/* Typography & Reset */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { color-scheme: light dark; }
body {
    font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, 'Apple Color Emoji', 'Segoe UI Emoji', sans-serif;
    line-height: 1.6;
    color: #1a1a1a;
    background: #ffffff;
}

@media (prefers-color-scheme: dark) {
    body { color: #e6e6e6; background: #0f1115; }
}

.container {
    width: 100%;
    max-width: 980px;
    margin: 0 auto;
    padding: 0 16px;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(255,255,255,0.85);
    backdrop-filter: saturate(180%) blur(10px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
}

@media (prefers-color-scheme: dark) {
    .site-header { background: rgba(15,17,21,0.7); border-bottom-color: rgba(255,255,255,0.08); }
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
}

.brand {
    text-decoration: none;
    color: inherit;
    font-weight: 700;
    letter-spacing: 0.2px;
}

.nav {
    display: flex;
    gap: 16px;
}

.nav-link {
    color: inherit;
    text-decoration: none;
    opacity: 0.8;
}

.nav-link:hover, .nav-link.active { opacity: 1; }

/* Layout */
.page-title {
    margin: 28px 0 16px;
    font-size: 28px;
}

.view.hidden { display: none; }

/* Posts Grid */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: 16px;
}

@media (min-width: 640px) {
    .posts-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 960px) {
    .posts-grid { grid-template-columns: repeat(3, 1fr); }
}

.card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 16px;
    border: 1px solid rgba(0,0,0,0.08);
    border-radius: 12px;
    background: #fff;
    transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

@media (prefers-color-scheme: dark) {
    .card { background: #151821; border-color: rgba(255,255,255,0.08); }
}

.card:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,0.08); }

.card-title {
    margin: 0;
    font-size: 18px;
}

.card-excerpt { margin: 0; opacity: 0.85; }

.card-meta { font-size: 12px; opacity: 0.65; }

.card-link { text-decoration: none; color: inherit; }

/* Post */
.back-link {
    display: inline-block;
    margin: 24px 0 8px;
    text-decoration: none;
    color: #0f62fe;
}

@media (prefers-color-scheme: dark) {
    .back-link { color: #78a9ff; }
}

.post-title { margin: 8px 0 6px; font-size: 32px; }
.post-meta { margin: 0 0 20px; opacity: 0.65; }
.post-content {
    font-size: 17px;
}

.post-content p { margin: 0 0 16px; }
.post-content h2 { margin: 24px 0 12px; font-size: 24px; }
.post-content ul { padding-left: 20px; }

/* Footer */
.site-footer {
    margin-top: 48px;
    padding: 24px 0 48px;
    border-top: 1px solid rgba(0,0,0,0.06);
    opacity: 0.8;
}

@media (prefers-color-scheme: dark) {
    .site-footer { border-top-color: rgba(255,255,255,0.08); }
}

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