/* ========================================
   Rhythm Master ECG Patch - Main Stylesheet
   ======================================== */

/* CSS Variables */
:root {
    --primary-color: #0066CC;
    --primary-dark: #004C99;
    --primary-light: #4A90D9;
    --secondary-color: #0066CC;
    --accent-color: #0066CC;
    --text-primary: #111827;
    --text-secondary: #4B5563;
    --text-light: #6B7280;
    --bg-white: #FFFFFF;
    --bg-light: #F9FAFB;
    --bg-gray: #F3F4F6;
    --border-color: #E5E7EB;
    --success-color: #10B981;
    --warning-color: #F59E0B;
    --error-color: #EF4444;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 6px;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --container-max: 1200px;
    --header-height: 72px;
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul, ol {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Container */
.container {
    width: 100%;
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 32px;
}

/* Section Styles */
section {
    padding: 120px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-full);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    color: var(--bg-white);
}

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

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

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border-color: var(--border-color);
}

.btn-outline:hover {
    border-color: var(--primary-color);
    background: var(--bg-light);
    color: var(--primary-color);
}

/* Button focus states for accessibility */
.btn:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* ========================================
   Header
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--bg-white);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.header.scrolled {
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height);
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

.logo-img {
    height: 32px;
    width: auto;
}

.logo-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-list a {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 8px 0;
    position: relative;
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--primary-color);
    text-decoration: underline;
    text-underline-offset: 4px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.lang-switch {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.lang-switch:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.lang-icon {
    font-size: 0.75rem;
    color: var(--text-light);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
    background: var(--bg-white);
    overflow: hidden;
}

.hero-bg {
    display: none;
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-content {
    z-index: 1;
}

.hero-title {
    font-size: 3rem;
    font-weight: 600;
    line-height: 1.25;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 40px;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.device-showcase {
    position: relative;
    width: 100%;
    max-width: 450px;
}

.device-placeholder {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 40px;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 30px;
}

.ecg-wave {
    width: 100%;
    height: auto;
}



.device-icon {
    width: 80px;
    height: 50px;
    background: var(--primary-color);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--bg-white);
    font-weight: 700;
    font-size: 1rem;
}

.hero-product-image {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

/* ========================================
   Features Section
   ======================================== */
.features {
    background: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 32px;
    text-align: center;
}

.feature-card:hover {
    border-color: var(--primary-color);
}

.feature-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 20px;
    color: var(--primary-color);
    opacity: 0.8;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
    stroke-width: 1.5;
}

.feature-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.feature-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.feature-highlight {
    display: inline-block;
    padding: 6px 16px;
    background: var(--primary-color);
    color: var(--bg-white);
    font-size: 1.125rem;
    font-weight: 600;
    border-radius: 4px;
}

/* ========================================
   Products Section
   ======================================== */
.products {
    background: var(--bg-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.product-card {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 32px;
    position: relative;
    border: 1px solid var(--border-color);
}

.product-card:hover {
    border-color: var(--primary-color);
}

.product-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 4px 12px;
    background: var(--primary-color);
    color: var(--bg-white);
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 4px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.product-badge-pro {
    background: var(--primary-color);
}

.product-image {
    display: flex;
    justify-content: center;
    margin-bottom: 24px;
}

.product-placeholder {
    width: 120px;
    height: 120px;
    color: var(--primary-color);
}

.product-placeholder svg {
    width: 100%;
    height: 100%;
}

.product-img {
    width: 100%;
    max-height: 200px;
    object-fit: contain;
    border-radius: var(--radius-md);
}

.product-name {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    text-align: center;
}

.product-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 24px;
}

.product-features {
    margin-bottom: 32px;
}

.product-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 0;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--bg-light);
}

.product-features li:last-child {
    border-bottom: none;
}

.product-features li::before {
    content: '✓';
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    background: var(--success-color);
    color: var(--bg-white);
    font-size: 0.75rem;
    border-radius: 50%;
    flex-shrink: 0;
}

.product-card .btn {
    width: 100%;
}

/* ========================================
   Specifications Section
   ======================================== */
.specs {
    background: var(--bg-white);
}

