:root {
    --blue: #75b8ff;
    --blue-deep: #2878c8;
    --blue-soft: #eaf6ff;
    --yellow: #fff3ba;
    --yellow-soft: #fff9dc;
    --orange: #ffa857;
    --orange-soft: #fff0df;
    --mint: #c9f2df;
    --text: #24384a;
    --muted: #64788b;
    --line: #dbeaf6;
    --white: #ffffff;
    --shadow: 0 18px 50px rgba(76, 125, 166, 0.16);
    --radius: 28px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: linear-gradient(180deg, #f7fcff 0%, #fffaf0 52%, #ffffff 100%);
    line-height: 1.75;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    width: min(1160px, calc(100% - 40px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 30;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(14px);
    box-shadow: 0 8px 30px rgba(94, 140, 178, 0.12);
}

.header-topline {
    height: 6px;
    background: linear-gradient(90deg, var(--blue), var(--yellow), var(--orange));
}

.nav-wrap {
    min-height: 78px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    min-width: max-content;
}

.brand-mark {
    width: 52px;
    height: 52px;
    border-radius: 18px;
    display: grid;
    place-items: center;
    font-weight: 900;
    color: var(--blue-deep);
    background: linear-gradient(135deg, var(--yellow), var(--blue-soft));
    box-shadow: 0 10px 24px rgba(89, 139, 188, 0.18);
}

.brand.compact .brand-mark {
    width: 46px;
    height: 46px;
}

.brand-text {
    display: grid;
    line-height: 1.2;
}

.brand-text strong {
    font-size: 20px;
}

.brand-text small {
    color: var(--muted);
    font-size: 12px;
    margin-top: 4px;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.main-nav a {
    padding: 10px 14px;
    border-radius: 999px;
    color: #35516a;
    font-weight: 700;
    transition: 0.2s ease;
}

.main-nav a:hover,
.main-nav a.active {
    background: var(--blue-soft);
    color: var(--blue-deep);
}

.nav-toggle {
    display: none;
    width: 44px;
    height: 44px;
    border: 0;
    background: var(--blue-soft);
    border-radius: 16px;
    padding: 10px;
}

.nav-toggle span {
    display: block;
    width: 100%;
    height: 3px;
    margin: 5px 0;
    background: var(--blue-deep);
    border-radius: 99px;
}

.hero,
.inner-hero {
    padding: 76px 0 58px;
    position: relative;
    overflow: hidden;
}

.hero::before,
.inner-hero::before {
    content: "";
    position: absolute;
    inset: 28px auto auto -120px;
    width: 320px;
    height: 320px;
    background: var(--yellow);
    border-radius: 50%;
    opacity: 0.55;
    z-index: -1;
}

.hero-grid,
.inner-hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
    align-items: center;
    gap: 48px;
}

.hero-copy h1,
.inner-hero h1 {
    font-size: clamp(36px, 5vw, 64px);
    line-height: 1.12;
    letter-spacing: -1.4px;
    margin: 14px 0 22px;
}

.inner-hero h1 {
    font-size: clamp(34px, 4vw, 54px);
}

.hero-desc,
.inner-hero p {
    font-size: 18px;
    color: var(--muted);
    max-width: 680px;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--blue-deep);
    font-weight: 900;
    letter-spacing: 0.08em;
}

.hero-actions,
.contact-strip-inner {
    display: flex;
    align-items: center;
    gap: 14px;
    flex-wrap: wrap;
    margin-top: 28px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 22px;
    border-radius: 999px;
    font-weight: 900;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn.primary {
    background: linear-gradient(135deg, var(--blue), #8ad0ff);
    color: #fff;
    box-shadow: 0 12px 24px rgba(54, 130, 204, 0.24);
}

.btn.secondary {
    background: #fff;
    border-color: var(--line);
    color: var(--blue-deep);
}

.text-link {
    display: inline-flex;
    margin-top: 20px;
    color: var(--blue-deep);
    font-weight: 900;
    border-bottom: 2px solid var(--orange);
}

