/* ===== CSS Variables ===== */
:root{--primary-color:#2563eb;--primary-dark:#1e40af;--primary-light:#3b82f6;--secondary-color:#10b981;--accent-color:#f59e0b;--text-primary:#1f2937;--text-secondary:#6b7280;--background:#ffffff;--background-alt:#f9fafb;--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-sm:0.375rem;--radius-md:0.5rem;--radius-lg:0.75rem}*{margin:0;padding:0;box-sizing:border-box}html{font-size:16px;scroll-behavior:smooth}body{font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Oxygen,Ubuntu,sans-serif;line-height:1.6;color:var(--text-primary);background-color:var(--background-alt);min-height:100vh;display:flex;flex-direction:column}h1,h2,h3,h4,h5,h6{font-weight:600;line-height:1.2;margin-bottom:1rem;color:var(--text-primary)}h1{font-size:2.5rem}h2{font-size:2rem}h3{font-size:1.75rem}h4{font-size:1.5rem}h5{font-size:1.25rem}h6{font-size:1rem}p{margin-bottom:1rem;color:var(--text-secondary)}a{color:var(--primary-color);text-decoration:none;transition:color 0.2s}a:hover{color:var(--primary-dark)}.container{max-width:1200px;margin:0 auto;padding:0 1.5rem}.site-header{background:var(--background);border-bottom:1px solid var(--border-color);box-shadow:var(--shadow-sm);position:sticky;top:0;z-index:100}.header-content{display:flex;justify-content:space-between;align-items:center;padding:1rem 0}.mobile-nav-toggle{display:none;background:none;border:none;color:var(--text-primary);cursor:pointer;padding:0.5rem}.logo a{display:flex;align-items:center;gap:0.75rem;font-size:1.5rem;font-weight:700;color:var(--text-primary);text-decoration:none}.logo svg{color:var(--primary-color)}.main-nav ul{list-style:none;display:flex;gap:2rem;align-items:center}.main-nav a{color:var(--text-secondary);font-weight:500;transition:color 0.2s}.main-nav a:hover{color:var(--primary-color)}.main-nav .nav-cta{background:var(--primary-color);color:white;padding:0.5rem 1.25rem;border-radius:var(--radius-md);transition:background 0.2s}.main-nav .nav-cta:hover{background:var(--primary-dark);color:white}#content{flex:1;padding:3rem 0}.button,button[type="submit"],input[type="submit"],.button-primary,a.button,a.button-primary{display:inline-block;padding:0.75rem 1.5rem;background:var(--primary-color);color:white;border:none;border-radius:var(--radius-md);font-size:1rem;font-weight:500;cursor:pointer;transition:all 0.2s;text-decoration:none}.button:hover,button[type="submit"]:hover,.button-primary:hover,a.button:hover,a.button-primary:hover{background:var(--primary-dark);transform:translateY(-1px);box-shadow:var(--shadow-md);color:white}.button:active{transform:translateY(0)}label{display:block;margin-bottom:0.5rem;font-weight:500;color:var(--text-primary)}input[type="text"],input[type="email"],input[type="number"],input[type="tel"],input[type="password"],input[type="file"],select,textarea{width:100%;padding:0.75rem;border:1px solid var(--border-color);border-radius:var(--radius-md);font-size:1rem;font-family:inherit;transition:border-color 0.2s,box-shadow 0.2s;scroll-margin-top:100px}.error-message{color:#dc3545!important;font-size:0.85rem!important;font-weight:600!important;margin-top:4px!important;margin-bottom:12px!important;display:none!important;clear:both!important}.show-errors input:invalid ~ .error-message,.show-errors select:invalid ~ .error-message,.show-errors textarea:invalid ~ .error-message{display:block!important}.show-errors input:invalid,.show-errors select:invalid,.show-errors textarea:invalid{border-color:#dc3545!important;background-color:#fff5f5!important}input:focus,select:focus,textarea:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px rgba(37,99,235,0.1)}.u-full-width{width:100%}.row{display:flex;flex-wrap:wrap;margin:0 -0.75rem}.row>*{padding:0 