* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Yu Gothic", "Meiryo", sans-serif;
}

body {
    background: #07111f;
    color: #ffffff;
    line-height: 1.6;
}

section {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    padding: 120px 30px;
}

/* ==========================================
   セクション背景色の切り替え（メリハリ）
   ========================================== */
.hero {
    background: linear-gradient(#02060f, #0d2848);
}

.problem,
.specifications,
.future {
    background: #081a2d;
}

.about,
.system-wiring,
.simulation {
    background: #0b2038;
}

/* ==========================================
   各セクション共通見出し (h2)
   ========================================== */
h2 {
    font-size: 36px;
    color: #5ec8ff;
    text-shadow: 0 0 15px rgba(94, 200, 255, 0.4);
    margin-bottom: 10px;
    text-align: center;
}

h2::after {
    content: "";
    display: block;
    width: 80px;
    height: 4px;
    background: #5ec8ff;
    margin: 15px auto 0;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(94, 200, 255, 0.8);
}

.section-lead {
    color: #a0c4e8;
    font-size: 16px;
    margin-top: 15px;
    margin-bottom: 40px;
    text-align: center;
}

/* HERO */
.hero h1 {
    font-size: 70px;
    color: #5ec8ff;
    text-shadow: 0 0 20px rgba(94, 200, 255, 0.5);
    text-align: center;
}

.hero .sub-team {
    margin-top: 15px;
    font-size: 18px;
    color: #d1e8ff;
    letter-spacing: 2px;
    text-align: center;
}

.scroll {
    margin-top: 80px;
    animation: float 2s infinite;
    color: #5ec8ff;
    font-weight: bold;
}

/* ==========================================
   カード配置エリア
   ========================================== */
.cards {
    display: flex;
    gap: 30px;
    margin-top: 40px;
    justify-content: center;
    flex-wrap: wrap;
    max-width: 1200px;
    width: 100%;
}

.card {
    position: relative; /* ::before の基準とする */
    background: rgba(255, 255, 255, 0.07);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    padding: 30px;
    border-radius: 15px;
    width: 420px;
    min-height: 480px;
    text-align: center;
    transition: 0.3s;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden; /* 上部アクセント線のアール落ちを防ぐ */
}

/* カード上部のアクセントライン */
.card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: #5ec8ff;
    box-shadow: 0 0 8px #5ec8ff;
}

.card:hover {
    transform: translateY(-10px);
    background: rgba(25, 130, 209, 0.25);
    border-color: #5ec8ff;
    box-shadow: 0 10px 30px rgba(94, 200, 255, 0.2);
}

.card h3 {
    color: #5ec8ff;
    font-size: 22px;
    margin-bottom: 10px;
}

.card p {
    font-size: 18px;
    margin-top: 15px;
    color: #e1f0ff;
}

.card img {
    width: 100%;
    max-width: 320px;
    height: auto;
    margin: 0 auto;
    border-radius: 10px;
}

/* 一般画像・動画 */
img {
    width: 700px;
    max-width: 100%;
    margin: 40px 0;
    border-radius: 20px;
}

video {
    width: 900px;
    max-width: 100%;
    border-radius: 15px;
    border: 1px solid rgba(94, 200, 255, 0.3);
    box-shadow: 0 0 25px rgba(94, 200, 255, 0.15);
}

/* ==========================================
   課題セクション
   ========================================== */
.problem h3 {
    font-size: 36px;
    color: #5ec8ff;
    margin-top: 60px;
    font-weight: bold;
    text-shadow: 0 0 20px rgba(94, 200, 255, 0.5);
    letter-spacing: 2px;
    text-align: center;
}

.solution-concept {
    margin-top: 40px;
    text-align: center;
    max-width: 800px;
    width: 100%;
}

.solution-title {
    font-size: 26px;
    font-weight: bold;
    color: #ffffff;
    margin-bottom: 30px;
    line-height: 1.6;
}

.solution-title span {
    color: #5ec8ff;
    font-size: 32px;
    text-shadow: 0 0 15px rgba(94, 200, 255, 0.6);
}

.concept-image-wrapper {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(94, 200, 255, 0.3);
    border-radius: 20px;
    padding: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    transition: 0.3s;
}

.concept-image-wrapper:hover {
    border-color: #5ec8ff;
    box-shadow: 0 10px 40px rgba(94, 200, 255, 0.2);
}

.concept-img {
    width: 100% !important;
    max-width: 750px;
    height: auto;
    margin: 0 !important;
    border-radius: 12px;
    display: block;
}

.solution-lead {
    margin-top: 25px;
    font-size: 20px;
    color: #d1e8ff;
    line-height: 1.8;
}

/* ==========================================
   作品概要（フロー）
   ========================================== */
.overview-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 50px;
    margin-top: 40px;
    width: 100%;
    max-width: 1100px;
}

.overview-media img {
    width: 450px;
    max-width: 100%;
    border-radius: 15px;
    border: 1px solid rgba(94, 200, 255, 0.3);
    box-shadow: 0 0 25px rgba(94, 200, 255, 0.15);
    margin: 0;
}

.flow-steps {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.step-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: rgba(255, 255, 255, 0.07);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    padding: 15px 25px;
    border-radius: 12px;
    width: 380px;
    transition: 0.3s;
}

.step-item:hover {
    border-color: #5ec8ff;
    transform: translateX(5px);
    background: rgba(255, 255, 255, 0.12);
}

