:root {
    --primary-blue: #4faaf7;
    --dark-blue: #1c2b4d;
    --bg-gray: #f9fbff;
    --text-main: #333;
    --text-light: #666;
    --primary-yellow: #ffcb40;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Noto Sans SC', 'Outfit', sans-serif;
}

body {
    background-color: #fff;
    color: var(--text-main);
    overflow-x: hidden;
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 80px;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 28px;
    font-weight: 700;
    color: var(--dark-blue);
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-blue);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-icon svg {
    width: 24px;
    height: 24px;
    fill: white;
}

nav {
    display: flex;
    gap: 40px;
}

nav a {
    font-size: 16px;
    font-weight: 500;
    color: var(--text-light);
    transition: var(--transition);
}

nav a:hover,
nav a.active {
    color: var(--primary-blue);
}

.header-btns {
    display: flex;
    gap: 15px;
}

.btn {
    padding: 10px 25px;
    border-radius: 25px;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    display: inline-block;
}

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

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

.btn-outline {
    border: 1px solid var(--primary-blue);
    color: var(--primary-blue);
}

.btn:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}

/* Hero Section */
.hero {
    padding: 180px 80px 100px;
    background: linear-gradient(135deg, #1c52a8 0%, #4faaf7 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    min-height: 80vh;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100px;
    background: linear-gradient(to top, #fff, transparent);
}

.hero-content {
    max-width: 600px;
    z-index: 1;
}

.hero h1 {
    font-size: 64px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.hero p {
    font-size: 24px;
    opacity: 0.9;
    margin-bottom: 40px;
}

.hero-img {
    flex: 1;
    display: flex;
    justify-content: flex-end;
    position: relative;
}

.hero-img img {
    max-width: 110%;
    transform: scale(1.1);
    filter: drop-shadow(0 20px 40px rgba(0, 0, 0, 0.2));
}

/* Section Global */
section {
    padding: 100px 80px;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 20px;
}

.section-header p {
    color: var(--text-light);
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto;
}

/* Intro Section */
.intro {
    background: var(--bg-gray);
    text-align: center;
}

.intro-box {
    background: white;
    border-radius: 30px;
    padding: 60px;
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.05);
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
    background-image: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('../img/login-bg.png');
    background-size: cover;
    background-position: center;
    color: white;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.intro-box h3 {
    font-size: 32px;
    margin-bottom: 30px;
}

.play-btn {
    width: 80px;
    height: 80px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 40px auto;
    cursor: pointer;
    transition: var(--transition);
}

.play-btn svg {
    width: 32px;
    height: 32px;
    fill: var(--primary-blue);
    margin-left: 5px;
}

.play-btn:hover {
    transform: scale(1.1);
    background: var(--primary-blue);
}

.play-btn:hover svg {
    fill: white;
}

/* Recognize Section */
.recognize {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 100px;
    max-width: 1400px;
    margin: 0 auto;
}

.recognize-img {
    position: relative;
    width: 500px;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.rec-bubble {
    position: absolute;
    background: white;
    padding: 10px 25px;
    border-radius: 20px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    color: var(--primary-blue);
    font-weight: 600;
    font-size: 14px;
    border: 1px solid #eee;
    z-index: 2;
}

.rec-bubble-1 {
    top: 0;
    left: 50%;
    transform: translateX(-50%);
}

.rec-bubble-2 {
    top: 40%;
    left: 0;
}

.rec-bubble-3 {
    top: 40%;
    right: 0;
}

.rec-bubble-4 {
    bottom: 0;
    left: 10%;
}

.rec-bubble-5 {
    bottom: 0;
    right: 10%;
}

.recognize-center {
    width: 320px;
    height: 320px;
    background: #eef7ff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.recognize-center img {
    width: 80%;
    height: auto;
}

.recognize-content h3 {
    font-size: 36px;
    margin-bottom: 25px;
    color: var(--dark-blue);
}

.recognize-content p {
    font-size: 18px;
    color: var(--text-light);
    max-width: 500px;
}

/* Grid Section */
.system {
    background: #fff;
}

.system-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.system-card {
    background: #f8fbff;
    border-radius: 20px;
    padding: 40px;
    display: flex;
    gap: 30px;
    transition: var(--transition);
    border: 1px solid #f0f5ff;
    cursor: pointer;
}

.system-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(79, 170, 247, 0.1);
    border-color: var(--primary-blue);
    background: #fff;
}

.card-info {
    flex: 1;
}

.card-info h4 {
    font-size: 24px;
    color: var(--primary-blue);
    margin-bottom: 15px;
}

.card-info p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 30px;
    height: 4.5em;
    overflow: hidden;
}

.card-link {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--primary-blue);
    font-weight: 600;
    font-size: 14px;
}

.card-img {
    width: 140px;
    height: 140px;
    background: white;
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.02);
    font-size: 64px;
}

.card-img i.fa-robot {
    color: var(--primary-blue);
}

.card-img i.fa-trophy {
    color: var(--primary-yellow);
}

.card-img i.fa-book {
    color: var(--primary-blue);
}

.card-img i.fa-images {
    color: var(--primary-yellow);
}

/* Footer */
footer {
    background: #fff;
    padding: 100px 80px 40px;
    border-top: 1px solid #f0f0f0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 80px;
    max-width: 1400px;
    margin: 0 auto 80px;
}

.footer-brand .logo {
    margin-bottom: 30px;
}

.social-icons {
    display: flex;
    gap: 15px;
}

.social-btn {
    width: 44px;
    height: 44px;
    background: #f5f5f5;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-btn:hover {
    background: var(--primary-blue);
    transform: scale(1.1);
}

.social-btn svg {
    width: 20px;
    height: 20px;
    fill: #999;
    transition: var(--transition);
}

.social-btn:hover svg {
    fill: white;
}

.footer-info {
    display: flex;
    gap: 80px;
}

.info-col h5 {
    font-size: 16px;
    margin-bottom: 25px;
    color: var(--text-light);
    font-weight: 400;
}

.info-col p {
    font-size: 18px;
    font-weight: 700;
    color: var(--dark-blue);
    margin-bottom: 10px;
}

.footer-bottom {
    max-width: 1400px;
    margin: 0 auto;
    padding-top: 40px;
    border-top: 1px solid #f0f0f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: #ccc;
}

@media (max-width: 1200px) {
    header {
        padding: 0 40px;
    }

    section,
    footer {
        padding: 80px 40px;
    }

    .hero {
        flex-direction: column;
        text-align: center;
        padding: 150px 40px 60px;
    }

    .hero-img {
        width: 100%;
        justify-content: center;
        margin-top: 50px;
    }

    .hero h1 {
        font-size: 48px;
    }

    .recognize {
        flex-direction: column;
        gap: 60px;
    }

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

    .footer-content {
        flex-direction: column;
        gap: 60px;
    }

    .footer-info {
        flex-direction: column;
        gap: 40px;
    }
}