/* ============================================
   QUANT TRADING - MAIN STYLES
   ============================================ */

/* ----- Cài đặt chung ----- */
:root {
    --primary: #0a1628;
    --secondary: #1a2a4a;
    --accent: #00d4ff;
    --accent-hover: #00b8d4;
    --text-light: #e0e8f0;
    --text-muted: #8899aa;
    --gradient-main: linear-gradient(135deg, #0a1628 0%, #1a3a5c 100%);
    --gradient-accent: linear-gradient(135deg, #00d4ff, #0070ff);
    --shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
    background: #0a1628;
    color: var(--text-light);
    line-height: 1.7;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ----- Navbar ----- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 18px 0;
    background: rgba(10, 22, 40, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
    transition: var(--transition);
}

.navbar.scrolled {
    padding: 12px 0;
    background: rgba(10, 22, 40, 0.98);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
}

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

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 24px;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

.navbar-brand .brand-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-accent);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.navbar-brand span {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
    align-items: center;
}

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-accent);
    transition: var(--transition);
}

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

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

.btn-nav {
    background: var(--gradient-accent);
    color: white !important;
    padding: 8px 24px !important;
    border-radius: 25px;
    font-weight: 600 !important;
    transition: var(--transition);
}

.btn-nav::after {
    display: none !important;
}

.btn-nav:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.3);
    color: white !important;
}

/* ----- Mobile Menu Toggle ----- */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 4px;
}

.menu-toggle span {
    display: block;
    width: 28px;
    height: 2.5px;
    background: white;
    transition: var(--transition);
}

/* ----- Hero Section ----- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    background: var(--gradient-main);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(0, 112, 255, 0.06) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-content h1 {
    font-size: 52px;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
}

.hero-content h1 .highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-content p {
    font-size: 18px;
    color: var(--text-muted);
    margin-bottom: 32px;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn-primary {
    display: inline-block;
    padding: 14px 36px;
    background: var(--gradient-accent);
    color: white;
    border: none;
    border-radius: 30px;
    font-weight: 600;
    font-size: 16px;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(0, 212, 255, 0.35);
    color: white;
}

.btn-secondary {
    display: inline-block;
    padding: 14px 36px;
    background: transparent;
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 30px;
    font-weight: 600;
    font-size: 16px;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
}

.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-3px);
}

.hero-stats {
    display: flex;
    gap: 48px;
    margin-top: 48px;
}

.hero-stats .stat-item h3 {
    font-size: 32px;
    font-weight: 700;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-stats .stat-item p {
    font-size: 14px;
    color: var(--text-muted);
    margin: 0;
}

/* ----- Hero Visual (Chart) ----- */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.chart-container {
    width: 100%;
    max-width: 500px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: 20px;
    padding: 30px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    backdrop-filter: blur(10px);
    position: relative;
}

.chart-container::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 22px;
    background: var(--gradient-accent);
    opacity: 0.1;
    z-index: -1;
    filter: blur(20px);
}

.chart-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.chart-title h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
}

.chart-title .live-dot {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    color: #00ff88;
}

.chart-title .live-dot::before {
    content: '';
    width: 8px;
    height: 8px;
    background: #00ff88;
    border-radius: 50%;
    animation: pulse-dot 1.5s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.8); }
}

.chart-grid {
    display: flex;
    align-items: flex-end;
    gap: 6px;
    height: 180px;
    padding: 10px 0;
}

.chart-bar {
    flex: 1;
    background: var(--gradient-accent);
    border-radius: 4px 4px 0 0;
    height: 60%;
    transition: var(--transition);
    position: relative;
    min-height: 10px;
}

.chart-bar:nth-child(1) { height: 45%; }
.chart-bar:nth-child(2) { height: 65%; }
.chart-bar:nth-child(3) { height: 35%; }
.chart-bar:nth-child(4) { height: 85%; }
.chart-bar:nth-child(5) { height: 55%; }
.chart-bar:nth-child(6) { height: 95%; }
.chart-bar:nth-child(7) { height: 70%; }
.chart-bar:nth-child(8) { height: 50%; }
.chart-bar:nth-child(9) { height: 80%; }
.chart-bar:nth-child(10) { height: 40%; }
.chart-bar:nth-child(11) { height: 75%; }
.chart-bar:nth-child(12) { height: 90%; }

.chart-bar:hover {
    opacity: 0.7;
    transform: scaleY(1.05);
    transform-origin: bottom;
}

.chart-labels {
    display: flex;
    gap: 6px;
    margin-top: 8px;
}

.chart-labels span {
    flex: 1;
    text-align: center;
    font-size: 10px;
    color: var(--text-muted);
}

/* ----- Features Section ----- */
.features {
    padding: 80px 0;
    background: #0d1a2e;
}

.section-header {
    text-align: center;
    margin-bottom: 56px;
}

.section-header h2 {
    font-size: 38px;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-header h2 .highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.section-header p {
    color: var(--text-muted);
    font-size: 18px;
    max-width: 600px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 30px;
}

.feature-card {
    background: rgba(255, 255, 255, 0.03);
    padding: 36px 28px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(0, 212, 255, 0.2);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.feature-card .icon {
    width: 64px;
    height: 64px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin: 0 auto 20px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 15px;
}

/* ----- CTA Section ----- */
.cta-section {
    padding: 80px 0;
    background: var(--gradient-main);
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.cta-section h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
}

.cta-section p {
    color: var(--text-muted);
    font-size: 18px;
    max-width: 500px;
    margin: 0 auto 32px;
}

/* ----- Footer ----- */
.footer {
    padding: 40px 0;
    background: #060e1a;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer p {
    color: var(--text-muted);
    font-size: 14px;
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

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

/* ----- Responsive ----- */
@media (max-width: 992px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content p {
        margin: 0 auto 32px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-content h1 {
        font-size: 40px;
    }

    .chart-container {
        max-width: 100%;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10, 22, 40, 0.98);
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }

    .nav-links.active {
        display: flex;
    }

    .menu-toggle {
        display: flex;
    }

    .hero-content h1 {
        font-size: 32px;
    }

    .hero-stats {
        gap: 24px;
        flex-wrap: wrap;
    }

    .hero-stats .stat-item h3 {
        font-size: 24px;
    }

    .section-header h2 {
        font-size: 28px;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .cta-section h2 {
        font-size: 28px;
    }

    .footer .container {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 28px;
    }

    .btn-primary, .btn-secondary {
        padding: 12px 28px;
        font-size: 14px;
        width: 100%;
        text-align: center;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
}