/* ROOT VARIABLES (LIGHT MODE) */
:root {
    --bg: #f8f8f8;
    --text: #1a1a1a;
    --card-bg: #ffffff;
    --border: #e0e0e0;
    --accent: #0057b7;
}

/* DARK MODE VARIABLES */
body.dark {
    --bg: #121212;
    --text: #e6e6e6;
    --card-bg: #1d1d1d;
    --border: #333;
    --accent: #4da3ff;
}

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

body {
    font-family: "Helvetica Neue", Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    transition: background 0.3s, color 0.3s;
    line-height: 1.65;
}

/* HEADER */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.4rem 2rem;
    border-bottom: 1px solid var(--border);
}

.site-title {
    font-size: 1.9rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.theme-toggle {
    font-size: 1.2rem;
    padding: 0.5rem 0.7rem;
    cursor: pointer;
    border: 1px solid var(--border);
    background: var(--card-bg);
    color: var(--text);
    border-radius: 6px;
    transition: background 0.3s, color 0.3s;
}

/* MAIN CONTENT */
.content {
    width: 90%;
    max-width: 1100px;
    margin: 2rem auto;
}

/* MAIN ARTICLE */
.main-article img {
    width: 100%;
    border-radius: 8px;
}

.main-article h2 {
    margin: 1rem 0 0.6rem;
    font-size: 1.7rem;
}

.main-article p {
    color: var(--text);
}

/* ARTICLE GRID */
.article-grid {
    margin-top: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.8rem;
}

.card {
    background: var(--card-bg);
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 18px rgba(0,0,0,0.1);
}

.card img {
    width: 100%;
    border-radius: 6px;
}

.card h3 {
    margin: 0.8rem 0 0.4rem;
    font-size: 1.25rem;
    color: var(--accent);
}

.card p {
    color: var(--text);
}

/* FOOTER */
.footer {
    text-align: center;
    padding: 2rem 0;
    color: var(--text);
    border-top: 1px solid var(--border);
}