/* --- 1. THEME VARIABLES --- */
:root {
    --primary: #00f2ff;
    --bg: #050a15;
    --sidebar-bg: #0b1222;
    --card-bg: #111a2d;
    --input-bg: #0f172a;
    --text: #ffffff;
    --dim: #94a3b8;
    --border: rgba(255, 255, 255, 0.08);
    --danger: #ff5f56;
    --success: #4ade80;
    --ebay: #e53238;
}

/* --- 2. BASE RESET --- */
* { box-sizing: border-box; }

body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', -apple-system, sans-serif;
    line-height: 1.6;
    min-height: 100vh;
}

/* --- 3. APP LAYOUT (Sidebar & Content) --- */
.sidebar {
    width: 280px;
    height: 100vh;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    position: fixed;
    left: 0;
    top: 0;
    padding: 40px 20px;
    z-index: 1000;
}

.main-content {
    margin-left: 280px; /* Pushes content to the right of sidebar */
    padding: 60px;
    width: calc(100% - 280px);
    min-height: 100vh;
}

/* --- 4. NAVIGATION --- */
.logo {
    text-decoration: none;
    color: white;
    font-weight: 900;
    font-size: 1.5rem;
    letter-spacing: 1px;
    display: block;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--dim);
    text-decoration: none;
    padding: 12px 15px;
    border-radius: 10px;
    transition: 0.2s;
}

.nav-item:hover {
    background: rgba(255,255,255,0.05);
    color: white;
}

/* --- 5. UI COMPONENTS --- */
.card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 30px;
    border: 1px solid var(--border);
    margin-bottom: 30px;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 25px;
}

.btn-save {
    background: var(--primary);
    color: #000;
    border: none;
    padding: 14px 28px;
    border-radius: 10px;
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    transition: transform 0.1s, opacity 0.2s;
}

.btn-save:hover { opacity: 0.9; }
.btn-save:active { transform: scale(0.97); }

/* --- 6. FORMS --- */
label {
    display: block;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--dim);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input, textarea, select {
    width: 100%;
    padding: 12px 15px;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: white;
    font-family: inherit;
    font-size: 0.95rem;
    margin-bottom: 20px;
}

input:focus {
    outline: none;
    border-color: var(--primary);
}

/* --- 7. TABS --- */
.tab-menu { display: flex; gap: 10px; margin-bottom: 25px; border-bottom: 1px solid var(--border); }
.tab-btn { background: transparent; border: none; color: var(--dim); padding: 12px 20px; cursor: pointer; font-weight: 600; }
.tab-btn.active { color: var(--primary); border-bottom: 2px solid var(--primary); }
.tab-content { display: none; }
.tab-content.active { display: block; }

/* --- 8. MOBILE RESPONSIVE --- */
@media (max-width: 900px) {
    .sidebar { display: none; }
    .main-content { margin-left: 0; width: 100%; padding: 30px 20px; }
}