/* =============================
   DESIGN TOKENS
   ============================= */
:root {
  --bg:        #080b12;
  --bg2:       #0c1018;
  --bg3:       #101520;
  --surface:   #141b25;
  --surface2:  #192030;
  --border:    rgba(255,255,255,0.06);
  --border2:   rgba(255,255,255,0.11);
  --border3:   rgba(255,255,255,0.18);

  --green:     #3ecf8e;
  --green-bg:  rgba(62,207,142,0.08);
  --green-dim: rgba(62,207,142,0.15);
  --amber:     #f6ad55;
  --amber-bg:  rgba(246,173,85,0.08);
  --red:       #fc5a5a;
  --red-bg:    rgba(252,90,90,0.08);
  --blue:      #60a5fa;
  --blue-bg:   rgba(96,165,250,0.08);
  --purple:    #a78bfa;
  --purple-bg: rgba(167,139,250,0.08);

  --text:      #e2e8f0;
  --text2:     #94a3b8;
  --text3:     #475569;

  --mono: "JetBrains Mono", monospace;
  --sans: "Space Grotesk", sans-serif;
  --body: "Inter", sans-serif;

  --r:    10px;
  --r-lg: 16px;
  --r-xl: 22px;
}

/* =============================
   RESET
   ============================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: var(--body); font-size: 16px; line-height: 1.7; overflow-x: hidden; }
a { color: var(--green); text-decoration: none; }
code { font-family: var(--mono); font-size: 0.83em; background: rgba(62,207,142,0.1); color: var(--green); padding: 1px 6px; border-radius: 4px; }
strong { color: var(--text); font-weight: 600; }
em { color: var(--amber); font-style: normal; }
table { border-collapse: collapse; width: 100%; }
.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* =============================
   NAV
   ============================= */
#navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  background: rgba(8,11,18,0.9); backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1080px; margin: 0 auto; padding: 0 24px;
  height: 60px; display: flex; align-items: center; gap: 32px;
}
.nav-logo { font-family: var(--sans); font-weight: 700; font-size: 1.05rem; display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.logo-hex { font-size: 1.2rem; }
.green { color: var(--green); }
.nav-center { display: flex; gap: 20px; flex: 1; }
.nl { color: var(--text2); font-size: 0.88rem; font-weight: 500; transition: color 0.2s; }
.nl:hover { color: var(--text); }
.nav-right { margin-left: auto; }
.badge-interview {
  background: var(--purple-bg); color: var(--purple);
  border: 1px solid rgba(167,139,250,0.25);
  font-size: 0.75rem; font-weight: 600; padding: 4px 12px; border-radius: 20px;
}

/* =============================
   HERO
   ============================= */
.hero {
  min-height: 100vh; padding: 80px 24px 80px;
  position: relative; display: flex; align-items: center;
  overflow: hidden;
}
.hero-glow {
  position: absolute; border-radius: 50%;
  filter: blur(100px); opacity: 0.25; pointer-events: none;
}
.g1 { width: 700px; height: 700px; background: radial-gradient(#3ecf8e, transparent 70%); top: -200px; left: -150px; animation: glow 9s ease-in-out infinite; }
.g2 { width: 500px; height: 500px; background: radial-gradient(#6366f1, transparent 70%); bottom: -100px; right: 0; animation: glow 11s ease-in-out infinite reverse; }
.hero-grid { position: absolute; inset: 0; background-image: linear-gradient(var(--border) 1px, transparent 1px), linear-gradient(90deg, var(--border) 1px, transparent 1px); background-size: 56px 56px; }
@keyframes glow { 0%,100% { transform: translate(0,0); } 50% { transform: translate(40px,-40px); } }

