/* ============================================
   条码扫描 - 智能快递柜管理系统
   响应式样式表
   ============================================ */

/* ---------- CSS Variables ---------- */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #3b82f6;
    --color-secondary: #0f172a;
    --color-accent: #f59e0b;
    --color-white: #ffffff;
    --color-gray-50: #f8fafc;
    --color-gray-100: #f1f5f9;
    --color-gray-200: #e2e8f0;
    --color-gray-300: #cbd5e1;
    --color-gray-400: #94a3b8;
    --color-gray-500: #64748b;
    --color-gray-600: #475569;
    --color-gray-700: #334155;
    --color-gray-800: #1e293b;
    --color-gray-900: #0f172a;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-error: #ef4444;

    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --transition: all 0.3s ease;
    --container-max: 1200px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-gray-800);
    background: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

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

ul {
    list-style: none;
}

/* ---------- Container ---------- */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- Section ---------- */
section {
    padding: 80px 0;
}

section:nth-child(even) {
    background: var(--color-gray-50);
}

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--color-gray-900);
    text-align: center;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-desc {
    font-size: 1.1rem;
    color: var(--color-gray-500);
    text-align: center;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    text-align: center;
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    color: var(--color-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-outline:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-download {
    width: 100%;
    justify-content: center;
    font-size: 1.1rem;
    padding: 18px 32px;
}

.btn-store {
    background: var(--color-white);
    border: 1px solid var(--color-gray-200);
    color: var(--color-gray-700);
    padding: 10px 20px;
    font-size: 0.9rem;
}

.btn-store:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
    background: var(--color-gray-50);
}

/* ---------- Navbar ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-gray-200);
    transition: var(--transition);
}

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

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--color-gray-900);
    font-weight: 800;
    font-size: 1.3rem;
}

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

.logo-icon {
    font-size: 1.6rem;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    color: var(--color-gray-600);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
    background: var(--color-gray-100);
}

/* Mobile nav toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-gray-700);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

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

/* ---------- Hero ---------- */
.hero {
    padding-top: 150px;
    padding-bottom: 100px;
    background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 50%, #f0f9ff 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
    border-radius: 50%;
}

.hero-container {
    display: flex;
    align-items: center;
    gap: 60px;
    position: relative;
    z-index: 1;
}

.hero-content {
    flex: 1;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    color: var(--color-gray-900);
    line-height: 1.2;
    letter-spacing: -0.03em;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-top: 8px;
    margin-bottom: 24px;
}

.hero-desc {
    font-size: 1.1rem;
    color: var(--color-gray-500);
    line-height: 1.8;
    margin-bottom: 32px;
    max-width: 520px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.hero-info {
    font-size: 0.9rem;
    color: var(--color-gray-400);
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.divider {
    color: var(--color-gray-300);
}

/* Hero Mockup */
.hero-image {
    flex: 0 0 320px;
    display: flex;
    justify-content: center;
}

.hero-mockup {
    position: relative;
}

.mockup-screen {
    width: 260px;
    height: 460px;
    background: var(--color-white);
    border-radius: 28px;
    box-shadow: var(--shadow-xl), 0 0 0 8px var(--color-gray-800);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.mockup-status-bar {
    height: 24px;
    background: var(--color-gray-800);
}

.mockup-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 16px;
    padding: 40px 20px;
    background: linear-gradient(180deg, #f0f9ff 0%, #ffffff 100%);
}

.mockup-icon {
    font-size: 60px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.mockup-text {
    font-size: 0.95rem;
    color: var(--color-gray-600);
    font-weight: 500;
}

.mockup-scan-line {
    width: 180px;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
    animation: scanPulse 2s ease-in-out infinite;
}

@keyframes scanPulse {
    0%, 100% { opacity: 0.3; transform: scaleX(0.8); }
    50% { opacity: 1; transform: scaleX(1); }
}

.mockup-btn {
    padding: 10px 24px;
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

/* ---------- Features ---------- */
.features {
    background: var(--color-white);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary-light);
}

.feature-icon {
    font-size: 2.8rem;
    margin-bottom: 16px;
    display: block;
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 0.92rem;
    color: var(--color-gray-500);
    line-height: 1.7;
}

/* ---------- Screenshots / Scenarios ---------- */
.scenario-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.scenario-card {
    background: var(--color-white);
    border: 1px solid var(--color-gray-200);
    border-radius: var(--radius-lg);
    padding: 32px;
    display: flex;
    gap: 20px;
    transition: var(--transition);
}

.scenario-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
}

.scenario-num {
    font-size: 2rem;
    font-weight: 900;
    color: var(--color-primary);
    opacity: 0.3;
    line-height: 1;
    flex-shrink: 0;
}

.scenario-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 8px;
}

.scenario-card p {
    font-size: 0.92rem;
    color: var(--color-gray-500);
    line-height: 1.7;
}

/* ---------- Update Notice ---------- */
.update-notice {
    margin: 16px 0;
    padding: 16px 20px;
    background: #fffbeb;
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-warning);
}

.update-notice h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 8px;
}

.update-notice p {
    font-size: 0.92rem;
    color: var(--color-gray-600);
    line-height: 1.7;
}

.btn-sm {
    padding: 8px 20px;
    font-size: 0.85rem;
}

/* ---------- Download ---------- */
.download {
    background: linear-gradient(135deg, var(--color-secondary) 0%, #1a2744 100%);
}

