/* a2zlessons.com — Structured Courses & Tutorials */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--green:#059669;--green-light:#10B981;--green-dark:#047857;--orange:#EA580C;--orange-light:#F97316;--white:#FFFFFF;--sage:#F0FDF4;--gray-50:#F8FAFC;--gray-100:#F1F5F9;--gray-200:#E2E8F0;--gray-300:#CBD5E1;--gray-400:#94A3B8;--gray-500:#64748B;--gray-700:#334155;--gray-800:#1E293B;--gray-900:#0F172A;--radius:8px;--shadow:0 1px 3px rgba(0,0,0,.1),0 1px 2px rgba(0,0,0,.06);--shadow-md:0 4px 6px -1px rgba(0,0,0,.1),0 2px 4px -2px rgba(0,0,0,.1);--shadow-lg:0 10px 15px -3px rgba(0,0,0,.1),0 4px 6px -4px rgba(0,0,0,.1)}
html{scroll-behavior:smooth}
body{font-family:system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;color:var(--gray-800);background:var(--white);line-height:1.6}
a{color:var(--green);text-decoration:none;transition:color .2s}
a:hover{color:var(--green-dark)}

/* Skip link */
.skip-link{position:absolute;top:-100%;left:50%;transform:translateX(-50%);background:var(--green);color:#fff;padding:.5rem 1rem;border-radius:0 0 var(--radius) var(--radius);z-index:1000;font-weight:600}
.skip-link:focus{top:0}

/* Header */
.site-header{background:var(--white);border-bottom:1px solid var(--gray-200);padding:.75rem 0;position:sticky;top:0;z-index:100;box-shadow:var(--shadow)}
.header-inner{max-width:1200px;margin:0 auto;padding:0 1.5rem;display:flex;align-items:center;justify-content:space-between;gap:1rem}
.logo{font-size:1.5rem;font-weight:800;color:var(--gray-900);display:flex;align-items:center;gap:.5rem}
.logo .accent{color:var(--green)}
.nav-toggle{display:none;background:none;border:none;cursor:pointer;padding:.5rem}
.nav-toggle svg{width:24px;height:24px}
.main-nav ul{list-style:none;display:flex;gap:1.5rem}
.main-nav a{color:var(--gray-500);font-weight:500;font-size:.95rem;transition:color .2s}
.main-nav a:hover,.main-nav a[aria-current="page"]{color:var(--green)}

/* Hero */
.hero{background:linear-gradient(135deg,var(--green) 0%,var(--green-light) 50%,#34D399 100%);color:#fff;padding:5rem 1.5rem 4rem;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-50%;right:-30%;width:80%;height:200%;background:radial-gradient(circle,rgba(255,255,255,.08) 0%,transparent 70%);pointer-events:none}
.hero h1{font-size:clamp(2rem,5vw,3.5rem);font-weight:800;margin-bottom:1rem;position:relative}
.hero p{font-size:1.2rem;opacity:.9;max-width:600px;margin:0 auto 2.5rem;position:relative}
.hero-stats{display:flex;justify-content:center;gap:3rem;flex-wrap:wrap;margin-top:2rem;position:relative}
.hero-stat{text-align:center}
.hero-stat-num{font-size:2rem;font-weight:800}
.hero-stat-label{font-size:.85rem;opacity:.8}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.75rem 1.5rem;border-radius:var(--radius);font-weight:600;font-size:.95rem;border:none;cursor:pointer;transition:all .2s;font-family:inherit}
.btn-green{background:var(--green);color:#fff}
.btn-green:hover{background:var(--green-dark);color:#fff}
.btn-orange{background:var(--orange);color:#fff}
.btn-orange:hover{background:#C2410C;color:#fff}
.btn-white{background:#fff;color:var(--green)}
.btn-white:hover{background:var(--gray-100);color:var(--green)}
.btn-outline{background:transparent;border:2px solid var(--green);color:var(--green)}
.btn-outline:hover{background:var(--green);color:#fff}
.btn-outline-white{background:transparent;border:2px solid #fff;color:#fff}
.btn-outline-white:hover{background:rgba(255,255,255,.15);color:#fff}

/* Sections */
.section{max-width:1200px;margin:0 auto;padding:4rem 1.5rem}
.section-header{text-align:center;margin-bottom:3rem}
.section-header h2{font-size:clamp(1.5rem,3vw,2.2rem);font-weight:800;color:var(--gray-900);margin-bottom:.5rem}
.section-header p{color:var(--gray-500);font-size:1.05rem;max-width:600px;margin:0 auto}
.section-sage{background:var(--sage)}
.section-gray{background:var(--gray-50)}

/* Course Category Cards */
.cat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:1.5rem}
.cat-card{background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius);padding:2rem;display:flex;gap:1.25rem;align-items:flex-start;transition:all .3s;box-shadow:var(--shadow)}
.cat-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--green)}
.cat-icon{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;flex-shrink:0}
.cat-icon svg{width:24px;height:24px}
.cat-body h3{font-size:1.1rem;font-weight:700;margin-bottom:.35rem}
.cat-body p{font-size:.9rem;color:var(--gray-500);margin-bottom:.5rem}
.cat-body .count{font-size:.8rem;font-weight:600;color:var(--green)}