.hero-body { max-width: 1080px; margin: 0 auto; display: grid; grid-template-columns: 1fr 440px; gap: 60px; align-items: center; position: relative; z-index: 1; width: 100%; }
.chip { display: inline-flex; align-items: center; gap: 8px; font-size: 0.8rem; font-weight: 600; color: var(--green); background: var(--green-dim); border: 1px solid rgba(62,207,142,0.22); padding: 5px 14px; border-radius: 20px; margin-bottom: 22px; }
.chipdot { width: 7px; height: 7px; border-radius: 50%; background: var(--green); animation: blink 2s infinite; }
@keyframes blink { 0%,100% { opacity:1; } 50% { opacity: 0.3; } }
h1 { font-family: var(--sans); font-size: clamp(2.4rem, 5vw, 3.6rem); font-weight: 700; line-height: 1.15; letter-spacing: -0.03em; margin-bottom: 20px; }
.grad { background: linear-gradient(135deg, var(--green), #7fff5f); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero-p { color: var(--text2); font-size: 1.05rem; max-width: 480px; margin-bottom: 32px; }
.hero-pills { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 40px; }
.pill { display: inline-flex; align-items: center; gap: 8px; padding: 9px 18px; border-radius: 24px; font-size: 0.88rem; font-weight: 600; transition: transform 0.2s; }
.pill:hover { transform: translateY(-2px); }
.p-green { background: var(--green-bg); color: var(--green); border: 1px solid rgba(62,207,142,0.28); }
.p-amber { background: var(--amber-bg); color: var(--amber); border: 1px solid rgba(246,173,85,0.28); }
.p-red   { background: var(--red-bg);   color: var(--red);   border: 1px solid rgba(252,90,90,0.28); }
.hero-counters { display: flex; align-items: center; gap: 24px; }
.hc { display: flex; flex-direction: column; }
.hcn { font-family: var(--sans); font-size: 2rem; font-weight: 700; line-height: 1; }
.hcl { font-size: 0.75rem; color: var(--text3); text-transform: uppercase; letter-spacing: 0.06em; margin-top: 3px; }
.hcd { width: 1px; height: 40px; background: var(--border2); }

/* TERMINAL */
.term { background: #0d1117; border: 1px solid var(--border2); border-radius: var(--r-lg); overflow: hidden; box-shadow: 0 24px 64px rgba(0,0,0,0.5); }
.term-bar { display: flex; align-items: center; gap: 7px; padding: 10px 14px; background: #161b22; border-bottom: 1px solid var(--border); }
.td { width: 11px; height: 11px; border-radius: 50%; }
.td.r { background: #ff5f57; } .td.y { background: #febc2e; } .td.g { background: #28c840; }
.tname { margin-left: 8px; font-family: var(--mono); font-size: 0.75rem; color: var(--text3); }
.term-body { padding: 20px; min-height: 200px; font-family: var(--mono); font-size: 0.85rem; }
.tl { min-height: 1.6em; }
.tp { color: var(--green); margin-right: 8px; }
.tc { color: #c9d1d9; }
.tout { color: var(--green); opacity: 0; transition: opacity 0.4s; }
.tout.vis { opacity: 1; }
.tcursor { display: inline-block; color: var(--green); animation: curblink 1s step-end infinite; }
@keyframes curblink { 0%,100% { opacity:1; } 50% { opacity: 0; } }
.type-me { overflow: hidden; white-space: nowrap; border-right: 2px solid var(--green); width: 0; animation: type 1.2s steps(20) forwards, nocar 0s 1.3s forwards; }
@keyframes type { to { width: 100%; } }
@keyframes nocar { to { border-color: transparent; } }

.hero-note { margin-top: 16px; background: rgba(246,173,85,0.06); border: 1px solid rgba(246,173,85,0.2); border-radius: var(--r); padding: 14px 16px; display: flex; gap: 10px; align-items: flex-start; font-size: 0.88rem; color: var(--text2); }
.hn-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 1px; }

/* =============================
   BIG PICTURE
   ============================= */
.big-picture { padding: 100px 0; background: linear-gradient(var(--bg), var(--bg2)); }
.sec-label { font-size: 0.73rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--green); margin-bottom: 10px; }
.sec-title { font-family: var(--sans); font-size: clamp(1.9rem, 3.5vw, 2.8rem); font-weight: 700; letter-spacing: -0.02em; margin-bottom: 14px; }
.sec-sub { color: var(--text2); font-size: 1.02rem; max-width: 600px; margin-bottom: 56px; }

