:root{--primary-color:#4f46e5;--primary-hover:#4338ca;--secondary-color:#10b981;--background-color:#f9fafb;--surface-color:#ffffff;--text-primary:#111827;--text-secondary:#6b7280;--border-color:#e5e7eb;--shadow-sm:0 1px 2px 0 rgba(0,0,0,0.05);--shadow-md:0 4px 6px -1px rgba(0,0,0,0.1),0 2px 4px -1px rgba(0,0,0,0.06);--shadow-lg:0 10px 15px -3px rgba(0,0,0,0.1),0 4px 6px -2px rgba(0,0,0,0.05);--radius-md:0.5rem;--radius-lg:0.75rem;--font-family:'Inter',system-ui,-apple-system,sans-serif;--transition-speed:0.2s;}[data-theme="dark"]{--primary-color:#6366f1;--primary-hover:#818cf8;--secondary-color:#34d399;--background-color:#111827;--surface-color:#1f2937;--text-primary:#f9fafb;--text-secondary:#9ca3af;--border-color:#374151;--shadow-sm:0 1px 2px 0 rgba(0,0,0,0.3);--shadow-md:0 4px 6px -1px rgba(0,0,0,0.4);--shadow-lg:0 10px 15px -3px rgba(0,0,0,0.4);}.theme-toggle{background:none;border:none;cursor:pointer;color:var(--text-secondary);font-size:1.5rem;padding:0.5rem;border-radius:50%;transition:all var(--transition-speed);display:flex;align-items:center;justify-content:center;}.theme-toggle:hover{color:var(--primary-color);background-color:rgba(99,102,241,0.1);}*{box-sizing:border-box;margin:0;padding:0;}body{font-family:var(--font-family);background-color:var(--background-color);color:var(--text-primary);line-height:1.6;-webkit-font-smoothing:antialiased;}a{text-decoration:none;color:inherit;}.container{max-width:1200px;margin:0 auto;padding:0 1.5rem;}.section{padding:4rem 0;}.grid{display:grid;gap:2rem;}.grid-2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));}.grid-3{grid-template-columns:repeat(auto-fit,minmax(300px,1fr));}.grid-4{grid-template-columns:repeat(auto-fit,minmax(200px,1fr));}header{background-color:var(--surface-color);border-bottom:1px solid var(--border-color);position:sticky;top:0;z-index:100;box-shadow:var(--shadow-sm);}.nav-container{display:flex;justify-content:space-between;align-items:center;height:4rem;}.logo{font-size:1.5rem;font-weight:700;color:var(--primary-color);display:flex;align-items:center;gap:0.5rem;}.nav-links{display:flex;gap:2rem;}.nav-link{font-weight:500;color:var(--text-secondary);transition:color var(--transition-speed);}.nav-link:hover{color:var(--primary-color);}.hero{background:linear-gradient(135deg,#4f46e5 0%,#1e1b4b 100%);color:white;padding:6rem 0;text-align:center;overflow:hidden;position:relative;}.hero .container{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1.5rem;}.hero-content{max-width:800px;margin:0 auto;}.hero h1{font-size:clamp(2.5rem,5vw,4rem);font-weight:800;margin-bottom:1.5rem;letter-spacing:-0.03em;line-height:1.1;text-shadow:0 2px 4px rgba(0,0,0,0.2);}.hero p{font-size:clamp(1.1rem,2vw,1.5rem);color:rgba(255,255,255,0.95);margin-bottom:2.5rem;max-width:700px;margin-left:auto;margin-right:auto;}@media (max-width:768px){.hero{padding:4rem 1.5rem;}}.btn{display:inline-flex;justify-content:center;align-items:center;padding:0.75rem 1.5rem;border-radius:var(--radius-md);font-weight:600;transition:all var(--transition-speed);cursor:pointer;border:none;font-size:1rem;}.btn-primary{background-color:var(--primary-color);color:white;}.btn-primary:hover{background-color:var(--primary-hover);transform:translateY(-1px);box-shadow:var(--shadow-md);}.btn-lg{padding:1rem 2rem;font-size:1.125rem;}.card{background-color:var(--surface-color);border-radius:var(--radius-lg);border:1px solid var(--border-color);padding:2rem;transition:all var(--transition-speed);box-shadow:var(--shadow-sm);display:flex;flex-direction:column;}.