/* Modern CSS Reset and Variables */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --success-hover: #059669;
    --warning-color: #f59e0b;
    --warning-hover: #d97706;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --info-color: #06b6d4;
    --info-hover: #0891b2;
    --background-color: #f8fafc;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --border-radius: 12px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 14px;
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

/* Container and Layout */
.container {
    max-width: 100vw;
    margin: 0 auto;
    background: var(--card-background);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding: 0;
}

/* Header Styles */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    z-index: 1000;
    margin-bottom: 0;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 2rem;
    gap: 2rem;
}

.nav h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-center {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.auction-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.auction-info span {
    font-size: 1.1rem;
    font-weight: 600;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

#welcome-user {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Tab Navigation */
.tab-navigation {
    display: flex;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem;
    border-radius: var(--border-radius);
    backdrop-filter: blur(10px);
}

.tab-navigation:empty,
.tab-navigation[style*="display: none"] {
    display: none !important;
}

.nav-center:has(.tab-navigation[style*="display: none"]) {
    gap: 0;
}

.tab-link {
    padding: 0.75rem 1.5rem;
    border-radius: calc(var(--border-radius) - 2px);
    text-decoration: none;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid transparent;
}

.tab-link:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.tab-link.active {
    background: white;
    color: var(--primary-color);
    font-weight: 600;
    box-shadow: var(--shadow-sm);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 0.25rem 2rem;
    background: var(--background-color);
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.tab-content.active {
    display: block;
}

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

/* Page Header */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
    padding: 1rem 2rem;
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.page-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.quick-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.help-text {
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-style: italic;
    margin-left: 1rem;
}

/* Brochure upload section */
.brochure-upload {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: #f8fafc;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.brochure-upload .bu-row {
    display: grid;
    grid-template-columns: repeat(4, minmax(180px, 1fr));
    gap: 0.75rem;
}

.brochure-upload .bu-item {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: calc(var(--border-radius) - 4px);
    padding: 0.5rem 0.75rem;
}

.brochure-upload .bu-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.brochure-upload .bu-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

@media (max-width: 900px) {
    .brochure-upload .bu-row {
        grid-template-columns: repeat(2, minmax(180px, 1fr));
    }
}

@media (max-width: 520px) {
    .brochure-upload .bu-row {
        grid-template-columns: 1fr;
    }
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: calc(var(--border-radius) - 2px);
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    gap: 0.5rem;
    box-shadow: var(--shadow-sm);
    font-family: inherit;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
}

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

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-secondary {
    background: var(--secondary-color);
    color: white;
}

.btn-secondary:hover {
    background: #475569;
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: var(--success-hover);
}

.btn-warning {
    background: var(--warning-color);
    color: white;
}

.btn-warning:hover {
    background: var(--warning-hover);
}

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

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

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    background: var(--info-hover);
}

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

.btn-edit {
    background: var(--warning-color);
    color: white;
}

.btn-edit:hover {
    background: var(--warning-hover);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn:disabled:hover {
    transform: none;
    box-shadow: var(--shadow-sm);
}

/* Logout Button */
.logout-btn {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: calc(var(--border-radius) - 4px);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.logout-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

/* Grid Container */
.grid-container,
.lottery-grid-container,
.invoice-grid-container,
.buyers-grid-container,
.auctions-grid-container {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.grid-wrapper {
    overflow: auto;
    max-height: 70vh;
}

/* Table Styles */
table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th {
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    color: var(--text-primary);
    font-weight: 600;
    padding: 1rem 0.75rem;
    text-align: left;
    border-bottom: 2px solid var(--border-color);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.025em;
    position: sticky;
    top: 0;
    z-index: 10;
}

td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    background: white;
    transition: var(--transition);
}

tr:hover td {
    background: #f8fafc;
}

.scheduler-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.scheduler-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.scheduler-view-toggle {
    display: inline-flex;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    background: #fff;
    overflow: hidden;
}

.view-toggle-btn {
    border: none;
    background: transparent;
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.view-toggle-btn:hover {
    color: var(--primary-color);
}

.view-toggle-btn.active {
    background: var(--primary-color);
    color: white;
}

.year-switcher {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1.1rem;
}

.scheduler-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.legend-color {
    display: inline-block;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    margin-right: 0.4rem;
}

.legend-normal { background: #2563eb; }
.legend-property { background: #d97706; }
.legend-animals { background: #16a34a; }

.scheduler-calendar {
    width: 100%;
}

.scheduler-calendar.grid-mode {
    display: grid;
    grid-template-columns: repeat(3, minmax(260px, 1fr));
    gap: 1.25rem;
    align-items: start;
}

