/* planets page + embedded #space-stage */
        body.page-planets,
        #space-stage {
            font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
            color: #fff;
            touch-action: manipulation;
            background: #050510;
        }

        /*
         * 调试：夜景自发光开关（地球等带 nightMap 的天体）
         * 独立页 / 首页 embed 共用；默认显示，确认后可改为 display:none
         */
        .space-night-glow-toggle {
            /* 调试面板默认隐藏；需要时改为 display:flex */
            display: none;
            position: fixed;
            right: max(12px, env(safe-area-inset-right, 0px));
            bottom: max(12px, env(safe-area-inset-bottom, 0px));
            z-index: 9000;
            flex-direction: column;
            gap: 6px;
            padding: 10px 12px;
            border-radius: 12px;
            background: rgba(8, 12, 28, 0.9);
            border: 1px solid rgba(125, 211, 252, 0.35);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
            color: #e8f4ff;
            font-size: 12px;
            line-height: 1.35;
            max-width: min(240px, calc(100vw - 24px));
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            user-select: none;
            pointer-events: auto;
        }
        .space-night-glow-toggle strong {
            font-size: 11px;
            letter-spacing: 0.04em;
            color: #9ad8ff;
            font-weight: 700;
        }
        .space-night-glow-toggle label {
            display: flex;
            align-items: flex-start;
            gap: 8px;
            cursor: pointer;
            margin: 0;
        }
        .space-night-glow-toggle input {
            margin-top: 2px;
            flex-shrink: 0;
            accent-color: #38bdf8;
        }
        .space-night-glow-toggle .hint {
            color: rgba(255, 255, 255, 0.5);
            font-size: 10px;
            margin: 0;
        }
        body.page-planets {
            margin: 0;
            padding:
                env(safe-area-inset-top, 0px)
                env(safe-area-inset-right, 0px)
                env(safe-area-inset-bottom, 0px)
                env(safe-area-inset-left, 0px);
            width: 100%;
            height: 100%;
            overflow: hidden;
            overscroll-behavior: none;
        }
        html:has(body.page-planets) {
            width: 100%;
            height: 100%;
            overscroll-behavior: none;
        }
        #space-stage {
            position: fixed;
            inset: 0;
            /* 默认低于起飞 veil（peak/handoff=9000） */
            z-index: 1500;
            display: none;
            width: 100%;
            height: 100%;
            overflow: hidden;
            overscroll-behavior: none;
            padding:
                env(safe-area-inset-top, 0px)
                env(safe-area-inset-right, 0px)
                env(safe-area-inset-bottom, 0px)
                env(safe-area-inset-left, 0px);
            box-sizing: border-box;
        }
        #space-stage.is-open {
            display: block;
        }
        /* 起飞构建期：舞台在后台，不可见 */
        body.hero-flying:not(.space-crossfading) #space-stage,
        body.hero-flying-peak:not(.space-crossfading) #space-stage,
        body.space-handoff:not(.space-crossfading) #space-stage {
            z-index: 1500 !important;
        }
        /* 正式进入太空后 */
        body.space-embed-open:not(.hero-flying):not(.hero-flying-peak):not(.space-handoff):not(.space-crossfading) #space-stage.is-open {
            z-index: 5000;
        }
        /* 构建中：不可见、不可点（WebGL 仍可在后台跑） */
        #space-stage.is-building {
            z-index: 1500 !important;
            pointer-events: none !important;
            opacity: 0 !important;
            visibility: hidden;
        }
        /*
         * 真正叠化：太空舞台叠在首页之上。
         * opacity 一律由 space-embed 用 inline 控制，这里不写 opacity，
         * 避免 CSS 与 JS 抢状态导致「先闪 0/1 再过渡」。
         */
        body.space-crossfading #space-stage.is-open {
            display: block;
            pointer-events: none;
            z-index: 5200 !important;
            background: #050510;
        }
        /* 叠化中先不露 UI，避免导航条突然弹出 */
        body.space-crossfading #space-stage .km-site-nav,
        body.space-crossfading #space-stage #bottom-dock,
        body.space-crossfading #space-stage #side-panel,
        body.space-crossfading #space-stage #mode-badge,
        body.space-crossfading #space-stage #hint,
        body.space-crossfading #space-stage .coach-mark,
        body.space-crossfading #space-stage #loading {
            opacity: 0 !important;
            pointer-events: none !important;
        }
        /* 首页地球保持可见作底层；叠化完成后才 dispose */
        body.space-crossfading {
            overflow: hidden;
        }
        body.space-crossfading #hero .hero-inner,
        body.space-crossfading #hero .km-site-nav,
        body.space-crossfading .hero-atmosphere,
        body.space-crossfading .hero-fog,
        body.space-crossfading .hero-orbits,
        body.space-crossfading .hero-bg {
            opacity: 0 !important;
            pointer-events: none !important;
            visibility: hidden !important;
        }
        /* 叠化期间 veil 不挡画面 */
        body.space-crossfading #hero-fly-veil {
            opacity: 0 !important;
            pointer-events: none !important;
            z-index: 1000 !important;
            transition: opacity 0.25s ease;
        }
        #space-stage.is-revealing {
            opacity: 1;
            visibility: visible;
            pointer-events: none;
        }
        #space-stage *,
        body.page-planets * {
            box-sizing: border-box;
        }
        /* 嵌入舞台：导航浮在场景上（对齐 page-planets） */
        #space-stage .km-site-nav {
            position: absolute;
            left: 0;
            right: 0;
            top: 0;
            z-index: 1000;
            background: rgba(6, 10, 24, 0.55);
        }
        #space-stage #header {
            top: calc(var(--km-nav-h, 56px) + 10px + env(safe-area-inset-top, 0px));
        }
        #space-stage #age-selector {
            top: calc(var(--km-nav-h, 56px) + 10px + env(safe-area-inset-top, 0px));
        }
        #space-stage #mode-badge {
            top: calc(var(--km-nav-h, 56px) + 12px + env(safe-area-inset-top, 0px));
        }
        #space-stage #info-panel {
            top: calc(var(--km-nav-h, 56px) + 72px);
        }
        #space-stage #canvas-container {
            height: 100%;
        }
        @supports (height: 100dvh) {
            #space-stage {
                height: 100dvh;
            }
            #space-stage #canvas-container {
                height: 100%;
            }
        }
        body.space-embed-open {
            overflow: hidden;
        }

