:root {
    --bg-dark: #121212;
    --bg-panel: #1e1e1e;
    --bg-panel-hover: #2c2c2c;
    --text-primary: #ffffff;
    --text-secondary: #aaaaaa;
    --accent: #E5FF00; /* Neon yellow-green common in fitness */
    --accent-hover: #cce600;
    --danger: #ff4757;
    --danger-hover: #ff6b81;
    --success: #2ed573;
    --border: #333333;
    --input-bg: #2a2a2a;
    --radius: 8px;
    --transition: 0.3s ease;
    --font-family: 'Inter', sans-serif;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Typography */
h1, h2, h3 { font-weight: 700; color: var(--text-primary); margin-bottom: 1rem; }
a { color: var(--accent); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-hover); }

/* Layouts */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.w-full { width: 100%; }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.6rem 1.2rem;
    background-color: var(--bg-panel-hover);
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 600;
    transition: var(--transition);
}
.btn:hover { background-color: var(--border); }
.btn-primary {
    background-color: var(--accent);
    color: #000;
    border: none;
}
.btn-primary:hover { background-color: var(--accent-hover); }
.btn-danger {
    background-color: var(--danger);
    color: #fff;
    border: none;
}
.btn-danger:hover { background-color: var(--danger-hover); }

/* Forms */
.form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 1rem;
}
.form-group label {
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}
.form-control {
    background-color: var(--input-bg);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 0.8rem;
    border-radius: var(--radius);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}
.form-control:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(229, 255, 0, 0.2);
}

/* Cards */
.card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}
th {
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.85rem;
}
tbody tr:hover { background-color: rgba(255,255,255,0.02); }

/* Badges */
.badge {
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}
.badge-success { background-color: rgba(46, 213, 115, 0.2); color: var(--success); }
.badge-danger { background-color: rgba(255, 71, 87, 0.2); color: var(--danger); }
.badge-warning { background-color: rgba(255, 165, 2, 0.2); color: #ffa502; }
.badge-return { background-color: rgba(155, 89, 182, 0.2); color: #9b59b6; }

/* Dashboard Shell */
.app-container {
    display: flex;
    height: 100vh;
}
.sidebar {
    width: 250px;
    background-color: var(--bg-panel);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 1rem;
}
.sidebar-logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--accent);
    margin-bottom: 2rem;
    text-align: center;
}
.nav-link {
    display: flex;
    align-items: center;
    padding: 0.8rem 1rem;
    color: var(--text-secondary);
    border-radius: var(--radius);
    margin-bottom: 0.5rem;
    font-weight: 500;
}
.nav-link i { margin-right: 0.8rem; width: 20px; text-align: center; }
.nav-link:hover, .nav-link.active {
    background-color: rgba(229, 255, 0, 0.1);
    color: var(--accent);
}
.main-content {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    background-color: var(--bg-dark);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.7);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}
.modal-overlay.active { display: flex; }
.modal {
    background: var(--bg-panel);
    width: 90%;
    max-width: 500px;
    border-radius: var(--radius);
    padding: 1.5rem;
    border: 1px solid var(--border);
}
.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}
.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

/* Toasts */
#toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 9999;
}
.toast {
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    margin-top: 10px;
}