/* ===== Reset & Tokens ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

[data-theme="dark"] {
  --bg: #090c10; --bg2: #0d1017; --bg-card: #111620; --bg-code: #0c1015; --bg-nav: #0b0f16;
  --border: #1a2030; --border-h: #2a3648;
  --text: #b4bcc8; --text-dim: #5f7088; --text-bright: #e4eaf0;
  --accent: #58a6ff; --accent2: #3fb950; --accent3: #d2a8ff; --accent4: #f778ba;
  --accent-glow: rgba(88,166,255,.1); --accent-glow2: rgba(88,166,255,.04);
  --sh-card: 0 1px 3px rgba(0,0,0,.2), 0 4px 16px rgba(0,0,0,.25);
  --sh-card-h: 0 4px 12px rgba(0,0,0,.3), 0 12px 40px rgba(0,0,0,.35);
  --c-cm: #4b5d73; --c-kw: #ff7b72; --c-st: #a5d6ff; --c-ty: #d2a8ff;
  --c-fn: #d19a66; --c-dc: #79c0ff; --c-nm: #79c0ff;
  --br-raw: linear-gradient(90deg,#3d4550,#5a6370);
  --br-vel: linear-gradient(90deg,#3d8bdb,#34a853);
  --br-ely: linear-gradient(90deg,#b88ee0,#e06098);
  --br-hon: linear-gradient(90deg,#e08830,#c06828);
  --glass: rgba(14,18,26,.75); --glass-b: rgba(88,166,255,.06);
  --overlay: rgba(0,0,0,.65);
  --scrollbar-thumb: #1e2a3a;
  --progress: var(--accent);
}
[data-theme="light"] {
  --bg: #f7f8fb; --bg2: #edf0f4; --bg-card: #fff; --bg-code: #f4f6f9; --bg-nav: #fbfcfd;
  --border: #d4dae2; --border-h: #afb8c4;
  --text: #3a424c; --text-dim: #6a7788; --text-bright: #181d24;
  --accent: #0969da; --accent2: #1a7f37; --accent3: #8250df; --accent4: #bf3989;
  --accent-glow: rgba(9,105,218,.06); --accent-glow2: rgba(9,105,218,.03);
  --sh-card: 0 1px 3px rgba(0,0,0,.04), 0 4px 12px rgba(0,0,0,.06);
  --sh-card-h: 0 4px 8px rgba(0,0,0,.06), 0 10px 30px rgba(0,0,0,.1);
  --c-cm: #6e7781; --c-kw: #cf222e; --c-st: #0a3069; --c-ty: #8250df;
  --c-fn: #953800; --c-dc: #0550ae; --c-nm: #0550ae;
  --br-raw: linear-gradient(90deg,#a0a8b4,#828a96);
  --br-vel: linear-gradient(90deg,#0969da,#1a7f37);
  --br-ely: linear-gradient(90deg,#8250df,#bf3989);
  --br-hon: linear-gradient(90deg,#a63c00,#803000);
  --glass: rgba(255,255,255,.82); --glass-b: rgba(0,0,0,.03);
  --overlay: rgba(240,242,246,.78);
  --scrollbar-thumb: #c4cad2;
  --progress: var(--accent);
}
:root {
  --grad: linear-gradient(135deg,#58a6ff 0%,#3fb950 50%,#d2a8ff 100%);
  --grad-t: linear-gradient(135deg,#79c0ff,#56d364,#d2a8ff);
  --r: 12px; --nav-w: 264px;
  --mono: 'SF Mono','Fira Code','Cascadia Code','JetBrains Mono',Consolas,monospace;
  --sans: -apple-system,BlinkMacSystemFont,'Segoe UI',Inter,Roboto,sans-serif;
  --fs: 16px;
}
html { scroll-behavior: smooth; font-size: var(--fs); }
body { font-family: var(--sans); background: var(--bg); color: var(--text); line-height: 1.72; overflow-x: hidden; transition: background .4s ease, color .4s ease; }
a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: var(--text-bright); }
::selection { background: rgba(88,166,255,.22); color: var(--text-bright); }
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 3px; }

