/* ============================================================
   HyperToolbox v2 — Design System (inspired by Tesla, DESIGN.md)
   ------------------------------------------------------------
   디자인 철학: 급진적 감산. 사진과 콘텐츠가 중심이 되고 UI 는 최소한.
   단일 액센트 색(Electric Blue) + 회색 계열 텍스트 + 흰 캔버스.
   그림자, 그라디언트, 보더 장식 없음. 4px 라운드, 0.33s 전환.
   ============================================================ */

:root {
    /* Color */
    --v2-electric-blue: #3E6AE1;
    --v2-electric-blue-hover: #355dc4;
    --v2-white: #FFFFFF;
    --v2-light-ash: #F4F4F4;
    --v2-carbon-dark: #171A20;
    --v2-graphite: #393C41;
    --v2-pewter: #5C5E62;
    --v2-silver-fog: #8E8E8E;
    --v2-cloud-gray: #EEEEEE;
    --v2-pale-silver: #D0D1D2;
    --v2-frost: rgba(255, 255, 255, 0.75);
    --v2-overlay: rgba(128, 128, 128, 0.65);

    /* Motion */
    --v2-transition: 0.33s cubic-bezier(0.5, 0, 0, 0.75);

    /* Radius */
    --v2-radius: 4px;
    --v2-radius-lg: 12px;

    /* Layout */
    --v2-nav-height: 56px;
    --v2-sidebar-width: 260px;
    --v2-max-width: 1200px;

    /* Type */
    --v2-font: 'Noto Sans', 'Noto Sans KR', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, Arial, sans-serif;
    --v2-font-display: 'Noto Sans', 'Noto Sans KR', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, Arial, sans-serif;
}

* { box-sizing: border-box; }

html[lang="ko"] { --v2-font: 'Noto Sans KR', 'Noto Sans', sans-serif; --v2-font-display: 'Noto Sans KR', 'Noto Sans', sans-serif; }
html[lang="ja"] { --v2-font: 'Noto Sans JP', 'Noto Sans', sans-serif; --v2-font-display: 'Noto Sans JP', 'Noto Sans', sans-serif; }

body.v2 {
    margin: 0;
    background: var(--v2-white);
    color: var(--v2-graphite);
    font-family: var(--v2-font);
    font-size: 14px;
    font-weight: 400;
    line-height: 1.43;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.v2 a { color: inherit; text-decoration: none; }

/* ---------- Navigation (frosted, floats over hero) ---------- */
.v2-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--v2-nav-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    background: var(--v2-frost);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid var(--v2-cloud-gray);
}
.v2-nav__brand {
    font-family: var(--v2-font-display);
    font-size: 16px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    letter-spacing: 0.04em;
}
.v2-nav__right { display: flex; align-items: center; gap: 4px; }
.v2-nav__btn {
    background: transparent;
    border: none;
    color: var(--v2-carbon-dark);
    font-size: 14px;
    font-weight: 500;
    padding: 6px 16px;
    min-height: 32px;
    border-radius: var(--v2-radius);
    cursor: pointer;
    transition: color var(--v2-transition), background-color var(--v2-transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.v2-nav__btn:hover { background: var(--v2-cloud-gray); }
.v2-nav__menu-toggle { display: none; }

@media (max-width: 1023.98px) {
    .v2-nav__menu-toggle { display: inline-flex; }
}

/* ---------- Layout shell ---------- */
.v2-shell { flex: 1; display: flex; align-items: flex-start; }
.v2-sidebar {
    width: var(--v2-sidebar-width);
    flex-shrink: 0;
    position: sticky;
    top: var(--v2-nav-height);
    height: calc(100vh - var(--v2-nav-height));
    overflow-y: auto;
    padding: 32px 16px 48px;
    background: var(--v2-white);
    border-right: 1px solid var(--v2-cloud-gray);
}
.v2-main { flex: 1; min-width: 0; }

@media (max-width: 1023.98px) {
    .v2-sidebar {
        position: fixed;
        top: var(--v2-nav-height);
        left: 0;
        z-index: 900;
        transform: translateX(-100%);
        transition: transform var(--v2-transition);
        box-shadow: none;
    }
    .v2-sidebar.is-open { transform: translateX(0); }
    .v2-sidebar-backdrop {
        display: none;
        position: fixed;
        inset: var(--v2-nav-height) 0 0 0;
        background: var(--v2-overlay);
        z-index: 850;
    }
    .v2-sidebar-backdrop.is-open { display: block; }
}

/* ---------- Sidebar nav list ---------- */
.v2-side__group {
    font-size: 12px;
    font-weight: 500;
    color: var(--v2-silver-fog);
    text-transform: none;
    padding: 0 12px;
    margin: 24px 0 8px;
}
.v2-side__group:first-child { margin-top: 0; }
.v2-side__list { list-style: none; margin: 0; padding: 0; }
.v2-side__link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 9px 12px;
    border-radius: var(--v2-radius);
    color: var(--v2-graphite);
    font-size: 14px;
    font-weight: 400;
    transition: color var(--v2-transition), background-color var(--v2-transition);
}
.v2-side__link:hover { background: var(--v2-light-ash); color: var(--v2-carbon-dark); }
.v2-side__link i { width: 18px; text-align: center; color: var(--v2-pewter); font-size: 14px; }

