/* =============================================================================
   CSS Variables & Design Tokens
   ============================================================================= */

:root {
    /* Color Palette - Deep navy with amber accent */
    --color-bg: #0d1117;
    --color-bg-elevated: #161b22;
    --color-bg-subtle: #1c2128;
    --color-bg-hover: #21262d;
    
    --color-border: #30363d;
    --color-border-strong: #484f58;
    
    --color-text: #e6edf3;
    --color-text-muted: #8b949e;
    --color-text-subtle: #6e7681;
    
    --color-accent: #f0b429;
    --color-accent-hover: #ffc942;
    --color-accent-muted: rgba(240, 180, 41, 0.15);
    
    --color-success: #3fb950;
    --color-success-muted: rgba(63, 185, 80, 0.15);
    --color-error: #f85149;
    --color-error-muted: rgba(248, 81, 73, 0.15);
    --color-warning: #d29922;
    --color-warning-muted: rgba(210, 153, 34, 0.15);
    --color-info: #58a6ff;
    --color-info-muted: rgba(88, 166, 255, 0.15);
    
    /* Typography */
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
}

/* =============================================================================
   Reset & Base Styles
   ============================================================================= */

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--color-accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent-hover);
}

/* =============================================================================
   Navigation
   ============================================================================= */

.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--color-bg-elevated);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(12px);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 64px;
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.nav-brand:hover {
    color: var(--color-accent);
}

.nav-icon {
    width: 24px;
    height: 24px;
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    gap: var(--space-xs);
    flex: 1;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-md);
    color: var(--color-text-muted);
    font-weight: 500;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.nav-link svg {
    width: 18px;
    height: 18px;
}

.nav-link:hover {
    color: var(--color-text);
    background: var(--color-bg-hover);
}

.nav-link.active {
    color: var(--color-accent);
    background: var(--color-accent-muted);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.user-badge {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.admin-indicator {
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
    box-shadow: 0 0 8px var(--color-accent);
}

/* =============================================================================
   Main Content
   ============================================================================= */

.main {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-lg);
}

/* =============================================================================
   Flash Messages
   ============================================================================= */

.flash-messages {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
}

.flash {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    font-weight: 500;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.flash-success {
    background: var(--color-success-muted);
    color: var(--color-success);
    border: 1px solid rgba(63, 185, 80, 0.3);
}

.flash-error {
    background: var(--color-error-muted);
    color: var(--color-error);
    border: 1px solid rgba(248, 81, 73, 0.3);
}

.flash-info {
    background: var(--color-info-muted);
    color: var(--color-info);
    border: 1px solid rgba(88, 166, 255, 0.3);
}

.flash-warning {
    background: var(--color-warning-muted);
    color: var(--color-warning);
    border: 1px solid rgba(210, 153, 34, 0.3);
}

.flash-close {
    background: none;
    border: none;
    color: inherit;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.flash-close:hover {
    opacity: 1;
}

/* =============================================================================
   Page Headers
   ============================================================================= */

.page-header {
    margin-bottom: var(--space-xl);
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-sm);
}

.page-subtitle {
    color: var(--color-text-muted);
    font-size: 1.1rem;
}

/* =============================================================================
   Cards
   ============================================================================= */

.card {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.card-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
}

.card-body {
    padding: var(--space-lg);
}

/* =============================================================================
   Buttons
   ============================================================================= */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-lg);
    border: none;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn svg {
    width: 18px;
    height: 18px;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-bg);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    color: var(--color-bg);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(240, 180, 41, 0.3);
}

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

.btn-secondary:hover {
    background: var(--color-bg-hover);
    border-color: var(--color-border-strong);
    color: var(--color-text);
}

.btn-ghost {
    background: transparent;
    color: var(--color-text-muted);
}

.btn-ghost:hover {
    background: var(--color-bg-hover);
    color: var(--color-text);
}

.btn-danger {
    background: var(--color-error-muted);
    color: var(--color-error);
    border: 1px solid rgba(248, 81, 73, 0.3);
}

.btn-danger:hover {
    background: var(--color-error);
    color: white;
}

.btn-sm {
    padding: var(--space-xs) var(--space-md);
    font-size: 0.85rem;
}

.btn-lg {
    padding: var(--space-md) var(--space-xl);
    font-size: 1rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* =============================================================================
   Forms
   ============================================================================= */

.form-group {
    margin-bottom: var(--space-lg);
}

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

.form-input {
    width: 100%;
    padding: var(--space-md);
    background: var(--color-bg-subtle);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    color: var(--color-text);
    transition: all var(--transition-fast);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-accent-muted);
}

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

.form-checkbox {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.form-checkbox input {
    width: 18px;
    height: 18px;
    accent-color: var(--color-accent);
}

/* =============================================================================
   Upload Zone
   ============================================================================= */

.upload-zone {
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    text-align: center;
    transition: all var(--transition-base);
    cursor: pointer;
    position: relative;
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--color-accent);
    background: var(--color-accent-muted);
}