        #canvas-container {
            width: 100%;
            height: 100%;
            position: absolute;
            inset: 0;
            z-index: 1;
            touch-action: none;
        }
        @supports (height: 100dvh) {
            #canvas-container {
                height: 100dvh;
            }
        }

        #header {
            position: absolute;
            top: 16px;
            left: 20px;
            z-index: 10;
            pointer-events: none;
            max-width: min(320px, 46vw);
        }
        #logo {
            font-size: 24px;
            font-weight: 800;
            letter-spacing: 0.5px;
            text-shadow: 0 0 18px rgba(100, 200, 255, 0.75);
        }
        #subtitle {
            font-size: 13px;
            color: rgba(255, 255, 255, 0.65);
            margin-top: 4px;
        }
        #progress-wrap {
            margin-top: 10px;
            pointer-events: auto;
            padding: 8px 12px;
            border-radius: 14px;
            background: rgba(8, 12, 28, 0.55);
            border: 1px solid rgba(255, 255, 255, 0.1);
            backdrop-filter: blur(10px);
            min-width: 180px;
        }
        #progress-label {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 12px;
            color: rgba(255, 255, 255, 0.8);
            margin-bottom: 6px;
            gap: 8px;
        }
        #progress-label strong {
            color: #9ad8ff;
            font-size: 13px;
        }
        #progress-bar {
            height: 8px;
            border-radius: 999px;
            background: rgba(255, 255, 255, 0.12);
            overflow: hidden;
        }
        #progress-bar > span {
            display: block;
            height: 100%;
            width: 0%;
            border-radius: 999px;
            background: linear-gradient(90deg, #64c8ff, #a78bfa, #f0abfc);
            box-shadow: 0 0 12px rgba(100, 200, 255, 0.45);
            transition: width 0.45s ease;
        }

        #age-selector {
            position: absolute;
            top: 18px;
            right: 18px;
            z-index: 10;
            display: flex;
            gap: 8px;
            align-items: center;
        }
        .age-btn {
            padding: 8px 14px;
            border: 2px solid rgba(255, 255, 255, 0.25);
            border-radius: 999px;
            background: rgba(8, 12, 28, 0.65);
            color: #fff;
            cursor: pointer;
            font-size: 12px;
            backdrop-filter: blur(8px);
            transition: all 0.25s ease;
        }
        .age-btn.active {
            border-color: #64c8ff;
            background: rgba(100, 200, 255, 0.28);
            box-shadow: 0 0 16px rgba(100, 200, 255, 0.25);
        }
        #mute-btn {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            border: 2px solid rgba(255, 255, 255, 0.25);
            background: rgba(8, 12, 28, 0.65);
            color: #fff;
            cursor: pointer;
            font-size: 16px;
            backdrop-filter: blur(8px);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.25s ease;
        }
        #mute-btn:hover { border-color: rgba(255, 255, 255, 0.5); }
        #mute-btn.muted {
            border-color: rgba(255, 160, 160, 0.55);
            background: rgba(80, 30, 30, 0.45);
        }

        #mode-badge {
            position: absolute;
            top: 18px;
            left: 50%;
            transform: translateX(-50%);
            z-index: 10;
            padding: 6px 14px;
            border-radius: 999px;
            background: rgba(8, 12, 28, 0.55);
            border: 1px solid rgba(255, 255, 255, 0.12);
            font-size: 12px;
            color: rgba(255, 255, 255, 0.75);
            backdrop-filter: blur(8px);
            pointer-events: none;
            transition: opacity 0.3s;
        }