.download .section-title {
    color: var(--color-white);
}

.download .section-desc {
    color: var(--color-gray-400);
}

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

.download-card {
    background: var(--color-white);
    border-radius: var(--radius-xl);
    padding: 40px 32px;
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
}

.download-card-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 16px;
}

.download-icon {
    font-size: 2.4rem;
}

.download-card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-gray-900);
}

.download-card > p {
    color: var(--color-gray-500);
    margin-bottom: 20px;
    line-height: 1.7;
}

.download-features {
    margin-bottom: 24px;
}

.download-features li {
    padding: 8px 0;
    color: var(--color-gray-600);
    font-size: 0.95rem;
    position: relative;
    padding-left: 24px;
}

.download-features li::before {
    content: '\2713';
    position: absolute;
    left: 0;
    color: var(--color-success);
    font-weight: 700;
}

.store-buttons {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}

.store-label {
    font-size: 0.85rem;
}

.download-note {
    font-size: 0.82rem;
    color: var(--color-gray-400);
    text-align: center;
    margin-top: auto;
    padding-top: 16px;
}

/* ---------- About ---------- */
.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.05rem;
    color: var(--color-gray-600);
    line-height: 1.9;
    margin-bottom: 20px;
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 24px;
}

.tech-tag {
    background: var(--color-gray-100);
    color: var(--color-gray-700);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid var(--color-gray-200);
}

/* ---------- Privacy & Terms ---------- */
.privacy-content,
.terms-content {
    max-width: 800px;
    margin: 0 auto;
}

.privacy-block {
    margin-bottom: 32px;
    padding: 24px;
    background: var(--color-gray-50);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-primary);
}

.privacy-block h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 12px;
}

.privacy-block p {
    font-size: 0.98rem;
    color: var(--color-gray-600);
    line-height: 1.8;
}

.permission-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.permission-item {
    font-size: 0.95rem;
    color: var(--color-gray-600);
    line-height: 1.7;
}

.permission-item strong {
    color: var(--color-gray-800);
}

/* ---------- Contact ---------- */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.contact-item {
    text-align: center;
    padding: 32px 16px;
    background: var(--color-white);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-gray-200);
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary-light);
}

.contact-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: 12px;
}

.contact-item h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--color-gray-900);
    margin-bottom: 8px;
}

.contact-item a,
.contact-item p {
    font-size: 0.92rem;
    color: var(--color-gray-500);
}

/* ---------- Footer ---------- */
.footer {
    background: var(--color-gray-900);
    color: var(--color-gray-400);
    padding: 48px 0 32px;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-white);
}

.footer-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    color: var(--color-gray-400);
    font-size: 0.95rem;
}

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

.footer-copyright {
    font-size: 0.85rem;
    color: var(--color-gray-500);
    line-height: 1.8;
}

.footer-icp {
    margin: 4px 0;
}

.footer-icp a {
    color: var(--color-gray-500);
    font-size: 0.82rem;
}

.footer-icp a:hover {
    color: var(--color-gray-300);
}

/* ---------- Back to Top ---------- */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: var(--color-white);
    border: none;
    border-radius: 50%;
    font-size: 1.4rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.back-to-top:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
}

/* ============================================
   响应式布局
   ============================================ */

/* Tablet (≤1024px) */
@media (max-width: 1024px) {
    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .hero-container {
        flex-direction: column;
        text-align: center;
        gap: 40px;
    }

    .hero-desc {
        margin: 0 auto 32px;
    }

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

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

    .hero-image {
        flex: 0 0 auto;
    }

    .mockup-screen {
        width: 220px;
        height: 400px;
    }

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

    .scenario-grid {
        grid-template-columns: 1fr;
    }
}

/* Mobile (≤768px) */
@media (max-width: 768px) {
    html {
        scroll-padding-top: 60px;
    }

    section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.7rem;
    }

    .section-desc {
        font-size: 1rem;
        margin-bottom: 36px;
    }

    /* Nav */
    .nav-container {
        height: 60px;
    }

    .nav-toggle {
        display: flex;
        z-index: 1001;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--color-white);
        flex-direction: column;
        padding: 80px 24px 24px;
        gap: 4px;
        box-shadow: var(--shadow-xl);
        transition: var(--transition);
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-link {
        width: 100%;
        padding: 12px 16px;
        font-size: 1rem;
    }

    /* Hero */
    .hero {
        padding-top: 110px;
        padding-bottom: 60px;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    .mockup-screen {
        width: 180px;
        height: 340px;
        border-radius: 22px;
    }

    /* Features */
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    /* Download */
    .download-cards {
        grid-template-columns: 1fr;
    }

    /* Scenarios */
    .scenario-card {
        flex-direction: column;
    }

    /* Contact */
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .privacy-block {
        padding: 20px;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
}

/* Small Mobile (≤480px) */
@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 1.8rem;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .mockup-screen {
        width: 150px;
        height: 280px;
        border-radius: 18px;
        box-shadow: var(--shadow-lg), 0 0 0 5px var(--color-gray-800);
    }

    .download-card {
        padding: 24px 20px;
    }
}

/* Large Desktop (≥1440px) */
@media (min-width: 1440px) {
    .hero-container {
        gap: 100px;
    }

    .hero-title {
        font-size: 3.5rem;
    }

    .mockup-screen {
        width: 300px;
        height: 520px;
    }
}

/* Print styles */
@media print {
    .navbar,
    .back-to-top,
    .hero-image {
        display: none;
    }

    section {
        padding: 20px 0;
        page-break-inside: avoid;
    }

    body {
        color: #000;
    }
}