.specs-table-wrapper {
    max-width: 800px;
    margin: 0 auto;
    overflow-x: auto;
}

.specs-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-white);
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.specs-table th,
.specs-table td {
    padding: 16px 24px;
    text-align: left;
}

.specs-table thead {
    background: var(--primary-color);
    color: var(--bg-white);
}

.specs-table th {
    font-weight: 600;
    font-size: 0.9375rem;
}

.specs-table tbody tr {
    border-bottom: 1px solid var(--bg-light);
    transition: background var(--transition-fast);
}

.specs-table tbody tr:hover {
    background: var(--bg-light);
}

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

.specs-table td:first-child {
    font-weight: 500;
    color: var(--text-primary);
}

.specs-table td:last-child {
    color: var(--text-secondary);
}

/* Multi-model Specs Table */
.specs-table-compare {
    min-width: 800px;
}

.specs-table-compare th,
.specs-table-compare td {
    text-align: center;
    vertical-align: middle;
}

.specs-table-compare td:first-child {
    text-align: left;
    background: var(--bg-light);
}

.specs-table-compare td[colspan] {
    background: var(--bg-light);
}

.model-header {
    min-width: 160px;
    padding: 16px 12px !important;
}

.model-badge {
    display: block;
    font-size: 0.6875rem;
    font-weight: 500;
    text-transform: uppercase;
    padding: 4px 10px;
    border-radius: 4px;
    margin-bottom: 8px;
    background: rgba(255, 255, 255, 0.2);
}

.model-header.bluetooth {
    background: var(--primary-color);
}

.model-header.wired {
    background: var(--primary-color);
}

.model-header.wired-pro {
    background: var(--primary-color);
}

.specs-table-compare .support {
    color: var(--success-color);
    font-weight: 600;
    font-size: 1.25rem;
}

.specs-table-compare .not-support {
    color: var(--text-light);
}

/* ========================================
   Guide Section
   ======================================== */
.guide {
    background: var(--bg-light);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-bottom: 60px;
}

.step-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 32px;
    text-align: center;
    position: relative;
}

.step-card:hover {
    border-color: var(--primary-color);
}

.step-number {
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: var(--bg-white);
    font-size: 1rem;
    font-weight: 600;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.step-icon {
    width: 80px;
    height: 80px;
    margin: 20px auto 24px;
    color: var(--primary-color);
}

.step-icon svg {
    width: 100%;
    height: 100%;
}

.step-icon .step-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: var(--radius-md);
}

.step-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.step-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Patch Position Guide */
.patch-guide {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 40px;
    margin-bottom: 40px;
    border: 1px solid var(--border-color);
}

.patch-guide-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: 24px;
}

.patch-guide-image {
    text-align: center;
    margin-bottom: 24px;
}

.patch-guide-image img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.patch-guide-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 20px;
}

.patch-step {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 12px;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.patch-step-num {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: var(--primary-color);
    color: var(--bg-white);
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 600;
    flex-shrink: 0;
}

.patch-guide-note {
    text-align: center;
    font-size: 0.8125rem;
    color: var(--text-light);
    padding: 12px;
    background: #FEF3C7;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--warning-color);
}

.guide-download {
    text-align: center;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

.guide-download h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.manual-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.manual-buttons .btn {
    min-width: 280px;
}

/* ========================================
   Video Section
   ======================================== */
.video-section {
    background: var(--bg-white);
}

.video-container {
    max-width: 900px;
    margin: 0 auto;
}

.video-label {
    text-align: center;
    font-size: 1rem;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 16px;
    padding: 8px 20px;
    background: var(--bg-light);
    border-radius: var(--radius-full);
    display: inline-block;
    margin-left: 50%;
    transform: translateX(-50%);
}

.video-wrapper {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.video-placeholder {
    aspect-ratio: 16 / 9;
    background: var(--bg-light);
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-placeholder-content {
    text-align: center;
    color: var(--text-light);
}

.video-placeholder-content svg {
    margin-bottom: 16px;
    opacity: 0.5;
}

.video-placeholder-content p {
    font-size: 1rem;
}

.tutorial-video {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: #f0f0f0;
    border-radius: var(--radius-lg);
}