.scheduler-calendar.linear-mode {
    display: block;
}

@media (max-width: 1400px) {
    .scheduler-calendar.grid-mode {
        grid-template-columns: repeat(2, minmax(240px, 1fr));
    }
}

@media (max-width: 900px) {
    .scheduler-calendar.grid-mode {
        grid-template-columns: minmax(220px, 1fr);
        gap: 1rem;
    }
}

.calendar-month {
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.5rem 0.75rem 0.75rem;
    background: white;
    box-shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
    margin-bottom: 1.25rem;
    min-height: 100%;
}

.linear-calendar-scroll {
    display: flex;
    gap: 1rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    scroll-snap-type: x proximity;
}

.linear-month {
    min-width: 240px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: white;
    box-shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
    scroll-snap-align: start;
    display: flex;
    flex-direction: column;
    max-height: 90vh;
}

.linear-month .month-title {
    padding: 0.65rem 0.9rem;
    margin-bottom: 0;
    border-bottom: 1px solid var(--border-color);
}

.linear-days {
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.linear-day-row {
    padding: 0.45rem 0.75rem;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    cursor: pointer;
    background: #fff;
    transition: background 0.2s ease;
}

.linear-day-row:nth-child(odd) {
    background: #f8fafc;
}

.linear-day-row:hover {
    background: #eef2ff;
}

.linear-day-row.has-events {
    border-left: 3px solid var(--primary-color);
}

.linear-day-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-primary);
    font-weight: 600;
}

.linear-day-header .weekday {
    font-size: 0.78rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.linear-day-row .schedule-chips {
    flex-direction: column;
    gap: 0.3rem;
}

.linear-day-row .schedule-chip {
    width: 100%;
    justify-content: flex-start;
}

.month-title {
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.weekday-row,
.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.25rem;
}

.weekday-row span {
    text-align: center;
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
}

.calendar-day {
    min-height: 90px;
    border: 1px dashed var(--border-color);
    border-radius: 10px;
    background: #f8fafc;
    padding: 0.35rem 0.4rem;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    cursor: pointer;
    transition: var(--transition);
}

.calendar-day.empty {
    background: transparent;
    border-color: transparent;
    cursor: default;
}

.calendar-day:hover {
    border-color: var(--primary-color);
    background: #eef2ff;
}

.calendar-day.has-events {
    border-style: solid;
    background: #fff;
}

.calendar-day .day-number {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.calendar-day .schedule-chips {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.schedule-chip {
    border-radius: 8px;
    padding: 0.2rem 0.4rem;
    color: #fff;
    font-size: 0.72rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.warning-text {
    background: #fef3c7;
    color: #92400e;
    border: 1px solid #fcd34d;
    padding: 0.75rem;
    border-radius: 8px;
    margin: 0.75rem 0;
    font-size: 0.9rem;
}

.loading,
.error-state {
    padding: 1rem;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.error-state {
    color: var(--danger-color);
}

/* Excel-like cell behavior */
.excel-cell {
    border: 2px solid transparent;
    border-radius: 4px;
    padding: 0.5rem 0.75rem;
    transition: var(--transition);
    cursor: text;
    min-width: 80px;
    background: white;
}

.excel-cell[data-field="btw"],
td[data-field="btw"] {
    min-width: 150px;
    white-space: normal;
    word-break: break-word;
}

.excel-cell:hover {
    border-color: var(--border-color);
    background: #f8fafc;
}

.excel-cell:focus {
    outline: none;
    border-color: var(--primary-color);
    background: white;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.number-cell {
    text-align: right;
    font-family: 'SF Mono', 'Monaco', 'Cascadia Code', monospace;
    font-weight: 500;
}

.commission-cell {
    position: relative;
    padding-right: 1.75rem;
}

.commission-cell::after {
    content: '%';
    position: absolute;
    right: 0.5rem;
    color: #475569;
    pointer-events: none;
    font-weight: 600;
}

.empty-row {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-left: 4px solid var(--info-color);
}

.empty-row td {
    background: transparent;
}

/* Action Buttons in Tables */
.actions-cell {
    width: 160px;
    text-align: center;
    padding: 0.5rem;
}

.actions-cell .btn {
    margin: 0 0.25rem;
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
}

.delete-row {
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.delete-row:hover {
    background: var(--danger-hover);
    transform: scale(1.05);
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    animation: fadeIn 0.3s ease-in-out;
}

.modal-content {
    background: var(--card-background);
    margin: 5% auto;
    padding: 0;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 800px;
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease-in-out;
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    border-radius: var(--border-radius) var(--border-radius) 0 0;
}

.modal-header h3 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: white;
    padding: 0.5rem;
    border-radius: 50%;
    transition: var(--transition);
}