.step-number {
    font-size: 20px;
    font-weight: bold;
    color: #07111f;
    background: #5ec8ff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 0 10px rgba(94, 200, 255, 0.8);
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 18px;
    color: #ffffff;
}

.step-content p {
    font-size: 13px;
    color: #a0c4e8;
    margin-top: 2px;
}

.step-arrow {
    color: #5ec8ff;
    font-size: 20px;
    font-weight: bold;
    text-shadow: 0 0 8px #5ec8ff;
}

/* ==========================================
   アーム仕様
   ========================================== */
.spec-image-wrapper {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(94, 200, 255, 0.3);
    border-radius: 20px;
    padding: 20px;
    max-width: 900px;
    width: 100%;
    margin-bottom: 30px;
}

.spec-image-wrapper img {
    margin: 0;
    width: 100%;
}

/* 特長リスト (feature-list) */
.feature-list {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    list-style: none;
    max-width: 900px;
    width: 100%;
}

.feature-list li {
    background: rgba(94, 200, 255, 0.1);
    border: 1px solid rgba(94, 200, 255, 0.4);
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 16px;
    color: #d1e8ff;
    display: flex;
    align-items: center;
    gap: 8px;
}

.feature-list li::before {
    content: "✔";
    color: #5ec8ff;
    font-weight: bold;
}

/* ==========================================
   システム配線 & センサモジュール
   ========================================== */
.wiring-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 25px;
    width: 100%;
    max-width: 1100px;
    margin-top: 20px;
}

.wiring-card, .sensor-card, .camera-card {
    background: rgba(255, 255, 255, 0.07);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 15px;
    padding: 25px;
    transition: 0.3s;
}

.wiring-card:hover, .sensor-card:hover, .camera-card:hover {
    border-color: #5ec8ff;
    box-shadow: 0 5px 20px rgba(94, 200, 255, 0.15);
}

.wiring-card h3, .sensor-card h3, .camera-card h3 {
    font-size: 20px;
    color: #5ec8ff;
    margin-bottom: 15px;
    border-bottom: 1px solid rgba(94, 200, 255, 0.3);
    padding-bottom: 8px;
}

.wiring-card img {
    margin: 10px 0 0 0;
    width: 100%;
    border-radius: 10px;
}

.sensor-card ul, .camera-card ul {
    list-style-type: disc;
    padding-left: 20px;
    margin-top: 10px;
}

.sensor-card li, .camera-card li {
    font-size: 14px;
    color: #d1e8ff;
    margin-bottom: 8px;
}

code {
    background: rgba(0, 0, 0, 0.4);
    color: #5ec8ff;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: monospace;
}

/* ==========================================
   シミュレーション
   ========================================== */
.sim-container {
    display: flex;
    gap: 40px;
    align-items: center;
    justify-content: center;
    max-width: 1100px;
    width: 100%;
    margin-top: 20px;
}

.sim-media img {
    width: 450px;
    margin: 0;
    border-radius: 15px;
    border: 1px solid rgba(94, 200, 255, 0.3);
}

.sim-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.sim-box {
    background: rgba(255, 255, 255, 0.07);
    border: 1px solid rgba(255, 255, 255, 0.15);
    padding: 20px;
    border-radius: 12px;
}

.sim-box h4 {
    color: #5ec8ff;
    font-size: 18px;
    margin-bottom: 10px;
}

.sim-box ul {
    list-style: none;
}

.sim-box li {
    font-size: 15px;
    color: #d1e8ff;
    margin-bottom: 5px;
}

.sim-box.insight {
    background: rgba(94, 200, 255, 0.08);
    border-color: rgba(94, 200, 255, 0.4);
}

.sim-box.insight p {
    font-size: 14px;
    color: #e1f0ff;
    line-height: 1.7;
}

.demo video {
    width: 100%;
    max-width: 650px; /* ここでお好みの大きさに調整（例: 600px〜700px） */
}

video {
    width: 100%;       /* 700px指定から100%に変更してレスポンシブ対応を確実に */
    max-width: 650px;  /* 元の900pxから小さく調整 */
    border-radius: 15px;
    border: 1px solid rgba(94, 200, 255, 0.3);
    box-shadow: 0 0 25px rgba(94, 200, 255, 0.15);
}
/* Keyframes */
@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(12px);
    }
}

/* ==========================================
   レスポンシブ対応（スマホ・タブレット）
   ========================================== */
@media (max-width: 768px) {
    section {
        padding: 80px 20px;
    }

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

    h2 {
        font-size: 28px;
    }

    .card {
        width: 100%;
        max-width: 340px;
        min-height: auto;
        padding: 20px;
    }

    .problem h3 {
        font-size: 24px;
        margin-top: 40px;
    }

    img {
        margin: 20px 0;
    }

    .solution-title {
        font-size: 20px;
    }

    .solution-title span {
        font-size: 24px;
    }

    .solution-lead {
        font-size: 16px;
    }

    .overview-container, .sim-container {
        flex-direction: column;
        gap: 30px;
    }

    .step-item {
        width: 100%;
        max-width: 340px;
        padding: 12px 18px;
    }

    .feature-list {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }

    .feature-list li {
        width: 100%;
        max-width: 340px;
        justify-content: center;
    }

    .sim-media img {
        width: 100%;
    }
}