/* ==========================================================
 * 吉他和弦 · 音阶工具 /tools/guitar_chord
 *
 * 设计系统（三端优化版）
 *   · 配色：语义化 token 分层（页面 / 卡片 / 内嵌 / 边框 / 文字三层 / 主色及派生 / 音级色）
 *     暗色为默认舞台配色，亮色主题整组覆盖，两种主题均满足 WCAG AA 对比度
 *   · 排版：8px 基准；桌面宽屏两列选择区 + 三列参数、平板单列宽卡、手机纵向单手操作
 *   · 指板：品位数与品宽随视口自适应（手机 12 品 / 平板 16 品 / 桌面 20 品），宽屏自动放大铺满
 *   · 交互：触区 ≥36–40px、焦点可见、hover/active 反馈、尊重 prefers-reduced-motion
 * ========================================================== */

.gc-page {
    /* ---- 主色 ---- */
    --gc-accent: #f59e0b;
    --gc-accent-strong: #d97706;
    --gc-accent-soft: rgba(245, 158, 11, .14);
    --gc-accent-ring: rgba(245, 158, 11, .32);

    /* ---- 中性（暗色主题）---- */
    --gc-bg: #0b0b0f;
    --gc-surface: #141417;
    --gc-inset: #1c1c21;
    --gc-inset-2: #26262c;
    --gc-line: #2a2a31;
    --gc-line-strong: #3f3f46;
    --gc-text: #f5f5f6;
    --gc-muted: #a8a8b3;
    --gc-dim: #7c7c88;

    /* ---- 形状 ---- */
    --gc-radius: 16px;
    --gc-radius-sm: 10px;
    --gc-gap: 14px;

    position: relative;
    max-width: 1240px;
    margin: 0 auto;
    padding: 16px 14px 40px;
    display: flex;
    flex-direction: column;
    gap: var(--gc-gap);
    color: var(--gc-text);
    font-size: 15px;
    line-height: 1.55;
}

/* 亮色：站点浅色主题或用户在设置里强制亮色 */
[data-theme="light"] .gc-page,
.gc-page[data-gc-theme="light"] {
    --gc-accent: #c2410c;
    --gc-accent-strong: #9a3412;
    --gc-accent-soft: rgba(194, 65, 12, .10);
    --gc-accent-ring: rgba(194, 65, 12, .26);
    --gc-bg: #f7f7f8;
    --gc-surface: #ffffff;
    --gc-inset: #f2f2f4;
    --gc-inset-2: #e9e9ec;
    --gc-line: #e3e3e7;
    --gc-line-strong: #d4d4d8;
    --gc-text: #17171a;
    --gc-muted: #52525b;
    --gc-dim: #71717a;
}
/* 强制暗色 */
.gc-page[data-gc-theme="dark"] {
    --gc-accent: #f59e0b;
    --gc-accent-strong: #d97706;
    --gc-accent-soft: rgba(245, 158, 11, .14);
    --gc-accent-ring: rgba(245, 158, 11, .32);
    --gc-bg: #0b0b0f;
    --gc-surface: #141417;
    --gc-inset: #1c1c21;
    --gc-inset-2: #26262c;
    --gc-line: #2a2a31;
    --gc-line-strong: #3f3f46;
    --gc-text: #f5f5f6;
    --gc-muted: #a8a8b3;
    --gc-dim: #7c7c88;
}

.gc-page *,
.gc-page *::before,
.gc-page *::after { box-sizing: border-box; }
.gc-page h1 { margin: 0; font-size: clamp(17px, 2.4vw, 22px); font-weight: 800; letter-spacing: -.01em; }
.gc-page button { font-family: inherit; color: inherit; border: 0; background: none; cursor: pointer; }
.gc-page select, .gc-page input { font-family: inherit; }
.gc-page [hidden] { display: none !important; }
.gc-page :focus-visible { outline: 2px solid var(--gc-accent); outline-offset: 2px; border-radius: var(--gc-radius-sm); }
.gc-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.gc-grow { flex: 1; min-width: 0; }
.gc-hint { color: var(--gc-dim); font-size: 11.5px; line-height: 1.5; }