/* ---------- Content container ---------- */
.v2-container {
    max-width: var(--v2-max-width);
    margin: 0 auto;
    padding: 64px 48px;
}
@media (max-width: 767.98px) { .v2-container { padding: 40px 20px; } }

/* ---------- Hero (tool title block) ---------- */
.v2-hero { padding: 56px 0 8px; }
.v2-hero__eyebrow {
    font-size: 13px;
    font-weight: 500;
    color: var(--v2-electric-blue);
    margin: 0 0 12px;
}
.v2-hero__title {
    font-family: var(--v2-font-display);
    font-size: 40px;
    font-weight: 500;
    line-height: 1.2;
    color: var(--v2-carbon-dark);
    margin: 0 0 16px;
}
@media (max-width: 767.98px) { .v2-hero__title { font-size: 28px; } }
.v2-hero__lede {
    font-size: 16px;
    line-height: 1.6;
    color: var(--v2-pewter);
    max-width: 720px;
    margin: 0;
}

/* ---------- Tool UI card ---------- */
.v2-panel {
    background: var(--v2-white);
    border: 1px solid var(--v2-cloud-gray);
    border-radius: var(--v2-radius);
    padding: 24px;
}
.v2-panel--ash { background: var(--v2-light-ash); border-color: transparent; }

/* 통화 카드 (환율 계산기): 통화 select와 금액 input을 하나의 외곽선으로 묶은 그룹 (세로 배치) */
.v2-ccy-card {
    background: var(--v2-white);
    border: 3px solid var(--v2-pale-silver);
    border-radius: var(--v2-radius);
    overflow: hidden;
    transition: border-color var(--v2-transition);
}
.v2-ccy-card:focus-within { border-color: var(--v2-electric-blue); }
/* 통화 드롭다운: 회색 배경, 전체 너비 */
.v2-ccy-card__select {
    display: block;
    width: 100%;
    height: auto !important;
    background: var(--v2-light-ash) !important;
    border: none !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    padding: 10px 14px !important;
    line-height: 1.4 !important;
    font-size: 14px !important;
    font-weight: 500 !important;
    color: var(--v2-carbon-dark) !important;
    cursor: pointer;
}
.v2-ccy-card__select:focus { outline: none; }
/* 금액 입력: 흰 배경, 우측 정렬, 큰 글씨, Electric Blue 액센트 */
.v2-ccy-card__input {
    display: block;
    width: 100%;
    height: auto !important;
    background: var(--v2-white) !important;
    border: none !important;
    border-top: 1px solid var(--v2-cloud-gray) !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    padding: 18px !important;
    line-height: 1.3 !important;
    text-align: right !important;
    font-size: 24px !important;
    font-weight: 500 !important;
    color: var(--v2-electric-blue) !important;
    font-variant-numeric: tabular-nums;
    transition: color var(--v2-transition);
}
.v2-ccy-card__input:focus { outline: none; }
.v2-ccy-card__input::placeholder { color: var(--v2-electric-blue); opacity: 0.4; }
@media (max-width: 767.98px) {
    .v2-ccy-card__input { font-size: 20px; padding: 14px !important; }
}

/* Form controls (Bootstrap 동작 호환, Tesla 미니멀 덮어쓰기) */
.v2 .form-control,
.v2 textarea.form-control,
.v2 select.form-control,
.v2 input.form-control {
    background: var(--v2-white);
    color: var(--v2-carbon-dark);
    border: 1px solid var(--v2-pale-silver);
    border-radius: var(--v2-radius);
    font-size: 14px;
    padding: 12px 14px;
    transition: border-color var(--v2-transition), box-shadow var(--v2-transition);
}
.v2 .form-control::placeholder { color: var(--v2-silver-fog); }
.v2 .form-control:focus {
    border-color: var(--v2-electric-blue);
    box-shadow: 0 0 0 2px rgba(62, 106, 225, 0.18);
    background: var(--v2-white);
}
.v2 textarea.form-control { resize: vertical; line-height: 1.6; }

/* Buttons */
.v2-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-height: 40px;
    padding: 8px 20px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--v2-radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: border-color var(--v2-transition), background-color var(--v2-transition), color var(--v2-transition);
    text-decoration: none;
}
.v2-btn--primary { background: var(--v2-electric-blue); color: var(--v2-white); }
.v2-btn--primary:hover { background: var(--v2-electric-blue-hover); }
.v2-btn--secondary { background: var(--v2-white); color: var(--v2-graphite); border-color: var(--v2-pale-silver); }
.v2-btn--secondary:hover { background: var(--v2-light-ash); }
.v2-btn--ghost { background: transparent; color: var(--v2-pewter); }
.v2-btn--ghost:hover { color: var(--v2-carbon-dark); }