.bp-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 56px; }
.bp-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-lg); padding: 28px 24px; }
.bpn { font-family: var(--mono); font-size: 0.7rem; color: var(--text3); margin-bottom: 12px; font-weight: 700; }
.bpi { font-size: 2rem; margin-bottom: 12px; }
.bp-card h3 { font-family: var(--sans); font-size: 1rem; font-weight: 700; margin-bottom: 10px; }
.bp-card p { color: var(--text2); font-size: 0.88rem; line-height: 1.65; margin-bottom: 14px; }
.bp-why { background: rgba(255,255,255,0.03); border-left: 2px solid var(--green); padding: 10px 12px; font-size: 0.82rem; color: var(--text2); border-radius: 0 6px 6px 0; }

/* ARCH VIS */
.arch-vis { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-xl); padding: 40px; }
.av-title { font-family: var(--sans); font-size: 0.9rem; font-weight: 700; color: var(--text2); text-align: center; margin-bottom: 32px; }
.av-flow { display: flex; align-items: center; gap: 0; justify-content: center; flex-wrap: wrap; }
.av-col { flex: 1; min-width: 140px; }
.av-arr { color: var(--text3); font-size: 1.5rem; padding: 0 8px; flex-shrink: 0; }
.av-box { border-radius: var(--r); border: 1px solid; overflow: hidden; }
.av-box-label { font-family: var(--sans); font-size: 0.75rem; font-weight: 700; padding: 8px 12px; }
.av-items { padding: 10px 12px; display: flex; flex-direction: column; gap: 5px; }
.av-item { font-family: var(--mono); font-size: 0.72rem; padding: 3px 0; color: var(--text2); }
.av-js    { border-color: rgba(62,207,142,0.3);  } .av-js .av-box-label    { background: rgba(62,207,142,0.12);  color: var(--green); }
.av-v8    { border-color: rgba(96,165,250,0.3);  } .av-v8 .av-box-label    { background: rgba(96,165,250,0.12);  color: var(--blue); }
.av-el    { border-color: rgba(246,173,85,0.3);  } .av-el .av-box-label    { background: rgba(246,173,85,0.12);  color: var(--amber); }
.av-libuv { border-color: rgba(252,90,90,0.3);   } .av-libuv .av-box-label { background: rgba(252,90,90,0.12);   color: var(--red); }
.av-os    { border-color: rgba(167,139,250,0.3); } .av-os .av-box-label    { background: rgba(167,139,250,0.12); color: var(--purple); }

.spin-badge { display: inline-block; font-size: 0.65rem; padding: 1px 6px; background: rgba(246,173,85,0.15); border-radius: 20px; margin-left: 6px; animation: fadeoscil 2s ease-in-out infinite; }
@keyframes fadeoscil { 0%,100% { opacity: 0.5; } 50% { opacity: 1; } }

/* =============================
   LEVEL SECTIONS
   ============================= */
.level-sec { padding: 96px 0; }
.basics-sec       { background: var(--bg2); }
.intermediate-sec { background: var(--bg3); }
.advanced-sec     { background: var(--bg2); }
.interview-sec    { background: var(--bg3); }

.level-head { text-align: center; margin-bottom: 64px; }
.level-head h2 { font-family: var(--sans); font-size: clamp(1.9rem,4vw,2.8rem); font-weight: 700; letter-spacing: -0.02em; margin-bottom: 12px; }
.level-head p { color: var(--text2); font-size: 1rem; max-width: 560px; margin: 0 auto 12px; }
.ltime { color: var(--text3); font-size: 0.83rem; }
.lbadge { display: inline-block; font-size: 0.8rem; font-weight: 700; letter-spacing: 0.04em; padding: 5px 16px; border-radius: 20px; margin-bottom: 16px; border: 1px solid; }
.lb-green  { background: var(--green-bg);  color: var(--green);  border-color: rgba(62,207,142,0.28); }
.lb-amber  { background: var(--amber-bg);  color: var(--amber);  border-color: rgba(246,173,85,0.28); }
.lb-red    { background: var(--red-bg);    color: var(--red);    border-color: rgba(252,90,90,0.28); }
.lb-purple { background: var(--purple-bg); color: var(--purple); border-color: rgba(167,139,250,0.28); }