.video-download-fallback {
    text-align: center;
    margin-top: 16px;
}

.video-download-fallback .btn {
    display: inline-flex;
}

/* ========================================
   Download Section
   ======================================== */
.download-section {
    background: var(--bg-light);
}

.download-block {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 40px;
    margin-bottom: 40px;
    border: 1px solid var(--border-color);
}

.download-block:last-of-type {
    margin-bottom: 40px;
}

.download-block-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 32px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--bg-light);
}

.download-desc {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
    padding: 12px 16px;
    background: var(--bg-light);
    border-radius: 4px;
}

.download-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.app-preview {
    display: flex;
    justify-content: center;
}

.pc-software .app-preview {
    flex-direction: column;
    align-items: center;
    gap: 16px;
}

.app-screenshots {
    display: flex;
    gap: 16px;
    justify-content: center;
    align-items: flex-start;
}

.app-screenshots .phone-frame {
    width: 180px;
    background: #1A1A2E;
    border-radius: 24px;
    padding: 8px;
    box-shadow: var(--shadow-xl);
}

.app-screenshot {
    width: 100%;
    height: auto;
    border-radius: 18px;
    display: block;
}

/* Vertical layout for app screenshots */
.app-screenshots-vertical {
    display: flex;
    flex-direction: column;
    gap: 20px;
    align-items: center;
}

.app-screenshots-vertical .phone-frame {
    width: 220px;
    background: #333;
    border-radius: 20px;
    padding: 5px;
    box-shadow: var(--shadow-lg);
}

.ecg-screen-frame {
    width: 100%;
    max-width: 400px;
}

.app-screenshot-landscape {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    border: 3px solid #1A1A2E;
}

.ecg-screen-label {
    text-align: center;
    font-size: 0.8125rem;
    color: var(--text-light);
    margin-top: 8px;
}

.phone-frame {
    width: 280px;
    background: #1A1A2E;
    border-radius: 36px;
    padding: 12px;
    box-shadow: var(--shadow-xl);
}

.phone-screen {
    background: var(--bg-white);
    border-radius: 28px;
    padding: 20px;
    min-height: 480px;
}

.app-header-mock {
    text-align: center;
    font-weight: 600;
    color: var(--primary-color);
    padding-bottom: 16px;
    border-bottom: 1px solid var(--bg-light);
    margin-bottom: 20px;
}

.ecg-preview {
    background: var(--bg-light);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 20px;
}

.ecg-wave-small path {
    stroke-dasharray: 300;
    stroke-dashoffset: 300;
    animation: drawWave 2s ease-in-out infinite;
}

.app-stats-mock {
    display: flex;
    justify-content: center;
    gap: 40px;
}

.stat-item {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-light);
    text-transform: uppercase;
}

.download-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 20px;
}

.app-features {
    margin-bottom: 32px;
}

.app-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.app-features li::before {
    content: '✓';
    color: var(--success-color);
    font-weight: 700;
}

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

.download-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: var(--text-primary);
    color: var(--bg-white);
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

.download-btn:hover {
    background: var(--primary-color);
    color: var(--bg-white);
    box-shadow: var(--shadow-md);
}

.download-btn-text {
    display: flex;
    flex-direction: column;
}

.download-btn-small {
    font-size: 0.625rem;
    opacity: 0.8;
}

.download-btn-large {
    font-size: 1.125rem;
    font-weight: 600;
}

.qr-code-section {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    background: var(--bg-white);
    border-radius: var(--radius-md);
    margin-bottom: 24px;
}


.qr-placeholder {
    color: var(--text-light);
}

.qr-code-section p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.cloud-platform {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
}

.cloud-platform p {
    color: var(--text-secondary);
}

.cloud-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    color: var(--primary-color);
    font-weight: 500;
}

.cloud-link:hover {
    text-decoration: underline;
}

/* PC Software Screenshot */
.pc-screenshot {
    margin-top: 0;
    width: 100%;
    max-width: 380px;
}

.pc-screenshot-img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
    border: 1px solid #e0e0e0;
}

.pc-screenshot-label {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 8px;
}

/* PC Software Mockup - Real Style */
.pc-mockup-real {
    display: flex;
    justify-content: center;
}

