*{margin:0;padding:0;box-sizing:border-box}:root{--primary-50: #eff6ff;--primary-100: #dbeafe;--primary-200: #bfdbfe;--primary-300: #93c5fd;--primary-400: #60a5fa;--primary-500: #3b82f6;--primary-600: #2563eb;--primary-700: #1d4ed8;--primary-800: #1e40af;--primary-900: #1e3a8a;--secondary-50: #f0fdf4;--secondary-100: #dcfce7;--secondary-200: #bbf7d0;--secondary-300: #86efac;--secondary-400: #4ade80;--secondary-500: #22c55e;--secondary-600: #16a34a;--secondary-700: #15803d;--secondary-800: #166534;--secondary-900: #14532d;--accent-50: #fef3c7;--accent-100: #fde68a;--accent-200: #fcd34d;--accent-300: #fbbf24;--accent-400: #f59e0b;--accent-500: #d97706;--accent-600: #b45309;--accent-700: #92400e;--accent-800: #78350f;--accent-900: #451a03;--gray-50: #f9fafb;--gray-100: #f3f4f6;--gray-200: #e5e7eb;--gray-300: #d1d5db;--gray-400: #9ca3af;--gray-500: #6b7280;--gray-600: #4b5563;--gray-700: #374151;--gray-800: #1f2937;--gray-900: #111827;--dark-bg: #0f0f23;--dark-surface: #1a1a2e;--dark-surface-hover: #16213e;--dark-border: #eee3ff15;--dark-text: #e2e8f0;--dark-text-secondary: #94a3b8;--space-1: .25rem;--space-2: .5rem;--space-3: .75rem;--space-4: 1rem;--space-6: 1.5rem;--space-8: 2rem;--space-12: 3rem;--space-16: 4rem;--space-20: 5rem;--space-24: 6rem;--font-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;--font-mono: "JetBrains Mono", "SF Mono", Monaco, monospace;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .1), 0 4px 6px -4px rgb(0 0 0 / .1);--shadow-xl: 0 20px 25px -5px rgb(0 0 0 / .1), 0 8px 10px -6px rgb(0 0 0 / .1);--transition-fast: .15s ease;--transition-normal: .25s ease;--transition-slow: .35s ease}body{font-family:var(--font-body);line-height:1.6;color:var(--dark-text);background:var(--dark-bg);overflow-x:hidden}.stars{position:fixed;top:0;left:0;width:100%;height:100%;pointer-events:none;z-index:-2}.stars:before,.stars:after{content:"";position:absolute;width:2px;height:2px;background:#fff;border-radius:50%;box-shadow:25px 5px #fff,50px 25px #fff,75px 15px #fff,100px 35px #fff,125px 8px #fff,150px 45px #fff,200px 12px #fff,250px 38px #fff,300px 22px #fff,350px 55px #fff,400px 18px #fff,450px 42px #fff,500px 28px #fff,550px 8px #fff,600px 48px #fff,650px 32px #fff,700px 15px #fff,750px 58px #fff,800px 25px #fff,850px 42px #fff,900px 18px #fff,950px 52px #fff,1000px 28px #fff,1050px 38px #fff,1100px 15px #fff,1150px 45px #fff,1200px 32px #fff,1250px 8px #fff,1300px 55px #fff,1350px 22px #fff,1400px 48px #fff,1450px 35px #fff,1500px 12px #fff;animation:twinkle 3s infinite linear}.stars:after{animation-delay:1.5s;transform:translate(50px)}@keyframes twinkle{0%,to{opacity:.3}50%{opacity:1}}.nebula{position:fixed;top:0;left:0;width:100%;height:100%;pointer-events:none;z-index:-1;background:radial-gradient(ellipse at 20% 50%,rgba(120,119,198,.1) 0%,transparent 50%),radial-gradient(ellipse at 80% 20%,rgba(255,119,198,.1) 0%,transparent 50%),radial-gradient(ellipse at 40% 80%,rgba(120,219,255,.1) 0%,transparent 50%);animation:nebula-flow 20s ease-in-out infinite alternate}@keyframes nebula-flow{0%{transform:translate(-10px) translateY(-5px) scale(1)}to{transform:translate(10px) translateY(5px) scale(1.02)}}.header{position:fixed;top:0;left:0;right:0;z-index:100;background:#0f0f23cc;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-bottom:1px solid var(--dark-border)}.navbar{padding:var(--space-4) 0}.nav-container{max-width:1200px;margin:0 auto;padding:0 var(--space-6);display:flex;align-items:center;justify-content:space-between}.logo{display:flex;align-items:center;gap:var(--space-3);font-weight:600;font-size:1.125rem;color:var(--dark-text)}.logo-icon{font-size:1.5rem;background:linear-gradient(135deg,var(--primary-400),var(--secondary-400));padding:var(--space-2);border-radius:12px;display:flex;align-items:center;justify-content:center}.nav-menu{display:flex;gap:var(--space-8)}.nav-link{color:var(--dark-text-secondary);text-decoration:none;font-weight:500;transition:var(--transition-fast);position:relative}.nav-link:hover,.nav-link.active{color:var(--primary-400)}.nav-link:after{content:"";position:absolute;bottom:-4px;left:0;width:0;height:2px;background:var(--primary-400);transition:var(--transition-fast)}.nav-link.active:after,.nav-link:hover:after{width:100%}.container{max-width:1200px;margin:0 auto;padding:0 