
.btt:hover{transform:translateY(-2px)}
.btt svg{width:20px;height:20px;stroke:#fff;fill:none;stroke-width:2.5}

/* ===== Accordion ===== */
.accordion{border:1px solid var(--c-border);border-radius:var(--radius);overflow:hidden;margin:16px 0}
.accordion-trigger{
  width:100%;display:flex;align-items:center;justify-content:space-between;
  padding:14px 18px;background:var(--c-surface);border:none;cursor:pointer;
  font-size:.95rem;font-weight:600;color:var(--c-text);text-align:left;
}
.accordion-trigger:hover{background:rgba(123,104,208,.04)}
.accordion-trigger svg{width:18px;height:18px;stroke:var(--c-accent);fill:none;stroke-width:2;transition:transform .2s}
.accordion-trigger[aria-expanded="true"] svg{transform:rotate(45deg)}
.accordion-panel{display:grid;grid-template-rows:0fr;overflow:hidden;transition:grid-template-rows .35s ease}
.accordion-panel[aria-hidden="false"]{grid-template-rows:1fr}
.accordion-panel>div{padding:0 18px 16px;font-size:.9rem;color:var(--c-text2);line-height:1.6}

/* ===== Tab Switcher ===== */
.tabs{display:flex;gap:0;border-bottom:2px solid var(--c-border);margin:20px 0}
.tab-btn{
  padding:10px 20px;border:none;background:none;cursor:pointer;
  font-size:.9rem;color:var(--c-text2);border-bottom:2px solid transparent;
  margin-bottom:-2px;transition:all .15s;
}
.tab-btn.active{color:var(--c-accent);border-bottom-color:var(--c-accent);font-weight:600}
.tab-panel{display:none}
.tab-panel.active{display:block}

/* ===== Dir Tree ===== */
.dir-tree{font-family:var(--font-mono);font-size:.85rem;line-height:2;color:var(--c-text2);padding:12px 0}
.dir-tree .d{color:#6BA3D6}
.dir-tree .f{color:var(--c-code-text)}
.dir-tree .c{color:var(--c-muted)}

/* ===== Badges ===== */
.badge{
  display:inline-block;padding:2px 10px;border-radius:100px;
  font-size:.75rem;font-weight:600;margin-right:6px;margin-bottom:6px;
}
.badge.purple{background:rgba(123,104,208,.12);color:#7B68D0}
.badge.blue{background:rgba(107,163,214,.12);color:#6BA3D6}
.badge.green{background:rgba(16,185,129,.12);color:#10B981}
.badge.amber{background:rgba(245,158,11,.12);color:#F59E0B}
.badge.pink{background:rgba(236,72,153,.12);color:#EC4899}

/* ===== Progress Bar ===== */
.progress-bar{
  position:fixed;top:0;left:0;height:3px;z-index:500;
  background:linear-gradient(90deg,var(--c-accent),#A78BFA);
  transform:scaleX(0);transform-origin:left;transition:transform .1s linear;
}

/* ===== highlight.js overrides ===== */
.hljs{background:transparent!important;color:var(--c-code-text)!important;padding:0!important}

/* ===== Print-friendly ===== */
@media print{
  .sidebar,.menu-btn,.btt,.progress-bar,.overlay{display:none!important}
  .layout{display:block}
  .main{max-width:100%;padding:0}
}