/* =============================
   CONCEPT BLOCKS
   ============================= */
.concept-block {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-xl); margin-bottom: 24px;
  overflow: hidden; transition: border-color 0.3s;
}
.concept-block:hover { border-color: var(--border2); }
.concept-block.open { border-color: rgba(62,207,142,0.3); }

.cb-header {
  display: flex; align-items: center; gap: 16px;
  padding: 24px 28px; cursor: pointer;
}
.cb-num { font-family: var(--mono); font-size: 0.7rem; font-weight: 700; color: var(--text3); min-width: 24px; }
.cb-icon { font-size: 1.6rem; flex-shrink: 0; }
.cb-meta { flex: 1; }
.cb-meta h3 { font-family: var(--sans); font-size: 1.1rem; font-weight: 700; margin-bottom: 7px; }
.cb-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.ct { font-family: var(--mono); font-size: 0.71rem; padding: 2px 8px; background: rgba(255,255,255,0.04); border: 1px solid var(--border); border-radius: 4px; color: var(--text3); }
.cb-toggle { background: none; border: 1px solid var(--border2); color: var(--text2); font-size: 0.85rem; font-weight: 600; padding: 7px 16px; border-radius: 8px; cursor: pointer; white-space: nowrap; transition: all 0.2s; font-family: var(--sans); flex-shrink: 0; }
.cb-toggle:hover { border-color: var(--green); color: var(--green); }

.cb-body {
  display: none; border-top: 1px solid var(--border);
  animation: slideIn 0.3s ease;
}
.cb-body.open { display: block; }
@keyframes slideIn { from { opacity:0; transform: translateY(-10px); } to { opacity:1; transform: translateY(0); } }

.cb-explain { padding: 32px 28px; border-bottom: 1px solid var(--border); }
.cb-explain h4 { font-family: var(--sans); font-size: 0.85rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text3); margin-bottom: 16px; }
.cb-explain p { color: var(--text2); margin-bottom: 14px; font-size: 0.97rem; }

/* CALLOUTS */
.callout { display: flex; gap: 14px; padding: 16px 18px; border-radius: var(--r); margin-top: 20px; margin-bottom: 6px; align-items: flex-start; }
.co-icon { font-size: 1.2rem; flex-shrink: 0; margin-top: 1px; }
.callout p, .callout div { font-size: 0.9rem; color: var(--text2); }
.callout-warn   { background: rgba(246,173,85,0.07); border: 1px solid rgba(246,173,85,0.22); }
.callout-danger { background: rgba(252,90,90,0.07);  border: 1px solid rgba(252,90,90,0.22); }
.callout-info   { background: rgba(96,165,250,0.07); border: 1px solid rgba(96,165,250,0.22); }

/* =============================
   CODE TABS
   ============================= */
.cb-code-wrap { padding: 0 28px 28px; border-bottom: 1px solid var(--border); }
.code-tabs { display: flex; gap: 4px; padding: 16px 0 0; flex-wrap: wrap; }
.ctab { background: transparent; border: 1px solid var(--border); color: var(--text3); font-family: var(--mono); font-size: 0.78rem; padding: 6px 14px; border-radius: 6px 6px 0 0; cursor: pointer; transition: all 0.2s; }
.ctab.active { background: #0d1117; border-color: var(--border2); border-bottom-color: #0d1117; color: var(--green); }
.ctab:hover:not(.active) { color: var(--text2); }
.code-panel { display: none; background: #0d1117; border: 1px solid var(--border2); border-top: none; border-radius: 0 var(--r) var(--r) var(--r); padding: 24px; overflow-x: auto; }
.code-panel.active { display: block; }
.code-panel pre { font-family: var(--mono); font-size: 0.82rem; line-height: 1.75; color: #c9d1d9; white-space: pre; }

