/* ══════════════════════════════════════════════════════════════
           Apple-Style Design System — 梨课程
           ══════════════════════════════════════════════════════════════ */

        :root {
            --white: #ffffff;
            --bg-gray: #f5f5f7;
            --text: #1d1d1f;
            --text-s: #6e6e73;
            --text-xs: #86868b;
            --accent: #e2b007;
            --accent-soft: #fff9e6;
            --fill-dark: #1d1d1f;
            --border: #d2d2d7;
            --border-l: #e8e8ed;
            --ph-bg: #e8e8ed;
            --ph-icon: #c7c7cc;
            --radius: 28px;
            --radius-sm: 18px;
            --radius-xs: 12px;
            --shadow-card: 0 4px 32px rgba(0, 0, 0, .04);
            --ease-apple: cubic-bezier(0.25, 1, 0.5, 1);
            --transition: all 0.5s var(--ease-apple);
        }

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

        html {
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
                "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
                "Helvetica Neue", sans-serif;
            background: var(--white);
            color: var(--text);
            line-height: 1.47059;
            font-size: 17px;
            font-weight: 400;
            letter-spacing: -0.022em;
        }

        /* ── Section wrapper ─────────────────────── */
        .section {
            padding: 100px 24px;
        }

        .section--gray {
            background: var(--bg-gray);
        }

        .wrap {
            max-width: 980px;
            margin: 0 auto;
        }

        .wrap--narrow {
            max-width: 780px;
        }

        /* ── Typography ─────────────────────────── */
        .eyebrow {
            font-size: 14px;
            font-weight: 600;
            letter-spacing: 0.04em;
            text-transform: uppercase;
            color: var(--accent);
            margin-bottom: 12px;
        }

        .heading-xl {
            font-size: 56px;
            font-weight: 600;
            letter-spacing: -0.025em;
            line-height: 1.07143;
            color: var(--text);
        }

        .heading-lg {
            font-size: 40px;
            font-weight: 600;
            letter-spacing: -0.025em;
            line-height: 1.1;
            color: var(--text);
        }

        .heading-md {
            font-size: 28px;
            font-weight: 600;
            letter-spacing: -0.022em;
            line-height: 1.14286;
            color: var(--text);
        }

        .heading-sm {
            font-size: 21px;
            font-weight: 600;
            letter-spacing: -0.02em;
            line-height: 1.19048;
        }

        .body-text {
            font-size: 17px;
            line-height: 1.47059;
            color: var(--text-s);
        }

        .caption {
            font-size: 12px;
            line-height: 1.33337;
            color: var(--text-xs);
        }

        @media (max-width: 734px) {
            .heading-xl {
                font-size: 40px;
            }

            .heading-lg {
                font-size: 32px;
            }

            .heading-md {
                font-size: 24px;
            }

            .heading-sm {
                font-size: 19px;
            }

            .section {
                padding: 64px 20px;
            }
        }

        /* ── Buttons ────────────────────────────── */
        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 6px;
            padding: 14px 28px;
            border-radius: 980px;
            font-size: 17px;
            font-weight: 500;
            letter-spacing: -0.01em;
            text-decoration: none;
            cursor: pointer;
            transition: var(--transition);
            white-space: nowrap;
        }

        .btn--fill {
            background: var(--fill-dark);
            color: #fff;
            border: none;
        }

        .btn--fill:hover {
            background: #2d2d2f;
            transform: translateY(-1px);
            box-shadow: 0 8px 24px rgba(0, 0, 0, .12);
        }

        .btn--text {
            background: transparent;
            color: #06c;
            border: none;
            padding: 14px 16px;
            font-weight: 400;
        }

        .btn--text:hover {
            text-decoration: underline;
        }

        .btn--text .arrow {
            display: inline-block;
            transition: var(--transition);
        }

        .btn--text:hover .arrow {
            transform: translateX(3px);
        }

        .btn-group {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 12px;
        }

        /* ── Hero ────────────────────────────────── */
        .hero {
            padding: 72px 24px 0;
            text-align: center;
        }

        .hero .wrap {
            padding-bottom: 0;
        }

        .hero .heading-xl {
            margin-bottom: 16px;
        }

        .hero .body-text {
            font-size: 19px;
            max-width: 520px;
            margin: 0 auto 32px;
        }

        .hero .btn-group {
            justify-content: center;
            align-items: flex-start;
            margin-bottom: 8px;
        }

        .btn-stack {
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        .hero .ios-note {
            margin-top: 10px;
            font-size: 13px;
            color: var(--text-xs);
            max-width: 460px;
            margin-left: auto;
            margin-right: auto;
            line-height: 1.4;
        }