/* ===== Reading progress bar ===== */
.progress-bar { position: fixed; top: 0; left: 0; height: 2px; background: var(--grad); z-index: 999; width: 0; transition: width .15s linear; }

/* ===== Settings panel ===== */
.settings-overlay { position: fixed; inset: 0; background: var(--overlay); backdrop-filter: blur(5px); z-index: 400; opacity: 0; pointer-events: none; transition: opacity .3s; display: flex; align-items: center; justify-content: center; }
.settings-overlay.show { opacity: 1; pointer-events: auto; }
.settings-panel { background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; max-width: 380px; width: 90%; box-shadow: 0 20px 60px rgba(0,0,0,.3); transform: translateY(16px) scale(.97); transition: transform .3s, background .4s; padding: 28px; position: relative; }
.settings-overlay.show .settings-panel { transform: translateY(0) scale(1); }
.settings-panel h3 { font-size: 1.1rem; font-weight: 700; color: var(--text-bright); margin-bottom: 18px; transition: color .4s; }
.settings-row { display: flex; align-items: center; justify-content: space-between; padding: 10px 0; border-bottom: 1px solid var(--border); }
.settings-row:last-child { border-bottom: none; }
.settings-label { font-size: .85rem; color: var(--text); }
.settings-ctrl { display: flex; align-items: center; gap: 8px; }
.settings-ctrl button { width: 30px; height: 30px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text); font-size: .85rem; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: border-color .2s, background .4s; }
.settings-ctrl button:hover { border-color: var(--accent); color: var(--accent); }
.settings-ctrl span { font-size: .82rem; font-family: var(--mono); color: var(--text-dim); min-width: 36px; text-align: center; }
.settings-close { position: absolute; top: 10px; right: 12px; width: 28px; height: 28px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text-dim); font-size: .82rem; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: border-color .2s; }
.settings-close:hover { border-color: var(--accent); color: var(--accent); }

/* Toggle switch */
.toggle { position: relative; width: 40px; height: 22px; background: var(--border); border-radius: 11px; cursor: pointer; transition: background .3s; }
.toggle.on { background: var(--accent); }
.toggle::after { content: ''; position: absolute; top: 2px; left: 2px; width: 18px; height: 18px; border-radius: 50%; background: var(--bg-card); transition: transform .3s, background .4s; box-shadow: 0 1px 3px rgba(0,0,0,.2); }
.toggle.on::after { transform: translateX(18px); }

/* Compact mode */
html.compact section { padding-top: 48px; padding-bottom: 48px; }
html.compact .step { margin-bottom: 36px; }
html.compact .sh { margin-bottom: 28px; }
html.compact pre { padding: 12px 16px; margin: 8px 0 14px; }

