/* ========== Base ========== */
:root {
    --nabu-blue: #0c7eab;
    --nabu-yellow: #f8d348;
    --bg-page: #f5f7fb;
    --text-main: #222222;
    --text-muted: #666666;
    --border-soft: #e0e4f0;
    --max-width: 1080px;
}

* {
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--bg-page);
}

a {
    color: var(--nabu-blue);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 16px;
}

section {
    padding: 48px 0;
    border-bottom: 1px solid var(--border-soft);
}

[id]:not(html) {
    scroll-margin-top: 61px;  /* ここをヘッダーの実高さ + 余白くらいにする */
}
h1, h2, h3 {
    margin: 0 0 16px;
    line-height: 1.3;
}

p {
    margin: 0 0 12px;
}

.section-title {
    font-size: 1.4rem;
    margin-bottom: 24px;
}

.section-lead {
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.badge {
    display: inline-block;
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 999px;
    background-color: rgba(50, 102, 204, 0.08);
    color: var(--nabu-blue);
    margin-bottom: 8px;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 18px;
    border-radius: 999px;
    border: none;
    background: linear-gradient(135deg, var(--nabu-blue), #234a96);
    color: #ffffff;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
}

.btn-primary:hover {
    opacity: 0.94;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 14px;
    border-radius: 999px;
    border: 1px solid var(--border-soft);
    background-color: #ffffff;
    color: var(--text-main);
    font-size: 0.85rem;
    cursor: pointer;
}

.btn-secondary:hover {
    background-color: #f1f3fb;
}

.tagline {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.muted {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.pill {
    display: inline-flex;
    align-items: center;
    padding: 3px 8px;
    border-radius: 999px;
    border: 1px solid var(--border-soft);
    font-size: 0.75rem;
    color: var(--text-muted);
    background-color: #ffffff;
    margin-right: 4px;
    margin-bottom: 4px;
}

.grid {
    display: grid;
    gap: 16px;
}

.card {
    background-color: #ffffff;
    border-radius: 12px;
    padding: 16px;
    border: 1px solid var(--border-soft);
}

.card-title {
    font-size: 1rem;
    margin-bottom: 8px;
}

.card-label {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 4px;
}

.label-small {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.section-header {
    margin-bottom: 24px;
    position:sticky;
    top: 61px;
    z-index: 10;
}

.section-header p {
    max-width: 640px;
}

.section-header small {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.flow-list,
.faq-list,
.usecase-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.flow-list li,
.faq-list li,
.usecase-list li {
    margin-bottom: 12px;
}

.faq-question {
    font-weight: 600;
    margin-bottom: 4px;
}

.faq-answer {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Header */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(245, 247, 251, 0.96);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-soft);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
}

.hero-logo img {
    max-width: 240px;   /* ←ここでロゴの大きさを調整できる */
    width: 100%;
    height: auto;
    display: block;
    margin: 0 auto 12px;
}
.hero-logo-wrap {
    text-align: center;
}
@media (min-width: 768px) {
    .hero-logo-wrap {
        text-align: left;
    }
}

.hero-content {
    max-width: 620px;
}

.logo-link {
    display: flex;
    align-items: center;
}

.logo-image {
    height: 40px;        /* ヘッダーバランス的にこのくらいが最適 */
    width: auto;
    display: block;
}

.logo-mark {
    width: 32px;
    height: 32px;
    border-radius: 10px;
    background: radial-gradient(circle at 30% 20%, var(--nabu-yellow) 0, var(--nabu-blue) 60%, #182848 100%);
}

.logo-text-main {
    font-size: 0.95rem;
    font-weight: 700;
}

.logo-text-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.header-cta {
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-nav {
    display: none; /* モバイルでは非表示。後で展開する前提のプレースホルダ */
    gap: 12px;
    font-size: 0.8rem;
}
.header-nav a {
    color: var(--nabu-blue);
    font-weight: 500;
    padding: 6px 8px;
    border-radius: 6px;
    transition: 0.2s ease;
    position: relative;
    text-decoration: none;
}

.header-nav a:hover {
    color: #3266CC;            /* ブランドブルー */
    background-color: rgba(50, 102, 204, 0.06); /* 軽いホバー背景 */
}

.header-nav a:active {
    color: #234a96;            /* 押し込んだような濃い青 */
}

.header-nav a::after {
    content: '';
    position: absolute;
    left: 8px;
    right: 8px;
    bottom: 4px;
    height: 2px;
    background: #3266cc;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.25s ease;
}

.header-nav a:hover::after {
    transform: scaleX(1);
}

/* Hero */
.hero {
    padding: 40px 0 40px;
    background: linear-gradient(to bottom, #fafcff 0%, #ffffff 40%);
}

.hero-inner {
    display: grid;
    gap: 32px;
}

.hero-main-copy {
    line-height: 1.35;
    margin-bottom: 16px;
}

.hero-sub-copy {

    margin-bottom: 20px;
}

.hero-cta-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 14px;
}

.hero-cta-row .btn-primary,
.hero-cta-row .btn-secondary {
    padding: 10px 20px;
    font-size: 0.9rem;
}

.hero-meta {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.hero-device-frame {
    background: #ffffff;
    border-radius: 16px;
    border: 1px dashed var(--border-soft);
    padding: 16px;
    display:none;
}

.hero-device-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.hero-device-dots {
    display: flex;
    gap: 4px;
}

.hero-device-dot {
    width: 6px;
    height: 6px;
    border-radius: 999px;
    background-color: var(--border-soft);
}

.hero-device-tabs {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.hero-device-tab {
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 999px;
    border: 1px solid var(--border-soft);
    color: var(--text-muted);
}

.hero-device-tab.is-active {
    border-color: var(--nabu-blue);
    color: var(--nabu-blue);
    background: rgba(50, 102, 204, 0.06);
}

.hero-device-layouts {
    margin-top: 12px;
    display: grid;
    gap: 8px;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.hero-device-row {
    display: flex;
    gap: 8px;
    align-items: center;
}

.hero-device-box {
    flex: 1;
    border-radius: 8px;
    border: 1px solid var(--border-soft);
    padding: 8px;
    text-align: center;
    background-color: #fafbff;
}

.hero-device-label {
    font-size: 0.7rem;
    margin-top: 4px;
    color: var(--text-muted);
}

/* Form */
.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    margin-bottom: 4px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid var(--border-soft);
    font-size: 0.9rem;
    font-family: inherit;
    background-color: #ffffff;
}

.form-note {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.form-row-inline {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Footer */
footer {
    padding: 24px 0 32px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer-inner {
    border-top: 1px solid var(--border-soft);
    padding-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    font-size: 0.8rem;
}
/* トップへ戻るボタン（初期は非表示） */
#back-to-top {
    position: fixed;
    bottom: 24px;
    right: 200px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    background: var(--nabu-blue);
    color: #fff;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: 0.25s ease;
    z-index: 999;
}

/* 表示状態 */
#back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* スマホ向け：少し小さく */
@media (max-width: 480px) {
    #back-to-top {
        width: 40px;
        height: 40px;
        font-size: 18px;
        bottom: 16px;
        right: 16px;
    }
}

/* ========== Responsive ========== */
@media (min-width: 768px) {
    .header-inner {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 10px 8px 10px 16px;
    }
    .header-nav {
        display: flex;
    }

    .hero-inner {
        grid-template-columns: 1fr 1.5fr; /* 左ロゴ1:右テキスト1.5 */
        align-items: center;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .grid-2 {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .grid-3 {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .form-row-inline {
        flex-direction: row;
    }
}