.trust-strip {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 24px;
}

.trust-strip span,
.pill,
.tag {
    display: inline-flex;
    align-items: center;
    padding: 8px 14px;
    border-radius: 999px;
    background: var(--yellow-soft);
    color: #7b5d0d;
    font-weight: 800;
    font-size: 14px;
}

.pill.blue {
    background: var(--blue-soft);
    color: var(--blue-deep);
}

.pill.mint {
    background: var(--mint);
    color: #24764f;
}

.pill.orange {
    background: var(--orange-soft);
    color: #a85400;
}

.card-illustration,
.rounded-art,
.inner-hero img,
.weekly-panel img,
.image-stack img {
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    background: #fff;
}

.section {
    padding: 76px 0;
}

.soft-band {
    background: linear-gradient(180deg, rgba(234, 246, 255, 0.88), rgba(255, 249, 220, 0.7));
}

.warm-band {
    background: linear-gradient(180deg, rgba(255, 240, 223, 0.84), rgba(255, 255, 255, 0.78));
}

.section-head {
    max-width: 760px;
    margin-bottom: 34px;
}

.section-head.centered {
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.section-head h2,
.content-block h2,
.feedback-box h2,
.qa-box h2,
.contact-card h2,
.value-card h2,
.playlist-card h2,
.video-card h2,
.timeline-card h2,
.age-detail-card h2,
.qa-wide h2 {
    font-size: clamp(26px, 3vw, 40px);
    line-height: 1.18;
    margin: 0 0 14px;
}

.section-head p,
.content-block p,
.value-card p,
.playlist-card p,
.video-card p,
.timeline-card p,
.age-detail-card p,
.qa-wide p {
    color: var(--muted);
}

.age-grid,
.content-card-grid,
.feature-grid,
.mini-card-grid,
.values-grid,
.numbered-grid,
.age-detail-grid,
.safety-grid,
.video-grid,
.conversation-grid {
    display: grid;
    gap: 20px;
}

.age-grid {
    grid-template-columns: repeat(4, 1fr);
}

.age-card,
.content-card,
.feature-card,
.mini-card,
.value-card,
.playlist-card,
.age-detail-card,
.safety-grid article,
.video-card,
.timeline-card,
.conversation-grid article,
.contact-card,
.feedback-box,
.qa-box,
.qa-wide details {
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 12px 34px rgba(76, 125, 166, 0.1);
}

.age-card h3,
.content-card h3,
.feature-card h3,
.mini-card h3,
.numbered-grid h3,
.conversation-grid h3 {
    margin: 16px 0 8px;
    font-size: 22px;
}

.age-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 78px;
    height: 38px;
    padding: 0 14px;
    border-radius: 999px;
    background: var(--yellow);
    color: #7b5d0d;
    font-weight: 900;
}

.age-badge.orange {
    background: var(--orange-soft);
    color: #a85400;
}

.age-badge.blue {
    background: var(--blue-soft);
    color: var(--blue-deep);
}

.age-badge.mint {
    background: var(--mint);
    color: #24764f;
}

.split-layout,
.two-column-text,
.feedback-and-qa,
.contact-grid,
.inner-hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 44px;
    align-items: center;
}

.split-layout.reverse {
    grid-template-columns: 0.9fr 1.1fr;
}

.check-list {
    list-style: none;
    padding: 0;
    margin: 22px 0 0;
}

.check-list li {
    position: relative;
    padding: 12px 0 12px 36px;
    border-bottom: 1px dashed var(--line);
}

.check-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    top: 12px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    background: var(--mint);
    color: #24764f;
    font-weight: 900;
}

.content-card-grid {
    grid-template-columns: repeat(3, 1fr);
}

.content-card img,
.feature-card img {
    width: 100%;
    border-radius: 22px;
    background: var(--blue-soft);
}