/* ===== Sidebar ===== */
.sidebar { position: fixed; top: 0; left: 0; width: var(--nav-w); height: 100vh; background: var(--bg-nav); border-right: 1px solid var(--border); overflow-y: auto; z-index: 100; padding: 16px 0; transition: transform .3s ease, background .4s, border-color .4s; }
.sb-top { padding: 0 16px 12px; border-bottom: 1px solid var(--border); margin-bottom: 8px; display: flex; align-items: center; justify-content: space-between; gap: 6px; }
.sb-brand { display: flex; flex-direction: column; }
.sb-logo { font-size: 1.2rem; font-weight: 800; letter-spacing: -.5px; background: var(--grad-t); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.sb-ver { font-size: .66rem; color: var(--text-dim); margin-top: 1px; }
.sb-btns { display: flex; gap: 5px; }
.ng { padding: 0 8px; margin-bottom: 3px; }
.ng-t { font-size: .64rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1.3px; color: var(--text-dim); padding: 6px 8px 2px; margin-top: 3px; }
.nl { display: block; padding: 4px 10px; font-size: .8rem; color: var(--text-dim); border-radius: 6px; transition: all .15s; cursor: pointer; line-height: 1.5; }
.nl:hover { color: var(--text-bright); background: var(--accent-glow); }
.nl.on { color: var(--accent); background: var(--accent-glow); font-weight: 600; }
.tb { width: 30px; height: 30px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg-card); color: var(--text-dim); font-size: .88rem; cursor: pointer; display: flex; align-items: center; justify-content: center; flex-shrink: 0; transition: border-color .2s, background .4s, color .2s; }
.tb:hover { border-color: var(--accent); color: var(--accent); }
.nt { display: none; position: fixed; top: 10px; left: 10px; z-index: 200; width: 36px; height: 36px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg-card); color: var(--text); font-size: 1rem; cursor: pointer; align-items: center; justify-content: center; transition: background .4s; }
@media (max-width:960px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); box-shadow: 4px 0 30px rgba(0,0,0,.4); }
  .nt { display: flex; }
  .main { margin-left: 0 !important; }
  .hero-stats { flex-direction: column; gap: 12px !important; }
}

/* ===== Main ===== */
.main { margin-left: var(--nav-w); min-height: 100vh; transition: margin-left .3s; }

/* ===== Hero ===== */
.hero { position: relative; padding: 84px 48px 68px; overflow: hidden; }
.hero-bg { position: absolute; inset: 0; pointer-events: none; background: radial-gradient(ellipse at 20% 10%,rgba(88,166,255,.06) 0%,transparent 55%), radial-gradient(ellipse at 80% 80%,rgba(63,185,80,.04) 0%,transparent 50%), radial-gradient(ellipse at 50% 50%,rgba(210,168,255,.025) 0%,transparent 60%); transition: background .4s; }
.hero-grid { position: absolute; inset: 0; pointer-events: none; opacity: .08; background-image: linear-gradient(var(--border) 1px,transparent 1px), linear-gradient(90deg,var(--border) 1px,transparent 1px); background-size: 52px 52px; mask-image: radial-gradient(ellipse at 40% 50%,black 15%,transparent 65%); -webkit-mask-image: radial-gradient(ellipse at 40% 50%,black 15%,transparent 65%); }
.hero-orb { position: absolute; border-radius: 50%; filter: blur(90px); pointer-events: none; opacity: .3; animation: float 14s ease-in-out infinite; }
.hero-orb.o1 { width: 280px; height: 280px; top: -70px; left: 8%; background: rgba(88,166,255,.18); }
.hero-orb.o2 { width: 220px; height: 220px; bottom: -50px; right: 12%; background: rgba(63,185,80,.12); animation-delay: -5s; }
.hero-orb.o3 { width: 180px; height: 180px; top: 35%; left: 55%; background: rgba(210,168,255,.1); animation-delay: -9s; }
@keyframes float { 0%,100% { transform: translateY(0) scale(1); } 50% { transform: translateY(-18px) scale(1.04); } }
.hero-badge { display: inline-flex; align-items: center; gap: 6px; padding: 4px 13px; border-radius: 20px; font-size: .7rem; font-weight: 600; letter-spacing: .4px; color: var(--accent2); background: rgba(63,185,80,.06); border: 1px solid rgba(63,185,80,.15); margin-bottom: 20px; backdrop-filter: blur(4px); }
.hero-badge::before { content: ''; width: 6px; height: 6px; border-radius: 50%; background: var(--accent2); animation: pulse 2s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .3; } }
.hero h1 { font-size: clamp(2rem,4.8vw,3.4rem); font-weight: 800; letter-spacing: -1.8px; line-height: 1.08; background: var(--grad-t); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; max-width: 640px; margin-bottom: 16px; }
.hero-sub { font-size: 1.05rem; color: var(--text-dim); max-width: 520px; line-height: 1.65; margin-bottom: 36px; }
.hero-stats { display: flex; gap: 14px; flex-wrap: wrap; }
.stat { background: var(--glass); backdrop-filter: blur(12px); border: 1px solid var(--glass-b); border-radius: var(--r); padding: 14px 20px; min-width: 132px; box-shadow: var(--sh-card); transition: transform .3s cubic-bezier(.22,1,.36,1), border-color .3s, box-shadow .3s, background .4s; }
.stat:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: var(--sh-card-h); }
.stat-v { font-size: 1.5rem; font-weight: 700; font-family: var(--mono); background: var(--grad-t); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.stat-l { font-size: .7rem; color: var(--text-dim); margin-top: 2px; }