/* Syntax colors */
.cc { color: #6e7681; }
.ck { color: #ff7b72; }
.cf { color: #d2a8ff; }
.cm { color: #79c0ff; }
.cs { color: #a5d6ff; }
.cv { color: #ffa657; }

/* =============================
   INTERVIEW BOX
   ============================= */
.interview-box { padding: 24px 28px; }
.ib-title { font-family: var(--sans); font-size: 0.88rem; font-weight: 700; color: var(--amber); text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 16px; }
.iq-list { display: flex; flex-direction: column; gap: 14px; }
.iq { background: rgba(255,255,255,0.025); border: 1px solid var(--border); border-radius: var(--r); overflow: hidden; }
.iq-q { padding: 14px 16px; font-weight: 600; font-size: 0.92rem; color: var(--text); border-bottom: 1px solid var(--border); cursor: pointer; position: relative; }
.iq-q::after { content: "▼"; position: absolute; right: 14px; top: 50%; transform: translateY(-50%); font-size: 0.65rem; color: var(--text3); }
.iq-a { padding: 14px 16px; font-size: 0.9rem; color: var(--text2); line-height: 1.7; display: none; background: rgba(62,207,142,0.03); }
.iq.open .iq-a { display: block; }
.iq.open .iq-q::after { content: "▲"; }

/* =============================
   EVENT LOOP PHASES
   ============================= */
.phases-vis { display: flex; flex-direction: column; align-items: flex-start; gap: 0; margin: 20px 0; max-width: 560px; }
.phase { padding: 14px 18px; border-radius: var(--r); border: 1px solid var(--border); background: var(--bg); width: 100%; }
.phase.active-phase { border-color: rgba(62,207,142,0.4); background: rgba(62,207,142,0.05); }
.ph-name { font-family: var(--mono); font-size: 0.82rem; font-weight: 700; color: var(--text); margin-bottom: 5px; }
.ph-detail { font-size: 0.85rem; color: var(--text2); }
.ph-arrow { color: var(--text3); font-size: 1.2rem; padding: 4px 18px; }

.microtask-box { background: rgba(96,165,250,0.06); border: 1px solid rgba(96,165,250,0.2); border-radius: var(--r); padding: 18px 20px; margin-top: 20px; }
.mt-title { font-family: var(--sans); font-size: 0.88rem; font-weight: 700; color: var(--blue); margin-bottom: 12px; }
.microtask-box p { font-size: 0.88rem; color: var(--text2); margin-bottom: 12px; }
.mt-order { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.mt-item { padding: 10px 14px; border-radius: var(--r); font-size: 0.85rem; }
.mt-nexttick { background: rgba(252,90,90,0.08); border: 1px solid rgba(252,90,90,0.22); }
.mt-promise  { background: rgba(62,207,142,0.08); border: 1px solid rgba(62,207,142,0.22); }
.mt-arr { color: var(--text3); font-size: 0.8rem; }

/* =============================
   STREAM TYPES
   ============================= */
.stream-types-vis { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin: 20px 0; }
.st-card { padding: 18px 16px; border-radius: var(--r); border: 1px solid var(--border); background: var(--bg); text-align: center; }
.st-icon { font-size: 1.6rem; margin-bottom: 8px; }
.st-name { font-family: var(--sans); font-size: 0.88rem; font-weight: 700; margin-bottom: 8px; }
.st-ex { font-family: var(--mono); font-size: 0.7rem; color: var(--text3); line-height: 1.5; }
.st-read      { border-color: rgba(62,207,142,0.25); }
.st-write     { border-color: rgba(96,165,250,0.25); }
.st-duplex    { border-color: rgba(246,173,85,0.25); }
.st-transform { border-color: rgba(167,139,250,0.25); }

