/* ============================================
   价值阅读 统一设计系统 (Shared Base Styles)
   ============================================ */

/* ============================================
   GOOGLE FONTS
   ============================================ */
@import url('https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500&family=Noto+Serif+SC:wght@300;400;500;600;700;900&family=EB+Garamond:ital,wght@0,400;0,500;0,600;1,400;1,500&display=swap');

/* ============================================
   CSS VARIABLES (Design Tokens)
   ============================================ */
:root {
    /* Refined paper palette */
    --paper-pure: #fefefe;
    --paper-soft: #faf9f7;
    --paper-warm: #f5f3ef;
    --paper-aged: #eae6df;
    --paper-tinted: #e0dbd2;

    /* Ink hierarchy */
    --ink-deep: #1c1917;
    --ink-rich: #292524;
    --ink-medium: #44403c;
    --ink-soft: #78716c;
    --ink-pale: #a8a29e;
    --ink-ghost: #d6d3d1;

    /* Accent - warm terracotta (铜金色) */
    --accent: #b45309;
    --accent-deep: #92400e;
    --accent-soft: #d97706;
    --accent-pale: #fef3c7;

    /* Typography */
    --font-display: 'Cormorant Garamond', 'EB Garamond', Georgia, serif;
    --font-serif-cn: 'Noto Serif SC', 'Songti SC', 'SimSun', serif;
    --font-mono: 'SF Mono', 'Monaco', 'Consolas', monospace;

    /* Spacing rhythm */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 40px;
    --space-2xl: 64px;
    --space-3xl: 96px;
}

/* ============================================
   RESET STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 17px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-serif-cn);
    background: var(--paper-warm);
    color: var(--ink-rich);
    line-height: 1.85;
    min-height: 100vh;
}

/* Subtle paper texture */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    pointer-events: none;
    opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    z-index: 1;
}

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

/* ============================================
   PAGE CONTAINER
   ============================================ */
.page {
    max-width: 1200px;
    margin: 0 auto;
    background: var(--paper-pure);
    min-height: 100vh;
    box-shadow: 0 1px 3px rgba(28,25,23,0.04), 0 8px 40px rgba(28,25,23,0.06);
    position: relative;
    z-index: 2;
}

/* ============================================
   NAVIGATION — 统一导航条
   ============================================ */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--paper-pure);
    border-bottom: 2px solid var(--ink-ghost);
}

.site-nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-nav-brand {
    font-family: var(--font-serif-cn);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--ink-deep);
    letter-spacing: 0.12em;
    text-decoration: none;
}

.site-nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.site-nav-link {
    font-family: var(--font-serif-cn);
    font-size: 1rem;
    font-weight: 500;
    color: var(--paper-pure);
    background: var(--accent);
    text-decoration: none;
    letter-spacing: 0.03em;
    padding: 10px 20px;
    border: 2px solid var(--accent);
    transition: all 0.2s;
}

.site-nav-link:hover {
    background: var(--accent-deep);
    border-color: var(--accent-deep);
}

/* ============================================
   FOOTER — 统一 Footer
   ============================================ */
.footer {
    padding: var(--space-xl);
    border-top: 3px double var(--ink-ghost);
    text-align: center;
}

.footer-brand {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--ink-deep);
    margin-bottom: var(--space-sm);
}

.footer-tagline {
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-style: italic;
    color: var(--ink-pale);
    margin-bottom: var(--space-lg);
}

.footer-copy {
    font-size: 0.72rem;
    color: var(--ink-pale);
}

/* ============================================
   MOBILE RESPONSIVE — 导航和 Footer
   ============================================ */
@media (max-width: 768px) {
    .site-nav-inner {
        padding: 14px var(--space-md);
    }

    .site-nav-brand {
        font-size: 1rem;
        letter-spacing: 0.05em;
        white-space: nowrap;
        flex-shrink: 0;
    }

    .site-nav-links {
        gap: 5px;
        flex-wrap: nowrap;
    }

    .site-nav-link {
        font-size: 0.78rem;
        padding: 7px 10px;
        white-space: nowrap;
    }

    /* Footer 响应式 */
    .footer {
        padding: var(--space-lg) var(--space-md);
    }
}