var(--space-6)}.hero{min-height:100vh;display:flex;align-items:center;justify-content:center;text-align:center;padding:var(--space-24) var(--space-6);position:relative}.hero-content{max-width:800px;animation:fade-in-up 1s ease-out}.hero-title{font-size:clamp(2.5rem,5vw,4rem);font-weight:700;line-height:1.1;margin-bottom:var(--space-6);background:linear-gradient(135deg,var(--primary-300),var(--secondary-300),var(--accent-300));background-clip:text;-webkit-background-clip:text;-webkit-text-fill-color:transparent}.title-line{display:block}.hero-description{font-size:1.25rem;color:var(--dark-text-secondary);margin-bottom:var(--space-8);line-height:1.7}.hero-buttons{display:flex;gap:var(--space-4);justify-content:center;margin-bottom:var(--space-12);flex-wrap:wrap}.btn{padding:var(--space-4) var(--space-8);border-radius:12px;font-weight:600;text-decoration:none;border:none;cursor:pointer;transition:var(--transition-normal);font-size:1rem;display:inline-flex;align-items:center;gap:var(--space-2)}.btn-primary{background:linear-gradient(135deg,var(--primary-500),var(--primary-600));color:#fff;box-shadow:var(--shadow-lg)}.btn-primary:hover{transform:translateY(-2px);box-shadow:var(--shadow-xl);background:linear-gradient(135deg,var(--primary-600),var(--primary-700))}.btn-secondary{background:var(--dark-surface);color:var(--dark-text);border:1px solid var(--dark-border)}.btn-secondary:hover{background:var(--dark-surface-hover);transform:translateY(-2px)}.hero-stats{display:flex;justify-content:center;gap:var(--space-12);flex-wrap:wrap}.stat{text-align:center}.stat-number{display:block;font-size:2rem;font-weight:700;color:var(--primary-400)}.stat-label{color:var(--dark-text-secondary);font-size:.875rem;margin-top:var(--space-1)}.calculators-section{padding:var(--space-24) 0}.section-header{text-align:center;margin-bottom:var(--space-16)}.section-title{font-size:2.5rem;font-weight:700;margin-bottom:var(--space-4);color:var(--dark-text)}.section-description{font-size:1.125rem;color:var(--dark-text-secondary);max-width:600px;margin:0 auto}.category-filter{display:flex;justify-content:center;gap:var(--space-2);margin-bottom:var(--space-12);flex-wrap:wrap}.filter-btn{padding:var(--space-3) var(--space-6);border:1px solid var(--dark-border);background:var(--dark-surface);color:var(--dark-text-secondary);border-radius:25px;cursor:pointer;transition:var(--transition-fast);font-weight:500}.filter-btn:hover,.filter-btn.active{background:var(--primary-500);color:#fff;border-color:var(--primary-500)}.calculators-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:var(--space-6)}.calculator-card{background:var(--dark-surface);border:1px solid var(--dark-border);border-radius:16px;padding:var(--space-6);cursor:pointer;transition:var(--transition-normal);position:relative;overflow:hidden}.calculator-card:before{content:"";position:absolute;top:0;left:0;width:100%;height:100%;background:linear-gradient(135deg,var(--primary-500)/.1,var(--secondary-500)/.1);opacity:0;transition:var(--transition-normal)}.calculator-card:hover{transform:translateY(-4px);border-color:var(--primary-400);box-shadow:var(--shadow-xl)}.calculator-card:hover:before{opacity:1}.card-icon{font-size:2rem;margin-bottom:var(--space-4);display:block}.card-title{font-size:1.25rem;font-weight:600;margin-bottom:var(--space-2);color:var(--dark-text);position:relative;z-index:1}.card-description{color:var(--dark-text-secondary);margin-bottom:var(--space-4);line-height:1.5;position:relative;z-index:1}.card-formula{font-family:var(--font-mono);background:var(--dark-bg);padding:var(--space-3);border-radius:8px;font-size:.875rem;color:var(--accent-300);border:1px solid var(--dark-border);position:relative;z-index:1}.modal{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:#000c;z-index:1000;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.modal-content{position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);background:var(--dark-surface);border-radius:16px;max-width:600px;width:90%;max-height:80vh;overflow-y:auto;border:1px solid var(--dark-border)}.modal-header{display:flex;justify-content:space-between;align-items:center;padding:var(--space-6);border-bottom:1px solid var(--dark-border)}.modal-header h2{color:var(--dark-text);font-size:1.5rem;font-weight:600}.close-btn{background:none;border:none;font-size:1.5rem;color:var(--dark-text-secondary);cursor:pointer;padding:var(--space-2);line-height:1;border-radius:8px;transition:var(--transition-fast)}.close-btn:hover{background:var(--dark-bg);color:var(--dark-text)}.modal-body{padding:var(--space-6)}.calculator-interface{display:flex;flex-direction:column;gap:var(--space-6)}.input-group{display:flex;flex-direction:column;gap:var(--space-2)}.input-label{color:var(--dark-text);font-weight:500;font-size:.875rem}.input-field{padding:var(--space-4);border:1px solid var(--dark-border);border-radius:8px;background:var(--dark-bg);color:var(--dark-text);font-size:1rem;transition:var(--transition-fast)}.input-field:focus{outline:none;border-color:var(--primary-400);box-shadow:0 0 0 3px #3b82f61a}.input-unit{color:var(--dark-text-secondary);font-size:.875rem;margin-top:var(--space-1)}.calculator-formula{background:var(--dark-bg);padding:var(--space-4);border-radius:8px;border:1px solid var(--dark-border)}.formula-title{color:var(--dark-text);font-weight:600;margin-bottom:var(--space-2);font-size:.875rem;text-transform:uppercase;letter-spacing:.5px}.formula-text{font-family:var(--font-mono);color:var(--accent-300);font-size:1.125rem}.result-section{background:var(--dark-bg);padding:var(--space-6);border-radius:12px;border:1px solid var(--dark-border);text-align:center}.result-label{color:var(--dark-text-secondary);font-size:.875rem;margin-bottom:var(--space-2);text-transform:uppercase;letter-spacing:.5px}.result-value{font-size:1.5rem;font-weight:700;color:var(--primary-400);font-family:var(--font-mono)}.result-unit{color:var(--dark-text-secondary);font-size:1rem;margin-top:var(--space-1)}.constants-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:var(--space-4)}.constant-item{background:var(--dark-bg);padding:var(--space-4);border-radius:8px;border:1px solid var(--dark-border);text-align:center}.constant-symbol{font-family:var(--font-mono);font-size:1.5rem;font-weight:700;color:var(--primary-400);margin-bottom:var(--space-2)}.constant-name{color:var(--dark-text);font-weight:500;margin-bottom:var(--space-2)}.constant-value{font-family:var(--font-mono);color:var(--accent-300);font-size:.875rem}.footer{background:var(--dark-surface);border-top:1px solid var(--dark-border);padding:var(--space-16) 0 var(--space-8);margin-top:var(--space-24)}.footer-content{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:var(--space-8);margin-bottom:var(--space-8)}.footer-section h3,.footer-section h4{color:var(--dark-text);margin-bottom:var(--space-4)}.footer-section p,.footer-section li{color:var(--dark-text-secondary);line-height:1.6}.footer-section ul{list-style:none}.footer-section li{margin-bottom:var(--space-2)}.footer-bottom{text-align:center;padding-top:var(--space-8);border-top:1px solid var(--dark-border);color:var(--dark-text-secondary)}@keyframes fade-in-up{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}.calculator-card{animation:fade-in-up .6s ease-out forwards}.calculator-card:nth-child(1){animation-delay:.1s}.calculator-card:nth-child(2){animation-delay:.2s}.calculator-card:nth-child(3){animation-delay:.3s}.calculator-card:nth-child(4){animation-delay:.4s}.calculator-card:nth-child(5){animation-delay:.5s}.calculator-card:nth-child(6){animation-delay:.6s}@media (max-width: 768px){.nav-container{flex-direction:column;gap:var(--space-4)}.nav-menu{gap:var(--space-4)}.hero{min-height:80vh;padding:var(--space-16) var(--space-4)}.hero-buttons{flex-direction:column;align-items:center}.hero-stats{gap:var(--space-8)}.calculators-grid{grid-template-columns:1fr}.category-filter{gap:var(--space-1)}.filter-btn{padding:var(--space-2) var(--space-4);font-size:.875rem}.modal-content{width:95%;margin:var(--space-4)}.constants-grid{grid-template-columns:1fr}}@media (max-width: 480px){.hero-title{font-size:2rem}.hero-description{font-size:1rem}.btn{padding:var(--space-3) var(--space-6);font-size:.875rem}.section-title{font-size:2rem}.calculator-card{padding:var(--space-4)}.card-title{font-size:1.125rem}}.hidden{display:none!important}.loading{display:inline-block;width:20px;height:20px;border:3px solid rgba(255,255,255,.3);border-radius:50%;border-top-color:var(--primary-400);animation:spin 1s ease-in-out infinite}@keyframes spin{to{transform:rotate(360deg)}}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-track{background:var(--dark-bg)}::-webkit-scrollbar-thumb{background:var(--dark-border);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--gray-600)}