*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --orange:      #f97316;
  --orange-dark: #ea6c0a;
  --orange-pale: rgba(249,115,22,.08);
  --orange-glow: rgba(249,115,22,.20);
  --teal:        #0d9488;
  --teal-pale:   rgba(13,148,136,.08);
  --amber:       #f59e0b;
  --rose:        #f43f5e;
  --indigo:      #6366f1;
  --dark:  #ffffff;
  --dark2: #fdf8f4;
  --dark3: #fff7ed;
  --dark4: #ffedd5;
  --border:   rgba(249,115,22,.14);
  --border-o: rgba(249,115,22,.35);
  --text:       #1c1008;
  --text-muted: #78604a;
  --mono: 'JetBrains Mono', monospace;
  --sans: 'Sora', sans-serif;
}

html { scroll-behavior: smooth; }
body { font-family: var(--sans); background: var(--dark); color: var(--text); overflow-x: hidden; min-height: 100vh; }

::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: var(--dark4); }
::-webkit-scrollbar-thumb { background: var(--orange); border-radius: 3px; }

nav {
  position: sticky; top: 0; z-index: 200;
  width: 100%;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 48px; height: 64px;
  box-shadow: 0 1px 24px rgba(249,115,22,.07);
}
.nav-logo { display: flex; align-items: center; gap: 12px; text-decoration: none; }
.nav-logo img { height: 38px; width: auto; }
.nav-logo-text { display: flex; flex-direction: column; line-height: 1.1; }
.nav-logo-text .brand { font-size: 17px; font-weight: 700; color: var(--orange); letter-spacing: .01em; }
.nav-logo-text .tagline { font-size: 9.5px; font-weight: 500; color: var(--text-muted); letter-spacing: .1em; text-transform: uppercase; }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a { padding: 8px 16px; border-radius: 8px; font-size: 13.5px; font-weight: 500; color: var(--text-muted); text-decoration: none; transition: color .2s, background .2s; }
.nav-links a:hover { color: var(--text); background: var(--orange-pale); }
.nav-links a.active { color: var(--orange); background: var(--orange-pale); }
.nav-cta { display: flex; gap: 10px; align-items: center; }
.btn-ghost { padding: 8px 20px; border-radius: 8px; border: 1px solid var(--border-o); color: var(--orange); font-size: 13.5px; font-weight: 600; font-family: var(--sans); cursor: pointer; background: transparent; transition: background .2s; text-decoration: none; }
.btn-ghost:hover { background: var(--orange-pale); }
.btn-solid { padding: 8px 22px; border-radius: 8px; background: var(--orange); color: #fff; font-size: 13.5px; font-weight: 600; font-family: var(--sans); cursor: pointer; border: none; transition: background .2s, transform .15s; text-decoration: none; }
.btn-solid:hover { background: var(--orange-dark); transform: translateY(-1px); }

