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

:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --background: #f8fafc;
    --surface: #ffffff;
    --border: #e2e8f0;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --shadow: rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Login Box */
.login-box {
    background: var(--surface);
    border-radius: 16px;
    padding: 3rem;
    box-shadow: 0 4px 6px var(--shadow);
    width: 100%;
    max-width: 400px;
}

.logo {
    text-align: center;
    margin-bottom: 2rem;
}

.logo-icon {
    width: 48px;
    height: 48px;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.logo h1 {
    font-size: 1.75rem;
    color: var(--text-primary);
}

.login-form h2 {
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.subtitle {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input[type="text"],
.form-group input[type="number"],
.form-group input[type="email"] {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s;
}

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

.error-message {
    color: var(--danger);
    font-size: 0.875rem;
    margin-top: 0.5rem;
    display: none;
}

.error-message.show {
    display: block;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

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

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

.btn-block {
    width: 100%;
}

.btn-icon {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    color: var(--text-secondary);
    transition: color 0.3s;
}

.btn-icon:hover {
    color: var(--text-primary);
}

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.3s;
}

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

/* Icons */
.icon {
    width: 20px;
    height: 20px;
}

/* Navbar */
.navbar {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 600;
    text-decoration: none;
    color: var(--text-primary);
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.balance-display {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--background);
    border-radius: 8px;
    font-weight: 600;
    color: var(--primary);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Dashboard */
.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.tabs {
    display: flex;
    gap: 0.5rem;
    background: var(--surface);
    padding: 0.25rem;
    border-radius: 8px;
}

.tab {
    padding: 0.5rem 1.5rem;
    border: none;
    background: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all 0.3s;
}

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

.tab-content {
    display: none;
}

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

/* Auctions Grid */
.auctions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.auction-card {
    background: var(--surface);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 4px var(--shadow);
    transition: all 0.3s;
    cursor: pointer;
    border: 2px solid transparent;
}

.auction-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px var(--shadow);
    border-color: var(--primary);
}

.auction-card-header {
    margin-bottom: 1rem;
}

.auction-card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.auction-card-meta {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
}

.badge-active {
    background: #dcfce7;
    color: #166534;
}

.badge-completed {
    background: #f1f5f9;
    color: #475569;
}

.auction-card-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1rem;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.stat-value {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.user-status {
    margin-top: 1rem;
    padding: 0.75rem;
    background: var(--background);
    border-radius: 8px;
    font-size: 0.875rem;
}

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

.status-losing {
    color: var(--danger);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal.show {
    display: flex;
}

.modal-content {
    background: var(--surface);
    border-radius: 16px;
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-sm {
    max-width: 400px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.modal-header h2 {
    font-size: 1.5rem;
}

.modal-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    color: var(--text-secondary);
}

.modal-body {
    padding: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.radio-group {
    display: flex;
    gap: 1rem;
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

/* Auction Page */
.auction-container {
    background: var(--surface);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 2px 4px var(--shadow);
}

.auction-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border);
}

.auction-info h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.auction-meta {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    flex-direction: column;
}

.meta-item .label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.meta-item .value {
    font-size: 1.125rem;
    font-weight: 600;
}

.auction-timer {
    text-align: center;
}

.timer-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.timer-display {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    font-variant-numeric: tabular-nums;
}

.auction-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 2rem;
}

/* Leaderboard */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.section-header h2 {
    font-size: 1.5rem;
}

.live-indicator {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--success);
    font-size: 0.875rem;
    font-weight: 600;
}

.pulse {
    width: 8px;
    height: 8px;
    background: var(--success);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.leaderboard {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.leaderboard-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--background);
    border-radius: 8px;
    transition: all 0.3s;
}

.leaderboard-item.highlight {
    background: linear-gradient(135deg, #3b82f6 0%, #60a5fa 100%);
    color: white;
}

.position {
    font-size: 1.25rem;
    font-weight: 700;
    min-width: 40px;
}

.leaderboard-item.rank-1 .position {
    color: #fbbf24;
}

.leaderboard-item.rank-2 .position {
    color: #94a3b8;
}

.leaderboard-item.rank-3 .position {
    color: #cd7f32;
}

.username {
    flex: 1;
    font-weight: 600;
}

.bid-amount {
    font-weight: 700;
    font-size: 1.125rem;
}

.your-position {
    margin-top: 1.5rem;
    padding: 1rem;
    background: var(--primary-light);
    color: white;
    border-radius: 8px;
}

.position-label {
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.position-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.25rem;
    font-weight: 700;
}

/* Bid Section */
.bid-section {
    background: var(--background);
    border-radius: 12px;
    padding: 1.5rem;
}

.bid-info {
    background: var(--surface);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border);
}

.info-row:last-child {
    border-bottom: none;
}

.bid-controls {
    margin-bottom: 2rem;
}

.input-with-slider input[type="number"] {
    margin-bottom: 0.75rem;
}

.input-with-slider input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--border);
    outline: none;
    -webkit-appearance: none;
}

.input-with-slider input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
}

.input-with-slider input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    border: none;
}

.stress-test-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.stress-test-section h3 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--text-primary);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 12px var(--shadow);
    transform: translateX(400px);
    transition: transform 0.3s;
    z-index: 1001;
}

.toast.show {
    transform: translateX(0);
}

.toast.success {
    background: var(--success);
}

.toast.error {
    background: var(--danger);
}

/* Loader */
.loader {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .auction-content {
        grid-template-columns: 1fr;
    }
    
    .auction-header {
        flex-direction: column;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .nav-user {
        gap: 0.5rem;
    }
    
    .balance-display {
        font-size: 0.875rem;
        padding: 0.5rem;
    }
}