.pc-window-frame {
    width: 380px;
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid #e0e0e0;
}

.pc-window-titlebar {
    display: flex;
    align-items: center;
    padding: 6px 12px;
    background: #f5f5f5;
    border-bottom: 1px solid #e0e0e0;
}

.pc-window-icon {
    margin-right: 8px;
}

.pc-window-title {
    flex: 1;
    font-size: 12px;
    color: #333;
}

.pc-window-controls {
    display: flex;
    gap: 8px;
}

.pc-window-controls span {
    font-size: 12px;
    color: #666;
    cursor: pointer;
    width: 20px;
    text-align: center;
}

.pc-btn-close:hover {
    color: #e74c3c;
}

/* App Header - Green bar */
.pc-app-header {
    display: flex;
    align-items: center;
    padding: 8px 16px;
    background: #4ecdc4;
    color: white;
    font-size: 11px;
    gap: 12px;
}

.pc-app-logo svg {
    display: block;
}

.pc-app-menu-icon {
    font-size: 16px;
    cursor: pointer;
}

.pc-app-spacer {
    flex: 1;
}

.pc-app-view,
.pc-app-user,
.pc-app-lang {
    opacity: 0.9;
    font-size: 10px;
}

/* App Body - Sidebar + Content */
.pc-app-body {
    display: flex;
    min-height: 180px;
}

.pc-sidebar {
    width: 100px;
    background: #fafafa;
    border-right: 1px solid #eee;
    padding: 8px 0;
    font-size: 10px;
}

.pc-sidebar-section {
    padding: 4px 10px;
    color: #999;
    font-size: 9px;
    text-transform: uppercase;
}

.pc-sidebar-divider {
    padding: 8px 10px 4px;
    color: #999;
    font-size: 9px;
    margin-top: 4px;
    border-top: 1px solid #eee;
}

.pc-sidebar-item {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    color: #555;
    cursor: pointer;
    transition: background 0.2s;
}

.pc-sidebar-item:hover {
    background: #f0f0f0;
}

.pc-sidebar-item.active {
    color: #4ecdc4;
    font-weight: 500;
}

.pc-sidebar-item svg {
    flex-shrink: 0;
}

.pc-sidebar-arrow {
    margin-left: auto;
    color: #999;
}

/* Main Content with ECG */
.pc-main-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: var(--bg-light);
}

.pc-ecg-display {
    width: 100%;
    background: white;
    border-radius: 8px;
    padding: 16px;
    border: 1px solid #e0e0e0;
    position: relative;
}

.ecg-wave-animated {
    width: 100%;
    height: 60px;
}

.pc-ecg-info {
    position: absolute;
    top: 12px;
    right: 16px;
    text-align: right;
}

.pc-heart-rate {
    font-size: 28px;
    font-weight: 700;
    color: #2980b9;
    line-height: 1;
}

.pc-bpm {
    display: block;
    font-size: 10px;
    color: #666;
    margin-top: 2px;
}

/* Keep old styles for backward compatibility */
.pc-mockup {
    display: flex;
    justify-content: center;
}

.pc-frame {
    width: 320px;
    background: #1A1A2E;
    border-radius: 8px;
    padding: 8px;
}

.pc-screen {
    background: var(--bg-white);
    border-radius: 8px;
    overflow: hidden;
}

.pc-titlebar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    background: var(--bg-light);
    border-bottom: 1px solid var(--border-color);
}

.pc-dots {
    display: flex;
    gap: 6px;
}

.pc-dots i {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border-color);
}

.pc-dots i:first-child {
    background: #EF4444;
}

.pc-dots i:nth-child(2) {
    background: #F59E0B;
}

.pc-dots i:last-child {
    background: #10B981;
}

.pc-title {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.pc-content {
    padding: 24px;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pc-content .ecg-preview {
    width: 100%;
    background: var(--bg-light);
    border-radius: var(--radius-md);
    padding: 16px;
}

.download-btn.windows {
    background: #0078D4;
}

.download-btn.windows:hover {
    background: #106EBE;
}

.system-req {
    font-size: 0.8125rem;
    color: var(--text-light);
    margin-top: 16px;
}

.ios-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 8px;
    width: 100%;
}