/* =============================
   COMPARISON TABLE
   ============================= */
.compare-table { margin: 20px 0; border-radius: var(--r); overflow: hidden; border: 1px solid var(--border2); }
.compare-table th { background: var(--surface2); padding: 10px 14px; text-align: left; font-size: 0.82rem; font-weight: 700; color: var(--text2); font-family: var(--sans); }
.compare-table td { padding: 10px 14px; font-size: 0.85rem; border-top: 1px solid var(--border); color: var(--text2); }
.compare-table tr:hover td { background: rgba(255,255,255,0.02); }

/* =============================
   INTERVIEW SECTION
   ============================= */
.iq-categories { display: flex; flex-direction: column; gap: 40px; }
.iqc-title { font-family: var(--sans); font-size: 1rem; font-weight: 700; color: var(--text); margin-bottom: 16px; padding-bottom: 12px; border-bottom: 1px solid var(--border); }

/* CHEAT SHEET */
.cheat-sheet { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-xl); padding: 36px; margin-top: 48px; }
.cs-title { font-family: var(--sans); font-size: 0.95rem; font-weight: 700; margin-bottom: 24px; }
.cs-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.cs-item { padding: 16px; border-radius: var(--r); border: 1px solid var(--border); }
.cs-rank { font-family: var(--mono); font-size: 0.75rem; font-weight: 700; margin-bottom: 6px; }
.cs-name { font-weight: 600; font-size: 0.9rem; margin-bottom: 5px; }
.cs-ex { font-size: 0.8rem; color: var(--text3); }
.cs-sync     { border-color: rgba(255,255,255,0.12);  } .cs-sync .cs-rank     { color: var(--text); }
.cs-nexttick { border-color: rgba(252,90,90,0.3);    } .cs-nexttick .cs-rank  { color: var(--red); }
.cs-promise  { border-color: rgba(62,207,142,0.3);   } .cs-promise .cs-rank   { color: var(--green); }
.cs-immediate{ border-color: rgba(246,173,85,0.3);   } .cs-immediate .cs-rank { color: var(--amber); }
.cs-timeout  { border-color: rgba(96,165,250,0.3);   } .cs-timeout .cs-rank   { color: var(--blue); }
.cs-io       { border-color: rgba(167,139,250,0.3);  } .cs-io .cs-rank        { color: var(--purple); }

/* =============================
   RESOURCES
   ============================= */
.resources-sec { padding: 96px 0; background: var(--bg2); }
.res-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; margin-top: 8px; }
.res-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-lg); padding: 26px; transition: transform 0.2s, border-color 0.2s; display: block; color: var(--text); }
.res-card:hover { transform: translateY(-3px); border-color: rgba(62,207,142,0.3); color: var(--text); }
.rc-icon { font-size: 1.8rem; margin-bottom: 12px; }
.rc-title { font-family: var(--sans); font-weight: 700; margin-bottom: 8px; }
.rc-desc { color: var(--text2); font-size: 0.87rem; margin-bottom: 14px; line-height: 1.6; }
.rc-url { color: var(--green); font-size: 0.84rem; font-weight: 600; }

/* =============================
   FOOTER
   ============================= */
.footer { background: var(--bg); border-top: 1px solid var(--border); padding: 36px 0; }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 10px; text-align: center; }
.footer-logo { font-family: var(--sans); font-weight: 700; font-size: 1rem; }
.footer p { color: var(--text3); font-size: 0.84rem; }
.footer a { color: var(--text2); } .footer a:hover { color: var(--green); }

/* =============================
   RESPONSIVE
   ============================= */
@media (max-width: 900px) {
  .hero-body { grid-template-columns: 1fr; padding: 0; }
  .hero { padding: 90px 24px 60px; }
  .hero-right { display: none; }
  .bp-grid { grid-template-columns: 1fr 1fr; }
  .av-flow { flex-direction: column; align-items: stretch; }
  .av-arr { transform: rotate(90deg); text-align: center; padding: 6px 0; }
  .stream-types-vis { grid-template-columns: 1fr 1fr; }
  .cs-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .nav-center { display: none; }
  .bp-grid { grid-template-columns: 1fr; }
  .stream-types-vis { grid-template-columns: 1fr; }
  .cs-grid { grid-template-columns: 1fr; }
  .cb-header { gap: 10px; }
  .cb-icon { display: none; }
  .compare-table { font-size: 0.78rem; }
}