/* ===== Sections ===== */
section { padding: 64px 48px; border-top: 1px solid var(--border); transition: background .4s, border-color .4s; }
section.alt { background: var(--bg2); }
.sh { margin-bottom: 36px; }
.sh-tag { font-size: .66rem; font-weight: 700; text-transform: uppercase; letter-spacing: 1.5px; color: var(--accent); margin-bottom: 7px; }
.sh-title { font-size: 1.8rem; font-weight: 700; color: var(--text-bright); letter-spacing: -1px; margin-bottom: 7px; transition: color .4s; }
.sh-desc { font-size: .91rem; color: var(--text-dim); max-width: 560px; line-height: 1.6; }

/* ===== Feature Grid ===== */
.fg { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; }
.fc { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 20px; position: relative; overflow: hidden; box-shadow: var(--sh-card); transition: all .3s cubic-bezier(.22,1,.36,1); cursor: pointer; }
.fc:hover { border-color: var(--accent); transform: translateY(-4px); box-shadow: var(--sh-card-h); }
.fc::before { content: ''; position: absolute; inset: 0; background: radial-gradient(circle at 50% 0%, var(--accent-glow2), transparent 70%); opacity: 0; transition: opacity .3s; pointer-events: none; }
.fc:hover::before { opacity: 1; }
.fc::after { content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px; background: var(--grad); opacity: 0; transition: opacity .3s; }
.fc:hover::after { opacity: 1; }
.fc-n { font-size: .93rem; font-weight: 600; color: var(--text-bright); margin-bottom: 4px; transition: color .4s; display: flex; align-items: center; justify-content: space-between; }
.fc-n .fc-arr { font-size: .68rem; color: var(--text-dim); transition: transform .3s cubic-bezier(.22,1,.36,1), color .3s; }
.fc:hover .fc-arr { transform: translateX(4px); color: var(--accent); }
.fc-d { font-size: .8rem; color: var(--text-dim); line-height: 1.5; }
/* Why-section cards (no click action) */
.fcard { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 20px; box-shadow: var(--sh-card); transition: all .3s cubic-bezier(.22,1,.36,1); position: relative; overflow: hidden; }
.fcard:hover { border-color: var(--accent); transform: translateY(-3px); box-shadow: var(--sh-card-h); }
.fcard::before { content: ''; position: absolute; inset: 0; background: radial-gradient(circle at 50% 0%, var(--accent-glow2), transparent 70%); opacity: 0; transition: opacity .3s; pointer-events: none; }
.fcard:hover::before { opacity: 1; }

/* ===== Feature Modal ===== */
.modal-overlay { position: fixed; inset: 0; background: var(--overlay); backdrop-filter: blur(8px); z-index: 300; opacity: 0; pointer-events: none; transition: opacity .3s; display: flex; align-items: center; justify-content: center; }
.modal-overlay.show { opacity: 1; pointer-events: auto; }
.modal { background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px; max-width: 620px; width: 92%; max-height: 82vh; overflow-y: auto; box-shadow: 0 16px 50px rgba(0,0,0,.35); transform: translateY(16px) scale(.97); transition: transform .35s cubic-bezier(.22,1,.36,1), background .4s; padding: 28px; position: relative; }
.modal-overlay.show .modal { transform: translateY(0) scale(1); }
.modal-close { position: absolute; top: 10px; right: 12px; width: 28px; height: 28px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg); color: var(--text-dim); font-size: .85rem; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: border-color .2s, background .4s; }
.modal-close:hover { border-color: var(--accent); color: var(--accent); }
.modal h3 { font-size: 1.15rem; font-weight: 700; color: var(--text-bright); margin-bottom: 8px; transition: color .4s; }
.modal p { font-size: .85rem; color: var(--text-dim); margin-bottom: 12px; }