.cloud-platform-section {
    text-align: center;
    padding: 32px;
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.cloud-platform-section .cloud-platform {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

.cloud-platform-section .cloud-platform svg {
    color: var(--primary-color);
}

/* ========================================
   FAQ Section
   ======================================== */
.faq {
    background: var(--bg-light);
}

.faq-list {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-white);
    border-radius: 8px;
    margin-bottom: 12px;
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.faq-item:hover {
    border-color: var(--primary-color);
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    background: none;
    border: none;
    cursor: pointer;
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: color 0.3s ease;
}

.faq-question:hover {
    color: var(--primary-color);
}

.faq-icon {
    flex-shrink: 0;
    transition: transform 0.3s ease;
    color: var(--text-secondary);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
    color: var(--primary-color);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 24px 20px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
    background: var(--bg-white);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 24px;
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.contact-item:hover {
    border-color: var(--primary-color);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: var(--bg-white);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.contact-text h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-light);
    margin-bottom: 4px;
    text-transform: uppercase;
}

.contact-text p {
    font-size: 0.9375rem;
    color: var(--text-primary);
}

.contact-text a {
    color: var(--primary-color);
}

.contact-text a:hover {
    text-decoration: underline;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--text-primary);
    color: var(--bg-white);
    padding: 60px 0 24px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 24px;
}

.footer .logo {
    color: var(--bg-white);
}

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

.footer .logo-icon {
    color: var(--accent-color);
}

.footer-logo {
    filter: brightness(1.2);
}

.footer-tagline {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 8px;
}

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
}

.footer-links a:hover {
    color: var(--bg-white);
}

.footer-bottom {
    text-align: center;
}

.footer-bottom p {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
}

/* ========================================
   Back to Top Button
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: var(--bg-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-normal);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .download-block {
        padding: 24px;
    }

    .pc-frame {
        width: 280px;
    }
    
    .pc-window-frame {
        width: 320px;
    }
    
    .pc-sidebar {
        width: 80px;
        font-size: 9px;
    }
    
    .pc-sidebar-item {
        padding: 5px 8px;
    }

    .nav {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .nav.active {
        display: block;
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--bg-white);
        padding: 24px;
        z-index: 999;
    }

    .nav.active .nav-list {
        flex-direction: column;
        gap: 0;
    }

    .nav.active .nav-list li {
        border-bottom: 1px solid var(--bg-light);
    }

    .nav.active .nav-list a {
        display: block;
        padding: 16px 0;
        font-size: 1.125rem;
    }

    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-content {
        order: 1;
    }

    .hero-image {
        order: 0;
        margin-bottom: 40px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        margin: 0 auto 40px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .features-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }

    .products-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }

    .steps-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto 60px;
    }

    .download-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .app-preview {
        order: 0;
        margin-bottom: 40px;
    }

    .download-info {
        order: 1;
    }

    .download-buttons {
        justify-content: center;
    }

    .qr-code-section {
        justify-content: center;
    }

    .cloud-platform {
        justify-content: center;
        flex-wrap: wrap;
    }

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

@media (max-width: 768px) {
    section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px;
    }

    .manual-buttons {
        flex-direction: column;
        align-items: center;
    }

    .manual-buttons .btn {
        width: 100%;
        max-width: 320px;
    }

    .patch-guide-steps {
        grid-template-columns: repeat(2, 1fr);
    }

    .patch-guide {
        padding: 24px;
    }

    .specs-table-wrapper {
        overflow-x: auto;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.875rem;
    }

    .feature-card,
    .step-card,
    .product-card {
        padding: 24px 20px;
    }

    .download-btn {
        width: 100%;
        justify-content: center;
    }

    .phone-frame {
        width: 240px;
    }

    .phone-screen {
        min-height: 400px;
    }

    .patch-guide-steps {
        grid-template-columns: 1fr;
    }

    .app-screenshots {
        flex-direction: column;
        align-items: center;
    }

    .app-screenshots .phone-frame {
        width: 200px;
    }

    .app-screenshots-vertical .phone-frame {
        width: 180px;
    }

    .ecg-screen-frame {
        max-width: 100%;
    }
}

/* Mobile menu animation */
.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}