/* ---------- 顶栏 ---------- */
.gc-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.gc-top__l { display: flex; align-items: center; gap: 12px; flex: 1; min-width: 0; }
.gc-top__icon {
    width: 46px; height: 46px;
    display: grid; place-items: center;
    border-radius: 14px;
    font-size: 24px;
    background: var(--gc-accent-soft);
    border: 1px solid var(--gc-line);
    flex-shrink: 0;
}
.gc-top__sub { margin: 2px 0 0; font-size: 12px; color: var(--gc-muted); }
.gc-top__r { display: flex; align-items: center; gap: 8px; }

.gc-icon-btn {
    width: 40px; height: 40px;
    display: grid; place-items: center;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    color: var(--gc-muted);
    transition: background .15s, color .15s, border-color .15s;
}
.gc-icon-btn:hover { color: var(--gc-accent); border-color: var(--gc-accent); }
.gc-icon-btn svg { width: 18px; height: 18px; }

/* ---------- 页签 ---------- */
.gc-tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--gc-line); overflow-x: auto; padding-bottom: 2px; }
.gc-tab {
    flex: 0 0 auto;
    min-height: 42px;
    padding: 9px 14px;
    border-radius: var(--gc-radius-sm) var(--gc-radius-sm) 0 0;
    font-size: 13px;
    font-weight: 700;
    color: var(--gc-muted);
    border-bottom: 2px solid transparent;
    transition: .15s;
    white-space: nowrap;
}
.gc-tab:hover { color: var(--gc-text); background: var(--gc-inset); }
.gc-tab.is-active { color: var(--gc-accent); border-bottom-color: var(--gc-accent); background: var(--gc-accent-soft); }

/* ---------- 卡片 ---------- */
.gc-card {
    background: var(--gc-surface);
    border: 1px solid var(--gc-line);
    border-radius: var(--gc-radius);
    padding: 16px;
}
.gc-card__head { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; flex-wrap: wrap; }
.gc-card__label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    font-size: 10px;
    font-weight: 800;
    letter-spacing: .1em;
    text-transform: uppercase;
    color: var(--gc-muted);
}
.gc-card__label::before { content: ""; width: 3px; height: 12px; border-radius: 2px; background: var(--gc-accent); }
.gc-chord-big {
    font-size: 18px;
    font-weight: 900;
    letter-spacing: -.01em;
    color: var(--gc-accent);
    padding: 0 4px;
}
.gc-sublabel { font-size: 11.5px; font-weight: 700; color: var(--gc-muted); margin-bottom: 6px; }
.gc-meta { font-size: 11.5px; color: var(--gc-dim); }
.gc-desc { margin: 10px 0 0; font-size: 12.5px; color: var(--gc-muted); line-height: 1.6; }
.gc-empty { margin: 10px 0 0; font-size: 12.5px; color: var(--gc-muted); }
.gc-field-val { font-size: 11.5px; color: var(--gc-dim); text-align: right; }
.gc-field-val span { color: var(--gc-accent); font-weight: 800; font-family: ui-monospace, Menlo, Consolas, monospace; }

.gc-grid2 { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: var(--gc-gap); }
.gc-grid3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--gc-gap); }

/* ---------- 按钮 ---------- */
.gc-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    min-height: 38px;
    padding: 8px 14px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    color: var(--gc-text);
    font-size: 12.5px;
    font-weight: 700;
    transition: background .15s, border-color .15s, color .15s, transform .1s;
}
.gc-btn:hover { border-color: var(--gc-accent); color: var(--gc-accent); }
.gc-btn:active { transform: scale(.97); }
.gc-btn svg { width: 14px; height: 14px; }
.gc-btn--sm { min-height: 34px; padding: 6px 12px; font-size: 11.5px; }
.gc-btn--primary { background: var(--gc-accent); border-color: var(--gc-accent); color: #1a1206; }
.gc-btn--primary:hover { background: var(--gc-accent-strong); border-color: var(--gc-accent-strong); color: #1a1206; }