/* Result list (lettercount 등 통계 표시) */
.v2-stat {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding: 16px 0;
    border-bottom: 1px solid var(--v2-cloud-gray);
}
.v2-stat:last-child { border-bottom: none; }
.v2-stat__label { font-size: 14px; color: var(--v2-pewter); }
.v2-stat__value {
    font-family: var(--v2-font-display);
    font-size: 24px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    font-variant-numeric: tabular-nums;
}

/* Check option row */
.v2-check { display: flex; align-items: center; gap: 10px; padding: 8px 0; cursor: pointer; }
.v2-check input { width: 18px; height: 18px; accent-color: var(--v2-electric-blue); margin: 0; }
.v2-check label { margin: 0; font-size: 14px; color: var(--v2-graphite); cursor: pointer; }

/* ---------- Long-form content (SEO descriptions / FAQ) ---------- */
.v2-prose { max-width: 760px; }
.v2-prose h2 {
    font-family: var(--v2-font-display);
    font-size: 24px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    margin: 10px 0 16px;
}
.v2-prose h3 {
    font-size: 18px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    margin: 32px 0 12px;
}
.v2-prose p { margin: 0 0 16px; line-height: 1.7; color: var(--v2-graphite); }
.v2-prose ul, .v2-prose ol { margin: 0 0 20px; padding-left: 20px; }
.v2-prose li { margin-bottom: 8px; line-height: 1.7; color: var(--v2-graphite); }

/* FAQ accordion (Bootstrap accordion 호환 + v2 스타일) */
.v2 .accordion-item {
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--v2-cloud-gray) !important;
    border-radius: 0 !important;
}
.v2 .accordion-button {
    font-size: 15px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    padding: 20px 0;
    background: transparent;
    box-shadow: none;
}
.v2 .accordion-button:not(.collapsed) { color: var(--v2-carbon-dark); background: transparent; }
.v2 .accordion-button:focus { box-shadow: none; border-color: transparent; }
.v2 .accordion-button::after { background-size: 16px; opacity: 0.6; }
.v2 .accordion-body { padding: 0 0 20px; color: var(--v2-graphite); line-height: 1.7; }

/* ---------- Home: tool grid ---------- */
.v2-section-title {
    font-family: var(--v2-font-display);
    font-size: 22px;
    font-weight: 500;
    color: var(--v2-carbon-dark);
    margin: 0 0 24px;
}
.v2-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
}
.v2-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 24px;
    background: var(--v2-white);
    border: 1px solid var(--v2-cloud-gray);
    border-radius: var(--v2-radius);
    transition: border-color var(--v2-transition), background-color var(--v2-transition);
    height: 100%;
}
.v2-card:hover { border-color: var(--v2-pale-silver); background: var(--v2-light-ash); }
.v2-card i { font-size: 22px; color: var(--v2-electric-blue); }
.v2-card__title { font-size: 15px; font-weight: 500; color: var(--v2-carbon-dark); }
.v2-card__desc { font-size: 13px; line-height: 1.5; color: var(--v2-pewter); }
.v2-card__arrow {
    margin-top: auto;
    font-size: 13px;
    color: var(--v2-electric-blue);
    font-weight: 500;
}

/* ---------- Share bar ---------- */
.v2-share { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: center; }
.v2-share__btn {
    width: 40px; height: 40px;
    display: inline-flex; align-items: center; justify-content: center;
    border-radius: var(--v2-radius);
    background: var(--v2-light-ash);
    color: var(--v2-graphite);
    border: 1px solid transparent;
    transition: background-color var(--v2-transition), color var(--v2-transition);
}
.v2-share__btn:hover { background: var(--v2-cloud-gray); color: var(--v2-carbon-dark); }

/* ---------- Related tools ---------- */
.v2-related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
}
.v2-related-link {
    padding: 16px;
    border: 1px solid var(--v2-cloud-gray);
    border-radius: var(--v2-radius);
    color: var(--v2-graphite);
    transition: border-color var(--v2-transition), background-color var(--v2-transition);
}
.v2-related-link:hover { border-color: var(--v2-pale-silver); background: var(--v2-light-ash); }
.v2-related-link i { color: var(--v2-pewter); margin-right: 8px; }

/* ---------- Footer ---------- */
.v2-footer {
    border-top: 1px solid var(--v2-cloud-gray);
    padding: 32px 48px;
    text-align: center;
    color: var(--v2-silver-fog);
    font-size: 13px;
}

/* Utility */
.v2-mt-0 { margin-top: 0; }
.v2-text-center { text-align: center; }
.v2-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
@media (max-width: 767.98px) { .v2-grid-2 { grid-template-columns: 1fr; } }