        #planet-nav {
            position: absolute;
            bottom: 22px;
            left: 50%;
            transform: translateX(-50%);
            z-index: 10;
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
            justify-content: center;
            max-width: min(960px, 96vw);
            padding: 10px 12px;
            border-radius: 20px;
            background: rgba(6, 10, 24, 0.55);
            border: 1px solid rgba(255, 255, 255, 0.08);
            backdrop-filter: blur(12px);
        }
        .planet-btn {
            position: relative;
            width: 56px;
            min-height: 64px;
            border-radius: 14px;
            border: 2px solid rgba(255, 255, 255, 0.18);
            background: rgba(255, 255, 255, 0.04);
            cursor: pointer;
            transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 4px;
            padding: 6px 4px;
            color: #fff;
        }
        .planet-btn .dot {
            width: 22px;
            height: 22px;
            border-radius: 50%;
            box-shadow: inset -3px -2px 6px rgba(0, 0, 0, 0.35), 0 0 10px rgba(255, 255, 255, 0.12);
        }
        .planet-btn .label {
            font-size: 11px;
            font-weight: 700;
            line-height: 1;
        }
        .planet-btn:hover {
            transform: translateY(-3px) scale(1.05);
            border-color: rgba(255, 255, 255, 0.55);
        }
        .planet-btn.active {
            transform: translateY(-3px) scale(1.08);
            border-color: #fff;
            box-shadow: 0 0 18px rgba(100, 200, 255, 0.45);
            background: rgba(100, 200, 255, 0.15);
        }
        .planet-btn.visited {
            border-color: rgba(120, 230, 170, 0.75);
            background: rgba(80, 200, 140, 0.12);
        }
        .planet-btn.visited::after {
            content: '✓';
            position: absolute;
            top: 2px;
            right: 4px;
            font-size: 10px;
            font-weight: 800;
            color: #7dffa8;
            text-shadow: 0 0 6px rgba(80, 255, 160, 0.8);
        }
        .planet-btn.guide-pulse {
            animation: guidePulse 1.1s ease-in-out infinite;
            border-color: #fff;
            z-index: 2;
        }
        @keyframes guidePulse {
            0%, 100% {
                transform: translateY(-2px) scale(1.05);
                box-shadow: 0 0 0 0 rgba(100, 200, 255, 0.55);
            }
            50% {
                transform: translateY(-6px) scale(1.14);
                box-shadow: 0 0 0 12px rgba(100, 200, 255, 0);
            }
        }

        #coach-mark {
            position: absolute;
            z-index: 30;
            max-width: min(280px, 80vw);
            padding: 12px 14px;
            border-radius: 16px;
            background: rgba(12, 18, 40, 0.92);
            border: 1px solid rgba(100, 200, 255, 0.35);
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
            color: #fff;
            font-size: 14px;
            line-height: 1.5;
            opacity: 0;
            pointer-events: none;
            transform: translateY(8px);
            transition: opacity 0.3s ease, transform 0.3s ease;
        }
        #coach-mark.show {
            opacity: 1;
            pointer-events: auto;
            transform: translateY(0);
        }
        #coach-mark .coach-title {
            font-weight: 800;
            font-size: 15px;
            margin-bottom: 4px;
        }
        #coach-mark .coach-actions {
            display: flex;
            gap: 8px;
            margin-top: 10px;
        }
        #coach-mark button {
            flex: 1;
            border: none;
            border-radius: 10px;
            padding: 8px 10px;
            font-size: 13px;
            font-weight: 700;
            cursor: pointer;
        }
        #coach-go {
            background: linear-gradient(135deg, #64c8ff, #4a9eff);
            color: #fff;
        }
        #coach-skip {
            background: rgba(255, 255, 255, 0.1);
            color: #fff;
        }

        #celebrate {
            position: absolute;
            inset: 0;
            z-index: 50;
            display: flex;
            align-items: center;
            justify-content: center;
            background: rgba(5, 8, 20, 0.55);
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.35s ease;
        }
        #celebrate.show {
            opacity: 1;
            pointer-events: auto;
        }
        #celebrate-card {
            width: min(360px, 88vw);
            text-align: center;
            padding: 28px 22px 22px;
            border-radius: 22px;
            background: linear-gradient(160deg, rgba(30, 40, 80, 0.95), rgba(20, 16, 40, 0.96));
            border: 1px solid rgba(160, 200, 255, 0.35);
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
        }
        #celebrate-card h2 {
            font-size: 26px;
            margin-bottom: 8px;
        }
        #celebrate-card p {
            font-size: 15px;
            line-height: 1.6;
            color: rgba(255, 255, 255, 0.85);
            margin-bottom: 18px;
        }
        #celebrate-close {
            border: none;
            border-radius: 12px;
            padding: 12px 18px;
            font-size: 15px;
            font-weight: 800;
            cursor: pointer;
            color: #fff;
            background: linear-gradient(135deg, #64c8ff, #a78bfa);
            min-width: 140px;
        }

