/* Shared site header (logo, tagline, nav) — loaded before each page stylesheet. */

.header {
    background: #ffffff;
    border-bottom: 1px solid #e5e5e5;
    padding: 20px 0;
    margin-bottom: 30px;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.logo-section {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 28px;
    height: 28px;
    fill: none;
    stroke: #000000;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: #000000;
    letter-spacing: -0.025em;
}

.tagline {
    font-size: 0.9rem;
    color: #666666;
    font-weight: 500;
    letter-spacing: 0.025em;
}

.nav-section {
    display: flex;
    flex-direction: column;
    gap: 15px;
    align-items: flex-end;
}

.nav-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: rgba(0, 0, 0, 0.05);
    border: 2px solid transparent;
    border-radius: 8px;
    text-decoration: none;
    color: #333333;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.nav-btn.active,
.nav-btn:hover {
    background: rgba(0, 0, 0, 0.1);
    border-color: #000000;
    color: #000000;
    transform: translateY(-1px);
}

.nav-icon {
    width: 16px;
    height: 16px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

:root[data-theme="dark"] body .header {
    background: #1a1a1a;
    border-bottom: 1px solid #404040;
}

:root[data-theme="dark"] body .logo-icon {
    stroke: #ffffff;
}

:root[data-theme="dark"] body .logo-text {
    color: #ffffff;
}

:root[data-theme="dark"] body .tagline {
    color: #cccccc;
}

:root[data-theme="dark"] body .nav-btn {
    background: rgba(255, 255, 255, 0.1);
    color: #cccccc;
    border: 2px solid transparent;
}

:root[data-theme="dark"] body .nav-btn.active,
:root[data-theme="dark"] body .nav-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: #ffffff;
    color: #ffffff;
}

@media (max-width: 768px) {
    .header-top {
        flex-direction: column;
        align-items: center;
        gap: 20px;
        text-align: center;
    }

    .logo-section {
        align-items: center;
    }

    .nav-section {
        align-items: center;
        width: 100%;
    }

    .nav-buttons {
        justify-content: center;
    }

    .nav-btn {
        padding: 10px 6px;
    }
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) body .header {
        background: #1a1a1a;
        border-bottom: 1px solid #404040;
    }

    :root:not([data-theme]) body .logo-icon {
        stroke: #ffffff;
    }

    :root:not([data-theme]) body .logo-text {
        color: #ffffff;
    }

    :root:not([data-theme]) body .tagline {
        color: #cccccc;
    }

    :root:not([data-theme]) body .nav-btn {
        background: rgba(255, 255, 255, 0.1);
        color: #cccccc;
        border: 2px solid transparent;
    }

    :root:not([data-theme]) body .nav-btn.active,
    :root:not([data-theme]) body .nav-btn:hover {
        background: rgba(255, 255, 255, 0.2);
        border-color: #ffffff;
        color: #ffffff;
    }
}