        .help-tip {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 22px;
            height: 22px;
            border-radius: 50%;
            border: 1.2px solid var(--text-xs);
            font-size: 13px;
            font-weight: 600;
            color: var(--text-xs);
            cursor: pointer;
            vertical-align: middle;
            user-select: none;
            transition: all 0.2s;
        }
        .help-tip:hover {
            border-color: var(--text-s);
            color: var(--text-s);
        }

        .help-popover {
            display: none;
            position: fixed;
            transform: translateX(-50%);
            background: #1d1d1f;
            color: #fff;
            font-size: 13px;
            line-height: 1.5;
            padding: 10px 14px;
            border-radius: 10px;
            max-width: 280px;
            width: max-content;
            text-align: left;
            z-index: 100;
            pointer-events: none;
        }
        .help-popover::after {
            content: '';
            position: absolute;
            top: 100%;
            left: 50%;
            transform: translateX(-50%);
            border: 6px solid transparent;
            border-top-color: #1d1d1f;
        }
        .help-popover.show {
            display: block;
        }

        /* ── Screenshot Showcase (Carousel → Grid) ── */
        .showcase {
            margin: 64px auto 0;
            max-width: 1140px;
            padding: 0;
            position: relative;
            overflow: hidden;
            user-select: none;
            -webkit-user-select: none;
        }

        /* Track — holds all slides in a row */
        .showcase-track {
            display: flex;
            gap: 0;
            transition: transform 0.45s var(--ease-apple);
            will-change: transform;
        }

        /* Each slide */
        .showcase .mockup-item {
            flex-shrink: 0;
            width: 100%;
        }

        .showcase .mockup-frame {
            width: 100%;
            max-height: 520px;
            border-radius: 24px;
            overflow: hidden;
            box-shadow:
                0 2px 8px rgba(0, 0, 0, .06),
                0 12px 40px rgba(0, 0, 0, .10);
            transition: var(--transition);
            background: var(--bg-gray);
        }

        .showcase .mockup-frame img {
            display: block;
            width: 100%;
            height: auto;
            max-height: 520px;
            object-fit: cover;
            object-position: top;
        }

        .showcase .mockup-caption {
            display: block;
            text-align: center;
            font-size: 13px;
            color: var(--text-xs);
            margin-top: 8px;
            letter-spacing: 0;
            font-weight: 400;
        }

        /* ── Dots ── */
        .showcase-dots {
            display: flex;
            justify-content: center;
            gap: 8px;
            margin-top: 20px;
        }

        .showcase-dots button {
            width: 8px;
            height: 8px;
            border-radius: 50%;
            border: none;
            background: #d2d2d7;
            cursor: pointer;
            padding: 0;
            transition: all 0.3s var(--ease-apple);
        }

        .showcase-dots button.active {
            background: #1d1d1f;
            width: 24px;
            border-radius: 20px;
        }

        /* ── Images clickable hint ── */
        .showcase .mockup-frame img,
        .phone-ph img {
            cursor: pointer;
            transition: filter 0.35s var(--ease-apple);
        }

        .showcase .mockup-frame img:hover,
        .phone-ph img:hover {
            filter: brightness(0.92);
        }

        /* ── Lightbox ── */
        .lightbox {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, .88);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            z-index: 9999;
            display: flex;
            align-items: center;
            justify-content: center;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.35s var(--ease-apple);
        }

        .lightbox.open {
            opacity: 1;
            pointer-events: auto;
        }

        .lightbox img {
            max-width: 92vw;
            max-height: 90vh;
            border-radius: 12px;
            box-shadow: 0 24px 80px rgba(0, 0, 0, .5);
            transform: scale(.92);
            transition: transform 0.35s var(--ease-apple);
        }

        .lightbox.open img {
            transform: scale(1);
        }

        .lightbox-close {
            position: absolute;
            top: 24px;
            right: 24px;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            border: none;
            background: rgba(255, 255, 255, .12);
            color: #fff;
            font-size: 22px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background .2s;
            line-height: 1;
        }

        .lightbox-close:hover {
            background: rgba(255, 255, 255, .22);
        }

        /* ── Carousel mode: 2-up, no gaps ── */
        @media (max-width: 1099px) {
            .showcase .mockup-item {
                width: 50%;
            }
            .showcase .mockup-frame {
                max-height: 70vh;
            }
            .showcase .mockup-frame img {
                max-height: 70vh;
                object-fit: contain;
            }
        }

        /* ── Desktop: grid, no carousel chrome ── */
        @media (min-width: 1100px) {
            .showcase-track {
                transform: none !important;
                gap: 20px;
            }

            .showcase .mockup-item {
                flex: 1;
                min-width: 0;
            }

            .showcase-dots {
                display: none;
            }
        }

        /* ── Bento Grid ──────────────────────────── */
        .bento {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
        }

        .bento .card--span-2 {
            grid-column: span 2;
        }

        @media (max-width: 734px) {
            .bento {
                grid-template-columns: 1fr;
            }