        /* 徽章解锁 toast */
        #badge-toast {
            position: absolute;
            left: 50%;
            bottom: calc(96px + env(safe-area-inset-bottom, 0px));
            transform: translateX(-50%) translateY(16px);
            z-index: 55;
            min-width: min(300px, 88vw);
            max-width: 92vw;
            padding: 12px 14px;
            border-radius: 16px;
            background: linear-gradient(135deg, rgba(30, 24, 60, 0.96), rgba(12, 28, 48, 0.96));
            border: 1px solid rgba(250, 204, 21, 0.45);
            box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4), 0 0 24px rgba(250, 204, 21, 0.15);
            display: flex;
            align-items: center;
            gap: 12px;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.35s ease, transform 0.35s ease;
            cursor: pointer;
        }
        #badge-toast.show {
            opacity: 1;
            pointer-events: auto;
            transform: translateX(-50%) translateY(0);
            animation: badgePop 0.55s ease;
        }
        @keyframes badgePop {
            0% { transform: translateX(-50%) translateY(20px) scale(0.9); }
            60% { transform: translateX(-50%) translateY(-4px) scale(1.04); }
            100% { transform: translateX(-50%) translateY(0) scale(1); }
        }
        #badge-toast-icon {
            width: 48px;
            height: 48px;
            border-radius: 14px;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 28px;
            background: rgba(250, 204, 21, 0.15);
            flex-shrink: 0;
        }
        #badge-toast-title {
            font-size: 14px;
            font-weight: 800;
            color: #fde68a;
        }
        #badge-toast-desc {
            font-size: 12px;
            color: rgba(255, 255, 255, 0.78);
            margin-top: 2px;
            line-height: 1.4;
        }

        /* 每日一探 chip */
        #daily-chip {
            position: absolute;
            left: 12px;
            bottom: calc(88px + env(safe-area-inset-bottom, 0px));
            z-index: 25;
            max-width: min(260px, 70vw);
            padding: 10px 12px;
            border-radius: 14px;
            background: rgba(12, 20, 44, 0.88);
            border: 1px solid rgba(100, 200, 255, 0.35);
            backdrop-filter: blur(10px);
            box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
            opacity: 0;
            pointer-events: none;
            transform: translateY(8px);
            transition: opacity 0.3s ease, transform 0.3s ease;
            cursor: pointer;
        }
        #daily-chip.show {
            opacity: 1;
            pointer-events: auto;
            transform: translateY(0);
        }
        #daily-chip.done {
            border-color: rgba(110, 231, 160, 0.45);
        }
        .daily-chip-title {
            font-size: 13px;
            font-weight: 800;
            color: #9ad8ff;
            padding-right: 18px;
            line-height: 1.35;
        }
        .daily-chip-sub {
            font-size: 11px;
            color: rgba(255, 255, 255, 0.65);
            margin-top: 4px;
            line-height: 1.35;
        }
        #daily-chip-close {
            position: absolute;
            top: 6px;
            right: 6px;
            width: 22px;
            height: 22px;
            border: none;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.08);
            color: rgba(255, 255, 255, 0.7);
            font-size: 12px;
            cursor: pointer;
            line-height: 1;
        }
        #voice-source-hint {
            font-size: 11px;
            color: rgba(180, 210, 255, 0.7);
            margin-top: 4px;
            display: none;
        }
        #voice-source-hint.show { display: block; }

        #info-panel {
            position: absolute;
            top: calc(72px + 56px);
            right: 18px;
            bottom: 110px;
            width: min(360px, 38vw);
            z-index: 20;
            display: flex;
            flex-direction: column;
            gap: 12px;
            opacity: 0;
            transform: translateX(24px);
            pointer-events: none;
            transition: opacity 0.35s ease, transform 0.35s ease, max-height 0.35s ease;
        }
        #info-panel.show {
            opacity: 1;
            transform: translateX(0);
            pointer-events: auto;
        }
        #sheet-handle {
            display: none;
            align-items: center;
            justify-content: center;
            gap: 10px;
            flex-shrink: 0;
            padding: 8px 12px 4px;
            cursor: pointer;
            user-select: none;
            -webkit-tap-highlight-color: transparent;
            touch-action: manipulation;
        }
        #sheet-handle .grip {
            width: 42px;
            height: 5px;
            border-radius: 999px;
            background: rgba(255, 255, 255, 0.35);
        }
        #sheet-handle .sheet-toggle-label {
            font-size: 11px;
            font-weight: 700;
            color: rgba(200, 220, 255, 0.75);
        }
        #info-card {
            flex: 1;
            min-height: 0;
            overflow: auto;
            -webkit-overflow-scrolling: touch;
            overscroll-behavior: contain;
            touch-action: pan-y;
            background: rgba(10, 14, 32, 0.82);
            border-radius: 20px;
            padding: 22px;
            border: 1px solid rgba(100, 200, 255, 0.22);
            box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
            backdrop-filter: blur(14px);
        }
        #card-header {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            margin-bottom: 14px;
            gap: 12px;
        }
        #planet-name {
            font-size: 28px;
            font-weight: 800;
            line-height: 1.1;
        }
        #planet-english {
            font-size: 13px;
            color: rgba(255, 255, 255, 0.5);
            margin-top: 4px;
        }
        #close-btn {
            width: 34px;
            height: 34px;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.08);
            border: 1px solid rgba(255, 255, 255, 0.12);
            color: #fff;
            font-size: 18px;
            cursor: pointer;
            flex-shrink: 0;
        }
        #close-btn:hover { background: rgba(255, 255, 255, 0.16); }