/* Fade-in animations */
.fadein { opacity: 0; transform: translateY(20px); transition: opacity 0.5s, transform 0.5s; }
.fadein.vis { opacity: 1; transform: translateY(0); }

/* =============================
   YOUTUBE SECTION
   ============================= */
.videos-sec { padding: 96px 0; background: var(--bg); }

/* Creator banner */
.creator-banner {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  background: var(--surface); border: 1px solid var(--border2);
  border-radius: var(--r-xl); padding: 28px 32px; margin-bottom: 48px;
  position: relative; overflow: hidden;
}
.creator-banner::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 4px;
  background: linear-gradient(180deg, #ff0000, #cc0000);
}
.cb-left { display: flex; align-items: center; gap: 20px; }
.cb-avatar {
  width: 56px; height: 56px; border-radius: 50%; flex-shrink: 0;
  background: linear-gradient(135deg, #ff4444, #cc0000);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--sans); font-weight: 700; font-size: 1.1rem; color: #fff;
}
.cb-name { font-family: var(--sans); font-weight: 700; font-size: 1.05rem; margin-bottom: 3px; }
.cb-handle { font-family: var(--mono); font-size: 0.78rem; color: var(--green); margin-bottom: 8px; }
.cb-bio { font-size: 0.88rem; color: var(--text2); max-width: 540px; line-height: 1.6; }
.cb-channel-btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: #ff0000; color: #fff; padding: 10px 20px;
  border-radius: 8px; font-weight: 700; font-size: 0.88rem;
  transition: background 0.2s, transform 0.2s; white-space: nowrap; flex-shrink: 0;
}
.cb-channel-btn:hover { background: #cc0000; transform: translateY(-1px); color: #fff; }
.yt-icon { font-size: 0.8rem; }

/* Video grid */
.videos-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-bottom: 32px; }

.video-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-lg); overflow: hidden;
  transition: transform 0.25s, border-color 0.25s, box-shadow 0.25s;
  display: flex; flex-direction: column;
}
.video-card:hover { transform: translateY(-4px); box-shadow: 0 16px 48px rgba(0,0,0,0.4); }
.vc-beginner:hover     { border-color: rgba(62,207,142,0.35); }
.vc-intermediate:hover { border-color: rgba(246,173,85,0.35); }
.vc-advanced:hover     { border-color: rgba(252,90,90,0.35); }

.vc-level-tag {
  padding: 8px 16px; font-size: 0.75rem; font-weight: 700; letter-spacing: 0.05em;
}
.vc-beginner     .vc-level-tag { background: rgba(62,207,142,0.1);  color: var(--green); }
.vc-intermediate .vc-level-tag { background: rgba(246,173,85,0.1);  color: var(--amber); }
.vc-advanced     .vc-level-tag { background: rgba(252,90,90,0.1);   color: var(--red); }

/* Thumbnail */
.vc-thumb-wrap {
  display: block; position: relative; overflow: hidden;
  aspect-ratio: 16/9; background: #0d1117;
}
.vc-thumb {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.4s, filter 0.3s;
  filter: brightness(0.85);
}
.vc-thumb-wrap:hover .vc-thumb { transform: scale(1.04); filter: brightness(1); }
.vc-play-overlay {
  position: absolute; inset: 0; display: flex;
  align-items: center; justify-content: center;
  background: rgba(0,0,0,0.3); transition: background 0.2s;
}
.vc-thumb-wrap:hover .vc-play-overlay { background: rgba(0,0,0,0.15); }
.vc-play-btn {
  width: 52px; height: 52px; border-radius: 50%;
  background: rgba(255,0,0,0.9); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; padding-left: 3px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.4);
  transition: transform 0.2s, background 0.2s;
}
.vc-thumb-wrap:hover .vc-play-btn { transform: scale(1.1); background: #ff0000; }
.vc-duration {
  position: absolute; bottom: 8px; right: 8px;
  background: rgba(0,0,0,0.8); color: #fff;
  font-family: var(--mono); font-size: 0.72rem; padding: 2px 7px; border-radius: 4px;
}