.hero { position: relative; overflow: hidden; min-height: 88vh; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 80px 24px 60px; text-align: center; background: var(--dark); }
.hero::before { content: ''; position: absolute; inset: 0; background-image: linear-gradient(rgba(249,115,22,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(249,115,22,.06) 1px, transparent 1px); background-size: 44px 44px; animation: gridScroll 28s linear infinite; }
@keyframes gridScroll { from { background-position: 0 0; } to { background-position: 0 -880px; } }
.hero::after { content: ''; position: absolute; inset: 0; background: radial-gradient(ellipse 70% 55% at 50% 0%, rgba(249,115,22,.10) 0%, transparent 65%), radial-gradient(ellipse 40% 40% at 90% 90%, rgba(13,148,136,.07) 0%, transparent 60%); }
.hero-content { position: relative; z-index: 1; max-width: 860px; }
.hero-badge { display: inline-flex; align-items: center; gap: 8px; background: var(--orange-pale); border: 1px solid var(--border-o); border-radius: 50px; padding: 6px 18px; font-size: 12px; font-weight: 600; color: var(--orange); font-family: var(--mono); letter-spacing: .04em; margin-bottom: 28px; animation: fadeIn .6s ease both; }
.hero-badge::before { content: '▶'; font-size: 10px; }
.hero-title { font-size: clamp(38px, 6vw, 72px); font-weight: 800; line-height: 1.08; letter-spacing: -.02em; color: var(--text); margin-bottom: 24px; animation: fadeUp .7s .1s ease both; }
.hero-title .accent { color: var(--orange); position: relative; }
.hero-title .accent::after { content: ''; position: absolute; bottom: -4px; left: 0; right: 0; height: 3px; background: var(--orange); border-radius: 2px; opacity: .4; }
.hero-sub { font-size: 17px; font-weight: 400; color: var(--text-muted); line-height: 1.7; max-width: 600px; margin: 0 auto 40px; animation: fadeUp .7s .2s ease both; }
.hero-sub strong { color: var(--text); font-weight: 600; }
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 56px; animation: fadeUp .7s .3s ease both; }
.btn-hero-primary { padding: 14px 32px; border-radius: 10px; background: var(--orange); color: #fff; font-size: 15px; font-weight: 700; font-family: var(--sans); cursor: pointer; border: none; text-decoration: none; display: inline-flex; align-items: center; gap: 8px; transition: background .2s, transform .15s, box-shadow .2s; box-shadow: 0 4px 24px rgba(249,115,22,.35); }
.btn-hero-primary:hover { background: var(--orange-dark); transform: translateY(-2px); box-shadow: 0 8px 36px rgba(249,115,22,.45); }
.btn-hero-secondary { padding: 14px 32px; border-radius: 10px; background: #fff; color: var(--text); font-size: 15px; font-weight: 600; font-family: var(--sans); cursor: pointer; border: 1px solid var(--border); text-decoration: none; display: inline-flex; align-items: center; gap: 8px; transition: background .2s, border-color .2s; box-shadow: 0 2px 12px rgba(249,115,22,.08); }
.btn-hero-secondary:hover { background: var(--orange-pale); border-color: var(--border-o); }

.hero-terminal { max-width: 580px; margin: 0 auto; background: #1e1b2e; border: 1px solid rgba(249,115,22,.20); border-radius: 14px; overflow: hidden; box-shadow: 0 24px 64px rgba(249,115,22,.12), 0 0 0 1px rgba(249,115,22,.10); animation: fadeUp .7s .4s ease both; }
.terminal-bar { background: #2a2540; padding: 10px 16px; display: flex; align-items: center; gap: 8px; border-bottom: 1px solid rgba(249,115,22,.12); }
.t-dot { width: 11px; height: 11px; border-radius: 50%; }
.t-dot.r { background: #ff5f57; } .t-dot.y { background: #febc2e; } .t-dot.g { background: #28c840; }
.terminal-title { flex: 1; text-align: center; font-size: 11px; color: #8b82b0; font-family: var(--mono); }
.terminal-body { padding: 20px 24px; text-align: left; font-family: var(--mono); font-size: 13px; line-height: 1.9; color: #e2d9f3; }
.c-kw { color: #c792ea; } .c-fn { color: #82aaff; } .c-str { color: #c3e88d; } .c-num { color: #f78c6c; }
.c-cm { color: #6b5a8a; font-style: italic; } .c-or { color: var(--orange); font-weight: 700; } .c-op { color: #89ddff; }
.cursor { display: inline-block; width: 8px; height: 14px; background: var(--orange); vertical-align: middle; border-radius: 1px; animation: blink 1.1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }

.stats-bar { width: 100%; background: linear-gradient(135deg, var(--orange) 0%, var(--orange-dark) 100%); padding: 24px 48px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.stat-item { text-align: center; padding: 8px; }
.stat-num { font-size: 28px; font-weight: 800; color: #fff; font-family: var(--mono); letter-spacing: -.01em; text-shadow: 0 2px 12px rgba(0,0,0,.15); }
.stat-label { font-size: 12px; color: rgba(255,255,255,.80); font-weight: 500; margin-top: 2px; letter-spacing: .04em; text-transform: uppercase; }

section { padding: 80px 48px; }
.section-tag { display: inline-flex; align-items: center; gap: 6px; font-size: 11px; font-weight: 700; color: var(--orange); font-family: var(--mono); letter-spacing: .1em; text-transform: uppercase; margin-bottom: 14px; }
.section-tag::before { content: '//'; opacity: .5; }
.section-title { font-size: clamp(28px, 3.5vw, 42px); font-weight: 800; line-height: 1.15; letter-spacing: -.02em; color: var(--text); margin-bottom: 16px; }
.section-title .accent { color: var(--orange); }
.section-sub { font-size: 16px; color: var(--text-muted); line-height: 1.7; max-width: 580px; }

