/* CSS variables conforming to Clean Light Theme */
:root {
    --bg-color: #f8fafc; /* Slate 50 */
    --text-color: #0f172a; /* Slate 900 */
    --text-secondary: #475569; /* Slate 600 */
    --primary-color: #2563eb; /* Blue 600 */
    --primary-hover: #1d4ed8; /* Blue 700 */
    --accent-color: #f59e0b; /* Amber 500 */
    --secondary-bg: #ffffff; /* White */
    --border-color: #e2e8f0; /* Slate 200 */
    --font-family-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-family-heading: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --transition-speed: 0.2s;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family-body);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

.site-header {
    background: var(--secondary-bg);
    padding: 1.25rem 2.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.02);
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-color);
    letter-spacing: -0.025em;
}

.site-header h1 span {
    color: var(--primary-color);
}

.site-header nav {
    display: flex;
    gap: 1.5rem;
}

.site-header nav a {
    color: var(--text-secondary);
    font-weight: 500;
}

.site-header nav a:hover {
    color: var(--primary-color);
    text-decoration: none;
}

.post-container {
    max-width: 800px;
    margin: 3rem auto;
    padding: 2.5rem;
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
}

.post-container h1 {
    font-size: 2.25rem;
    font-weight: 800;
    line-height: 1.25;
    margin-top: 0;
    margin-bottom: 1.5rem;
    letter-spacing: -0.025em;
}

.post-meta {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.post-thumbnail {
    width: 100%;
    height: auto;
    margin-bottom: 2rem;
    border-radius: 8px;
    object-fit: cover;
    border: 1px solid var(--border-color);
}

.post-content {
    font-size: 1.125rem;
    color: #334155; /* Slate 700 */
    line-height: 1.8;
}

.post-content p {
    margin-bottom: 1.5rem;
}

/* Newsletter subscribe box rules */
.newsletter-subscribe {
    background: #f1f5f9; /* Slate 100 */
    border: 1px solid var(--border-color);
    padding: 2.5rem;
    margin: 3rem 0;
    text-align: center;
    border-radius: 12px;
    box-shadow: inset 0 2px 4px 0 rgba(0, 0, 0, 0.02);
}

.newsletter-subscribe h3 {
    margin-top: 0;
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.newsletter-subscribe p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    margin-top: 0;
}

.newsletter-subscribe form {
    display: flex;
    gap: 0.75rem;
    max-width: 500px;
    margin: 0 auto;
}

.newsletter-subscribe input[type="email"] {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.95rem;
    background: var(--secondary-bg);
}

.newsletter-subscribe input[type="email"]:focus {
    outline: 2px solid var(--primary-color);
    border-color: transparent;
}

.newsletter-subscribe button {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    font-family: inherit;
    font-size: 0.95rem;
    cursor: pointer;
    transition: background var(--transition-speed);
}

.newsletter-subscribe button:hover {
    background: var(--primary-hover);
}

/* 2-column layout for tech-pulse-daily */
.pulse-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2.5rem;
    max-width: 1200px;
    margin: 3rem auto;
    padding: 0 1.5rem;
}

.pulse-feed {
    display: flex;
    flex-direction: column;
}

.hero-header {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    margin-bottom: 2.5rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.hero-header img {
    width: 100%;
    height: auto;
    margin-bottom: 1.75rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    object-fit: cover;
}

.hero-header h1 {
    font-size: 2rem;
    font-weight: 800;
    margin-top: 0;
    margin-bottom: 1.25rem;
    letter-spacing: -0.025em;
}

.hero-header ul {
    margin: 0;
    padding-left: 1.25rem;
}

.hero-header li {
    font-size: 1.05rem;
    margin-bottom: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.pulse-feed .feed-item {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.02);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed);
}

.pulse-feed .feed-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

.pulse-feed .feed-item h2 {
    margin-top: 0;
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.pulse-feed .feed-item p {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 1.25rem;
    line-height: 1.6;
}

.pulse-feed .feed-item .read-more {
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.sidebar-widget {
    background: var(--secondary-bg);
    padding: 1.75rem;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.02);
}

.sidebar-widget h3 {
    margin-top: 0;
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 1.25rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.sidebar-widget ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.sidebar-widget li {
    margin-bottom: 0.75rem;
}

.sidebar-widget li:last-child {
    margin-bottom: 0;
}

.sidebar-widget li a {
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.95rem;
}

.sidebar-widget li a:hover {
    color: var(--primary-color);
}

.ad-space {
    background: #f8fafc;
    border: 1px dashed #cbd5e1;
    border-radius: 8px;
    padding: 3rem 1rem;
    text-align: center;
    color: #94a3b8;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.1em;
}

footer {
    text-align: center;
    padding: 2rem;
    border-top: 1px solid var(--border-color);
    margin-top: 5rem;
    background: var(--secondary-bg);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Category badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 4px;
    margin-bottom: 0.75rem;
}
.badge-ai { background: #eff6ff; color: #1e40af; }
.badge-hardware { background: #fef3c7; color: #92400e; }
.badge-policy { background: #fdf2f8; color: #9d174d; }
.badge-media { background: #f5f3ff; color: #5b21b6; }
.badge-security { background: #fef2f2; color: #991b1b; }
.badge-health { background: #ecfdf5; color: #065f46; }
.badge-telecom { background: #f0fdf4; color: #166534; }
.badge-finance { background: #eff6ff; color: #1e40af; }
.badge-gaming { background: #fff7ed; color: #9a3412; }
.badge-space { background: #faf5ff; color: #6b21a8; }
.badge-robotics { background: #f0fdfa; color: #075985; }

@media (max-width: 768px) {
    .pulse-layout {
        grid-template-columns: 1fr;
    }
    .site-header {
        padding: 1rem 1.5rem;
        flex-direction: column;
        gap: 1rem;
    }
    .post-container {
        padding: 1.5rem;
        margin: 1.5rem auto;
    }
    .post-container h1 {
        font-size: 1.75rem;
    }
    .newsletter-subscribe form {
        flex-direction: column;
    }
}