:root{--color-primary: #1a5f9e;--color-primary-dark: #0f3d6b;--color-primary-light: #2d7bbf;--color-primary-bg: #e8f1f9;--color-accent: #f59e0b;--color-accent-dark: #d97706;--color-accent-light: #fbbf24;--color-text: #1f2937;--color-text-secondary: #4b5563;--color-text-muted: #6b7280;--color-text-light: #9ca3af;--color-text-inverse: #ffffff;--color-bg: #ffffff;--color-bg-alt: #f8fafc;--color-bg-dark: #1e293b;--color-bg-footer: #0f172a;--color-border: #e5e7eb;--color-border-light: #f1f5f9;--color-success: #10b981;--color-warning: #f59e0b;--color-error: #ef4444;--space-xs: .5rem;--space-sm: .75rem;--space-md: 1rem;--space-lg: 1.5rem;--space-xl: 2rem;--space-2xl: 3rem;--space-3xl: 4rem;--font-xs: .75rem;--font-sm: .875rem;--font-base: 1rem;--font-lg: 1.125rem;--font-xl: 1.25rem;--font-2xl: 1.5rem;--font-3xl: 1.875rem;--font-4xl: 2.5rem;--font-5xl: 3rem;--radius-sm: .25rem;--radius-md: .5rem;--radius-lg: .75rem;--radius-xl: 1rem;--radius-full: 9999px;--shadow-sm: 0 1px 2px rgba(0, 0, 0, .05);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .08), 0 2px 4px -2px rgba(0, 0, 0, .06);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1), 0 4px 6px -4px rgba(0, 0, 0, .06);--shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .12), 0 8px 10px -6px rgba(0, 0, 0, .08);--transition-fast: .15s ease;--transition-base: .25s ease;--transition-slow: .4s ease;--container-max: 1200px;--container-padding: 1.5rem}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Microsoft YaHei,Hiragino Sans GB,Helvetica Neue,Helvetica,Arial,sans-serif;font-size:var(--font-base);line-height:1.6;color:var(--color-text);background-color:var(--color-bg);min-height:100vh}img{max-width:100%;height:auto;display:block}a{color:inherit;text-decoration:none;transition:color var(--transition-fast)}button{font-family:inherit;border:none;background:none;cursor:pointer}ul,ol{list-style:none}h1,h2,h3,h4,h5,h6{font-weight:600;line-height:1.3;color:var(--color-text)}.app{display:flex;flex-direction:column;min-height:100vh}.main-content{flex:1}.container{max-width:var(--container-max);margin:0 auto;padding:0 var(--container-padding);width:100%}.section{padding:var(--space-3xl) 0}.section-alt{background-color:var(--color-bg-alt)}.section-title{text-align:center;margin-bottom:var(--space-2xl)}.section-title h2{font-size:var(--font-3xl);color:var(--color-text);margin-bottom:var(--space-md);font-weight:700}.section-title .subtitle{font-size:var(--font-lg);color:var(--color-text-muted);letter-spacing:.05em}.section-title .line{display:block;width:60px;height:4px;background:linear-gradient(90deg,var(--color-primary),var(--color-accent));margin:var(--space-md) auto 0;border-radius:2px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-sm);padding:var(--space-sm) var(--space-xl);font-size:var(--font-base);font-weight:500;border-radius:var(--radius-md);transition:all var(--transition-base);cursor:pointer;white-space:nowrap;min-height:44px;min-width:44px}.btn-primary{background-color:var(--color-primary);color:var(--color-text-inverse)}.btn-primary:hover{background-color:var(--color-primary-dark);transform:translateY(-2px);box-shadow:var(--shadow-lg)}.btn-accent{background-color:var(--color-accent);color:var(--color-text-inverse)}.btn-accent:hover{background-color:var(--color-accent-dark);transform:translateY(-2px);box-shadow:var(--shadow-lg)}.btn-outline{background-color:transparent;color:var(--color-primary);border:2px solid var(--color-primary)}.btn-outline:hover{background-color:var(--color-primary);color:var(--color-text-inverse)}.btn-lg{padding:var(--space-md) var(--space-2xl);font-size:var(--font-lg)}.card{background-color:var(--color-bg);border-radius:var(--radius-lg);padding:var(--space-xl);box-shadow:var(--shadow-sm);transition:all var(--transition-base);border:1px solid var(--color-border)}.card:hover{box-shadow:var(--shadow-lg);transform:translateY(-4px);border-color:var(--color-primary-light)}.grid{display:grid;gap:var(--space-xl)}.grid-2{grid-template-columns:repeat(2,1fr)}.grid-3{grid-template-columns:repeat(3,1fr)}.grid-4{grid-template-columns:repeat(4,1fr)}.text-center{text-align:center}.text-primary{color:var(--color-primary)}.text-accent{color:var(--color-accent)}.text-muted{color:var(--color-text-muted)}.text-secondary{color:var(--color-text-secondary)}.font-bold{font-weight:700}.font-semibold{font-weight:600}.mt-1{margin-top:var(--space-xs)}.mt-2{margin-top:var(--space-sm)}.mt-3{margin-top:var(--space-md)}.mt-4{margin-top:var(--space-lg)}.mt-5{margin-top:var(--space-xl)}.mb-1{margin-bottom:var(--space-xs)}.mb-2{margin-bottom:var(--space-sm)}.mb-3{margin-bottom:var(--space-md)}.mb-4{margin-bottom:var(--space-lg)}.mb-5{margin-bottom:var(--space-xl)}@keyframes fadeIn{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes slideUp{0%{opacity:0;transform:translateY(40px)}to{opacity:1;transform:translateY(0)}}.fade-in{animation:fadeIn var(--transition-slow)}@media (max-width: 1024px){:root{--font-4xl: 2rem;--font-3xl: 1.5rem}.grid-4{grid-template-columns:repeat(2,1fr)}.section{padding:var(--space-2xl) 0}}@media (max-width: 768px){:root{--container-padding: 1rem;--font-5xl: 2.25rem;--font-4xl: 1.75rem;--font-3xl: 1.375rem}.grid-2,.grid-3,.grid-4{grid-template-columns:1fr;gap:var(--space-lg)}.section{padding:var(--space-xl) 0}.section-title h2{font-size:var(--font-2xl)}.section-title .subtitle{font-size:var(--font-base)}.card{padding:var(--space-lg)}}@media (max-width: 480px){.btn{padding:var(--space-sm) var(--space-lg)}.btn-lg{padding:var(--space-md) var(--space-xl)}}:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}@media (prefers-reduced-motion: reduce){*{animation-duration:.01ms!important;transition-duration:.01ms!important}html{scroll-behavior:auto}}::selection{background-color:var(--color-primary);color:var(--color-text-inverse)}::-webkit-scrollbar{width:8px;height:8px}::-webkit-scrollbar-track{background:var(--color-bg-alt)}::-webkit-scrollbar-thumb{background:var(--color-text-light);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}