/* Card content */
.vc-content { padding: 20px; flex: 1; display: flex; flex-direction: column; gap: 10px; }
.vc-title { font-family: var(--sans); font-size: 0.97rem; font-weight: 700; line-height: 1.4; }
.vc-meta { display: flex; align-items: center; gap: 6px; font-size: 0.8rem; color: var(--text3); }
.vc-creator { color: var(--text2); font-weight: 600; }
.vc-channel { font-family: var(--mono); color: var(--green); font-size: 0.76rem; }
.vc-dot { color: var(--text3); }
.vc-desc { font-size: 0.87rem; color: var(--text2); line-height: 1.65; flex: 1; }
.vc-pairs { display: flex; align-items: center; gap: 8px; font-size: 0.8rem; }
.vc-pair-label { color: var(--text3); }
.vc-pair-link { color: var(--green); font-weight: 600; font-size: 0.8rem; }
.vc-pair-link:hover { text-decoration: underline; }
.vc-watch-btn {
  display: inline-flex; align-items: center; gap: 8px; align-self: flex-start;
  background: #ff0000; color: #fff; padding: 9px 18px;
  border-radius: 8px; font-size: 0.85rem; font-weight: 700;
  transition: background 0.2s, transform 0.2s; margin-top: 4px;
}
.vc-watch-btn:hover { background: #cc0000; transform: translateY(-1px); color: #fff; }
.yt-icon-sm { font-size: 0.75rem; }

/* Playlist callout */
.playlist-callout {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  background: rgba(255,0,0,0.05); border: 1px solid rgba(255,0,0,0.2);
  border-radius: var(--r-lg); padding: 24px 28px; margin-bottom: 20px; flex-wrap: wrap;
}
.pc-left { display: flex; align-items: center; gap: 16px; }
.pc-icon { font-size: 2rem; flex-shrink: 0; }
.pc-title { font-family: var(--sans); font-weight: 700; font-size: 1rem; margin-bottom: 5px; }
.pc-desc { font-size: 0.88rem; color: var(--text2); max-width: 560px; line-height: 1.6; }
.pc-btn {
  background: #ff0000; color: #fff; padding: 10px 22px;
  border-radius: 8px; font-weight: 700; font-size: 0.88rem;
  white-space: nowrap; transition: background 0.2s; flex-shrink: 0;
}
.pc-btn:hover { background: #cc0000; color: #fff; }

/* Attribution note */
.attribution-note {
  display: flex; align-items: flex-start; gap: 12px;
  background: rgba(255,255,255,0.03); border: 1px solid var(--border);
  border-radius: var(--r); padding: 16px 18px;
}
.attr-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 1px; }
.attribution-note p { font-size: 0.85rem; color: var(--text3); line-height: 1.65; }
.attribution-note strong { color: var(--text2); }

/* Footer credits */
.footer-credits {
  display: flex; align-items: center; flex-wrap: wrap; gap: 8px;
  font-size: 0.82rem; color: var(--text3); margin-top: 6px;
}
.fc-label { color: var(--text3); }
.footer-credits a { color: var(--text2); transition: color 0.2s; }
.footer-credits a:hover { color: var(--green); }
.fc-dot { color: var(--text3); }

/* Responsive videos */
@media (max-width: 900px) {
  .videos-grid { grid-template-columns: 1fr; max-width: 480px; margin-left: auto; margin-right: auto; }
  .creator-banner { flex-direction: column; align-items: flex-start; }
  .playlist-callout { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 600px) {
  .cb-left { flex-direction: column; align-items: flex-start; }
}