        #feature-tag {
            display: inline-block;
            padding: 6px 14px;
            border-radius: 999px;
            font-size: 12px;
            font-weight: 700;
            margin-bottom: 14px;
        }
        #description {
            font-size: 15px;
            line-height: 1.75;
            color: rgba(255, 255, 255, 0.9);
        }
        #fun-facts {
            margin-top: 16px;
            padding: 12px 14px;
            border-radius: 14px;
            background: rgba(255, 255, 255, 0.05);
            font-size: 13px;
            line-height: 1.7;
            color: rgba(255, 255, 255, 0.78);
        }
        #compare-hint {
            margin-top: 10px;
            font-size: 12px;
            color: rgba(160, 210, 255, 0.85);
        }
        #compare-panel {
            margin-top: 16px;
            padding: 12px 12px 14px;
            border-radius: 16px;
            background: rgba(255, 255, 255, 0.05);
            border: 1px solid rgba(120, 180, 255, 0.18);
        }
        #compare-panel .compare-title {
            font-size: 13px;
            font-weight: 800;
            margin-bottom: 10px;
            color: rgba(200, 230, 255, 0.95);
        }
        .compare-size-row {
            display: flex;
            align-items: flex-end;
            justify-content: center;
            gap: 18px;
            min-height: 72px;
            padding: 6px 0 8px;
        }
        .compare-ball-wrap {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 6px;
            min-width: 64px;
        }
        .compare-ball {
            border-radius: 50%;
            box-shadow:
                inset -4px -3px 8px rgba(0, 0, 0, 0.35),
                0 0 12px rgba(255, 255, 255, 0.12);
            transition: width 0.45s ease, height 0.45s ease, background 0.3s ease;
        }
        .compare-ball.earth {
            background: radial-gradient(circle at 30% 30%, #9ad0ff, #3b82f6 55%, #1d4ed8);
        }
        .compare-ball.other {
            background: radial-gradient(circle at 30% 30%, #ddd, #999 60%, #666);
        }
        .compare-ball-label {
            font-size: 11px;
            font-weight: 700;
            color: rgba(255, 255, 255, 0.8);
        }
        #compare-size-text {
            text-align: center;
            font-size: 13px;
            line-height: 1.5;
            color: rgba(255, 255, 255, 0.88);
            margin-top: 2px;
        }
        #compare-size-badge {
            display: none;
            margin: 8px auto 0;
            width: fit-content;
            padding: 4px 10px;
            border-radius: 999px;
            font-size: 11px;
            font-weight: 800;
            background: rgba(250, 204, 21, 0.18);
            color: #fde68a;
            border: 1px solid rgba(250, 204, 21, 0.35);
        }
        #compare-size-badge.show { display: inline-block; }

        .compare-order {
            margin-top: 14px;
            padding-top: 12px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
        }
        .compare-order-title {
            font-size: 12px;
            font-weight: 700;
            color: rgba(200, 230, 255, 0.85);
            margin-bottom: 8px;
        }
        #compare-order-track {
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 4px;
            position: relative;
            padding: 4px 2px 2px;
        }
        #compare-order-track::before {
            content: '';
            position: absolute;
            left: 8px;
            right: 8px;
            top: 14px;
            height: 2px;
            background: linear-gradient(90deg, #fbbf24, #60a5fa, #a78bfa);
            opacity: 0.55;
            z-index: 0;
        }
        .order-dot {
            position: relative;
            z-index: 1;
            width: 18px;
            height: 18px;
            border-radius: 50%;
            border: 2px solid rgba(255, 255, 255, 0.35);
            background: rgba(20, 24, 40, 0.9);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 9px;
            font-weight: 800;
            color: rgba(255, 255, 255, 0.55);
            flex-shrink: 0;
            transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
        }
        .order-dot.sun-dot {
            background: radial-gradient(circle at 35% 35%, #fff7cc, #f59e0b);
            border-color: #fbbf24;
            color: transparent;
            width: 20px;
            height: 20px;
        }
        .order-dot.active {
            transform: scale(1.25);
            border-color: #fff;
            box-shadow: 0 0 12px rgba(100, 200, 255, 0.7);
            color: #fff;
            background: rgba(100, 180, 255, 0.35);
        }
        .order-dot.earth-mark {
            border-color: #60a5fa;
        }
        #compare-order-text {
            margin-top: 8px;
            font-size: 12px;
            line-height: 1.5;
            color: rgba(220, 235, 255, 0.9);
            text-align: center;
        }
        #compare-panel.hidden { display: none; }