.guide-points {
    display: grid;
    gap: 14px;
    margin-top: 22px;
}

.guide-points div,
.time-boxes div,
.domain-mini-list {
    padding: 18px;
    border-radius: 22px;
    background: #fff;
    border: 1px solid var(--line);
    display: grid;
    gap: 4px;
}

.guide-points strong,
.time-boxes strong {
    font-size: 18px;
    color: var(--blue-deep);
}

.guide-points span,
.time-boxes span,
.domain-mini-list span {
    color: var(--muted);
}

.feature-grid {
    grid-template-columns: repeat(3, 1fr);
}

.weekly-panel {
    display: grid;
    grid-template-columns: 1fr 0.9fr;
    gap: 30px;
    align-items: center;
    padding: 30px;
    border-radius: 34px;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.weekly-copy h3 {
    font-size: clamp(26px, 3vw, 42px);
    line-height: 1.2;
    margin: 18px 0 14px;
}

.mini-card-grid {
    grid-template-columns: repeat(4, 1fr);
}

.mini-card span {
    color: var(--orange);
    font-weight: 900;
}

.feedback-and-qa {
    align-items: start;
}

blockquote {
    margin: 20px 0;
    padding: 22px;
    border-left: 6px solid var(--orange);
    background: var(--yellow-soft);
    border-radius: 20px;
    font-size: 20px;
    color: #4a3e21;
}

details {
    margin: 14px 0;
}

summary {
    cursor: pointer;
    font-weight: 900;
    color: var(--text);
}

.contact-strip {
    padding: 54px 0;
    background: linear-gradient(135deg, var(--blue-soft), var(--yellow-soft));
}

.contact-strip-inner {
    justify-content: space-between;
    margin-top: 0;
}

.site-footer {
    background: #24465f;
    color: #f8fbff;
    margin-top: 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.4fr 0.8fr 1fr;
    gap: 34px;
    padding: 54px 0;
}

.footer-grid p,
.footer-grid a,
.footer-grid small {
    color: rgba(248, 251, 255, 0.78);
}

.footer-grid h2 {
    font-size: 20px;
    margin: 0 0 14px;
    color: #fff;
}

.footer-link-list {
    display: grid;
    gap: 10px;
}

.footer-link-list a:hover {
    color: var(--yellow);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.16);
    padding: 16px 0;
    color: rgba(248, 251, 255, 0.72);
}

.footer-bottom p {
    margin: 0;
}

.current-site,
.update-time {
    font-weight: 800;
}

.inner-hero.warm {
    background: linear-gradient(180deg, var(--yellow-soft), rgba(255, 255, 255, 0));
}

.inner-hero.blue {
    background: linear-gradient(180deg, var(--blue-soft), rgba(255, 255, 255, 0));
}

.values-grid {
    grid-template-columns: 1.2fr 1fr 1fr;
    align-items: stretch;
}

.value-card.highlight {
    background: linear-gradient(135deg, var(--blue-soft), var(--yellow-soft));
}

.numbered-grid {
    grid-template-columns: repeat(4, 1fr);
}

.numbered-grid article {
    padding: 24px;
    border-radius: var(--radius);
    background: #fff;
    border: 1px solid var(--line);
}

.numbered-grid span {
    font-size: 36px;
    font-weight: 900;
    color: var(--orange);
}

.playlist-grid {
    display: grid;
    grid-template-columns: 1.3fr 1fr 1fr;
    gap: 20px;
}

.playlist-card.large {
    grid-row: span 2;
    background: linear-gradient(135deg, var(--yellow-soft), #fff);
}

.playlist-card ul,
.age-detail-card ul {
    padding-left: 20px;
    color: var(--muted);
}

.theme-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.theme-card {
    border-radius: 26px;
    padding: 24px;
    background: #fff;
    border: 1px solid var(--line);
    display: grid;
    gap: 8px;
    text-align: center;
}

.theme-card strong {
    font-size: 28px;
    color: var(--blue-deep);
}

.age-detail-grid {
    grid-template-columns: repeat(3, 1fr);
}

.safety-grid {
    grid-template-columns: repeat(3, 1fr);
}

.timeline {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.timeline-card span {
    color: var(--orange);
    font-weight: 900;
}

