:root {
    --bg: #fbfbfc;
    --surface: #ffffff;
    --fg: #20232a;
    --muted: #747986;
    --border: #e7e8ec;
    --accent: #3f6fff;
    --accent-subtle: #eef3ff;
    --green: #239f63;
    --red: #d84a4a;
    --yellow: #c98714;
    --font-display: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'PingFang SC', system-ui, sans-serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'PingFang SC', system-ui, sans-serif;
    --font-mono: ui-monospace, 'SF Mono', 'JetBrains Mono', Menlo, monospace;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #17191f;
        --surface: #20232b;
        --fg: #f2f4f8;
        --muted: #a7adba;
        --border: #373b46;
        --accent: #6d91ff;
        --accent-subtle: #26355f;
        --green: #4fca83;
        --red: #f16a6a;
        --yellow: #e5b54c;
    }
}

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

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

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--fg);
    background: var(--bg);
    overflow-x: hidden;
}

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

a {
    color: inherit;
}

button,
a {
    -webkit-tap-highlight-color: transparent;
}

.container {
    max-width: 680px;
    margin: 0 auto;
    padding: 0 24px;
}

.comparison-section .container,
.nav-container,
.footer .container {
    max-width: 860px;
}

.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(251, 251, 252, 0.84);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}

@media (prefers-color-scheme: dark) {
    .navbar {
        background: rgba(23, 25, 31, 0.84);
    }
}

.nav-container {
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-size: 15px;
    font-weight: 600;
    color: var(--fg);
    letter-spacing: -0.01em;
}

.nav-brand i {
    color: var(--accent);
    font-size: 15px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    color: var(--muted);
    text-decoration: none;
    transition: color 0.15s ease;
}

.nav-link:hover {
    color: var(--fg);
}

.hero-section {
    padding: 72px 0 40px;
    text-align: center;
}

.hero-copy {
    margin-bottom: 40px;
}

.hero-eyebrow {
    font-family: var(--font-display);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    margin-bottom: 16px;
    font-weight: 600;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(36px, 9vw, 56px);
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1.08;
    margin-bottom: 20px;
    color: var(--fg);
}

.hero-desc {
    font-size: 17px;
    line-height: 1.65;
    color: var(--muted);
    max-width: 440px;
    margin: 0 auto 36px;
}

.hero-actions,
.update-actions,
.reminder-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-image {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 16px;
}

.hero-image img,
.feature-image img,
.recommendation-image img,
.live-faq-image img {
    width: 100%;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--surface);
}

section {
    padding: 56px 0;
}

section + section {
    border-top: 1px solid var(--border);
}

.section-title,
.table-title {
    font-family: var(--font-display);
    font-size: 22px;
    font-weight: 600;
    letter-spacing: -0.01em;
    line-height: 1.25;
    color: var(--fg);
    margin-bottom: 16px;
}

.section-title {
    display: flex;
    align-items: center;
    gap: 10px;
}

.section-title i,
.feature-header i,
.recommendation-note i,
.live-faq-question span i {
    color: var(--accent);
}

.section-description,
.feature-content p,
.recommendation-text,
.live-faq-content p,
.app-required-box p,
.modal-auth-code-notice p {
    color: var(--muted);
    line-height: 1.7;
}

.update-card,
.recommendation-card,
.auth-code-card,
.live-faq-item,
.app-required-box,
.modal-auth-code-notice,
.live-faq-notice,
.modal {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
}

.update-card,
.recommendation-card {
    padding: 24px;
}

.update-list {
    list-style: none;
    display: grid;
    gap: 6px;
    margin-bottom: 24px;
}

.update-list li {
    position: relative;
    padding-left: 16px;
    color: var(--muted);
    font-size: 15px;
    line-height: 1.65;
}

.update-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--border);
}

.update-btn,
.install-main-btn,
.btn,
.auth-copy-btn,
.app-store-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    border-radius: 8px;
    font-family: var(--font-display);
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.15s ease;
    white-space: nowrap;
}

.update-btn,
.btn-primary {
    padding: 10px 20px;
    border: 1px solid var(--accent);
    background: var(--accent);
    color: #fff;
}

.update-btn:hover,
.btn-primary:hover {
    filter: brightness(1.08);
}

.install-main-btn,
.btn-secondary {
    padding: 10px 20px;
    background: transparent;
    color: var(--fg);
    border: 1px solid var(--border);
}

.install-main-btn:hover,
.btn-secondary:hover {
    border-color: var(--muted);
}

.auth-code-card {
    display: none;
    margin-top: 28px;
    padding: 20px 24px;
    text-align: center;
}

.auth-code-card.show {
    display: grid;
    gap: 12px;
}

.auth-code-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-size: 12px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.auth-code-value {
    font-family: var(--font-mono);
    font-size: 22px;
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--fg);
    user-select: all;
    -webkit-user-select: all;
}

.auth-copy-btn {
    justify-self: center;
    padding: 6px 14px;
    border: none;
    background: var(--accent-subtle);
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
    border-radius: 6px;
}

