/* ============================================================
   Base Styles - 现代化基础样式
   ============================================================ */

/* ===== Box Sizing Reset ===== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ===== Document Defaults ===== */
html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height);
    background-color: var(--bg-body);
    color: var(--text-primary);
    transition: background-color var(--transition-normal),
                color var(--transition-normal);
    min-height: 100vh;
    overflow-x: hidden;
}

/* ===== Container ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    line-height: var(--line-height-tight);
    font-weight: 700;
    letter-spacing: var(--letter-spacing);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

a {
    color: var(--text-link);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--text-link-hover);
}

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

/* ===== Images ===== */
img {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
    display: block;
}

/* ===== Selection ===== */
::selection {
    background-color: var(--color-primary);
    color: #ffffff;
}

/* ===== Focus Styles ===== */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* ===== Scrollbar (Webkit) ===== */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-body);
}

::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--color-primary-light), var(--color-primary));
    border-radius: 5px;
    border: 2px solid var(--bg-body);
}

::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--color-primary), var(--color-primary-dark));
}

/* Firefox scrollbar */
* {
    scrollbar-width: thin;
    scrollbar-color: var(--color-primary) var(--bg-body);
}

/* ===== Section Styles ===== */
.section {
    padding: var(--space-2xl) 0;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
}

.section-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 0;
}

.section-title i {
    font-size: 1em;
}

.icon-primary {
    color: var(--color-primary);
}

.view-more {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 4px;
    transition: all var(--transition-fast);
}

.view-more:hover {
    color: var(--color-primary);
    gap: 8px;
}

/* ===== Button Styles ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: var(--font-size-sm);
    font-weight: 600;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-primary);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--color-primary);
}

.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: var(--border-radius-full);
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
}

.btn-icon:hover {
    background: var(--bg-highlight);
    color: var(--color-primary);
    border-color: var(--color-primary-light);
}

/* ===== Input Styles ===== */
.input,
.textarea,
select {
    width: 100%;
    padding: 12px 16px;
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.input:focus,
.textarea:focus,
select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(var(--color-primary-rgb), 0.1);
}

.input::placeholder,
.textarea::placeholder {
    color: var(--text-muted);
}

/* ===== Badge & Tag Styles ===== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    font-size: var(--font-size-xs);
    font-weight: 600;
    border-radius: var(--border-radius-full);
    background: var(--bg-highlight);
    color: var(--color-primary);
}

.badge-primary {
    background: var(--gradient-primary);
    color: white;
}

.badge-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--color-success);
}

.badge-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--color-warning);
}

.badge-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--color-danger);
}

/* ===== Helper Classes ===== */
.has-radius {
    border-radius: var(--border-radius);
}

.has-radius-lg {
    border-radius: var(--border-radius-lg);
}

.has-radius-full {
    border-radius: var(--border-radius-full);
}

.border-top {
    border-top: 1px solid var(--border-light);
}

.border-bottom {
    border-bottom: 1px solid var(--border-light);
}

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.line-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.line-clamp-3 {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ===== Text Utilities ===== */
.text-primary { color: var(--text-primary) !important; }
.text-secondary { color: var(--text-secondary) !important; }
.text-muted { color: var(--text-muted) !important; }
.text-accent { color: var(--color-primary) !important; }
.text-success { color: var(--color-success) !important; }
.text-warning { color: var(--color-warning) !important; }
.text-danger { color: var(--color-danger) !important; }

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

.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-medium { font-weight: 500; }
.font-normal { font-weight: 400; }

/* ===== Spacing Utilities ===== */
.mt-xs { margin-top: var(--space-xs); }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }

.mb-xs { margin-bottom: var(--space-xs); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }

.py-md { padding-top: var(--space-md); padding-bottom: var(--space-md); }
.py-lg { padding-top: var(--space-lg); padding-bottom: var(--space-lg); }
.py-xl { padding-top: var(--space-xl); padding-bottom: var(--space-xl); }
.py-2xl { padding-top: var(--space-2xl); padding-bottom: var(--space-2xl); }

.px-md { padding-left: var(--space-md); padding-right: var(--space-md); }
.px-lg { padding-left: var(--space-lg); padding-right: var(--space-lg); }
.px-xl { padding-left: var(--space-xl); padding-right: var(--space-xl); }

/* ===== Flex Utilities ===== */
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }

/* ===== Grid Utilities ===== */
.grid { display: grid; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ===== Animation Classes ===== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.animate-fade-in {
    animation: fadeIn 0.3s ease-out;
}

.animate-slide-up {
    animation: slideUp 0.4s ease-out;
}

/* ===== Code Blocks ===== */
pre, code {
    font-family: var(--font-family-mono);
    background-color: var(--bg-code);
    border-radius: var(--border-radius);
}

pre {
    padding: 1rem;
    overflow-x: auto;
    color: #e4e6eb;
}

code {
    padding: 0.2em 0.4em;
    font-size: 0.9em;
    color: var(--color-primary);
}

pre code {
    padding: 0;
    background: transparent;
    color: inherit;
}

/* ===== Image Modal ===== */
.image-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    cursor: zoom-out;
    animation: fadeIn 0.2s ease-out;
}

.image-modal img {
    max-width: 90%;
    max-height: 90vh;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-2xl);
}

.image-modal .close {
    position: absolute;
    top: 20px;
    right: 20px;
    color: white;
    font-size: 32px;
    cursor: pointer;
    opacity: 0.8;
    transition: opacity var(--transition-fast);
}

.image-modal .close:hover {
    opacity: 1;
}

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: var(--space-3xl) var(--space-xl);
    color: var(--text-muted);
}

.empty-state i {
    font-size: 48px;
    margin-bottom: var(--space-lg);
    opacity: 0.5;
}

.empty-state h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-sm);
    color: var(--text-secondary);
}

.empty-state p {
    font-size: var(--font-size-sm);
}

/* ===== Loading Skeleton ===== */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--border-light) 25%,
        var(--bg-card) 50%,
        var(--border-light) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: var(--border-radius-sm);
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-text {
    height: 1em;
    margin-bottom: 0.5em;
}

.skeleton-title {
    height: 1.5em;
    width: 60%;
    margin-bottom: 1em;
}

.skeleton-image {
    padding-top: 56.25%;
}

/* ===== Back to Top Button ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--border-radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: var(--z-sticky);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}