        #quiz-panel {
            margin-top: 16px;
            padding: 12px 12px 14px;
            border-radius: 16px;
            background: rgba(167, 139, 250, 0.1);
            border: 1px solid rgba(167, 139, 250, 0.28);
        }
        #quiz-panel.hidden { display: none; }
        #quiz-panel .quiz-title {
            font-size: 13px;
            font-weight: 800;
            margin-bottom: 8px;
            color: rgba(220, 200, 255, 0.95);
        }
        #quiz-question {
            font-size: 14px;
            line-height: 1.55;
            font-weight: 700;
            color: rgba(255, 255, 255, 0.95);
            margin-bottom: 10px;
        }
        #quiz-options {
            display: flex;
            flex-direction: column;
            gap: 8px;
        }
        .quiz-opt {
            width: 100%;
            text-align: left;
            border: 2px solid rgba(255, 255, 255, 0.14);
            border-radius: 12px;
            background: rgba(255, 255, 255, 0.06);
            color: #fff;
            padding: 10px 12px;
            font-size: 13px;
            font-weight: 700;
            cursor: pointer;
            transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease;
        }
        .quiz-opt:hover:not(:disabled) {
            transform: translateY(-1px);
            border-color: rgba(180, 160, 255, 0.6);
            background: rgba(167, 139, 250, 0.18);
        }
        .quiz-opt:disabled { cursor: default; opacity: 0.95; }
        .quiz-opt.correct {
            border-color: rgba(110, 231, 160, 0.85);
            background: rgba(52, 180, 120, 0.28);
        }
        .quiz-opt.wrong {
            border-color: rgba(252, 165, 165, 0.75);
            background: rgba(180, 60, 60, 0.25);
        }
        .quiz-opt.dim { opacity: 0.45; }
        #quiz-feedback {
            margin-top: 10px;
            font-size: 13px;
            line-height: 1.55;
            min-height: 1.2em;
            color: rgba(220, 240, 255, 0.92);
        }
        #quiz-feedback.ok { color: #86efac; }
        #quiz-feedback.bad { color: #fca5a5; }
        #quiz-solved-tag {
            display: none;
            margin-top: 8px;
            font-size: 12px;
            font-weight: 800;
            color: #86efac;
        }
        #quiz-solved-tag.show { display: block; }

        body.age-0-3 #quiz-question { font-size: 16px; }
        body.age-0-3 .quiz-opt { font-size: 15px; padding: 12px 14px; min-height: 48px; }
        body.age-0-3 #quiz-feedback { font-size: 14px; }

        #play-hint {
            margin-top: 14px;
            padding: 12px 14px;
            border-radius: 14px;
            background: rgba(255, 210, 120, 0.12);
            border: 1px solid rgba(255, 210, 120, 0.28);
            font-size: 14px;
            line-height: 1.55;
            color: rgba(255, 240, 210, 0.95);
            display: none;
        }

        /* 0-3 岁：更大更少字 */
        body.age-0-3 #planet-english,
        body.age-0-3 #fun-facts,
        body.age-0-3 #compare-hint,
        body.age-0-3 #mode-badge {
            display: none !important;
        }
        body.age-0-3 #play-hint { display: block; }
        body.age-0-3 #planet-name { font-size: 34px; }
        body.age-0-3 #feature-tag { font-size: 14px; padding: 8px 16px; }
        body.age-0-3 #description { font-size: 17px; line-height: 1.7; }
        body.age-0-3 .planet-btn {
            width: 64px;
            min-height: 74px;
            border-radius: 16px;
        }
        body.age-0-3 .planet-btn .dot {
            width: 28px;
            height: 28px;
        }
        body.age-0-3 .planet-btn .label { font-size: 13px; }
        body.age-0-3 #speak-btn { font-size: 15px; padding: 14px 10px; }
        body.age-0-3 #subtitle { display: none; }
        body.age-0-3 #compare-panel .compare-title { font-size: 14px; }
        body.age-0-3 #compare-size-text { font-size: 14px; }
        body.age-0-3 .compare-order-title { font-size: 13px; }
        body.age-0-3 #compare-order-text { font-size: 13px; }

        body.age-4-6 #play-hint { display: none !important; }

        #card-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            touch-action: manipulation;
        }
        #card-actions .action-btn {
            flex: 1 1 calc(50% - 6px);
            min-width: 0;
        }
        #card-actions #voice-source-hint {
            flex: 1 1 100%;
            margin-top: 0;
        }
        .action-btn {
            flex: 1;
            padding: 12px 10px;
            border-radius: 12px;
            border: none;
            font-size: 14px;
            font-weight: 700;
            cursor: pointer;
            transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
        }
        #speak-btn {
            background: linear-gradient(135deg, #64c8ff, #4a9eff);
            color: #fff;
        }
        #speak-btn:hover {
            transform: translateY(-1px);
            box-shadow: 0 8px 22px rgba(100, 200, 255, 0.35);
        }
        #return-btn {
            background: rgba(255, 255, 255, 0.1);
            color: #fff;
            border: 1px solid rgba(255, 255, 255, 0.12);
        }
        #return-btn:hover { background: rgba(255, 255, 255, 0.16); }