.gc-seg { display: flex; gap: 6px; }
.gc-seg__btn {
    flex: 1;
    min-height: 38px;
    padding: 8px 10px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    color: var(--gc-muted);
    font-size: 12.5px;
    font-weight: 700;
    transition: .15s;
}
.gc-seg__btn:hover { color: var(--gc-text); border-color: var(--gc-line-strong); }
.gc-seg__btn.is-active { background: var(--gc-accent-soft); border-color: var(--gc-accent); color: var(--gc-accent); }

/* ---------- 芯片 ---------- */
.gc-chips { display: flex; flex-wrap: wrap; gap: 7px; }
.gc-chip {
    min-height: 36px;
    padding: 7px 12px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid transparent;
    color: var(--gc-muted);
    font-size: 13px;
    font-weight: 700;
    transition: background .13s, color .13s, border-color .13s, box-shadow .13s;
    white-space: nowrap;
}
.gc-chip:hover { color: var(--gc-text); background: var(--gc-inset-2); }
.gc-chip.is-active {
    background: var(--gc-accent-soft);
    border-color: var(--gc-accent);
    color: var(--gc-accent);
    box-shadow: 0 0 0 3px var(--gc-accent-ring);
}

/* ---------- 输入 ---------- */
.gc-page select, .gc-page input[type=number] {
    width: 100%;
    min-height: 38px;
    padding: 8px 10px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    color: var(--gc-text);
    font-size: 13px;
    font-weight: 700;
    outline: none;
    transition: border-color .15s, box-shadow .15s;
}
.gc-page select:focus, .gc-page input:focus { border-color: var(--gc-accent); box-shadow: 0 0 0 3px var(--gc-accent-ring); }
.gc-page select { appearance: none; -webkit-appearance: none; padding-right: 26px;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a8a8b3' stroke-width='2.5'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat; background-position: right 8px center; background-size: 14px; }

.gc-page input[type=range] { -webkit-appearance: none; appearance: none; width: 100%; height: 24px; background: transparent; cursor: pointer; }
.gc-page input[type=range]::-webkit-slider-runnable-track { height: 6px; border-radius: 999px; background: var(--gc-inset-2); border: 1px solid var(--gc-line); }
.gc-page input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none; width: 18px; height: 18px; margin-top: -7px;
    border-radius: 50%; border: 2px solid var(--gc-surface); background: var(--gc-accent);
    box-shadow: 0 0 0 3px var(--gc-accent-ring);
}
.gc-page input[type=range]::-moz-range-track { height: 6px; border-radius: 999px; background: var(--gc-inset-2); border: 1px solid var(--gc-line); }
.gc-page input[type=range]::-moz-range-thumb { width: 16px; height: 16px; border-radius: 50%; border: 2px solid var(--gc-surface); background: var(--gc-accent); }

.gc-switch { display: inline-flex; align-items: center; gap: 8px; cursor: pointer; min-height: 34px; }
.gc-switch input { position: absolute; opacity: 0; width: 0; height: 0; }
.gc-switch__track {
    position: relative; width: 40px; height: 22px; border-radius: 999px;
    background: var(--gc-inset-2); border: 1px solid var(--gc-line-strong); transition: .2s; flex-shrink: 0;
}
.gc-switch__track::after {
    content: ""; position: absolute; top: 2px; left: 2px; width: 16px; height: 16px;
    border-radius: 50%; background: var(--gc-dim); transition: .2s;
}
.gc-switch input:checked + .gc-switch__track { background: var(--gc-accent); border-color: var(--gc-accent); }
.gc-switch input:checked + .gc-switch__track::after { transform: translateX(18px); background: #fff; }
.gc-switch__text { font-size: 12px; font-weight: 700; color: var(--gc-muted); }
.gc-switch input:checked ~ .gc-switch__text { color: var(--gc-text); }

