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

body {
    background: #0b0f1a;
    color: #e8f2ff;
    font-family: "Helvetica Neue", Arial, sans-serif;
    line-height: 1.8;
}

/* =========================
   SECTION
========================= */
.section {
    padding: 80px 20px;
    max-width: 900px;
    margin: 0 auto;
}

.section-title {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 40px;
    letter-spacing: 0.1em;
    color: #a8d8ff;
    text-shadow: 0 0 10px #4fa3ff;
}

/* =========================
   NAVIGATION
========================= */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 15, 25, 0.8);
    backdrop-filter: blur(6px);
    z-index: 1000;
}

.nav-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
}

.nav-title {
    font-size: 1.4rem;
    font-weight: bold;
    color: #4fa3ff;
}

/* ハンバーガー */
.nav-btn {
    width: 30px;
    height: 24px;
    position: relative;
    cursor: pointer;
}

.nav-btn span,
.nav-btn span::before,
.nav-btn span::after {
    position: absolute;
    content: "";
    width: 100%;
    height: 3px;
    background: #a8d8ff;
    transition: 0.3s;
}

.nav-btn span {
    top: 50%;
    transform: translateY(-50%);
}

.nav-btn span::before {
    top: -10px;
}

.nav-btn span::after {
    top: 10px;
}

/* メニュー */
#navToggle {
    display: none;
}

.nav-menu {
    position: fixed;
    top: 60px;
    right: -100%;
    width: 60%;
    height: 100vh;
    background: rgba(10, 15, 25, 0.95);
    padding: 40px 20px;
    transition: 0.4s;
}

#navToggle:checked ~ .nav-menu {
    right: 0;
}

.nav-menu a {
    display: block;
    padding: 15px 0;
    font-size: 1.2rem;
    color: #e8f2ff;
    text-decoration: none;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
/* =========================
   RESPONSIVE
========================= */

/* スマホ（〜768px） */
@media (max-width: 768px) {

    .section {
        padding: 60px 20px;
    }

    .section-title {
        font-size: 1.8rem;
        margin-bottom: 30px;
    }

    /* HERO */
    .hero-title {
        font-size: 1.6rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .hero-logo img {
        width: 60vw;
    }

    /* TIMELINE */
    .timeline-item {
        padding-left: 40px;
        font-size: 0.95rem;
    }

    .timeline-item::before {
        width: 10px;
        height: 10px;
    }

    .timeline-line {
        width: 3px;
    }

    /* ナビゲーション */
    .nav-menu {
        width: 70%;
    }
}

/* PC（769px〜） */
@media (min-width: 769px) {

    .nav-menu {
        position: static;
        display: flex;
        height: auto;
        background: none;
        width: auto;
        padding: 0;
        gap: 30px;
    }

    .nav-menu a {
        border: none;
        padding: 0;
    }

    .nav-btn {
        display: none;
    }
}