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

:root {
    --primary: #00f5ff;
    --secondary: #ff00ff;
    --accent: #7c3aed;
    --dark: #0a0a0f;
    --darker: #05050a;
    --light: #ffffff;
    --gray: #1a1a2e;
    --border: rgba(255, 255, 255, 0.1);
    --glow: rgba(0, 245, 255, 0.5);
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

@keyframes glow {
    0%, 100% { box-shadow: 0 0 20px var(--glow), 0 0 40px var(--glow); }
    50% { box-shadow: 0 0 30px var(--glow), 0 0 60px var(--glow); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes shimmer {
    0% { background-position: -1000px 0; }
    100% { background-position: 1000px 0; }
}

@keyframes particle {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg);
        opacity: 0.3;
    }
    25% {
        transform: translate(100px, -100px) rotate(90deg);
        opacity: 0.6;
    }
    50% {
        transform: translate(200px, 0) rotate(180deg);
        opacity: 0.3;
    }
    75% {
        transform: translate(100px, 100px) rotate(270deg);
        opacity: 0.6;
    }
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #0a0a0f 0%, #1a1a2e 50%, #0a0a0f 100%);
    color: var(--light);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Animated particles */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(124, 58, 237, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 245, 255, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 90%, rgba(255, 0, 255, 0.15) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
    animation: pulse 8s ease-in-out infinite;
}

body::after {
    content: '';
    position: fixed;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 245, 255, 0.1) 0%, transparent 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 0;
    animation: particle 20s ease-in-out infinite;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 30px;
    position: relative;
    z-index: 1;
}

/* Navigation */
.navbar {
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 30px;
}

.nav-brand h1 {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-size: 1.8em;
    font-weight: 800;
    letter-spacing: -1px;
    position: relative;
}

.nav-brand h1::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 50px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), transparent);
    border-radius: 2px;
}

.nav-menu {
    display: flex;
    gap: 20px;
    align-items: center;
}

.nav-link {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    position: relative;
    padding: 8px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s;
}

.nav-link:hover {
    color: var(--primary);
}

.nav-link:hover::after {
    width: 100%;
}

/* Buttons */
.btn {
    padding: 12px 28px;
    border: none;
    border-radius: 12px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.4s;
    font-size: 14px;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    box-shadow: 0 4px 20px rgba(0, 245, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 245, 255, 0.5);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--dark);
    box-shadow: 0 4px 20px rgba(0, 245, 255, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #10b981, #059669);
    color: white;
    box-shadow: 0 4px 20px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(16, 185, 129, 0.5);
}

.btn-block {
    width: 100%;
    padding: 16px;
}

/* Hero Section */
.hero {
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
}

.hero-title {
    font-size: 4em;
    font-weight: 900;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--light), var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: slideIn 0.8s ease-out;
    letter-spacing: -2px;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.4em;
    margin-bottom: 50px;
    color: rgba(255, 255, 255, 0.7);
    animation: slideIn 0.8s ease-out 0.2s both;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 80px;
    margin-bottom: 50px;
    animation: slideIn 0.8s ease-out 0.4s both;
}

.stat {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 30px 40px;
    transition: all 0.4s;
}

.stat:hover {
    transform: translateY(-10px);
    border-color: var(--primary);
    box-shadow: 0 20px 40px rgba(0, 245, 255, 0.2);
}

.stat h3 {
    font-size: 3em;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 900;
    margin-bottom: 8px;
}

.stat p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.95em;
    text-transform: uppercase;
    letter-spacing: 2px;
    font-weight: 600;
}

.search-bar {
    max-width: 700px;
    margin: 0 auto;
    display: flex;
    gap: 15px;
    animation: slideIn 0.8s ease-out 0.6s both;
}

.search-bar input {
    flex: 1;
    padding: 18px 25px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border);
    border-radius: 15px;
    color: white;
    font-size: 16px;
    transition: all 0.3s;
}

.search-bar input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 30px rgba(0, 245, 255, 0.3);
}

.search-bar input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

/* Categories */
.categories {
    padding: 80px 0;
}

.categories h2 {
    text-align: center;
    font-size: 2.8em;
    margin-bottom: 60px;
    background: linear-gradient(135deg, var(--light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 800;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 25px;
}

.category-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 245, 255, 0.1), transparent);
    transition: left 0.6s;
}

.category-card:hover::before {
    left: 100%;
}

.category-card:hover {
    transform: translateY(-10px) scale(1.02);
    border-color: var(--primary);
    box-shadow: 0 20px 60px rgba(0, 245, 255, 0.3);
}

.category-card.active {
    background: rgba(0, 245, 255, 0.1);
    border-color: var(--primary);
    box-shadow: 0 0 30px rgba(0, 245, 255, 0.4), inset 0 0 20px rgba(0, 245, 255, 0.2);
    transform: scale(1.05);
}

.category-card.active .category-icon {
    animation: float 3s ease-in-out infinite;
}

.category-icon {
    font-size: 3.5em;
    display: block;
    margin-bottom: 20px;
    filter: drop-shadow(0 0 20px rgba(0, 245, 255, 0.5));
    transition: all 0.4s;
}

