/* --- Base Styles --- */
:root {
    --primary-color: #003366; /* 信頼感のある濃紺 */
    --secondary-color: #4682B4; /* スチールブルー */
    --accent-color: #FFC107; /* ややオレンジがかったゴールド */
    --bg-light: #f8f9fa; /* 明るい背景色 */
    --bg-white: #ffffff;
    --text-color: #343a40;
    --heading-font: 'Noto Serif JP', serif;
    --body-font: 'Noto Sans JP', sans-serif;
}

body {
    font-family: var(--body-font);
    line-height: 1.8;
    margin: 0;
    color: var(--text-color);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 15px;
}

section {
    padding: 80px 0;
    border-bottom: 1px solid #e9ecef;
}

.bg-light { background-color: var(--bg-light); }
.bg-primary { background-color: var(--primary-color); color: white; }

img { max-width: 100%; height: auto; }
.text-center { text-align: center; }
.mt-4 { margin-top: 40px !important; }

/* --- Typography --- */
.section-title { font-family: var(--heading-font); font-size: 2.4rem; color: var(--primary-color); text-align: center; margin-top: 0; margin-bottom: 20px; }
.section-subtitle { font-size: 1.1rem; text-align: center; color: #6c757d; max-width: 800px; margin: 0 auto 50px auto; }
.section-title-light { font-family: var(--heading-font); font-size: 2.2rem; color: white; text-align: center; margin-bottom: 20px; }
.light-text { color: rgba(255, 255, 255, 0.9); line-height: 1.8; margin-bottom: 40px; text-align: center; }

/* --- Header --- */
header { background-color: var(--primary-color); color: white; text-align: center; padding: 15px 0; font-size: 0.9rem; }
header h1 { font-size: 1.1rem; margin: 0; font-weight: 400; }

/* --- Hero Section --- */
#hero .hero-image { border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); margin-bottom: 40px; }
#hero .main-title { font-size: 2.8rem; }
#hero .subtitle { font-size: 1.1rem; color: var(--text-color); line-height: 2; max-width: 800px; margin: 0 auto; }

/* --- Problem Section --- */
.problem-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(400px, 1fr)); gap: 30px; }
.problem-category { background: var(--bg-white); padding: 30px; border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.05); }
.problem-category h4 { font-family: var(--heading-font); color: var(--primary-color); font-size: 1.4rem; margin-top: 0; border-bottom: 2px solid var(--secondary-color); padding-bottom: 10px; }
.problem-category ul { padding-left: 20px; margin: 0; }
.problem-category li { margin-bottom: 10px; }

/* --- Agitation Section --- */
#agitation img { border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
#agitation p { max-width: 800px; margin-left: auto; margin-right: auto; }

/* --- Solution Section --- */
#solution img { border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
.solution-box { background-color: var(--bg-white); border-top: 5px solid var(--secondary-color); border-radius: 8px; padding: 40px; margin-top: 50px; text-align: left; box-shadow: 0 4px 20px rgba(0,0,0,0.1); }
.solution-box h4 { font-family: var(--heading-font); font-size: 1.6rem; color: var(--primary-color); margin-top: 0; text-align: center; }
.solution-box ol { list-style: none; padding-left: 0; counter-reset: solution-counter; }
.solution-box li { font-size: 1.1rem; margin-bottom: 20px; padding-left: 45px; position: relative; }
.solution-box li::before { counter-increment: solution-counter; content: counter(solution-counter); position: absolute; left: 0; top: 0; width: 30px; height: 30px; line-height: 30px; text-align: center; background: var(--primary-color); color: white; font-weight: 700; border-radius: 50%; }
.solution-box li strong { color: var(--secondary-color); }

/* --- How to Learn Section --- */
.learning-flow { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; text-align: left; }
.learning-flow img { border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
.learning-flow h4 { font-family: var(--heading-font); color: var(--primary-color); font-size: 1.4rem; margin-top: 30px; }
.learning-flow ul { list-style: none; padding-left: 0; }
.learning-flow li { background: var(--bg-light); margin-bottom: 8px; padding: 10px 15px; border-radius: 4px; }

/* --- Differentiation Section --- */
#differentiation img { border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }

/* --- Lecturers Section --- */
.lecturer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: flex-start; }
.lecturer-item { text-align: center; }
.lecturer-item img { width: 180px; height: 180px; object-fit: cover; border-radius: 50%; margin-bottom: 20px; border: 5px solid var(--bg-white); box-shadow: 0 4px 20px rgba(0,0,0,0.15); }
.lecturer-item h4 { font-family: var(--heading-font); font-size: 1.4rem; color: var(--primary-color); margin-bottom: 10px; }
.lecturer-item p { font-size: 0.95rem; text-align: left; }

/* --- Individual Lecturer Image Adjustments --- */
.lecturer-item img.lecturer-img-ueda { object-position: center 20%; }
.lecturer-item img.lecturer-img-hamada { object-position: 65% center; }

/* --- CTA Section --- */
.cta-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 30px; margin-top: 50px; align-items: stretch; }
.cta-item { background: var(--bg-light); color: var(--text-color); padding: 30px; border-radius: 8px; display: flex; flex-direction: column; }
.cta-target { display: inline-block; background: var(--secondary-color); color: white; padding: 5px 15px; font-size: 0.9rem; border-radius: 20px; margin-bottom: 15px; }
.cta-item h4 { font-size: 1.1rem; line-height: 1.6; font-weight: 700; flex-grow: 1; }
.cta-box { background: white; padding: 30px; border-radius: 8px; margin-top: 20px; box-shadow: 0 4px 10px rgba(0,0,0,0.05); flex-grow: 1; }
.cta-box h3 { font-family: var(--heading-font); color: var(--primary-color); font-size: 1.5rem; margin-top: 0; }
.cta-box p { font-size: 0.95rem; }
.cta-button { display: block; background: linear-gradient(45deg, var(--accent-color), #ffc107); color: var(--primary-color); padding: 15px 20px; font-size: 1.2rem; font-weight: 700; text-decoration: none; border-radius: 50px; transition: transform 0.3s, box-shadow 0.3s; box-shadow: 0 5px 20px rgba(255, 193, 7, 0.4); margin-top: 20px; }
.cta-button:hover { transform: translateY(-5px); box-shadow: 0 8px 30px rgba(255, 193, 7, 0.5); }

/* --- Footer --- */
footer { text-align: center; padding: 20px 0; background-color: #343a40; color: #adb5bd; font-size: 0.9rem; }

/* --- Responsive --- */
@media (max-width: 992px) {
    .problem-grid { grid-template-columns: 1fr; }
    .cta-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .section-title { font-size: 2rem; }
    #hero .main-title { font-size: 2.2rem; }
    .lecturer-grid { grid-template-columns: 1fr; gap: 40px; }
    .learning-flow { grid-template-columns: 1fr; }
}