*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    border-radius: var(--radius-xs);
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--color-bg-primary);
    color: var(--color-text);
    line-height: 1.6;
    font-weight: 400;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.8rem; }
h4 { font-size: 1.4rem; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition-normal), background-color var(--transition-normal);
}

ul, ol {
    list-style-position: inside;
    margin-bottom: var(--spacing-md);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.hidden {
    display: none !important;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 300px;
    color: var(--color-text-light);
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--color-border-light);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: var(--spacing-md);
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease forwards;
}

.slide-up {
    animation: slideUp 0.5s ease forwards;
}

/* 特殊圆角覆盖 */
.navbar {
    border-radius: 0;
}

.container {
    border-radius: 0;
}

.mobile-menu {
    border-radius: 0 var(--radius-large) var(--radius-large) 0;
}