style.css

:root {
    --color-bg: #0a0a0f;
    --color-surface: #14141f;
    --color-surface-light: #1c1c2e;
    --color-primary: #00d9ff;
    --color-primary-glow: rgba(0, 217, 255, 0.3);
    --color-accent: #ff006e;
    --color-text: #ffffff;
    --color-text-dim: #a0a0b8;
    --color-success: #00ff88;
    --color-error: #ff3366;
    --color-warning: #ffaa00;
    
    --font-display: 'Syne', sans-serif;
    --font-body: 'DM Sans', sans-serif;
    
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px var(--color-primary-glow);
    
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-body);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 20%, rgba(0, 217, 255, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 0, 110, 0.08) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
    animation: slideDown 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.logo {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

/* Wallet Section */
.wallet-section {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.wallet-info {
    display: none;
    align-items: center;
    gap: 1rem;
    background: var(--color-surface);
    padding: 0.75rem 1.25rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    animation: fadeIn 0.3s var(--transition-smooth);
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.95); }
    to { opacity: 1; transform: scale(1); }
}

.wallet-address {
    font-family: 'Courier New', monospace;
    color: var(--color-primary);
    font-size: 0.9rem;
    font-weight: 500;
}

.btn {
    font-family: var(--font-body);
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 10px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-smooth);
    position: relative;
    overflow: hidden;
    white-space: nowrap;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, #0099cc 100%);
    color: var(--color-bg);
    box-shadow: var(--shadow-sm), var(--shadow-glow);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md), 0 0 30px var(--color-primary-glow);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--color-surface-light);
    border-color: var(--color-primary);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Status Message */
.status-message {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    border-radius: 12px;
    font-weight: 500;
    display: none;
    z-index: 1000;
    animation: slideInRight 0.3s var(--transition-smooth);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-lg);
    max-width: 400px;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(100px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.status-message.info {
    background: rgba(0, 217, 255, 0.15);
    color: var(--color-primary);
    border-color: var(--color-primary);
}

.status-message.success {
    background: rgba(0, 255, 136, 0.15);
    color: var(--color-success);
    border-color: var(--color-success);
}

.status-message.error {
    background: rgba(255, 51, 102, 0.15);
    color: var(--color-error);
    border-color: var(--color-error);
}

/* Controls */
.controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    align-items: center;
    animation: slideUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) 0.1s both;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.search-box {
    flex: 1;
    min-width: 250px;
    position: relative;
}

.search-input {
    width: 100%;
    padding: 0.875rem 1.25rem;
    padding-left: 3rem;
    background: var(--color-surface);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    color: var(--color-text);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: all var(--transition-smooth);
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-glow);
}

.search-icon {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-dim);
    font-size: 1.1rem;
}

.filters {
    display: flex;
    gap: 0.5rem;
    background: var(--color-surface);
    padding: 0.5rem;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.filter-btn {
    padding: 0.5rem 1rem;
    background: transparent;
    color: var(--color-text-dim);
    border: none;
    border-radius: 8px;
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    color: var(--color-text);
    background: rgba(255, 255, 255, 0.05);
}

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

/* NFT Grid */
.nft-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    animation: fadeInUp 0.6s cubic-bezier(0.22, 1, 0.36, 1) 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.nft-card {
    background: var(--color-surface);
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.08);
    transition: all var(--transition-smooth);
    animation: cardAppear 0.4s cubic-bezier(0.22, 1, 0.36, 1) both;
    cursor: pointer;
}

.nft-card:hover {
    transform: translateY(-8px);
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg), 0 0 40px rgba(0, 217, 255, 0.2);
}

@keyframes cardAppear {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.nft-image-container {
    position: relative;
    width: 100%;
    padding-top: 100%;
    background: linear-gradient(135deg, var(--color-surface-light) 0%, var(--color-surface) 100%);
    overflow: hidden;
}

.nft-image {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-smooth);
}

.nft-card:hover .nft-image {
    transform: scale(1.05);
}

.nft-info {
    padding: 1.5rem;
}

.nft-name {
    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--color-text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.nft-description {
    font-size: 0.9rem;
    color: var(--color-text-dim);
    margin-bottom: 1rem;
    line-height: 1.5;
    height: 3em;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.nft-price {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: 1rem;
}

.nft-price.for-sale {
    background: rgba(0, 255, 136, 0.15);
    color: var(--color-success);
    border: 1px solid var(--color-success);
}

.nft-price.not-for-sale {
    background: rgba(160, 160, 184, 0.1);
    color: var(--color-text-dim);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.buy-button {
    width: 100%;
    padding: 0.875rem;
    border: none;
    border-radius: 10px;
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-smooth);
    background: linear-gradient(135deg, var(--color-primary) 0%, #0099cc 100%);
    color: var(--color-bg);
    position: relative;
    overflow: hidden;
}

.buy-button::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.buy-button:hover:not(:disabled)::before {
    width: 400px;
    height: 400px;
}

.buy-button:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md), 0 0 30px var(--color-primary-glow);
}

.buy-button:disabled {
    background: var(--color-surface-light);
    color: var(--color-text-dim);
    cursor: not-allowed;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

/* Loading and Empty States */
.loading,
.empty-state,
.error-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 4rem 2rem;
    animation: fadeIn 0.4s var(--transition-smooth);
}

.loading {
    font-size: 1.1rem;
    color: var(--color-text-dim);
}

.spinner {
    display: inline-block;
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-bottom: 1rem;
}

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

.empty-state h3,
.error-state h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.empty-state p,
.error-state p {
    color: var(--color-text-dim);
}

.error-state {
    background: rgba(255, 51, 102, 0.1);
    border: 1px solid var(--color-error);
    border-radius: 16px;
}

.error-state h3 {
    color: var(--color-error);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }

    .wallet-section {
        width: 100%;
        flex-direction: column;
    }

    .wallet-info {
        width: 100%;
        justify-content: center;
    }

    .controls {
        flex-direction: column;
    }

    .search-box {
        width: 100%;
    }

    .nft-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .status-message {
        top: 1rem;
        right: 1rem;
        left: 1rem;
    }
}

/* Skeleton loading */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--color-surface) 0%,
        var(--color-surface-light) 50%,
        var(--color-surface) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}