.languages-section { background: var(--dark); }
.languages-header { margin-bottom: 52px; }
.lang-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }
.lang-card { background: #fff; border: 1.5px solid rgba(249,115,22,.14); border-radius: 14px; padding: 28px 24px; cursor: pointer; transition: border-color .2s, transform .2s, box-shadow .2s; position: relative; overflow: hidden; text-decoration: none; color: inherit; display: block; box-shadow: 0 2px 16px rgba(249,115,22,.06); }
.lang-card::before { content: ''; position: absolute; inset: 0; background: var(--orange-pale); opacity: 0; transition: opacity .2s; }
.lang-card:hover { border-color: var(--border-o); transform: translateY(-4px); box-shadow: 0 12px 40px rgba(249,115,22,.14); }
.lang-card:hover::before { opacity: 1; }
.lang-icon { width: 48px; height: 48px; border-radius: 12px; display: flex; align-items: center; justify-content: center; font-family: var(--mono); font-size: 18px; font-weight: 800; margin-bottom: 16px; position: relative; z-index: 1; }
.lang-name { font-size: 16px; font-weight: 700; margin-bottom: 6px; position: relative; z-index: 1; color: var(--text); }
.lang-desc { font-size: 12.5px; color: var(--text-muted); line-height: 1.6; position: relative; z-index: 1; }
.lang-badge { position: absolute; top: 14px; right: 14px; font-size: 10px; font-weight: 700; font-family: var(--mono); padding: 3px 9px; border-radius: 50px; z-index: 1; }
.lang-badge.free { background: rgba(13,148,136,.10); color: var(--teal); border: 1px solid rgba(13,148,136,.25); }
.lang-badge.popular { background: var(--orange-pale); color: var(--orange); border: 1px solid var(--border-o); }

.features-section { background: var(--dark2); }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 20px; margin-top: 52px; }
.feat-card { background: #fff; border: 1.5px solid rgba(249,115,22,.12); border-radius: 16px; padding: 32px 28px; transition: border-color .2s, box-shadow .2s; box-shadow: 0 2px 12px rgba(249,115,22,.05); }
.feat-card:hover { border-color: var(--border-o); box-shadow: 0 8px 32px rgba(249,115,22,.10); }
.feat-icon { width: 50px; height: 50px; border-radius: 14px; background: var(--orange-pale); border: 1px solid var(--border-o); display: flex; align-items: center; justify-content: center; margin-bottom: 20px; color: var(--orange); }
.feat-title { font-size: 17px; font-weight: 700; margin-bottom: 10px; color: var(--text); }
.feat-desc { font-size: 14px; color: var(--text-muted); line-height: 1.7; }

.challenge-section { background: var(--dark3); }
.challenge-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; max-width: 1100px; margin: 0 auto; }
.challenge-code { background: #1e1b2e; border: 1px solid rgba(249,115,22,.18); border-radius: 16px; overflow: hidden; box-shadow: 0 20px 60px rgba(249,115,22,.10); }
.code-tabs { background: #2a2540; display: flex; gap: 2px; padding: 8px 12px; border-bottom: 1px solid rgba(249,115,22,.12); }
.code-tab { padding: 6px 16px; border-radius: 6px; font-size: 12px; font-family: var(--mono); color: #8b82b0; cursor: pointer; transition: background .2s, color .2s; }
.code-tab.active { background: var(--orange-pale); color: var(--orange); }
.code-body { padding: 24px; font-family: var(--mono); font-size: 13px; line-height: 1.9; color: #e2d9f3; }
.challenge-content { padding: 20px 0; }
.challenge-content .section-title { font-size: 34px; margin-bottom: 20px; }
.challenge-list { list-style: none; margin-bottom: 32px; }
.challenge-list li { display: flex; align-items: flex-start; gap: 12px; padding: 12px 0; border-bottom: 1px solid rgba(249,115,22,.10); font-size: 14.5px; color: var(--text-muted); }
.challenge-list li:last-child { border-bottom: none; }
.challenge-list li::before { content: '→'; color: var(--orange); font-weight: 700; font-family: var(--mono); margin-top: 1px; flex-shrink: 0; }
.challenge-list li strong { color: var(--text); }