            .bento .card--span-2 {
                grid-column: span 1;
            }
        }

        /* ── Card ────────────────────────────────── */
        .card {
            background: var(--white);
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-card);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            position: relative;
            overflow: hidden;
        }

        .card:hover {
            box-shadow: 0 4px 40px rgba(0, 0, 0, .07);
        }

        .card .card-icon {
            width: 48px;
            height: 48px;
            border-radius: 14px;
            background: var(--bg-gray);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            margin-bottom: 20px;
            flex-shrink: 0;
        }

        .card .heading-sm {
            margin-bottom: 8px;
        }

        .card .body-text {
            margin-bottom: 20px;
            max-width: 440px;
        }

        /* Card A — Setup (gold accent) */
        .card--setup {
            background: linear-gradient(160deg, #fffdf5 0%, #ffffff 55%);
            border: 1px solid #f5ebc0;
            flex-direction: row;
            gap: 40px;
            align-items: center;
        }

        .card--setup .card-body {
            flex: 1;
        }

        .card--setup .highlight {
            display: inline-block;
            background: var(--accent);
            color: #fff;
            border-radius: 6px;
            padding: 2px 10px;
            font-weight: 600;
            font-size: 17px;
            letter-spacing: -0.01em;
        }

        .card--setup .warn-tag {
            display: inline-block;
            margin-top: 16px;
            font-size: 14px;
            color: #b45309;
            font-weight: 500;
            background: #fef3c7;
            border-radius: 20px;
            padding: 4px 14px;
        }

        @media (max-width: 734px) {
            .card--setup {
                flex-direction: column;
            }
        }

        /* Phone mockup placeholder */
        .phone-ph {
            flex-shrink: 0;
            width: 180px;
            aspect-ratio: 9 / 16;
            background: var(--ph-bg);
            border-radius: var(--radius-sm);
            overflow: hidden;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 6px;
            border: 1px solid var(--border-l);
            position: relative;
        }

        .phone-ph .ph-icon {
            font-size: 28px;
            color: var(--ph-icon);
        }

        .phone-ph .ph-label {
            font-size: 11px;
            color: var(--text-xs);
            text-align: center;
            line-height: 1.4;
            padding: 0 8px;
        }

        /* Card B & C — half-width */
        .card--half {
            justify-content: space-between;
        }

        /* small browser placeholder */
        .browser-ph {
            width: 100%;
            aspect-ratio: 16 / 10;
            background: var(--ph-bg);
            border-radius: var(--radius-sm);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 4px;
            border: 1px solid var(--border-l);
        }

        .browser-ph .ph-icon {
            font-size: 24px;
            color: var(--ph-icon);
        }

        .browser-ph .ph-label {
            font-size: 11px;
            color: var(--text-xs);
            text-align: center;
        }

        /* Card D — Limits (full width) */
        .card--limits {
            flex-direction: row;
            gap: 48px;
            align-items: center;
        }

        .card--limits .card-body {
            flex: 1;
        }

        .card--limits ul {
            list-style: none;
            margin-top: 12px;
        }

        .card--limits ul li {
            position: relative;
            padding: 7px 0 7px 24px;
            font-size: 15px;
            color: var(--text-s);
        }

        .card--limits ul li::before {
            content: "";
            position: absolute;
            left: 0;
            top: 15px;
            width: 6px;
            height: 6px;
            border-radius: 50%;
            background: var(--accent);
        }

        /* wide comparison placeholder */
        .compare-ph {
            flex-shrink: 0;
            width: 260px;
            aspect-ratio: 4 / 3;
            background: var(--ph-bg);
            border-radius: var(--radius-sm);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 6px;
            border: 1px solid var(--border-l);
        }

        .compare-ph .ph-icon {
            font-size: 28px;
            color: var(--ph-icon);
        }

        .compare-ph .ph-label {
            font-size: 11px;
            color: var(--text-xs);
            text-align: center;
            padding: 0 12px;
        }

        @media (max-width: 734px) {
            .card--limits {
                flex-direction: column;
            }

            .compare-ph {
                width: 100%;
                aspect-ratio: 16/9;
            }
        }

        /* ── Community card ──────────────────────── */
        .community-card {
            background: var(--white);
            border-radius: var(--radius);
            padding: 44px 48px;
            box-shadow: var(--shadow-card);
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 24px;
            flex-wrap: wrap;
        }

        .community-card .heading-sm {
            flex: 1;
            min-width: 200px;
        }

        .community-card .desc {
            font-size: 15px;
            color: var(--text-s);
            margin-top: 4px;
        }

        @media (max-width: 734px) {
            .community-card {
                padding: 32px 28px;
                flex-direction: column;
                text-align: center;
            }
        }

        /* ── Footer ──────────────────────────────── */
        .site-footer {
            background: var(--bg-gray);
            padding: 24px 24px 32px;
            text-align: center;
        }

