:root {
    --ink: #0f172a;
    --muted: #475569;
    --line: #e2e8f0;
    --brand: #4f46e5;
    --brand-2: #4338ca;
    --bg: #f1f5f9;
    --card: #fff;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    color: var(--ink);
    display: flex;
    flex-direction: column;
}

.bg {
    position: fixed;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    z-index: -1;
    /* background-image: url('../img/bg3.png'); */
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    background-repeat: no-repeat;
}

header {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    gap: .55rem;
    padding: .9rem 1.5rem;
    font-weight: 700;
    letter-spacing: -.02em;
    background: rgba(255, 255, 255, .82);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--line);
}

header .dot {
    width: 11px;
    height: 11px;
    border-radius: 3px;
    background: var(--brand);
}

nav {
    margin-left: 1.4rem;
    display: flex;
    gap: 1.1rem;
    font-size: .88rem;
    font-weight: 600;
}

nav a {
    color: var(--muted);
    text-decoration: none;
}

nav a:hover {
    color: var(--ink);
}

header .login {
    margin-left: auto;
    font-size: .9rem;
    font-weight: 600;
    color: var(--brand);
    text-decoration: none;
}

header .login:hover {
    text-decoration: underline;
}

main {
    flex: 1
}

section {
    padding: 4.2rem 1.5rem
}

.wrap {
    max-width: 960px;
    margin: 0 auto
}

.hero {
    text-align: center;
    padding-top: 5rem
}

.hero h1 {
    font-size: 2.8rem;
    line-height: 1.15;
    letter-spacing: -.03em;
    margin: 0 0 1rem
}

.hero h1 em {
    font-style: normal;
    color: var(--brand)
}

.hero p {
    font-size: 1.08rem;
    line-height: 1.75;
    color: var(--muted);
    margin: 0 auto 2.2rem;
    max-width: 36rem
}

.cta {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    padding: .85rem 1.6rem;
    border-radius: 11px;
    background: var(--brand);
    color: #fff;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: .15s
}

.cta:hover {
    background: var(--brand-2)
}

.cta.ghost {
    background: transparent;
    color: var(--brand);
    border: 1px solid var(--line)
}

.cta.ghost:hover {
    background: #fff
}

.ctas {
    display: flex;
    gap: .8rem;
    justify-content: center;
    flex-wrap: wrap
}

h2 {
    font-size: 1.7rem;
    letter-spacing: -.02em;
    text-align: center;
    margin: 0 0 .6rem
}

.lead {
    text-align: center;
    color: var(--muted);
    margin: 0 auto 2.4rem;
    max-width: 38rem;
    line-height: 1.7
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1rem
}

.card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 1.3rem 1.35rem
}

.card b {
    display: block;
    font-size: 1rem;
    margin-bottom: .4rem
}

.card p {
    margin: 0;
    color: var(--muted);
    font-size: .9rem;
    line-height: 1.65
}

.card .tag {
    display: inline-block;
    font-size: .72rem;
    font-weight: 700;
    color: var(--brand);
    background: #eef2ff;
    border-radius: 6px;
    padding: .15rem .5rem;
    margin-bottom: .6rem;
    letter-spacing: .02em
}

/* 課題提起 */
.problem ul {
    max-width: 660px;
    margin: 0 auto;
    padding: 0;
    list-style: none;
    display: grid;
    gap: .7rem
}

.problem li {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: .9rem 1.1rem .9rem 2.6rem;
    color: var(--muted);
    font-size: .95rem;
    line-height: 1.6;
    position: relative
}

.problem li::before {
    content: "✕";
    position: absolute;
    left: 1.05rem;
    top: .9rem;
    color: #ef4444;
    font-weight: 700
}

.problem .after {
    text-align: center;
    margin: 2rem auto 0;
    max-width: 34rem;
    color: var(--ink);
    font-weight: 600;
    font-size: 1.05rem;
    line-height: 1.7
}

.problem .after em {
    font-style: normal;
    color: var(--brand)
}

/* 中核3本柱 */
.pillars {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.1rem
}

.pillar {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 1.7rem 1.5rem
}

.pillar .n {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.1rem;
    height: 2.1rem;
    border-radius: 9px;
    background: var(--brand);
    color: #fff;
    font-weight: 700;
    margin-bottom: .9rem
}

.pillar b {
    display: block;
    font-size: 1.15rem;
    letter-spacing: -.01em;
    margin-bottom: .5rem
}

.pillar p {
    margin: 0;
    color: var(--muted);
    font-size: .92rem;
    line-height: 1.7
}

.steps {
    counter-reset: step;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem
}

.step {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 1.2rem 1.25rem;
    position: relative
}

.step::before {
    counter-increment: step;
    content: counter(step);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.7rem;
    height: 1.7rem;
    border-radius: 8px;
    background: var(--brand);
    color: #fff;
    font-weight: 700;
    font-size: .9rem;
    margin-bottom: .7rem
}

.step b {
    display: block;
    margin-bottom: .35rem;
    font-size: .95rem
}

.step p {
    margin: 0;
    color: var(--muted);
    font-size: .86rem;
    line-height: 1.6
}

/* AI セクション */
.ai {
    background: #eef2ff;
}

.ai .split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: center
}

.ai .split h2 {
    text-align: left;
    margin-bottom: 1rem
}

.ai .split p {
    color: var(--muted);
    line-height: 1.8;
    font-size: .98rem;
    margin: 0 0 1rem
}

.ai .chips {
    display: flex;
    flex-wrap: wrap;
    gap: .5rem
}

.ai .chips span {
    background: #fff;
    border: 1px solid #c7d2fe;
    color: var(--brand-2);
    border-radius: 999px;
    padding: .35rem .8rem;
    font-size: .82rem;
    font-weight: 600
}

.ai .art {
    background: #0f172a;
    border-radius: 16px;
    padding: 1.4rem;
    color: #cbd5e1;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: .82rem;
    line-height: 1.7
}

.ai .art .k {
    color: #818cf8
}

.ai .art .c {
    color: #64748b
}

.strip {
    background: #0f172a;
    color: #cbd5e1
}

.strip h2 {
    color: #fff
}

.strip .lead {
    color: #94a3b8
}

.strip .items {
    display: flex;
    gap: 2.2rem;
    justify-content: center;
    flex-wrap: wrap;
    font-size: .92rem
}

.strip .items b {
    display: block;
    color: #fff;
    font-size: 1.25rem;
    margin-bottom: .2rem;
    letter-spacing: -.02em
}

/* 料金 */
.plans {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(258px, 1fr));
    gap: 1.1rem;
    align-items: stretch
}

.plan {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 1.6rem 1.45rem;
    display: flex;
    flex-direction: column
}

.plan.featured {
    border-color: var(--brand);
    box-shadow: 0 14px 34px -14px rgba(79, 70, 229, .45)
}

.plan .name {
    font-weight: 700;
    font-size: 1.2rem
}

.plan .badge {
    display: inline-block;
    font-size: .68rem;
    font-weight: 700;
    color: #fff;
    background: var(--brand);
    border-radius: 6px;
    padding: .12rem .5rem;
    margin-left: .5rem;
    vertical-align: middle;
    letter-spacing: .02em
}

.plan .price {
    margin: .5rem 0 .2rem;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -.02em
}

.plan .price small {
    font-size: .82rem;
    font-weight: 600;
    color: var(--muted)
}

.plan .who {
    color: var(--muted);
    font-size: .85rem;
    margin: 0 0 1.1rem;
    line-height: 1.5;
    min-height: 2.5em
}

.plan ul {
    list-style: none;
    padding: 0;
    margin: 0 0 1.4rem;
    display: grid;
    gap: .55rem
}

.plan li {
    color: var(--muted);
    font-size: .88rem;
    line-height: 1.55;
    padding-left: 1.45rem;
    position: relative
}

.plan li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--brand);
    font-weight: 700
}

.plan .cta {
    margin-top: auto;
    justify-content: center
}

.pricenote {
    text-align: center;
    color: #94a3b8;
    font-size: .82rem;
    margin-top: 1.5rem
}

/* 信頼・安心 */
.trust .card {
    padding-left: 1.35rem
}

.trust .card b {
    color: var(--brand-2)
}

.closing {
    text-align: center
}

.closing p {
    color: var(--muted);
    margin: 0 auto 1.8rem;
    max-width: 32rem;
    line-height: 1.7
}

footer {
    text-align: center;
    padding: 1.6rem;
    color: #94a3b8;
    font-size: .78rem;
    border-top: 1px solid var(--line)
}

@media (max-width:720px) {
    .ai .split {
        grid-template-columns: 1fr
    }
}

@media (max-width:640px) {
    nav {
        display: none
    }

    .hero h1 {
        font-size: 2.1rem
    }

    section {
        padding: 3rem 1.2rem
    }
}