/* ---------- 指板 ---------- */
.gc-board-scroll {
    overflow-x: auto;
    overflow-y: hidden;
    border-radius: var(--gc-radius-sm);
    background: linear-gradient(180deg, var(--gc-inset), var(--gc-surface));
    border: 1px solid var(--gc-line);
    padding: 8px 6px 4px;
    -webkit-overflow-scrolling: touch;
}
.gc-board-scroll::-webkit-scrollbar { height: 8px; }
.gc-board-scroll::-webkit-scrollbar-track { background: transparent; }
.gc-board-scroll::-webkit-scrollbar-thumb { background: var(--gc-dim); border-radius: 4px; }
.gc-board-scroll::-webkit-scrollbar-thumb:hover { background: var(--gc-muted); }
/* 宽屏铺满放大（SVG 有 viewBox，按比例缩放）；窄屏保留最小宽度横向滚动 */
.gc-board { display: block; width: 100%; min-width: 560px; height: auto; }
.gc-board--pick .gc-cell { cursor: pointer; }
.gc-board text { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

/* ---------- 变体（竖式和弦图） ---------- */
.gc-variants { display: grid; grid-template-columns: repeat(auto-fill, minmax(118px, 1fr)); gap: 10px; }
.gc-variant {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 8px 6px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    transition: transform .14s, border-color .14s, background .14s;
}
.gc-variant:hover { border-color: var(--gc-accent); transform: translateY(-2px); }
.gc-variant.is-active { border-color: var(--gc-accent); background: var(--gc-accent-soft); box-shadow: 0 0 0 3px var(--gc-accent-ring); }
.gc-variant svg { display: block; width: 100%; height: auto; max-width: 110px; }
.gc-variant__tag { font-size: 10.5px; color: var(--gc-muted); font-family: ui-monospace, Menlo, Consolas, monospace; }
.gc-variant.is-active .gc-variant__tag { color: var(--gc-accent); }

/* ---------- 图例 ---------- */
.gc-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 14px; margin-top: 12px; font-size: 11.5px; color: var(--gc-dim); }
.gc-legend span { display: inline-flex; align-items: center; gap: 5px; padding: 2px 8px; border-radius: 999px; background: var(--gc-inset); }
.gc-legend i { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }

/* ---------- 反推结果 ---------- */
.gc-result {
    margin-top: 14px;
    padding: 18px;
    border-radius: var(--gc-radius);
    background: linear-gradient(140deg, var(--gc-accent-soft), transparent);
    border: 1px solid var(--gc-accent-ring);
    text-align: center;
}
.gc-result__label { font-size: 10px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; color: var(--gc-muted); }
.gc-result__main { margin-top: 4px; font-size: clamp(30px, 7vw, 46px); font-weight: 800; letter-spacing: -.02em; color: var(--gc-accent); }
.gc-result__sub { margin-top: 4px; font-size: 12.5px; color: var(--gc-muted); }

/* ---------- 进行时间轴 ---------- */
.gc-timeline { display: flex; flex-wrap: wrap; gap: 8px; }
.gc-tl-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border-radius: var(--gc-radius-sm);
    background: var(--gc-inset);
    border: 1px solid var(--gc-line);
    transition: border-color .15s, background .15s;
}
.gc-tl-item.is-playing { border-color: var(--gc-accent); background: var(--gc-accent-soft); }
.gc-tl-item__name { font-size: 15px; font-weight: 800; color: var(--gc-text); }
.gc-tl-item__dur { font-size: 11px; color: var(--gc-dim); font-family: ui-monospace, Menlo, Consolas, monospace; }
.gc-tl-item button { width: 28px; height: 28px; display: grid; place-items: center; border-radius: 8px; color: var(--gc-dim); transition: .15s; }
.gc-tl-item button:hover { background: var(--gc-inset-2); color: var(--gc-accent); }
.gc-tl-item button:last-child:hover { color: #f87171; }
.gc-tl-item button svg { width: 13px; height: 13px; }
.gc-addrow { margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--gc-line); }
.gc-addrow select { width: auto; flex: 1 1 130px; }

