.header-bar {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.logo {
    font-size: 28px;
    margin: 0;
}

.logo a {
    text-decoration: none;
    color: var(--text-color);
}

.header-nav {
    display: flex;
    gap: 12px;
    font-family: monospace;
    font-size: 12px;
}

.header-nav a,
.header-nav button {
    text-decoration: none;
    color: var(--text-color);
    border: 2px solid var(--border-color);
    padding: 6px 10px;
    transition: all 0.1s;
    background: none;
    cursor: pointer;
    font-family: monospace;
    font-size: 12px;
    font-weight: bold;
}

.header-nav a:hover,
.header-nav button:hover {
    background: var(--hover-color);
    color: var(--hover-text);
}

@media (max-width: 640px) {
    .header-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }

    .logo {
        text-align: center;
    }

    .header-nav {
        justify-content: center;
        flex-wrap: wrap;
        gap: 8px;
    }

    .header-nav a,
    .header-nav button {
        flex: 1 1 auto;
        text-align: center;
        padding: 10px;
        font-size: 13px;
    }
}

.upload-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(3px);
    z-index: 9999;

    display: flex;
    align-items: center;
    justify-content: center;
}

.upload-overlay.hidden {
    display: none;
}

.upload-box {
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    padding: 30px 40px;
    text-align: center;
    box-shadow: 0 0 20px rgba(0,0,0,0.4);
}

.upload-text {
    margin-top: 15px;
    font-size: 13px;
    letter-spacing: 1px;
}

/* SPINNER */
.spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border-color);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.9s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}