.category-card h3 {
    font-size: 1.2em;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Marketplace */
.marketplace {
    padding: 80px 0;
    background: rgba(0, 0, 0, 0.2);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 2.8em;
    background: linear-gradient(135deg, var(--light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 800;
}

.filters select {
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border);
    border-radius: 12px;
    color: white;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.filters select:focus {
    outline: none;
    border-color: var(--primary);
}

.filters select option {
    background: var(--dark);
}

.gpts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
}

.gpt-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: 24px;
    overflow: hidden;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    position: relative;
    animation: slideIn 0.6s ease-out both;
}

.gpt-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(0, 245, 255, 0.1), transparent);
    transform: rotate(45deg);
    transition: all 0.6s;
}

.gpt-card:hover::before {
    top: -30%;
    left: -30%;
}

.gpt-card:hover {
    transform: translateY(-15px) scale(1.02);
    border-color: var(--primary);
    box-shadow: 0 30px 60px rgba(0, 245, 255, 0.4);
}

.gpt-image {
    width: 100%;
    height: 220px;
    background: linear-gradient(135deg, var(--accent), var(--primary), var(--secondary));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 5em;
    position: relative;
    overflow: hidden;
}

.gpt-image::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.3));
}

.gpt-content {
    padding: 25px;
}

.gpt-title {
    font-size: 1.4em;
    margin-bottom: 12px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gpt-creator {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.9em;
    margin-bottom: 12px;
    font-weight: 600;
}

.gpt-description {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
    line-height: 1.6;
}

.gpt-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}

.gpt-price {
    font-size: 1.8em;
    font-weight: 900;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gpt-rating {
    color: #fbbf24;
    font-size: 1.1em;
    font-weight: 600;
}

.loading {
    text-align: center;
    padding: 60px;
    font-size: 1.3em;
    color: rgba(255, 255, 255, 0.5);
}

/* Modals */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    overflow: auto;
    animation: fadeIn 0.3s;
}

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

.modal-content {
    background: rgba(26, 26, 46, 0.95);
    backdrop-filter: blur(30px);
    margin: 3% auto;
    padding: 40px;
    border: 1px solid var(--border);
    border-radius: 30px;
    width: 90%;
    max-width: 600px;
    box-shadow: 0 30px 90px rgba(0, 0, 0, 0.5);
    animation: slideIn 0.4s ease-out;
}

.modal-large {
    max-width: 900px;
}

.close {
    color: rgba(255, 255, 255, 0.5);
    float: right;
    font-size: 32px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
    line-height: 1;
}

.close:hover {
    color: var(--primary);
    transform: rotate(90deg);
}

/* Forms */
.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.9);
    text-transform: uppercase;
    font-size: 0.85em;
    letter-spacing: 1px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px 20px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border);
    border-radius: 12px;
    color: white;
    font-size: 15px;
    transition: all 0.3s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 20px rgba(0, 245, 255, 0.2);
}

.form-footer {
    text-align: center;
    margin-top: 25px;
    color: rgba(255, 255, 255, 0.6);
}

.form-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 700;
    transition: all 0.3s;
}

.form-footer a:hover {
    color: var(--secondary);
}

/* User Menu */
.user-menu {
    display: flex;
    gap: 15px;
    align-items: center;
}

.user-name {
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* GPT Detail */
.gpt-detail-header {
    display: flex;
    gap: 40px;
    margin-bottom: 40px;
}

.gpt-detail-image {
    width: 250px;
    height: 250px;
    background: linear-gradient(135deg, var(--accent), var(--primary), var(--secondary));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6em;
    box-shadow: 0 20px 60px rgba(0, 245, 255, 0.3);
    animation: float 6s ease-in-out infinite;
}

.gpt-detail-info {
    flex: 1;
}

.gpt-detail-info h2 {
    font-size: 2.5em;
    margin-bottom: 15px;
    background: linear-gradient(135deg, var(--light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 900;
}

.gpt-detail-meta {
    display: flex;
    gap: 25px;
    margin: 20px 0;
    color: rgba(255, 255, 255, 0.6);
    font-weight: 600;
}

.gpt-detail-price {
    font-size: 3em;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 900;
    margin: 20px 0;
}

.gpt-detail-description {
    margin: 30px 0;
    line-height: 1.8;
}

.gpt-detail-description h3 {
    font-size: 1.5em;
    margin-bottom: 15px;
    color: var(--primary);
}

.alert {
    padding: 18px 25px;
    border-radius: 15px;
    margin-bottom: 25px;
    border: 1px solid;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    border-color: #10b981;
    color: #10b981;
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    border-color: #ef4444;
    color: #ef4444;
}

@media (max-width: 968px) {
    .hero-title { font-size: 2.5em; }
    .hero-stats { flex-direction: column; gap: 20px; }
    .gpt-detail-header { flex-direction: column; }
    .gpts-grid { grid-template-columns: 1fr; }
    .nav-menu { flex-wrap: wrap; }
}