/* Course Cards */
.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:1.5rem}
.course-card{background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius);overflow:hidden;transition:all .3s;box-shadow:var(--shadow)}
.course-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.course-banner{height:8px}
.course-body{padding:1.5rem}
.course-body h3{font-size:1.1rem;font-weight:700;margin-bottom:.5rem}
.course-body h3 a{color:var(--gray-900)}
.course-body h3 a:hover{color:var(--green)}
.course-body p{font-size:.9rem;color:var(--gray-500);margin-bottom:1rem}
.course-meta{display:flex;flex-wrap:wrap;gap:.75rem;font-size:.8rem;color:var(--gray-400);align-items:center}
.course-meta svg{width:14px;height:14px;fill:currentColor;flex-shrink:0}
.course-meta span{display:flex;align-items:center;gap:.3rem}
.course-level{display:inline-block;padding:.15rem .5rem;border-radius:4px;font-size:.75rem;font-weight:600}
.level-beginner{background:#DCFCE7;color:#166534}
.level-intermediate{background:#FEF3C7;color:#92400E}
.level-advanced{background:#FCE7F3;color:#9D174D}

/* Filter Bar */
.filter-bar{display:flex;flex-wrap:wrap;gap:1rem;margin-bottom:2rem;align-items:center}
.filter-bar select,.filter-bar input{padding:.6rem 1rem;border:1px solid var(--gray-200);border-radius:var(--radius);font-size:.9rem;font-family:inherit;background:var(--white);color:var(--gray-800);outline:none}
.filter-bar select:focus,.filter-bar input:focus{border-color:var(--green)}
.filter-bar input{flex:1;min-width:200px}

/* Progress Bar */
.progress-bar{width:100%;height:8px;background:var(--gray-200);border-radius:4px;overflow:hidden;margin-bottom:.5rem}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--green),var(--green-light));border-radius:4px;transition:width .5s ease}
.progress-text{font-size:.8rem;color:var(--gray-500);font-weight:500}

/* Lesson Page */
.course-layout{max-width:1200px;margin:0 auto;padding:2rem 1.5rem;display:grid;grid-template-columns:280px 1fr;gap:2rem}
.course-sidebar{position:sticky;top:80px;height:fit-content}
.lesson-list{background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius);overflow:hidden}
.lesson-list-header{padding:1rem 1.25rem;background:var(--sage);border-bottom:1px solid var(--gray-200);font-weight:700;font-size:.95rem}
.lesson-link{display:flex;align-items:center;gap:.75rem;padding:.85rem 1.25rem;border-bottom:1px solid var(--gray-100);font-size:.85rem;color:var(--gray-500);transition:all .2s}
.lesson-link:hover{background:var(--sage);color:var(--green)}
.lesson-link.active{background:var(--sage);color:var(--green);font-weight:600;border-left:3px solid var(--green)}
.lesson-link.completed{color:var(--green)}
.lesson-num{width:24px;height:24px;border-radius:50%;background:var(--gray-100);display:flex;align-items:center;justify-content:center;font-size:.75rem;font-weight:700;flex-shrink:0}
.lesson-link.active .lesson-num{background:var(--green);color:#fff}
.lesson-link.completed .lesson-num{background:var(--green);color:#fff}

/* Course Content */
.course-content{min-width:0}
.course-content h1{font-size:clamp(1.5rem,3vw,2rem);font-weight:800;margin-bottom:.5rem}
.course-content h2{font-size:1.4rem;font-weight:700;margin:2rem 0 1rem;color:var(--gray-900)}
.course-content h3{font-size:1.1rem;font-weight:700;margin:1.5rem 0 .75rem}
.course-content p{margin-bottom:1rem;line-height:1.8;color:var(--gray-700)}
.course-content ul,.course-content ol{margin:0 0 1rem 1.5rem;color:var(--gray-700)}
.course-content li{margin-bottom:.5rem;line-height:1.7}

/* Code blocks (CSS-only syntax highlighting) */
.code-block{background:var(--gray-900);color:#E2E8F0;border-radius:var(--radius);padding:1.25rem 1.5rem;margin:1rem 0 1.5rem;overflow-x:auto;font-family:'SF Mono',Monaco,'Cascadia Code',monospace;font-size:.85rem;line-height:1.7;position:relative}
.code-block .tag{color:#7DD3FC}
.code-block .attr{color:#A78BFA}
.code-block .val{color:#86EFAC}
.code-block .comment{color:#64748B;font-style:italic}
.code-block .keyword{color:#F472B6}
.code-block .string{color:#86EFAC}
.code-block .fn{color:#FCD34D}
.code-label{position:absolute;top:.5rem;right:.75rem;font-size:.7rem;color:var(--gray-400);font-family:system-ui;text-transform:uppercase;letter-spacing:.05em}

