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

:root {
    --primary: #07c160;
    --primary-dark: #06ad56;
    --primary-light: #e8f8ee;
    --bg: #ffffff;
    --bg-alt: #f7f8fa;
    --text: #1a1a1a;
    --text-secondary: #666;
    --text-light: #999;
    --border: #e5e5e5;
    --shadow: 0 4px 24px rgba(0,0,0,0.06);
    --radius: 16px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    font-family: var(--font);
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}
a:hover {
    color: var(--primary-dark);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========== Header ========== */
header {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
    background: rgba(255,255,255,0.92);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 22px;
    color: var(--text);
}
.logo svg {
    width: 36px;
    height: 36px;
}

nav {
    display: flex;
    gap: 32px;
    align-items: center;
}
nav a {
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 500;
    position: relative;
    padding: 4px 0;
}
nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}
nav a:hover::after,
nav a.active::after {
    width: 100%;
}
nav a.active {
    color: var(--primary);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 8px;
}
.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ========== Hero ========== */
.hero {
    padding: 80px 0 60px;
    background: linear-gradient(135deg, #f0fff4 0%, #ffffff 50%, #f7f8fa 100%);
    text-align: center;
}

.hero h1 {
    font-size: 48px;
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #07c160, #00a854);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
}

.download-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
    margin-bottom: 32px;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 16px 36px;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition);
    background: var(--primary);
    color: #fff;
    box-shadow: 0 8px 24px rgba(7,193,96,0.3);
}
.btn-download:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(7,193,96,0.4);
}
.btn-download.secondary {
    background: var(--bg);
    color: var(--text);
    border: 1.5px solid var(--border);
    box-shadow: var(--shadow);
}
.btn-download.secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

.platform-tabs {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.platform-tab {
    padding: 10px 24px;
    border-radius: 50px;
    border: 1.5px solid var(--border);
    background: var(--bg);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}
.platform-tab:hover {
    border-color: var(--primary);
    color: var(--primary);
}
.platform-tab.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.qr-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    margin-top: 16px;
}

.qr-code {
    width: 160px;
    height: 160px;
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.qr-code img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}
.qr-label {
    font-size: 13px;
    color: var(--text-light);
}

/* ========== Features ========== */
.features {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 48px;
    letter-spacing: -0.5px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
}
.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.06);
    border-color: var(--primary);
}

.feature-icon {
    width: 56px;
    height: 56px;
    margin: 0 auto 16px;
    background: var(--primary-light);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.feature-icon svg {
    width: 28px;
    height: 28px;
    color: var(--primary);
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}
.feature-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ========== Changelog ========== */
.changelog {
    padding: 80px 0;
    background: var(--bg-alt);
}

.changelog-list {
    max-width: 800px;
    margin: 0 auto;
}

.changelog-item {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 24px 32px;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    transition: var(--transition);
}
.changelog-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.changelog-item .version {
    font-weight: 700;
    font-size: 18px;
    color: var(--primary);
    margin-bottom: 4px;
}
.changelog-item .date {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 12px;
}
.changelog-item ul {
    list-style: none;
    padding: 0;
}
.changelog-item ul li {
    padding: 4px 0;
    font-size: 14px;
    color: var(--text-secondary);
    position: relative;
    padding-left: 20px;
}
.changelog-item ul li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
}

/* ========== FAQ ========== */
.faq {
    padding: 80px 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 12px;
    overflow: hidden;
    transition: var(--transition);
}
.faq-item:hover {
    border-color: var(--primary);
}

.faq-question {
    padding: 20px 24px;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--bg);
    transition: var(--transition);
    user-select: none;
}
.faq-question:hover {
    background: var(--primary-light);
}
.faq-question .arrow {
    transition: var(--transition);
    font-size: 12px;
    color: var(--text-light);
}
.faq-item.open .faq-question .arrow {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    padding: 0 24px;
    background: var(--bg);
}
.faq-item.open .faq-answer {
    max-height: 300px;
    padding: 0 24px 20px;
}
.faq-answer p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========== Feedback ========== */
.feedback {
    padding: 80px 0;
    background: var(--bg-alt);
}

.feedback-form {
    max-width: 560px;
    margin: 0 auto;
    background: var(--bg);
    border-radius: var(--radius);
    padding: 40px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.feedback-form h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 24px;
    text-align: center;
}

.form-group {
    margin-bottom: 16px;
}
.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text);
}
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg);
    color: var(--text);
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(7,193,96,0.1);
}
.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.btn-submit {
    width: 100%;
    padding: 14px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}
.btn-submit:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

/* ========== Recommend ========== */
.recommend {
    padding: 80px 0;
    text-align: center;
}

.recommend-card {
    max-width: 500px;
    margin: 0 auto;
    background: linear-gradient(135deg, #07c160, #00a854);
    border-radius: var(--radius);
    padding: 48px 40px;
    color: #fff;
    box-shadow: 0 16px 48px rgba(7,193,96,0.3);
}
.recommend-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 12px;
}
.recommend-card p {
    font-size: 15px;
    opacity: 0.9;
    margin-bottom: 24px;
}
.recommend-card .btn-download {
    background: #fff;
    color: var(--primary);
    box-shadow: none;
}
.recommend-card .btn-download:hover {
    background: var(--primary-light);
}

/* ========== Footer ========== */
footer {
    background: var(--text);
    color: rgba(255,255,255,0.7);
    padding: 40px 0;
    text-align: center;
}
footer a {
    color: rgba(255,255,255,0.8);
}
footer a:hover {
    color: #fff;
}
footer .footer-links {
    display: flex;
    justify-content: center;
    gap: 32px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}
footer .footer-links a {
    font-size: 14px;
}
footer p {
    font-size: 13px;
}

/* ========== Toast ========== */
.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--text);
    color: #fff;
    padding: 14px 28px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 500;
    opacity: 0;
    transition: all 0.4s ease;
    z-index: 999;
    pointer-events: none;
}
.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
    .header-inner {
        height: 60px;
    }
    nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--bg);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        align-items: flex-start;
        box-shadow: var(--shadow);
    }
    nav.open {
        display: flex;
    }
    .mobile-menu-btn {
        display: flex;
    }

    .hero h1 {
        font-size: 32px;
    }
    .hero p {
        font-size: 16px;
    }
    .download-buttons {
        flex-direction: column;
        align-items: center;
    }
    .btn-download {
        width: 100%;
        max-width: 320px;
        justify-content: center;
    }

    .section-title {
        font-size: 26px;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }

    .feedback-form {
        padding: 24px;
    }

    .recommend-card {
        padding: 32px 24px;
    }

    footer .footer-links {
        gap: 16px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    .hero {
        padding: 48px 0 32px;
    }
    .hero h1 {
        font-size: 28px;
    }
    .qr-code {
        width: 130px;
        height: 130px;
    }
}