0.75rem;margin-bottom:1.5rem}.twelve.columns{width:100%}.eight.columns{width:66.666%}.six.columns{width:50%}.four.columns{width:33.333%}.three.columns{width:25%}@media (max-width:768px){.columns{width:100%!important}}.part-item{background:var(--background);border:1px solid var(--border-color);border-radius:var(--radius-lg);box-shadow:var(--shadow-sm);transition:box-shadow 0.2s}.part-item:hover{box-shadow:var(--shadow-md)}progress{width:100%;height:8px;border:none;border-radius:var(--radius-sm);background:var(--border-color)}progress::-webkit-progress-bar{background:var(--border-color);border-radius:var(--radius-sm)}progress::-webkit-progress-value{background:var(--primary-color);border-radius:var(--radius-sm)}progress::-moz-progress-bar{background:var(--primary-color);border-radius:var(--radius-sm)}.flash-container{position:fixed;top:1rem;right:1rem;z-index:1000;max-width:400px}.flash{background:var(--background);border-left:4px solid var(--primary-color);padding:1rem;margin-bottom:0.5rem;border-radius:var(--radius-md);box-shadow:var(--shadow-lg);display:flex;justify-content:space-between;align-items:center}.flash.success{border-left-color:var(--secondary-color)}.flash.error{border-left-color:#ef4444}.flash-close-btn{background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--text-secondary);padding:0;margin-left:1rem}.site-footer{background:var(--text-primary);color:white;padding:3rem 0 1rem;margin-top:auto}.footer-content{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:2rem;margin-bottom:2rem}.footer-section h4{color:white;margin-bottom:1rem}.footer-section p{color:rgba(255,255,255,0.8)}.footer-section ul{list-style:none}.footer-section a{color:rgba(255,255,255,0.8)}.footer-section a:hover{color:white}.footer-bottom{border-top:1px solid rgba(255,255,255,0.1);padding-top:1.5rem;text-align:center}.footer-bottom p{color:rgba(255,255,255,0.6);font-size:0.875rem}.hero-section{text-align:center;padding:4rem 0}.hero-section h1{font-size:3rem;margin-bottom:1rem}.hero-section .button-primary{font-size:1.125rem;padding:1rem 2rem}#uploadProgress{background:var(--background);padding:1.5rem;border-radius:var(--radius-lg);border:1px solid var(--border-color)}#uploadResult,#totalResult{animation:fadeIn 0.3s}@keyframes fadeIn{from{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.part-result{min-height:60px}@media (max-width:768px){.site-header{position:relative}.header-content{padding:0.75rem 0;flex-wrap:wrap}.mobile-nav-toggle{display:block}.main-nav{display:none;width:100%;padding:1rem 0;border-top:1px solid var(--border-color)}.main-nav.active{display:block}.main-nav ul{flex-direction:column;gap:1rem;align-items:flex-start}.main-nav ul li{width:100%}.main-nav a{display:block;padding:0.5rem 0}.main-nav .nav-cta{display:inline-block;width:100%;text-align:center;margin-top:0.5rem}h1{font-size:2rem}h2{font-size:1.75rem}.hero-section h1{font-size:2rem}#content{padding:1.5rem 0}}.text-center{text-align:center}.mt-1{margin-top:0.5rem}.mt-2{margin-top:1rem}.mt-3{margin-top:1.5rem}.mt-4{margin-top:2rem}.mb-1{margin-bottom:0.5rem}.mb-2{margin-bottom:1rem}.mb-3{margin-bottom:1.5rem}.mb-4{margin-bottom:2rem}@keyframes spin{from{transform:rotate(0deg)}to{transform:rotate(360deg)}}.rotating{animation:spin 1s linear infinite;display:inline-block}.spinner-segment{width:1rem;height:1rem;border:1.5px solid #e2e8f0;border-top-color:var(--primary-color);border-radius:50%}.tab-msg{font-size:0.65rem;color:var(--text-secondary);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;display:block;max-width:120px}.tab-progress-bg{width:100%;height:3px;background:#e2e8f0;border-radius:3px;margin-top:4px;overflow:hidden}.tab-progress-tiny{height:100%;background:var(--primary-color);transition:width 0.3s ease}