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:var(--primary-color);}.card-icon{font-size:2rem;margin-bottom:1rem;color:var(--primary-color);background:#eef2ff;width:3.5rem;height:3.5rem;display:flex;align-items:center;justify-content:center;border-radius:50%;}.card-title{font-size:1.25rem;font-weight:600;margin-bottom:0.5rem;color:var(--text-primary);}.card-desc{color:var(--text-secondary);font-size:0.95rem;flex-grow:1;}.calculator-wrapper{max-width:600px;margin:2rem auto;background:var(--surface-color);padding:2.5rem;border-radius:var(--radius-lg);box-shadow:var(--shadow-md);}.form-group{margin-bottom:1.5rem;}.form-label{display:block;margin-bottom:0.5rem;font-weight:500;color:var(--text-primary);}.form-input{width:100%;padding:0.875rem;border:1px solid var(--border-color);border-radius:var(--radius-md);font-size:1rem;font-family:inherit;transition:border-color var(--transition-speed);}.form-input:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px rgba(79,70,229,0.1);}.input-group{position:relative;}.input-suffix{position:absolute;right:1rem;top:50%;transform:translateY(-50%);color:var(--text-secondary);pointer-events:none;}.result-box{margin-top:2rem;padding:1.5rem;background-color:#f0fdf4;border:1px solid #bbf7d0;border-radius:var(--radius-md);display:none;animation:fadeIn 0.3s ease-out;}.result-box.visible{display:block;}.result-row{display:flex;justify-content:space-between;align-items:center;margin-bottom:0.5rem;}.result-label{color:#166534;font-weight:500;}.result-value{color:#15803d;font-weight:700;font-size:1.25rem;}@keyframes fadeIn{from{opacity:0;transform:translateY(10px);}to{opacity:1;transform:translateY(0);}}.ad-slot{background-color:#f3f4f6;border:1px dashed #d1d5db;display:flex;align-items:center;justify-content:center;color:#9ca3af;margin:2rem 0;padding:1rem;border-radius:var(--radius-md);min-height:100px;font-size:0.875rem;}.ad-slot.banner{min-height:250px;}footer{background-color:var(--surface-color);border-top:1px solid var(--border-color);padding:3rem 0;margin-top:4rem;text-align:center;color:var(--text-secondary);}.lang-switcher{position:relative;margin-left:1rem;}.lang-btn{background:none;border:1px solid var(--border-color);padding:0.5rem 0.75rem;border-radius:var(--radius-md);cursor:pointer;font-size:0.9rem;color:var(--text-primary);display:flex;align-items:center;gap:0.5rem;transition:all var(--transition-speed);}.lang-btn:hover{background-color:var(--border-color);}.lang-dropdown{position:absolute;top:100%;right:0;background-color:var(--surface-color);border:1px solid var(--border-color);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);display:none;flex-direction:column;min-width:120px;z-index:1000;overflow:hidden;}.lang-dropdown.show{display:flex;}.lang-option{padding:0.75rem 1rem;border:none;background:none;text-align:left;cursor:pointer;color:var(--text-primary);transition:background var(--transition-speed);display:flex;align-items:center;gap:0.5rem;width:100%;}.lang-option:hover{background-color:var(--background-color);}@media (max-width:640px){.hero h1{font-size:2.25rem;}.mobile-menu-btn{display:block;background:none;border:none;color:var(--text-primary);font-size:1.5rem;cursor:pointer;padding:0.5rem;}.nav-links{display:none;width:100%;flex-direction:column;position:absolute;top:100%;left:0;background-color:var(--surface-color);border-bottom:1px solid var(--border-color);padding:1rem 0;box-shadow:var(--shadow-md);gap:0;}.nav-links.active{display:flex;}.nav-link{padding:1rem 1.5rem;display:block;width:100%;border-bottom:1px solid var(--border-color);}.nav-link:last-child{border-bottom:none;}.grid-2,.grid-3,.grid-4{grid-template-columns:1fr;}.calculator-wrapper{padding:1.5rem 1rem;}.nav-links .theme-toggle,.nav-links .lang-switcher{margin:0.5rem 1.5rem;align-self:flex-start;}}.mobile-menu-btn{display:none;}