/* ===== Code ===== */
pre { background: var(--bg-code); border: 1px solid var(--border); border-radius: 10px; padding: 15px 18px; overflow-x: auto; font-family: var(--mono); font-size: .8rem; line-height: 1.65; margin: 10px 0 18px; position: relative; transition: background .4s, border-color .4s; }
pre .c { color: var(--c-cm); } pre .k { color: var(--c-kw); } pre .s { color: var(--c-st); }
pre .t { color: var(--c-ty); } pre .f { color: var(--c-fn); } pre .d { color: var(--c-dc); }
pre .n { color: var(--c-nm); }
code { font-family: var(--mono); font-size: .82em; background: var(--accent-glow); padding: 1.5px 5px; border-radius: 4px; transition: background .4s; }
pre code { background: none; padding: 0; font-size: inherit; }
.cl { position: absolute; top: 0; right: 0; padding: 2px 9px; font-size: .64rem; color: var(--text-dim); background: var(--border); border-radius: 0 10px 0 8px; font-family: var(--mono); transition: background .4s; }
.cp { position: absolute; top: 5px; right: 5px; width: 25px; height: 25px; border-radius: 6px; border: 1px solid var(--border); background: var(--bg-card); color: var(--text-dim); font-size: .68rem; cursor: pointer; display: flex; align-items: center; justify-content: center; opacity: 0; transition: opacity .2s, border-color .2s, background .4s; }
pre:hover .cp { opacity: 1; }
.cp:hover { border-color: var(--accent); color: var(--accent); }
.cp.ok { color: var(--accent2); border-color: var(--accent2); }

/* ===== Tables ===== */
.tw { overflow-x: auto; margin: 10px 0 18px; border-radius: var(--r); border: 1px solid var(--border); transition: border-color .4s; }
table { width: 100%; border-collapse: collapse; font-size: .84rem; }
th { text-align: left; padding: 9px 13px; background: var(--bg-card); font-weight: 600; color: var(--text-bright); border-bottom: 1px solid var(--border); white-space: nowrap; transition: background .4s, color .4s; }
td { padding: 8px 13px; border-bottom: 1px solid var(--border); transition: background .15s; }
tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--accent-glow); }
td.n { font-family: var(--mono); text-align: right; }
td.h { color: var(--accent2); font-weight: 600; }

/* ===== Steps ===== */
.step { margin-bottom: 44px; padding-left: 26px; border-left: 2px solid var(--border); position: relative; transition: border-color .4s; }
.step::before { content: attr(data-step); position: absolute; left: -14px; top: 0; width: 26px; height: 26px; border-radius: 50%; background: var(--bg); border: 2px solid var(--accent); color: var(--accent); font-size: .72rem; font-weight: 700; display: flex; align-items: center; justify-content: center; font-family: var(--mono); transition: background .4s; }
.step-t { font-size: 1.15rem; font-weight: 600; color: var(--text-bright); margin-bottom: 7px; transition: color .4s; }
.step-c p { margin-bottom: 8px; }

/* ===== Callouts ===== */
.co { border: 1px solid rgba(88,166,255,.1); border-left: 3px solid var(--accent); border-radius: 0 8px 8px 0; padding: 12px 15px; margin: 10px 0; font-size: .84rem; background: var(--accent-glow); transition: background .4s, border-color .4s; }
.co.w { border-color: rgba(210,168,255,.1); border-left-color: var(--accent3); background: rgba(130,80,223,.05); }
.co.s { border-color: rgba(63,185,80,.1); border-left-color: var(--accent2); background: rgba(63,185,80,.05); }
.co b { color: var(--text-bright); display: block; margin-bottom: 2px; transition: color .4s; }