/* Quiz */
.quiz-box{background:var(--sage);border:1px solid #BBF7D0;border-radius:var(--radius);padding:1.5rem;margin:2rem 0}
.quiz-box h3{font-size:1rem;font-weight:700;margin-bottom:1rem;color:var(--green-dark)}
.quiz-option{display:flex;align-items:center;gap:.75rem;padding:.75rem 1rem;background:var(--white);border:1px solid var(--gray-200);border-radius:var(--radius);margin-bottom:.5rem;cursor:pointer;transition:all .2s;font-size:.9rem}
.quiz-option:hover{border-color:var(--green);background:var(--sage)}
.quiz-option.correct{border-color:var(--green);background:#DCFCE7}
.quiz-option.wrong{border-color:#EF4444;background:#FEE2E2}
.quiz-radio{width:18px;height:18px;border:2px solid var(--gray-300);border-radius:50%;flex-shrink:0;position:relative}
.quiz-option.selected .quiz-radio{border-color:var(--green)}
.quiz-option.selected .quiz-radio::after{content:'';width:10px;height:10px;background:var(--green);border-radius:50%;position:absolute;top:50%;left:50%;transform:translate(-50%,-50%)}
.quiz-result{margin-top:1rem;padding:.75rem 1rem;border-radius:var(--radius);font-weight:600;font-size:.9rem;display:none}
.quiz-result.show{display:block}
.quiz-result.pass{background:#DCFCE7;color:#166534}
.quiz-result.fail{background:#FEE2E2;color:#991B1B}

/* Lesson Nav */
.lesson-nav{display:flex;justify-content:space-between;margin-top:3rem;padding-top:2rem;border-top:1px solid var(--gray-200)}
.lesson-nav a{display:flex;align-items:center;gap:.5rem;font-weight:600;font-size:.9rem}
.lesson-nav svg{width:16px;height:16px;fill:currentColor}

/* Page Hero */
.page-hero{background:linear-gradient(135deg,var(--green),var(--green-light));color:#fff;padding:3rem 1.5rem;text-align:center}
.page-hero h1{font-size:clamp(1.8rem,4vw,2.5rem);font-weight:800;margin-bottom:.5rem}
.page-hero p{opacity:.9;font-size:1.05rem;max-width:600px;margin:0 auto}
.breadcrumb{max-width:1200px;margin:0 auto;padding:1rem 1.5rem;font-size:.85rem;color:var(--gray-500)}
.breadcrumb a{color:var(--green)}

/* Form */
.form-section{max-width:700px;margin:0 auto}
.form-group{margin-bottom:1.5rem}
.form-group label{display:block;font-weight:600;margin-bottom:.5rem;color:var(--gray-800)}
.form-group input,.form-group textarea,.form-group select{width:100%;padding:.75rem 1rem;border:1px solid var(--gray-200);border-radius:var(--radius);font-size:.95rem;font-family:inherit;background:var(--white);outline:none;transition:border-color .2s}
.form-group input:focus,.form-group textarea:focus,.form-group select:focus{border-color:var(--green)}
.form-group textarea{min-height:120px;resize:vertical}

/* Stats */
.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1.5rem}
.stat-card{text-align:center;padding:2rem;background:var(--white);border-radius:var(--radius);box-shadow:var(--shadow)}
.stat-card .num{font-size:2.5rem;font-weight:800;color:var(--green)}
.stat-card .label{font-size:.9rem;color:var(--gray-500);font-weight:500}

/* GWN Footer */
.gwn-footer{background:var(--gray-900);color:var(--gray-400);padding:3rem 1.5rem 1.5rem}
.footer-inner{max-width:1200px;margin:0 auto}
.footer-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:2rem;margin-bottom:2rem}
.footer-col h4{color:#fff;font-size:.95rem;margin-bottom:1rem;font-weight:700}
.footer-col a{display:block;color:var(--gray-400);font-size:.85rem;padding:.2rem 0;transition:color .2s}
.footer-col a:hover{color:var(--green-light)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:1.5rem;display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:1rem;font-size:.8rem}
.footer-bottom a{color:var(--gray-400)}
.footer-bottom a:hover{color:var(--green-light)}

/* Responsive */
@media(max-width:768px){
  .nav-toggle{display:block}
  .main-nav{display:none;position:absolute;top:100%;left:0;right:0;background:var(--white);padding:1rem 1.5rem;border-top:1px solid var(--gray-200);box-shadow:var(--shadow)}
  .main-nav.open{display:block}
  .main-nav ul{flex-direction:column;gap:.5rem}
  .main-nav a{display:block;padding:.5rem 0}
  .hero{padding:3rem 1.5rem 2.5rem}
  .cat-grid{grid-template-columns:1fr}
  .course-grid{grid-template-columns:1fr}
  .course-layout{grid-template-columns:1fr}
  .course-sidebar{position:static;order:2}
  .hero-stats{gap:1.5rem}
  .footer-grid{grid-template-columns:1fr 1fr}
  .stats-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:480px){
  .footer-grid{grid-template-columns:1fr}
  .filter-bar{flex-direction:column}
  .stats-grid{grid-template-columns:1fr}
}