/* ====================================
   0x0ai Std. - 共享样式
   ==================================== */

:root {
    --bg-primary: #fafafa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f5f5f5;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --text-muted: #999999;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --border: #e5e5e5;
    --border-light: #f0f0f0;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --radius: 8px;
    --radius-lg: 12px;
    --container: 1100px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

a {
    color: inherit;
    text-decoration: none;
}

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

/* Container */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(250, 250, 250, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

.logo img {
    height: 36px;
    width: auto;
    margin-right: 8px;
}

.logo span {
    color: var(--accent);
}

nav {
    display: flex;
    gap: 32px;
}

nav a {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    transition: color 0.2s;
}

nav a:hover {
    color: var(--accent);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 0.9375rem;
    font-weight: 500;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

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

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* Section Header */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-header h2 {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.section-header p {
    color: var(--text-secondary);
}

/* Footer */
footer {
    padding: 32px 0;
    background: var(--bg-primary);
    border-top: 1px solid var(--border);
    text-align: center;
}

footer p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Loading & States */
.loading, .error, .empty {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.error {
    color: #dc2626;
}

/* Tags */
.tag {
    padding: 4px 10px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

/* Mobile */
@media (max-width: 768px) {
    nav {
        display: none;
    }

    .container {
        padding: 0 16px;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* Utility Classes */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }