/* ─── CSS VARIABLES (Tarami design system) ─── */
    :root {
        --navy-deepest: #050c1a;
        --navy-deep: #0a1628;
        --navy-mid: #0f2044;
        --navy-light: #1a3360;
        --gold: #b8963e;
        --gold-light: #d4af60;
        --gold-pale: #e8d49a;
        --ivory: #f5f0e8;
        --ivory-dim: #c8c2b4;
        --white: #ffffff;
        --text-body: #a8b8cc;
        --text-sub: #6a7e94;
        --border: rgba(184, 150, 62, 0.2);
        --error: #c0524a;
    }

    *,
    *::before,
    *::after {
        box-sizing: border-box;
        margin: 0;
        padding: 0;
    }

    html {
        scroll-behavior: smooth;
    }

    body {
        background: var(--navy-deepest);
        color: var(--text-body);
        font-family: 'Noto Serif JP', serif;
        font-weight: 300;
        min-height: 100vh;
        overflow-x: hidden;
        line-height: 1.8;
    }

    /* noise overlay */
    body::before {
        content: '';
        position: fixed;
        inset: 0;
        background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.04'/%3E%3C/svg%3E");
        pointer-events: none;
        z-index: 9999;
        opacity: 0.5;
    }

    /* scrollbar */
    ::-webkit-scrollbar {
        width: 4px;
    }

    ::-webkit-scrollbar-track {
        background: var(--navy-deepest);
    }

    ::-webkit-scrollbar-thumb {
        background: var(--gold);
        border-radius: 2px;
    }

    /* ─── HEADER ─── */
    header {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        z-index: 100;
        padding: 0 48px;
        height: 72px;
        display: flex;
        align-items: center;
        justify-content: space-between;
        background: rgba(5, 12, 26, 0.85);
        backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--border);
    }

    .logo {
        font-family: 'Josefin Sans', sans-serif;
        font-weight: 100;
        font-size: 18px;
        letter-spacing: 0.3em;
        color: var(--ivory);
        text-transform: uppercase;
        text-decoration: none;
    }

    .logo span {
        color: var(--gold);
    }

    nav {
        display: flex;
        gap: 40px;
    }

    nav a {
        font-family: 'Josefin Sans', sans-serif;
        font-weight: 300;
        font-size: 11px;
        letter-spacing: 0.2em;
        text-transform: uppercase;
        color: var(--text-sub);
        text-decoration: none;
        transition: color 0.3s;
    }

    nav a:hover,
    nav a.active {
        color: var(--gold-light);
    }

    /* ─── PAGE WRAPPER ─── */
    .page-wrap {
        min-height: 100vh;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        padding: 120px 48px 80px;
        position: relative;
    }

    /* background radial glow */
    .page-wrap::before {
        content: '';
        position: absolute;
        inset: 0;
        background:
            radial-gradient(ellipse 70% 50% at 50% 40%, rgba(26, 51, 96, 0.35) 0%, transparent 70%),
            radial-gradient(ellipse 40% 60% at 80% 80%, rgba(184, 150, 62, 0.05) 0%, transparent 60%);
        pointer-events: none;
    }

    /* diagonal grid */
    .page-wrap::after {
        content: '';
        position: absolute;
        inset: 0;
        background-image: repeating-linear-gradient(135deg,
                rgba(184, 150, 62, 0.03) 0px,
                rgba(184, 150, 62, 0.03) 1px,
                transparent 1px,
                transparent 80px);
        pointer-events: none;
    }

    /* ─── SECTION HEADER ─── */
    .form-header {
        width: 100%;
        max-width: 760px;
        margin-bottom: 64px;
        animation: fadeUp 0.9s ease both;
    }

    .section-number {
        font-family: 'Josefin Sans', sans-serif;
        font-size: 11px;
        letter-spacing: 0.3em;
        color: var(--gold);
        margin-bottom: 4px;
    }

    .section-title {
        font-family: 'Cormorant Garamond', serif;
        font-size: clamp(36px, 5vw, 56px);
        font-weight: 300;
        color: var(--ivory);
        line-height: 1;
    }

    .section-title-jp {
        font-family: 'Noto Serif JP', serif;
        font-size: 13px;
        font-weight: 300;
        color: var(--text-sub);
        letter-spacing: 0.1em;
        margin-top: 8px;
    }

    .header-divider {
        height: 1px;
        background: linear-gradient(to right, var(--border), transparent);
        margin-top: 24px;
    }

    /* ─── FORM CARD ─── */
    .form-card {
        width: 100%;
        max-width: 760px;
        background: var(--navy-mid);
        border: 1px solid var(--border);
        padding: 64px 72px;
        position: relative;
        animation: fadeUp 1s ease 0.15s both;
    }

    /* corner accent */
    .form-card::before {
        content: '';
        position: absolute;
        top: -1px;
        right: -1px;
        width: 48px;
        height: 48px;
        border-top: 2px solid var(--gold);
        border-right: 2px solid var(--gold);
    }

    .form-card::after {
        content: '';
        position: absolute;
        bottom: -1px;
        left: -1px;
        width: 48px;
        height: 48px;
        border-bottom: 2px solid var(--gold);
        border-left: 2px solid var(--gold);
    }

    /* ─── GLOBAL ERROR ─── */
    .alert-error {
        background: rgba(192, 82, 74, 0.12);
        border: 1px solid rgba(192, 82, 74, 0.35);
        padding: 16px 24px;
        margin-bottom: 40px;
        font-family: 'Josefin Sans', sans-serif;
        font-size: 12px;
        letter-spacing: 0.08em;
        color: #e07b74;
    }

    /* ─── FORM FIELDS ─── */
    .field {
        margin-bottom: 36px;
    }

    label {
        display: block;
        font-family: 'Josefin Sans', sans-serif;
        font-size: 10px;
        letter-spacing: 0.35em;
        text-transform: uppercase;
        color: var(--gold);
        margin-bottom: 10px;
    }

    label .required {
        color: var(--error);
        margin-left: 4px;
        font-size: 12px;
    }

    input[type="text"],
    input[type="email"],
    textarea {
        width: 100%;
        background: rgba(10, 22, 40, 0.6);
        border: 1px solid rgba(184, 150, 62, 0.25);
        border-bottom: 1px solid var(--gold);
        color: var(--ivory);
        font-family: 'Noto Serif JP', serif;
        font-size: 14px;
        font-weight: 300;
        padding: 14px 20px;
        outline: none;
        transition: border-color 0.3s, background 0.3s;
        appearance: none;
        -webkit-appearance: none;
    }

    input[type="text"]:focus,
    input[type="email"]:focus,
    textarea:focus {
        border-color: var(--gold-light);
        background: rgba(15, 32, 68, 0.8);
    }

    input[type="text"].is-error,
    input[type="email"].is-error,
    textarea.is-error {
        border-bottom-color: var(--error);
    }

    textarea {
        resize: vertical;
        min-height: 160px;
        line-height: 1.9;
    }

    /* placeholder */
    ::placeholder {
        color: var(--text-sub);
        font-size: 13px;
        opacity: 0.6;
    }

    /* field error message */
    .field-error {
        margin-top: 8px;
        font-family: 'Josefin Sans', sans-serif;
        font-size: 11px;
        letter-spacing: 0.08em;
        color: #e07b74;
    }

    /* ─── SUBMIT ─── */
    .submit-wrap {
        margin-top: 48px;
        display: flex;
        align-items: center;
        gap: 32px;
    }

    .btn-submit {
        display: inline-flex;
        align-items: center;
        gap: 16px;
        font-family: 'Josefin Sans', sans-serif;
        font-size: 11px;
        letter-spacing: 0.35em;
        text-transform: uppercase;
        color: var(--navy-deepest);
        background: var(--gold);
        border: none;
        padding: 18px 56px;
        cursor: pointer;
        transition: background 0.3s, letter-spacing 0.3s;
        position: relative;
        overflow: hidden;
    }

    .btn-submit::before {
        content: '';
        position: absolute;
        inset: 0;
        background: var(--gold-light);
        transform: translateX(-100%);
        transition: transform 0.4s ease;
        z-index: 0;
    }

    .btn-submit:hover::before {
        transform: translateX(0);
    }

    .btn-submit:hover {
        letter-spacing: 0.45em;
    }

    .btn-submit span {
        position: relative;
        z-index: 1;
    }

    .btn-back {
        font-family: 'Josefin Sans', sans-serif;
        font-size: 10px;
        letter-spacing: 0.25em;
        text-transform: uppercase;
        color: var(--text-sub);
        text-decoration: none;
        transition: color 0.3s;
    }

    .btn-back:hover {
        color: var(--gold-light);
    }

    .btn-back::before {
        content: '← ';
    }

    /* ─── FOOTER ─── */
    footer {
        border-top: 1px solid var(--border);
        padding: 40px 48px;
        display: flex;
        justify-content: space-between;
        align-items: center;
        font-family: 'Josefin Sans', sans-serif;
        font-size: 11px;
        letter-spacing: 0.15em;
        color: var(--text-sub);
        text-transform: uppercase;
    }

    footer nav {
        gap: 32px;
    }

    footer nav a {
        color: var(--text-sub);
        font-size: 10px;
    }

    /* ─── ANIMATIONS ─── */
    @keyframes fadeUp {
        from {
            opacity: 0;
            transform: translateY(24px);
        }

        to {
            opacity: 1;
            transform: translateY(0);
        }
    }

    /* ─── HAMBURGER BUTTON ─── */
    .btn {
        position: fixed;
        z-index: 200;
        top: 5px;
        right: 5px;
        width: 50px;
        margin: 5px;
        padding: 7.5px 0;
        display: none;
        cursor: pointer;
    }

    .btn span {
        display: none;
        background: white;
        text-align: center;
        height: 3px;
        width: 50%;
        margin: 5px 12px;
        transition: 0.8s;
    }

    /* ─── HAMBURGER SLIDE MENU ─── */
    .btn-menu-bar {
        display: none;
    }

    /* ─── MOBILE ─── */
    @media (max-width: 900px) {
        header {
            padding: 0 24px;
        }

        /* ハンバーガーボタン表示 */
        .btn {
            display: block;
            z-index: 200;
        }

        .btn span {
            display: block;
        }

        /* × 印アニメーション */
        .btn.active span:nth-child(1) {
            transform: rotate(45deg) translate(5px, 5px);
        }

        .btn.active span:nth-child(2) {
            opacity: 0;
        }

        .btn.active span:nth-child(3) {
            transform: rotate(-45deg) translate(6px, -6px);
        }

        /* PC ナビ非表示 */
        nav {
            display: none;
        }

        /* スライドメニュー */
        .btn-menu-bar {
            display: block;
            position: fixed;
            top: 0;
            right: 0;
            z-index: 150;
            width: 50%;
            height: 1500px;
            opacity: 0;
            visibility: hidden;
            transform: translate(300px, 0);
            transition: 1s;
        }

        .btn-menu-bar li {
            list-style: none;
            padding: 30px;
        }

        .btn-menu-bar li a {
            text-decoration: none;
            font-family: 'Josefin Sans', sans-serif;
            font-weight: 100;
            font-size: 2rem;
            letter-spacing: 0.3em;
            color: var(--navy-deepest);
        }

        .btn-menu-bar.show {
            opacity: 0.8;
            visibility: visible;
            transform: translate(0, 0);
            background-color: var(--gold);
        }

        /* コンテンツ */
        .page-wrap {
            padding: 100px 24px 60px;
        }

        .form-card {
            padding: 40px 28px;
        }

        .submit-wrap {
            flex-direction: column;
            align-items: flex-start;
            gap: 20px;
        }

        .btn-submit {
            width: 100%;
            justify-content: center;
        }

        footer {
            padding: 32px 24px;
            flex-direction: column;
            gap: 20px;
        }
    }