:root {
    --color-primary: #232F3E;
    --color-accent: #FF9900;
    --color-bg: #ffffff;
    --color-text: #232F3E;
    --color-text-muted: #5a6a7a;
    --color-surface: #f8f9fa;
    --color-border: #e2e8f0;
    --radius: 8px;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 24px rgba(0, 0, 0, 0.12);
    --transition: 0.25s ease;
    --font: 'Segoe UI', Arial, sans-serif;
}

[data-theme="dark"] {
    --color-bg: #0f1923;
    --color-text: #e8edf2;
    --color-text-muted: #8a9bb0;
    --color-surface: #1a2535;
    --color-border: #2a3a4e;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 24px rgba(0, 0, 0, 0.5);
}

*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.65;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    transition: background var(--transition), color var(--transition);
}

h1, h2, h3, h4, h5, h6 {
    line-height: 1.3;
    font-weight: 700;
    margin-top: 0;
}

a {
    color: var(--color-accent);
    transition: opacity var(--transition);
}

a:hover {
    opacity: 0.85;
}

/* ── Header ── */
.site-header {
    background: #f5f5f5;
    color: var(--color-primary);
    padding: 0 20px;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background var(--transition), color var(--transition);
}

[data-theme="dark"] .site-header {
    background: #1a2535;
    color: #e8edf2;
}

.site-header .header-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.site-header .logo {
    height: 44px;
    display: block;
}

.site-header nav a {
    color: var(--color-primary);
    margin-left: 28px;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition);
    position: relative;
}

.site-header nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: width var(--transition);
}

.site-header nav a:hover {
    color: var(--color-accent);
    opacity: 1;
}

.site-header nav a:hover::after {
    width: 100%;
}

[data-theme="dark"] .site-header nav a {
    color: #e8edf2;
}

[data-theme="dark"] .site-header nav a:hover {
    color: var(--color-accent);
}

/* ── Share buttons ── */
.share-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    margin: 32px 0;
    padding: 20px 24px;
    background: var(--color-surface, #f8f9fa);
    border: 1px solid var(--color-border, #e0e0e0);
    border-radius: var(--radius, 8px);
}

.share-bar span {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--color-text, #333);
    margin-right: 4px;
}

.share-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    transition: opacity 0.2s, transform 0.15s;
    color: #fff;
}

.share-btn:hover { opacity: 0.85; transform: translateY(-1px); }
.share-btn.linkedin { background: #0A66C2; }
.share-btn.twitter  { background: #000; }
.share-btn.whatsapp { background: #25D366; }

/* ── Hamburger button ── */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-primary);
    border-radius: 2px;
    transition: transform 0.25s ease, opacity 0.25s ease;
}

[data-theme="dark"] .hamburger span {
    background: #e8edf2;
}

/* ── Mobile nav ── */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }

    .site-header nav {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #232F3E;
        padding: 16px 20px 20px;
        flex-direction: column;
        gap: 4px;
        box-shadow: var(--shadow);
        z-index: 99;
    }

    .site-header nav.open {
        display: flex;
    }

    .site-header nav a {
        margin-left: 0;
        padding: 10px 0;
        border-bottom: 1px solid rgba(255,255,255,0.08);
        font-size: 1rem;
        color: #e8edf2;
    }

    .site-header nav a:last-child {
        border-bottom: none;
    }

    .site-header .header-content {
        position: relative;
    }
}

/* ── Content ── */
.content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 48px 20px;
}

/* ── Button ── */
.button {
    display: inline-block;
    padding: 11px 28px;
    background: var(--color-accent);
    color: #ffffff;
    text-decoration: none;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.95rem;
    border: none;
    cursor: pointer;
    transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 2px 8px rgba(255, 153, 0, 0.3);
}

.button:hover {
    background: #e68a00;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(255, 153, 0, 0.4);
    opacity: 1;
}

.button:active {
    transform: translateY(0);
}

/* ── Footer ── */
.site-footer {
    background: var(--color-primary);
    color: rgba(255, 255, 255, 0.8);
    text-align: center;
    padding: 32px 20px;
    margin-top: 80px;
    font-size: 0.9rem;
}

.site-footer a {
    color: var(--color-accent);
}