/* ---------- 设置 ---------- */
.gc-settings { display: flex; flex-direction: column; gap: 14px; }
.gc-offsets { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 8px; margin: 10px 0; }
.gc-offset { display: flex; flex-direction: column; align-items: center; gap: 4px; font-size: 11px; color: var(--gc-muted); }
.gc-offset input { text-align: center; }

.gc-foot { margin-top: 6px; text-align: center; font-size: 11.5px; color: var(--gc-dim); }

.gc-toast {
    position: fixed;
    left: 50%;
    bottom: calc(24px + env(safe-area-inset-bottom, 0px));
    z-index: 90;
    transform: translate(-50%, 20px);
    max-width: min(92vw, 460px);
    padding: 10px 18px;
    border-radius: 999px;
    background: var(--gc-surface);
    border: 1px solid var(--gc-line-strong);
    box-shadow: 0 16px 40px -16px rgba(0, 0, 0, .6);
    font-size: 13px;
    font-weight: 700;
    color: var(--gc-text);
    text-align: center;
    opacity: 0;
    pointer-events: none;
    transition: .22s ease-out;
}
.gc-toast.is-on { opacity: 1; transform: translate(-50%, 0); }

/* ==========================================================
 * 响应式
 * ========================================================== */

/* 大桌面：更宽容器、更疏朗的间距 */
@media (min-width: 1200px) {
    .gc-page { padding: 20px 20px 48px; gap: 16px; }
    .gc-card { padding: 18px; }
    .gc-variants { grid-template-columns: repeat(auto-fill, minmax(124px, 1fr)); gap: 12px; }
    .gc-chord-big { font-size: 22px; }
}

/* 平板横屏 / 小桌面 */
@media (min-width: 981px) and (max-width: 1199px) {
    .gc-page { max-width: 100%; padding: 16px 16px 40px; }
}

/* 平板竖屏：选择区收为单列，参数区两列 */
@media (max-width: 980px) {
    .gc-page { max-width: 100%; }
    .gc-grid2 { grid-template-columns: minmax(0, 1fr); }
    .gc-grid3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .gc-offsets { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .gc-variants { grid-template-columns: repeat(auto-fill, minmax(108px, 1fr)); }
}

/* 手机：纵向单手操作 */
@media (max-width: 700px) {
    .gc-page { padding: 10px 10px calc(28px + env(safe-area-inset-bottom, 0px)); gap: 12px; }
    .gc-card { padding: 13px; border-radius: 14px; }
    .gc-grid3 { grid-template-columns: minmax(0, 1fr); }
    .gc-top__icon { width: 40px; height: 40px; font-size: 20px; }
    .gc-tab { min-height: 40px; padding: 8px 12px; font-size: 12.5px; }
    .gc-chip { min-height: 36px; padding: 6px 11px; font-size: 12.5px; }
    .gc-variants { grid-template-columns: repeat(auto-fill, minmax(94px, 1fr)); gap: 8px; }
    .gc-addrow select { flex: 1 1 100%; }
    .gc-btn { min-height: 40px; }
    .gc-btn--sm { min-height: 36px; }
    .gc-board { min-width: 520px; }
    .gc-board-scroll { padding: 6px 4px 2px; }
    .gc-legend { gap: 4px 10px; font-size: 11px; }
    .gc-result { padding: 14px; }
}

/* 超小屏 */
@media (max-width: 400px) {
    .gc-offsets { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .gc-variants { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .gc-top__r { width: 100%; justify-content: flex-end; }
}

@media (prefers-reduced-motion: reduce) {
    .gc-page * { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}