        .site-footer .footer-text {
            font-size: 12px;
            font-weight: 400;
            line-height: 1.33337;
            color: var(--text-xs);
            max-width: 720px;
            margin: 0 auto;
            letter-spacing: 0;
        }

        .site-footer .footer-divider {
            width: 100%;
            height: 1px;
            background: var(--border-l);
            margin: 16px 0;
            max-width: 720px;
            margin-left: auto;
            margin-right: auto;
        }

        .site-footer a {
            color: #06c;
            text-decoration: none;
        }

        .site-footer a:hover {
            text-decoration: underline;
        }

        /* ── Divider between sections ────────────── */
        .section-divider {
            width: 100%;
            height: 1px;
            background: var(--border-l);
        }

        /* ── Emphasis span ───────────────────────── */
        .em-accent {
            color: #b8860b;
            font-weight: 600;
        }

        /* ── Spacing utilities ───────────────────── */
        .mt-8 {
            margin-top: 8px;
        }

        .mt-12 {
            margin-top: 12px;
        }

        .mt-16 {
            margin-top: 16px;
        }

        .mt-24 {
            margin-top: 24px;
        }

        .mt-40 {
            margin-top: 40px;
        }

        .mb-16 {
            margin-bottom: 16px;
        }

        .mb-24 {
            margin-bottom: 24px;
        }

        /* ── Download Confirm Modal ─────────── */
        .dl-modal {
            position: fixed;
            inset: 0;
            background: rgba(0,0,0,.5);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            z-index: 9998;
            display: flex;
            align-items: center;
            justify-content: center;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.3s var(--ease-apple);
            padding: 20px;
        }
        .dl-modal.open {
            opacity: 1;
            pointer-events: auto;
        }
        .dl-modal-card {
            background: #fff;
            border-radius: var(--radius);
            padding: 36px 32px 28px;
            max-width: 520px;
            width: 100%;
            max-height: 80vh;
            overflow-y: auto;
            box-shadow: 0 24px 80px rgba(0,0,0,.25);
            transform: translateY(8px);
            transition: transform 0.35s var(--ease-apple);
        }
        .dl-modal.open .dl-modal-card {
            transform: translateY(0);
        }
        .dl-modal-title {
            font-size: 21px;
            font-weight: 600;
            letter-spacing: -0.02em;
            color: var(--text);
            margin-bottom: 20px;
            text-align: center;
        }
        .dl-modal-steps {
            list-style: none;
            counter-reset: dl-step;
            margin-bottom: 24px;
        }
        .dl-modal-steps li {
            counter-increment: dl-step;
            position: relative;
            padding: 8px 0 8px 32px;
            font-size: 15px;
            color: var(--text-s);
            line-height: 1.5;
            border-bottom: 1px solid #f5f5f4;
        }
        .dl-modal-steps li:last-child {
            border-bottom: none;
        }
        .dl-modal-steps li::before {
            content: counter(dl-step);
            position: absolute;
            left: 0;
            top: 8px;
            width: 22px;
            height: 22px;
            border-radius: 50%;
            background: #f5f5f7;
            color: var(--text-s);
            font-size: 12px;
            font-weight: 600;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .dl-modal-steps .exclaim-btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            border: 1.8px solid #1d1d1f;
            font-size: 13px;
            font-weight: 700;
            color: #1d1d1f;
            vertical-align: middle;
            line-height: 1;
        }
        .dl-modal-steps li code {
            background: #f5f5f7;
            border-radius: 4px;
            padding: 1px 6px;
            font-size: 14px;
            color: #d97706;
        }
        .dl-modal-steps li a {
            color: #06c;
            text-decoration: none;
            word-break: break-all;
        }
        .dl-modal-steps li a:hover {
            text-decoration: underline;
        }
        .dl-modal-disclaimer {
            font-size: 12px;
            color: var(--text-xs);
            text-align: center;
            margin-top: 16px;
        }
        .dl-modal-actions {
            display: flex;
            gap: 12px;
            justify-content: flex-end;
            align-items: center;
        }
        .dl-modal-actions .btn--text {
            color: var(--text-s);
            padding: 12px 20px;
            font-size: 15px;
        }
        .dl-modal-actions .btn--fill {
            padding: 12px 24px;
            font-size: 15px;
            position: relative;
            overflow: hidden;
            z-index: 0;
            transition: none;
        }
        .dl-modal-actions .btn--fill.is-waiting {
            pointer-events: none;
            opacity: 0.5;
        }

        @media (max-width: 734px) {
            .dl-modal-card {
                padding: 28px 20px 22px;
                border-radius: var(--radius-sm);
            }
            .dl-modal-steps li {
                font-size: 14px;
                padding-left: 28px;
            }
        }

        .gap-20 {
            gap: 20px;
        }