/* ===== Bars ===== */
.bars { margin: 18px 0; }
.br { display: flex; align-items: center; margin-bottom: 8px; gap: 9px; }
.br-l { width: 96px; font-size: .8rem; color: var(--text-dim); text-align: right; flex-shrink: 0; }
.br-t { flex: 1; height: 26px; background: var(--bg-code); border-radius: 6px; overflow: hidden; transition: background .4s; }
.br-f { height: 100%; border-radius: 6px; display: flex; align-items: center; padding-left: 9px; font-size: .72rem; font-family: var(--mono); color: #fff; font-weight: 600; transition: width 1.3s cubic-bezier(.22,1,.36,1); width: 0; }
.br-f.velocity { background: var(--br-vel); }
.br-f.elysia { background: var(--br-ely); }
.br-f.hono { background: var(--br-hon); }
.br-f.raw { background: var(--br-raw); }

/* ===== Positioning cards ===== */
.pos-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px,1fr)); gap: 12px; margin-top: 18px; }
.pos-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--r); padding: 18px; box-shadow: var(--sh-card); transition: all .3s cubic-bezier(.22,1,.36,1); position: relative; overflow: hidden; }
.pos-card:hover { border-color: var(--accent); transform: translateY(-3px); box-shadow: var(--sh-card-h); }
.pos-card::before { content: ''; position: absolute; inset: 0; background: radial-gradient(circle at 50% 0%, var(--accent-glow2), transparent 70%); opacity: 0; transition: opacity .3s; pointer-events: none; }
.pos-card:hover::before { opacity: 1; }
.pos-q { font-size: .86rem; font-weight: 600; color: var(--text-bright); margin-bottom: 5px; transition: color .4s; }
.pos-a { font-size: .8rem; color: var(--text-dim); line-height: 1.5; }

/* ===== Scroll Reveal ===== */
.rv { opacity: 0; transform: translateY(20px); transition: opacity .5s ease, transform .5s ease; }
.rv.vis { opacity: 1; transform: translateY(0); }
.rv-1 { transition-delay: .06s; } .rv-2 { transition-delay: .12s; }
.rv-3 { transition-delay: .18s; } .rv-4 { transition-delay: .24s; }

/* ===== Back to top ===== */
.btt { position: fixed; bottom: 20px; right: 20px; width: 36px; height: 36px; border-radius: 10px; border: 1px solid var(--border); background: var(--bg-card); color: var(--text-dim); font-size: .9rem; cursor: pointer; z-index: 90; display: flex; align-items: center; justify-content: center; opacity: 0; transform: translateY(8px); pointer-events: none; transition: opacity .3s, transform .3s, border-color .2s, background .4s; }
.btt.show { opacity: 1; transform: translateY(0); pointer-events: auto; }
.btt:hover { border-color: var(--accent); color: var(--accent); }

/* ===== Footer ===== */
.footer { padding: 28px 48px; border-top: 1px solid var(--border); text-align: center; font-size: .8rem; color: var(--text-dim); transition: border-color .4s; }
.footer a { color: var(--accent); }

/* ===== Responsive ===== */
@media (max-width:960px) {
  .hero { padding: 64px 16px 48px; }
  section { padding: 48px 16px; }
  .fg { grid-template-columns: 1fr; }
  .pos-grid { grid-template-columns: 1fr; }
  .br-l { width: 64px; font-size: .7rem; }
  .footer { padding: 22px 16px; }
}
@media (max-width:600px) {
  .hero h1 { font-size: 1.7rem; letter-spacing: -1px; }
  .sh-title { font-size: 1.35rem; }
  pre { padding: 10px 12px; font-size: .74rem; }
}