        #hint {
            position: absolute;
            bottom: 108px;
            left: 50%;
            transform: translateX(-50%);
            z-index: 10;
            color: rgba(255, 255, 255, 0.55);
            font-size: 12px;
            padding: 8px 14px;
            border-radius: 999px;
            background: rgba(0, 0, 0, 0.25);
            pointer-events: none;
            transition: opacity 0.4s ease;
            white-space: nowrap;
        }
        #hint.hidden { opacity: 0; }

        #loading {
            position: absolute;
            inset: 0;
            z-index: 100;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 14px;
            background: radial-gradient(circle at center, #10152b 0%, #050510 70%);
            color: #fff;
            transition: opacity 0.4s ease;
        }
        #loading.hide {
            opacity: 0;
            pointer-events: none;
        }
        /* 首页起飞进入：加载层默认彻底隐藏，只用 veil 过渡 */
        body.entry-from-hero #loading,
        body.space-handoff #loading,
        #loading.km-silent {
            display: none !important;
            opacity: 0 !important;
            pointer-events: none !important;
            visibility: hidden !important;
        }
        body.from-hero-arrival .km-site-nav,
        body.from-hero-arrival #header,
        body.from-hero-arrival #age-selector,
        body.from-hero-arrival #planet-nav,
        body.from-hero-arrival #hint,
        #space-stage.from-hero-arrival .km-site-nav,
        #space-stage.from-hero-arrival #header,
        #space-stage.from-hero-arrival #age-selector,
        #space-stage.from-hero-arrival #planet-nav,
        #space-stage.from-hero-arrival #hint {
            opacity: 0.15;
            pointer-events: none;
            transition: opacity 0.5s ease;
        }
        
        #loading-title {
            font-size: 20px;
            font-weight: 700;
        }
        #loading-bar {
            width: min(280px, 70vw);
            height: 8px;
            border-radius: 999px;
            background: rgba(255, 255, 255, 0.1);
            overflow: hidden;
        }
        #loading-bar > span {
            display: block;
            height: 100%;
            width: 0%;
            background: linear-gradient(90deg, #64c8ff, #9b7bff);
            transition: width 0.2s ease;
        }
        #loading-text {
            font-size: 13px;
            color: rgba(255, 255, 255, 0.65);
        }

        /* —— 平板/窄屏通用 —— */
        @media (max-width: 900px) {
            #header {
                top: max(10px, env(safe-area-inset-top, 0px));
                left: max(10px, env(safe-area-inset-left, 0px));
                max-width: min(220px, 52vw);
            }
            #logo { font-size: 18px; }
            #subtitle { font-size: 11px; }
            #progress-wrap { min-width: 0; padding: 6px 10px; }
            #progress-label { font-size: 11px; }
            #age-selector {
                top: max(10px, env(safe-area-inset-top, 0px));
                right: max(10px, env(safe-area-inset-right, 0px));
            }
            #info-card { padding: 16px; }
            #planet-name { font-size: 22px; }
            #mode-badge { top: max(52px, calc(env(safe-area-inset-top, 0px) + 40px)); }
            .planet-btn { width: 48px; min-height: 58px; }
            .planet-btn .dot { width: 18px; height: 18px; }
            .planet-btn .label { font-size: 10px; }
            #hint {
                bottom: calc(98px + env(safe-area-inset-bottom, 0px));
                font-size: 11px;
                white-space: normal;
                text-align: center;
                max-width: 90vw;
            }
            body.age-0-3 .planet-btn { width: 56px; min-height: 66px; }
            body.age-0-3 .planet-btn .dot { width: 24px; height: 24px; }
            body.age-0-3 #planet-name { font-size: 26px; }
            #mute-btn { width: 36px; height: 36px; font-size: 14px; }
            .age-btn { padding: 6px 10px; font-size: 11px; }
        }

        /* —— 竖屏主布局：底部抽屉 + 导航横滑 —— */
        @media (orientation: portrait), (max-width: 700px) {
            body.layout-portrait #mode-badge {
                display: none;
            }
            body.layout-portrait #header {
                max-width: min(200px, 48vw);
            }
            body.layout-portrait #subtitle {
                display: none;
            }
            body.layout-portrait #progress-wrap {
                margin-top: 6px;
                min-width: 0;
            }
            body.layout-portrait #quiz-progress {
                font-size: 10px;
            }

