/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #ffcc00;
    --primary-dark: #e6b800;
    --primary-light: #ffdd33;
    --accent-color: #ff9900;
    --text-dark: #212121;
    --text-gray: #555555;
    --bg-light: #f5f5f5;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --success-color: #4caf50;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-dark);
    background-color: var(--bg-white);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header Navigation */
.header {
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-img {
    max-height: 50px;
    width: auto;
    transition: opacity 0.3s ease;
}

.logo-img:hover {
    opacity: 0.8;
}

.logo h1 {
    color: var(--primary-color);
    font-size: 28px;
    font-weight: 700;
}

.nav {
    display: flex;
    gap: 30px;
}

.nav a {
    color: var(--text-gray);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav a:hover {
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #f5f5f5 0%, #fafafa 100%);
    padding: 80px 20px;
    text-align: center;
}

.hero-content h2 {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 15px;
    font-weight: 700;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--text-gray);
    margin-bottom: 20px;
    font-weight: 600;
}

.hero-description {
    font-size: 16px;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

/* Download Box */
.download-box {
    background: var(--bg-white);
    border: 2px solid var(--primary-color);
    border-radius: 12px;
    padding: 30px;
    max-width: 600px;
    margin: 0 auto;
    box-shadow: 0 10px 30px rgba(30, 136, 229, 0.1);
}

.apk-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 30px;
    text-align: left;
}

.info-row {
    display: flex;
    flex-direction: column;
}

.info-row .label {
    font-weight: 600;
    color: var(--text-gray);
    font-size: 14px;
    margin-bottom: 5px;
}

.info-row .value {
    font-size: 16px;
    color: var(--primary-color);
    font-weight: 700;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(30, 136, 229, 0.3);
}

.btn-large {
    width: 100%;
    padding: 16px;
    font-size: 18px;
    border-radius: 8px;
}

.safety-note {
    margin-top: 20px;
    font-size: 14px;
    color: var(--success-color);
    font-weight: 600;
}

/* Overview Section */
.overview {
    padding: 60px 20px;
    background: var(--bg-white);
}

.overview h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 20px;
    font-weight: 700;
}

.overview > .container > p {
    text-align: center;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto 50px;
    font-size: 16px;
    line-height: 1.8;
}

.overview-highlights {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.highlight {
    text-align: center;
    padding: 30px;
    background: var(--bg-light);
    border-radius: 12px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.highlight:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.highlight .icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.highlight h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 18px;
    font-weight: 600;
}

.highlight p {
    color: var(--text-gray);
    font-size: 14px;
}

/* Features Section */
.features {
    padding: 60px 20px;
    background: linear-gradient(135deg, #f5f5f5 0%, #fafafa 100%);
}

.features h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 50px;
    font-weight: 700;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-white);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-top: 4px solid var(--primary-color);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(30, 136, 229, 0.15);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.feature-card h4 {
    color: var(--text-dark);
    margin-bottom: 12px;
    font-size: 18px;
    font-weight: 600;
}

.feature-card p {
    color: var(--text-gray);
    font-size: 14px;
    line-height: 1.6;
}

/* Installation Section */
.installation {
    padding: 60px 20px;
    background: var(--bg-white);
}

.installation h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 15px;
    font-weight: 700;
}

.intro-text {
    text-align: center;
    color: var(--text-gray);
    margin-bottom: 50px;
    font-size: 16px;
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.step {
    background: var(--bg-light);
    padding: 30px;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
    transition: transform 0.3s ease;
}

.step:hover {
    transform: translateX(5px);
}

.step-number {
    background: var(--primary-color);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    margin-bottom: 15px;
}

.step h4 {
    color: var(--text-dark);
    margin-bottom: 10px;
    font-size: 16px;
    font-weight: 600;
}

.step p {
    color: var(--text-gray);
    font-size: 14px;
    line-height: 1.6;
}

/* Specifications Section */
.specifications {
    padding: 60px 20px;
    background: linear-gradient(135deg, #f5f5f5 0%, #fafafa 100%);
}

.specifications h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 40px;
    font-weight: 700;
}

.table-wrapper {
    overflow-x: auto;
    background: var(--bg-white);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
}

.specs-table tr {
    border-bottom: 1px solid var(--border-color);
}

.specs-table tr:last-child {
    border-bottom: none;
}

.specs-table td {
    padding: 20px;
    font-size: 15px;
    color: var(--text-gray);
}