.auth-copy-btn:hover {
    background: var(--accent);
    color: #fff;
}

.feature-card {
    margin-top: 24px;
}

.feature-header h3 {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-size: 17px;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--fg);
    margin-bottom: 8px;
}

.feature-content p {
    margin-bottom: 16px;
}

.feature-image,
.recommendation-image,
.live-faq-image {
    margin: 24px 0;
}

.feature-note {
    font-size: 13px;
    color: var(--muted);
    text-align: center;
    margin-top: 8px;
}

.comparison-table {
    margin-top: 36px;
}

.table-container {
    overflow-x: auto;
    margin: 24px -24px 0;
    padding: 0 24px;
    -webkit-overflow-scrolling: touch;
}

table {
    width: 100%;
    min-width: 560px;
    border-collapse: collapse;
    font-size: 14px;
}

th,
td {
    padding: 11px 14px;
    text-align: left;
    border-bottom: 1px solid var(--border);
    vertical-align: top;
}

th {
    color: var(--muted);
    font-size: 13px;
    font-weight: 600;
}

td {
    color: var(--muted);
}

th:first-child,
td:first-child {
    color: var(--fg);
    font-weight: 500;
}

.highlight-green {
    color: var(--green);
    font-weight: 550;
}

.highlight-red {
    color: var(--red);
    font-weight: 550;
}

.recommendation-text {
    font-size: 16px;
    margin-bottom: 0;
}

.recommendation-note,
.live-faq-notice {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 14px 18px;
    color: var(--muted);
    font-size: 14px;
    line-height: 1.6;
}

.recommendation-note strong,
.live-faq-content strong {
    color: var(--fg);
    font-weight: 550;
}

.live-faq-list {
    display: grid;
    gap: 10px;
}

.live-faq-item {
    overflow: hidden;
}

.live-faq-question {
    width: 100%;
    border: none;
    background: transparent;
    padding: 16px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    color: var(--fg);
    font: inherit;
    font-size: 15px;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
}

.live-faq-question span {
    display: flex;
    align-items: center;
    gap: 8px;
}

.live-faq-toggle {
    color: var(--muted);
    transition: transform 0.2s ease;
}

.live-faq-item.active .live-faq-toggle {
    transform: rotate(180deg);
}

.live-faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
}

.live-faq-item.active .live-faq-answer {
    max-height: 1800px;
}

.live-faq-content {
    padding: 0 18px 18px;
}

.live-faq-content p {
    font-size: 14px;
    margin-bottom: 14px;
}

.live-faq-content a {
    color: var(--accent);
    font-weight: 550;
    text-decoration: none;
}

.live-faq-content a:hover {
    text-decoration: underline;
}

.live-faq-notice i,
.live-faq-notice strong,
.modal-auth-code-notice i,
.modal-auth-code-notice strong {
    color: var(--yellow);
}

.footer {
    padding: 32px 0;
    border-top: 1px solid var(--border);
    text-align: center;
}

.footer p {
    font-size: 13px;
    color: var(--muted);
}

.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 24px;
    background: rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.modal-overlay.active {
    display: flex;
}

.modal {
    width: 100%;
    max-width: 440px;
    max-height: 80vh;
    overflow: auto;
    color: var(--fg);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
}

.modal-header h3 {
    font-family: var(--font-display);
    font-size: 16px;
    font-weight: 600;
}

.modal-close {
    border: none;
    background: transparent;
    color: var(--muted);
    font-size: 18px;
    cursor: pointer;
}

.modal-body {
    padding: 20px;
}

.install-modal-content {
    display: grid;
    gap: 14px;
}

.app-required-box,
.modal-auth-code-notice {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 14px 18px;
}

.app-required-icon,
.app-store-link {
    color: var(--accent);
}

.app-required-box h4 {
    font-family: var(--font-display);
    font-size: 15px;
    font-weight: 600;
    color: var(--fg);
    margin-bottom: 6px;
}

.app-required-box p,
.modal-auth-code-notice p {
    font-size: 14px;
}

.app-store-link {
    justify-content: flex-start;
    padding: 8px 0 0;
    font-weight: 550;
}

.modal-auth-code-notice {
    display: none;
}

.modal-auth-code-notice.show {
    display: flex;
}

.toast {
    position: fixed;
    left: 50%;
    bottom: 28px;
    z-index: 1200;
    transform: translateX(-50%) translateY(60px);
    opacity: 0;
    pointer-events: none;
    background: var(--fg);
    color: var(--bg);
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.2s ease;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

.toast-icon {
    display: none;
}

@media (max-width: 600px) {
    .container,
    .nav-container {
        padding-left: 24px;
        padding-right: 24px;
    }

    .nav-link span {
        display: none;
    }

    .hero-section {
        padding: 56px 0 32px;
    }

    .hero-copy {
        margin-bottom: 32px;
    }

    .hero-desc {
        font-size: 16px;
        margin-bottom: 28px;
    }

    .hero-actions,
    .update-actions,
    .reminder-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .update-btn,
    .install-main-btn,
    .btn {
        width: 100%;
    }

    section {
        padding: 44px 0;
    }

    .section-title,
    .table-title {
        font-size: 21px;
    }

    .auth-code-value {
        font-size: 18px;
    }
}