.upload-zone.dragover {
    transform: scale(1.01);
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--space-lg);
    color: var(--color-text-muted);
    transition: all var(--transition-base);
}

.upload-zone:hover .upload-icon,
.upload-zone.dragover .upload-icon {
    color: var(--color-accent);
    transform: translateY(-4px);
}

.upload-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.upload-subtitle {
    color: var(--color-text-muted);
    margin-bottom: var(--space-lg);
}

.upload-formats {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-sm);
}

.format-tag {
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-bg-subtle);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.upload-input {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

/* =============================================================================
   Upload Progress
   ============================================================================= */

.upload-progress {
    margin-top: var(--space-lg);
}

.upload-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    background: var(--color-bg-subtle);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-sm);
}

.upload-item-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-elevated);
    border-radius: var(--radius-sm);
    color: var(--color-accent);
}

.upload-item-info {
    flex: 1;
    min-width: 0;
}

.upload-item-name {
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.upload-item-size {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.upload-item-status {
    width: 24px;
    height: 24px;
}

.upload-item-status.pending {
    animation: spin 1s linear infinite;
    color: var(--color-text-muted);
}

.upload-item-status.success {
    color: var(--color-success);
}

.upload-item-status.error {
    color: var(--color-error);
}

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

.progress-bar {
    height: 4px;
    background: var(--color-bg-hover);
    border-radius: 2px;
    overflow: hidden;
    margin-top: var(--space-sm);
}

.progress-bar-fill {
    height: 100%;
    background: var(--color-accent);
    border-radius: 2px;
    transition: width var(--transition-base);
}

/* =============================================================================
   Tables
   ============================================================================= */

.table-container {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th,
.table td {
    padding: var(--space-md);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}

.table th {
    font-weight: 600;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--color-bg-subtle);
}

.table tr:hover td {
    background: var(--color-bg-subtle);
}

.table td {
    font-size: 0.95rem;
}

/* =============================================================================
   Status Badges
   ============================================================================= */

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.status-uploaded {
    background: var(--color-info-muted);
    color: var(--color-info);
}

.status-processing {
    background: var(--color-warning-muted);
    color: var(--color-warning);
}

.status-delivered {
    background: var(--color-success-muted);
    color: var(--color-success);
}

.status-failed {
    background: var(--color-error-muted);
    color: var(--color-error);
}

.status-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: currentColor;
}

/* =============================================================================
   Pagination
   ============================================================================= */

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-sm);
    margin-top: var(--space-xl);
}

.pagination-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg-elevated);
    color: var(--color-text-muted);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.pagination-btn:hover:not(.disabled) {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.pagination-btn.active {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-bg);
}

.pagination-btn.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

/* =============================================================================
   Stats Grid
   ============================================================================= */

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.stat-card {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
}

.stat-label {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-sm);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-accent);
    letter-spacing: -0.02em;
}

/* =============================================================================
   Modal
   ============================================================================= */

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 480px;
    max-height: 90vh;
    overflow-y: auto;
    transform: translateY(20px);
    transition: transform var(--transition-base);
}

.modal-overlay.active .modal {
    transform: translateY(0);
}

.modal-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.modal-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--color-bg-hover);
    color: var(--color-text);
}

.modal-body {
    padding: var(--space-lg);
}

.modal-footer {
    padding: var(--space-lg);
    border-top: 1px solid var(--color-border);
    display: flex;
    justify-content: flex-end;
    gap: var(--space-sm);
}

/* =============================================================================
   Login Page
   ============================================================================= */

.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    background: 
        radial-gradient(ellipse at top, rgba(240, 180, 41, 0.1), transparent 50%),
        var(--color-bg);
}

.login-card {
    width: 100%;
    max-width: 400px;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
}

.login-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.login-brand svg {
    width: 32px;
    height: 32px;
    color: var(--color-accent);
}

.login-title {
    text-align: center;
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-xl);
}

/* =============================================================================
   Empty State
   ============================================================================= */

.empty-state {
    text-align: center;
    padding: var(--space-2xl);
    color: var(--color-text-muted);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: var(--space-lg);
    opacity: 0.5;
}

.empty-state-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

/* =============================================================================
   Utilities
   ============================================================================= */

.text-muted { color: var(--color-text-muted); }
.text-success { color: var(--color-success); }
.text-error { color: var(--color-error); }
.text-warning { color: var(--color-warning); }
.text-mono { font-family: var(--font-mono); }

.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }

/* =============================================================================
   Responsive
   ============================================================================= */

@media (max-width: 768px) {
    .nav-container {
        padding: 0 var(--space-md);
    }
    
    .nav-links {
        display: none;
    }
    
    .main {
        padding: var(--space-lg) var(--space-md);
    }
    
    .page-title {
        font-size: 1.5rem;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .table th,
    .table td {
        padding: var(--space-sm);
        font-size: 0.85rem;
    }
}