.specs-table td:first-child {
    width: 40%;
    color: var(--text-dark);
    font-weight: 600;
    background: var(--bg-light);
}

.specs-table tr:nth-child(even) td:first-child {
    background: var(--bg-white);
}

/* Content Section */
.content-section {
    padding: 60px 20px;
    background: var(--bg-white);
}

.content-section h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 20px;
    font-weight: 700;
}

.content-section > .container > p {
    text-align: center;
    color: var(--text-gray);
    margin-bottom: 40px;
    font-size: 16px;
}

.content-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.category {
    background: var(--bg-light);
    padding: 30px;
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
}

.category h4 {
    color: var(--text-dark);
    margin-bottom: 15px;
    font-size: 18px;
    font-weight: 600;
}

.category p {
    color: var(--text-gray);
    font-size: 14px;
    line-height: 1.8;
}

/* Troubleshooting Section */
.troubleshooting {
    padding: 60px 20px;
    background: linear-gradient(135deg, #f5f5f5 0%, #fafafa 100%);
}

.troubleshooting h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 20px;
    font-weight: 700;
}

.troubleshooting > .container > p {
    text-align: center;
    color: var(--text-gray);
    margin-bottom: 40px;
    font-size: 16px;
}

.issues-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.issue-card {
    background: var(--bg-white);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    border-top: 3px solid var(--primary-color);
}

.issue-card h4 {
    color: var(--text-dark);
    margin-bottom: 12px;
    font-size: 16px;
    font-weight: 600;
}

.issue-card p {
    color: var(--text-gray);
    font-size: 14px;
    line-height: 1.6;
}

/* FAQ Section */
.faq {
    padding: 60px 20px;
    background: var(--bg-white);
}

.faq h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 50px;
    font-weight: 700;
}

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

.faq-item {
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background: var(--bg-white);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background: var(--bg-light);
    cursor: pointer;
    transition: background 0.3s ease;
    user-select: none;
}

.faq-question:hover {
    background: #efefef;
}

.faq-question h4 {
    margin: 0;
    color: var(--text-dark);
    font-size: 16px;
    font-weight: 600;
}

.faq-toggle {
    color: var(--primary-color);
    font-size: 24px;
    font-weight: 700;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 20px;
    background: var(--bg-white);
    border-top: 1px solid var(--border-color);
    display: none;
}

.faq-item.active .faq-answer {
    display: block;
}

.faq-answer p {
    color: var(--text-gray);
    font-size: 15px;
    line-height: 1.8;
}

/* Safety Section */
.safety {
    padding: 60px 20px;
    background: linear-gradient(135deg, #f5f5f5 0%, #fafafa 100%);
}

.safety h3 {
    font-size: 36px;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 30px;
    font-weight: 700;
}

.safety > .container > p {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 20px;
    font-size: 16px;
}

.safety-list {
    list-style: none;
    max-width: 600px;
    margin: 0 auto 40px;
    padding: 0;
}

.safety-list li {
    padding: 12px 0;
    color: var(--text-gray);
    font-size: 15px;
    line-height: 1.8;
    border-bottom: 1px solid var(--border-color);
}

.safety-list li:last-child {
    border-bottom: none;
}

.disclaimer {
    background: var(--bg-white);
    padding: 30px;
    border-left: 4px solid var(--primary-color);
    border-radius: 8px;
    max-width: 800px;
    margin: 0 auto;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
}

.disclaimer p {
    color: var(--text-gray);
    font-size: 15px;
    line-height: 1.8;
    margin: 0;
}

.disclaimer strong {
    color: var(--text-dark);
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 40px 20px;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer p {
    margin: 10px 0;
    font-size: 14px;
}

.footer a {
    color: var(--primary-light);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: var(--accent-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .hero-content h2 {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .apk-info {
        grid-template-columns: 1fr;
    }

    .features-grid,
    .overview-highlights,
    .content-categories,
    .issues-grid,
    .steps {
        grid-template-columns: 1fr;
    }

    h3 {
        font-size: 28px !important;
    }

    .specs-table td {
        padding: 15px;
        font-size: 14px;
    }
}

@media (max-width: 480px) {
    .hero-content h2 {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .download-box {
        padding: 20px;
    }

    .btn-large {
        font-size: 16px;
        padding: 14px;
    }

    h3 {
        font-size: 22px !important;
    }

    .nav a {
        gap: 15px;
    }
}