:root {
    --primary-color: #E31B21;
    --secondary-color: #0f172a;
    --text-color: #334155;
    --bg-color: #f8fafc;
    --white: #ffffff;
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Encode Sans', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    color: var(--white);
    padding: 100px 0 140px;
    position: relative;
    text-align: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 160px;
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.badge {
    background: var(--primary-color);
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    display: inline-block;
    margin-bottom: 24px;
    box-shadow: 0 4px 12px rgba(227, 27, 33, 0.3);
}

h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
}

h1 span {
    color: var(--primary-color);
}

.hero-desc {
    font-size: 20px;
    max-width: 700px;
    margin: 0 auto;
    opacity: 0.9;
    font-weight: 400;
}

/* Behavior Grid */
.content-section {
    margin-top: -60px;
    padding-bottom: 80px;
    position: relative;
    z-index: 2;
}

.behavior-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.behavior-card {
    opacity: 0;
    transform: translateY(30px);
    transition: var(--transition), opacity 0.6s ease, transform 0.6s ease;
}

.behavior-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.card-inner {
    background: var(--white);
    border-radius: 20px;
    padding: 30px;
    height: 100%;
    display: flex;
    flex-direction: column;
    box-shadow: var(--card-shadow);
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.card-icon {
    position: absolute;
    top: -20px;
    right: -20px;
    width: 100px;
    height: 100px;
    background: rgba(227, 27, 33, 0.05);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    padding: 20px;
    opacity: 0.3;
}

.card-icon svg {
    width: 40px;
    height: 40px;
}

.card-header {
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.number {
    font-size: 32px;
    font-weight: 800;
    color: var(--primary-color);
    opacity: 0.2;
}

h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--secondary-color);
    line-height: 1.3;
}

.illustration {
    width: 100%;
    height: 140px;
    background: #f1f5f9;
    border-radius: 12px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.illustration svg {
    height: 100%;
    max-width: 100%;
}

.main-point {
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 15px;
    font-size: 17px;
}

.detail-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.5s ease;
    border-top: 1px solid #f1f5f9;
}

.detail-content p {
    padding-top: 15px;
    font-size: 15px;
    color: #64748b;
}

.expand-btn {
    margin-top: auto;
    background: none;
    border: none;
    color: var(--primary-color);
    font-weight: 700;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    padding-top: 20px;
}

.expand-btn svg {
    width: 16px;
    height: 16px;
    transition: transform 0.3s ease;
}

.behavior-card.active .detail-content {
    max-height: 300px;
}

.behavior-card.active .expand-btn svg {
    transform: rotate(180deg);
}

.card-inner:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.15);
}

/* Note Box */
.note-box {
    margin-top: 50px;
    background: #fff;
    border-left: 5px solid var(--primary-color);
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.note-icon {
    color: var(--primary-color);
    flex-shrink: 0;
}

.note-icon svg {
    width: 32px;
    height: 32px;
}

.note-content strong {
    display: block;
    margin-bottom: 5px;
    font-size: 18px;
    color: var(--secondary-color);
}

/* Footer */
.main-footer {
    padding: 60px 0;
    opacity: 0.6;
    font-size: 14px;
}

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

/* Responsive */
@media (max-width: 900px) {
    .behavior-grid {
        grid-template-columns: 1fr;
    }

    h1 {
        font-size: 32px;
    }

    .hero-section {
        padding: 80px 0 120px;
    }
}

@media (max-width: 600px) {
    .card-inner {
        padding: 20px;
    }

    h3 {
        font-size: 18px;
    }
}