.dsa-section { background: var(--dark2); }
.dsa-topics { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; margin-top: 48px; }
.dsa-chip { background: #fff; border: 1.5px solid rgba(249,115,22,.14); border-radius: 10px; padding: 16px 18px; display: flex; align-items: center; gap: 10px; cursor: pointer; transition: border-color .2s, background .2s, box-shadow .2s; text-decoration: none; color: inherit; box-shadow: 0 2px 8px rgba(249,115,22,.05); }
.dsa-chip:hover { border-color: var(--border-o); background: var(--orange-pale); box-shadow: 0 6px 20px rgba(249,115,22,.10); }
.dsa-chip-icon { font-size: 20px; }
.dsa-chip-text { font-size: 13px; font-weight: 600; color: var(--text); }
.dsa-chip-count { font-size: 11px; color: var(--text-muted); margin-top: 1px; font-family: var(--mono); }

.leaderboard-section { background: var(--dark); }
.lb-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; max-width: 1100px; margin: 0 auto; }
.lb-card { background: #fff; border: 1.5px solid rgba(249,115,22,.14); border-radius: 16px; overflow: hidden; box-shadow: 0 4px 24px rgba(249,115,22,.08); }
.lb-header { background: var(--orange); padding: 16px 22px; display: flex; align-items: center; justify-content: space-between; font-size: 13px; font-weight: 600; color: #fff; }
.lb-header span { color: rgba(255,255,255,.80); font-family: var(--mono); font-size: 12px; }
.lb-row { display: flex; align-items: center; gap: 14px; padding: 14px 22px; border-bottom: 1px solid rgba(249,115,22,.09); transition: background .15s; }
.lb-row:last-child { border-bottom: none; }
.lb-row:hover { background: var(--orange-pale); }
.lb-rank { width: 28px; height: 28px; border-radius: 7px; display: flex; align-items: center; justify-content: center; font-family: var(--mono); font-size: 12px; font-weight: 700; background: var(--dark4); color: var(--text-muted); flex-shrink: 0; }
.lb-rank.gold   { background: rgba(255,200,0,.15);   color: #d97706; }
.lb-rank.silver { background: rgba(100,116,139,.12); color: #64748b; }
.lb-rank.bronze { background: rgba(180,83,9,.12);    color: #b45309; }
.lb-avatar { width: 34px; height: 34px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; flex-shrink: 0; }
.lb-info { flex: 1; }
.lb-name { font-size: 14px; font-weight: 600; color: var(--text); }
.lb-lang { font-size: 11px; color: var(--text-muted); font-family: var(--mono); }
.lb-pts { font-family: var(--mono); font-size: 14px; font-weight: 700; color: var(--orange); }