.time-boxes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-top: 24px;
}

.conversation-grid {
    grid-template-columns: repeat(4, 1fr);
}

.conversation-grid .full-row {
    grid-column: 1 / -1;
}

.video-grid {
    grid-template-columns: repeat(3, 1fr);
}

.featured-video {
    grid-column: 1 / -1;
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 28px;
    align-items: center;
}

.video-cover {
    position: relative;
    border-radius: 24px;
    overflow: hidden;
    background: var(--blue-soft);
}

.video-cover img {
    width: 100%;
}

.play-dot {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 64px;
    height: 64px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.92);
    color: var(--blue-deep);
    font-weight: 900;
    box-shadow: 0 12px 28px rgba(36, 56, 74, 0.14);
}

.contact-grid {
    align-items: start;
}

.feedback-form {
    display: grid;
    gap: 16px;
}

.feedback-form label {
    display: grid;
    gap: 8px;
    font-weight: 900;
}

.feedback-form input,
.feedback-form select,
.feedback-form textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 13px 14px;
    font: inherit;
    color: var(--text);
    background: #fff;
    outline: none;
}

.feedback-form input:focus,
.feedback-form select:focus,
.feedback-form textarea:focus {
    border-color: var(--blue);
    box-shadow: 0 0 0 4px rgba(117, 184, 255, 0.18);
}

.form-result {
    min-height: 24px;
    color: var(--blue-deep);
    font-weight: 800;
}

.domain-display {
    border-radius: 28px;
    padding: 28px;
    background: linear-gradient(135deg, var(--blue-soft), var(--yellow-soft));
    font-size: clamp(24px, 4vw, 40px);
    font-weight: 900;
    color: var(--blue-deep);
    word-break: break-all;
    margin: 18px 0;
}

.domain-mini-list strong {
    word-break: break-all;
    color: var(--blue-deep);
}

.qa-wide {
    max-width: 860px;
}

.qa-wide details {
    padding: 22px 24px;
}

@media (max-width: 980px) {
    .nav-toggle {
        display: block;
    }

    .main-nav {
        position: absolute;
        left: 20px;
        right: 20px;
        top: 84px;
        display: none;
        padding: 18px;
        border-radius: 24px;
        background: #fff;
        box-shadow: var(--shadow);
        justify-content: flex-start;
    }

    .main-nav.open {
        display: flex;
    }

    .hero-grid,
    .inner-hero-grid,
    .split-layout,
    .split-layout.reverse,
    .two-column-text,
    .feedback-and-qa,
    .contact-grid,
    .weekly-panel,
    .featured-video,
    .footer-grid {
        grid-template-columns: 1fr;
    }

    .age-grid,
    .content-card-grid,
    .feature-grid,
    .mini-card-grid,
    .values-grid,
    .numbered-grid,
    .playlist-grid,
    .theme-row,
    .age-detail-grid,
    .safety-grid,
    .timeline,
    .time-boxes,
    .conversation-grid,
    .video-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .playlist-card.large {
        grid-row: auto;
        grid-column: 1 / -1;
    }
}

@media (max-width: 620px) {
    .container {
        width: min(100% - 28px, 1160px);
    }

    .hero,
    .inner-hero,
    .section {
        padding: 52px 0;
    }

    .brand-text small {
        display: none;
    }

    .main-nav {
        left: 14px;
        right: 14px;
    }

    .age-grid,
    .content-card-grid,
    .feature-grid,
    .mini-card-grid,
    .numbered-grid,
    .theme-row,
    .age-detail-grid,
    .safety-grid,
    .timeline,
    .time-boxes,
    .conversation-grid,
    .video-grid {
        grid-template-columns: 1fr;
    }

    .hero-actions,
    .contact-strip-inner {
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .footer-grid {
        padding: 40px 0;
    }
}