            /* 底部行星导航：单行横滑，不换行 */
            body.layout-portrait #planet-nav {
                bottom: max(10px, env(safe-area-inset-bottom, 0px));
                left: 0;
                right: 0;
                transform: none;
                width: 100%;
                max-width: none;
                justify-content: flex-start;
                flex-wrap: nowrap;
                overflow-x: auto;
                overflow-y: hidden;
                gap: 8px;
                padding: 10px 12px;
                padding-left: max(12px, env(safe-area-inset-left, 0px));
                padding-right: max(12px, env(safe-area-inset-right, 0px));
                border-radius: 0;
                border-left: none;
                border-right: none;
                border-bottom: none;
                -webkit-overflow-scrolling: touch;
                scrollbar-width: none;
                touch-action: pan-x;
            }
            body.layout-portrait #planet-nav::-webkit-scrollbar { display: none; }
            body.layout-portrait .planet-btn {
                flex: 0 0 auto;
                width: 54px;
                min-height: 62px;
            }
            body.layout-portrait.age-0-3 .planet-btn {
                width: 58px;
                min-height: 68px;
            }

            /* 信息卡：底部抽屉，默认半高，可展开 */
            body.layout-portrait #info-panel {
                top: auto;
                left: 0;
                right: 0;
                bottom: calc(78px + env(safe-area-inset-bottom, 0px));
                width: 100%;
                max-height: 38dvh;
                gap: 0;
                transform: translateY(110%);
                border-radius: 18px 18px 0 0;
                background: rgba(8, 12, 28, 0.88);
                border: 1px solid rgba(100, 200, 255, 0.18);
                border-bottom: none;
                box-shadow: 0 -8px 32px rgba(0, 0, 0, 0.4);
                backdrop-filter: blur(16px);
                overflow: hidden;
            }
            body.layout-portrait #info-panel.show {
                transform: translateY(0);
            }
            body.layout-portrait #info-panel.expanded {
                max-height: min(68dvh, calc(100dvh - 120px));
            }
            body.layout-portrait #sheet-handle {
                display: flex;
            }
            body.layout-portrait #info-card {
                border-radius: 0;
                border: none;
                box-shadow: none;
                background: transparent;
                padding: 4px 16px 14px;
            }
            body.layout-portrait #card-actions {
                padding: 0 12px 12px;
                background: transparent;
            }
            body.layout-portrait #hint {
                bottom: calc(88px + env(safe-area-inset-bottom, 0px));
            }
            body.layout-portrait #coach-mark {
                max-width: min(300px, 86vw);
            }
            body.layout-portrait #daily-chip {
                bottom: calc(100px + env(safe-area-inset-bottom, 0px));
            }
            body.layout-portrait #badge-toast {
                bottom: calc(110px + env(safe-area-inset-bottom, 0px));
            }
            body.layout-portrait #compare-order-track {
                overflow-x: auto;
                justify-content: flex-start;
                gap: 6px;
                padding-bottom: 4px;
            }
            body.layout-portrait .compare-size-row {
                min-height: 60px;
            }
        }

        /* 矮屏横屏手机（如横握 iPhone） */
        @media (orientation: landscape) and (max-height: 480px) {
            #header {
                top: 6px;
                left: 8px;
                max-width: 160px;
            }
            #logo { font-size: 14px; }
            #subtitle { display: none; }
            #progress-wrap { padding: 4px 8px; margin-top: 4px; }
            #progress-label { font-size: 10px; margin-bottom: 3px; }
            #progress-bar { height: 5px; }
            #quiz-progress { font-size: 10px; margin-top: 3px !important; }
            #age-selector { top: 6px; right: 8px; gap: 4px; }
            .age-btn { padding: 4px 8px; font-size: 10px; }
            #mute-btn { width: 30px; height: 30px; font-size: 12px; }
            #mode-badge { display: none; }
            #info-panel {
                top: 8px;
                right: 8px;
                bottom: 64px;
                width: min(280px, 42vw);
            }
            #info-card { padding: 12px; }
            #planet-name { font-size: 18px; }
            #planet-nav {
                bottom: max(6px, env(safe-area-inset-bottom, 0px));
                padding: 6px 8px;
                gap: 6px;
                flex-wrap: nowrap;
                overflow-x: auto;
                max-width: 98vw;
                scrollbar-width: none;
            }
            #planet-nav::-webkit-scrollbar { display: none; }
            .planet-btn {
                width: 44px;
                min-height: 50px;
                flex: 0 0 auto;
            }
            .planet-btn .dot { width: 16px; height: 16px; }
            .planet-btn .label { font-size: 9px; }
            #hint { display: none; }
            #card-actions { gap: 6px; }
            .action-btn { padding: 8px 6px; font-size: 12px; }
        }

        /* 极窄竖屏（小手机） */
        @media (orientation: portrait) and (max-width: 380px) {
            body.layout-portrait .planet-btn {
                width: 48px;
                min-height: 56px;
            }
            body.layout-portrait #planet-name { font-size: 20px; }
            body.layout-portrait #info-panel {
                max-height: 36dvh;
            }
            body.layout-portrait #info-panel.expanded {
                max-height: min(72dvh, calc(100dvh - 100px));
            }
        }