/* ============================================================
   shared.css  --  Common styles for all Nexus Autoparts pages
   ============================================================ */

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

/* --- CSS Variables (union of all pages) --- */
:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-card: #1a1a24;
    --bg-hover: #252532;
    --bg-tertiary: #1a1a25;
    --accent: #ff6b35;
    --accent-hover: #ff8555;
    --accent-glow: rgba(255, 107, 53, 0.3);
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --border: #2a2a3a;
    --success: #22c55e;
    --warning: #f59e0b;
    --info: #3b82f6;
    --danger: #ff4444;
}

/* --- Base body --- */
body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

/* --- Shared Button Styles --- */
.btn {
    padding: 0.7rem 1.5rem;
    border-radius: 10px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.9rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent) 0%, #ff4500 100%);
    color: white;
    box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px var(--accent-glow);
}

.btn-secondary {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text-primary);
}

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.2rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text-primary);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    margin-bottom: 1.5rem;
}

.btn-back:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* --- Shared Animations --- */
@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* --- Loading & Empty States --- */
.state-container {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.state-container i {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.state-container h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

/* --- Scrollbar Styling --- */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent);
}

/* --- Skip Link (accessibility) --- */
.skip-link {
    position: absolute;
    top: -50px;
    left: 0;
    background: var(--accent);
    color: white;
    padding: 0.75rem 1.5rem;
    z-index: 3000;
    text-decoration: none;
    font-weight: 600;
    border-radius: 0 0 8px 0;
}

.skip-link:focus {
    top: 0;
}

/* --- Screen Reader Only --- */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* --- Alert / Toast Styles --- */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.alert-success {
    background: rgba(0, 214, 143, 0.1);
    border: 1px solid var(--success);
    color: var(--success);
}

.alert-error {
    background: rgba(255, 68, 68, 0.1);
    border: 1px solid var(--danger);
    color: var(--danger);
}

/* --- Modal Base Styles --- */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.modal-overlay.active {
    display: flex;
}

/* --- Form Styles --- */
.form-group {
    margin-bottom: 1.25rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: border-color 0.2s;
}

.form-input:focus {
    outline: none;
    border-color: var(--accent);
}

.form-input::placeholder {
    color: var(--text-secondary);
}

/* --- Quality Badges --- */
.quality-badge {
    display: inline-block;
    padding: 0.25rem 0.6rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.quality-economy { background: var(--warning); color: #000; }
.quality-standard { background: var(--info); color: white; }
.quality-premium { background: var(--success); color: white; }
.quality-oem { background: #9b59b6; color: white; }