.close:hover {
    background: rgba(255, 255, 255, 0.1);
}

.modal-body {
    padding: 2rem;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    padding: 1.5rem 2rem;
    border-top: 1px solid var(--border-color);
    background: #f8fafc;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Form Styles */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    padding: 0 0.75rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: calc(var(--border-radius) - 4px);
    font-size: 0.9rem;
    transition: var(--transition);
    background: white;
    color: var(--text-primary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-row {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-row .form-group {
    flex: 1;
    margin-bottom: 0;
}

.form-row .form-group.full-width {
    flex: 100%;
}

/* Status Indicators */
.status-paid {
    color: var(--success-color);
    font-weight: 600;
}

.status-pending {
    color: var(--warning-color);
    font-weight: 600;
}

.status-failed {
    color: var(--danger-color);
    font-weight: 600;
}

.status-r {
    color: var(--danger-color);
    font-weight: 600;
}

.status-s {
    color: var(--success-color);
    font-weight: 600;
}

.status-p {
    color: var(--warning-color);
    font-weight: 600;
}

/* Currency Formatting */
.currency {
    text-align: right;
    font-family: 'SF Mono', 'Monaco', 'Cascadia Code', monospace;
    font-weight: 500;
}

/* Keyboard Shortcuts Panel */
.keyboard-shortcuts {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    font-size: 0.85rem;
    max-width: 300px;
    z-index: 1500;
    backdrop-filter: blur(10px);
}

.keyboard-shortcuts h4 {
    margin: 0 0 1rem 0;
    font-size: 1rem;
    color: var(--text-primary);
    font-weight: 600;
}

.keyboard-shortcuts ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.keyboard-shortcuts li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

.keyboard-shortcuts li:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.keyboard-shortcuts .key {
    background: var(--background-color);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-family: 'SF Mono', 'Monaco', 'Cascadia Code', monospace;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

/* Login Page Specific Styles */
.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    padding: 2rem;
}

.login-form {
    background: var(--card-background);
    padding: 3rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.logo h1 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 2rem;
    font-size: 1.75rem;
    font-weight: 700;
}

.login-form h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--text-primary);
    font-size: 1.75rem;
    font-weight: 700;
}

.login-form .form-group {
    margin-bottom: 1.5rem;
}

.login-form .btn {
    width: 100%;
    margin-top: 1rem;
}

.login-btn {
    width: 100%;
    padding: 0.75rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    border: none;
    border-radius: calc(var(--border-radius) - 4px);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.login-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.error-message {
    color: var(--danger-color);
    margin-top: 1rem;
    text-align: center;
    font-size: 0.9rem;
}

.demo-credentials {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--background-color);
    border-radius: calc(var(--border-radius) - 4px);
    border-left: 4px solid var(--primary-color);
}

.demo-credentials h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1rem;
    font-weight: 600;
}

.demo-credentials p {
    margin: 0.5rem 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Loading Spinner */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
        padding: 0.5rem;
    }
    
    .nav-center {
        width: 100%;
        order: 2;
    }
    
    .nav-right {
        order: 1;
    }
    
    .tab-navigation {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .main-content {
        padding: 0.25rem 1rem;
    }
    
    .page-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
        padding: 0.75rem;
        margin-bottom: 0.5rem;
    }
    
    .quick-actions {
        justify-content: center;
    }
    
    .grid-wrapper {
        max-height: 50vh;
    }
    
    .keyboard-shortcuts {
        bottom: 1rem;
        right: 1rem;
        left: 1rem;
        max-width: none;
    }
    
    .modal-content {
        width: 95%;
        margin: 2% auto;
    }
    
    .modal-body {
        padding: 1.5rem;
    }
    
    .form-row {
        flex-direction: column;
        gap: 0;
    }
    
    .form-row .form-group {
        margin-bottom: 1.5rem;
    }
}

@media (max-width: 480px) {
    .nav h1 {
        font-size: 1.25rem;
    }
    
    .tab-link {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.85rem;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        margin: 2% auto;
    }
    
    .login-form {
        padding: 2rem;
    }
}

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

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

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

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

/* Focus styles for accessibility */
.btn:focus,
.tab-link:focus,
input:focus,
select:focus,
textarea:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Action Button Groups */
.action-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    align-items: center;
}

/* Back Button */
#back-to-auctions {
    background: var(--secondary-color);
    color: white;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: calc(var(--border-radius) - 4px);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

#back-to-auctions:hover {
    background: #475569;
}

/* Print styles */
@media print {
    .header,
    .keyboard-shortcuts,
    .btn,
    .actions-cell {
        display: none !important;
    }
    
    .main-content {
        padding: 0;
    }
    
    .tab-content {
        display: block !important;
    }
}