.quiz-preview { background: #fff; border: 1.5px solid rgba(249,115,22,.14); border-radius: 16px; overflow: hidden; box-shadow: 0 4px 24px rgba(249,115,22,.08); }
.quiz-qn { padding: 24px 24px 16px; border-bottom: 1px solid rgba(249,115,22,.10); }
.quiz-qn-tag { font-size: 11px; font-family: var(--mono); color: var(--orange); margin-bottom: 10px; }
.quiz-qn-text { font-size: 15px; font-weight: 600; line-height: 1.5; color: var(--text); }
.quiz-options { padding: 16px 24px; display: flex; flex-direction: column; gap: 10px; }
.quiz-opt { padding: 11px 16px; border-radius: 8px; border: 1.5px solid rgba(249,115,22,.14); font-size: 13.5px; cursor: pointer; transition: border-color .2s, background .2s; display: flex; gap: 10px; align-items: center; font-family: var(--mono); color: var(--text); background: var(--dark); }
.quiz-opt:hover { border-color: var(--border-o); background: var(--orange-pale); }
.quiz-opt.correct { border-color: rgba(13,148,136,.4); background: rgba(13,148,136,.07); color: var(--teal); }
.quiz-opt.wrong   { border-color: rgba(244,63,94,.4);  background: rgba(244,63,94,.07);  color: var(--rose); }
.quiz-opt-key { width: 22px; height: 22px; border-radius: 5px; border: 1.5px solid rgba(249,115,22,.20); display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; flex-shrink: 0; color: var(--orange); }

.cta-section { background: linear-gradient(135deg, #fff7ed 0%, #fef3c7 50%, #fdf4ff 100%); padding: 100px 48px; text-align: center; position: relative; overflow: hidden; border-top: 1px solid rgba(249,115,22,.12); }
.cta-section::before { content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 600px; height: 300px; background: radial-gradient(ellipse, rgba(249,115,22,.12) 0%, rgba(245,158,11,.06) 50%, transparent 70%); }
.cta-section .section-title { font-size: clamp(30px, 4vw, 50px); margin-bottom: 18px; position: relative; }
.cta-section .section-sub { font-size: 17px; margin: 0 auto 40px; position: relative; }
.cta-btns { display: flex; gap: 14px; justify-content: center; position: relative; flex-wrap: wrap; }

footer { background: #1c1008; border-top: 3px solid var(--orange); padding: 48px; display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; }
.foot-brand .brand-name { font-size: 18px; font-weight: 700; color: var(--orange); margin-bottom: 10px; }
.foot-brand p { font-size: 13px; color: rgba(255,255,255,.50); line-height: 1.7; max-width: 240px; }
.foot-col h4 { font-size: 12px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: rgba(255,255,255,.40); margin-bottom: 16px; font-family: var(--mono); }
.foot-col a { display: block; font-size: 13.5px; color: rgba(255,255,255,.45); text-decoration: none; margin-bottom: 10px; transition: color .2s; }
.foot-col a:hover { color: var(--orange); }
.foot-bottom { background: #150d06; border-top: 1px solid rgba(249,115,22,.15); padding: 20px 48px; display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: rgba(255,255,255,.35); }
.foot-bottom span { font-family: var(--mono); }
.foot-bottom .orange { color: var(--orange); }

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

.lang-card:hover { box-shadow: 0 12px 40px rgba(249,115,22,.14), 0 0 0 2px rgba(249,115,22,.20); }
.feat-card:hover { box-shadow: 0 8px 32px rgba(249,115,22,.10), 0 0 0 2px rgba(249,115,22,.16); }
.stats-bar { background: linear-gradient(135deg, var(--orange) 0%, var(--orange-dark) 100%); }
.stat-num { text-shadow: 0 2px 12px rgba(0,0,0,.15); }
.btn-hero-primary { box-shadow: 0 4px 24px rgba(249,115,22,.35); }
.btn-hero-primary:hover { box-shadow: 0 8px 36px rgba(249,115,22,.50); }

@media (max-width: 900px) {
  nav { padding: 0 24px; }
  .nav-links { display: none; }
  section { padding: 60px 24px; }
  .stats-bar { padding: 20px 24px; grid-template-columns: repeat(2,1fr); }
  .challenge-inner, .lb-inner { grid-template-columns: 1fr; }
  footer { grid-template-columns: 1fr 1fr; padding: 40px 24px; }
  .foot-bottom { padding: 16px 24px; flex-direction: column; gap: 8px; text-align: center; }
}
@media (max-width: 600px) {
  .hero-actions { flex-direction: column; align-items: center; }
  .lang-grid { grid-template-columns: repeat(2, 1fr); }
  .dsa-topics { grid-template-columns: repeat(2, 1fr); }
  footer { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: repeat(2,1fr); }
}