:root {
    --bg-color: #ffffff;
    --text-color: #202124;
    --link-color: #1a0dab;
    --footer-bg: #f2f2f2;
    --border-color: #dadce0;
    --hover-bg: #f8f9fa;
    --btn-bg: #f8f9fa;
    --btn-hover: #f8f9fa;
    --btn-border: #f8f9fa;
    --btn-border-hover: #dadce0;
}

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

body {
    font-family: arial, sans-serif;
    font-size: 14px;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

a:hover {
    text-decoration: underline;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px;
    height: 60px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 15px;
    padding-right: 20px;
}

.header-right a {
    color: rgba(0,0,0,0.87);
    font-size: 13px;
    line-height: 24px;
}

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #5f6368;
    font-size: 18px;
}

.icon-btn:hover {
    background-color: rgba(60,64,67,0.08);
}

.sign-in-btn {
    background-color: #1a73e8;
    color: white !important;
    border: 1px solid transparent;
    font-weight: 500;
    font-size: 14px;
    padding: 9px 23px;
    border-radius: 4px;
    transition: background-color .2s;
}

.sign-in-btn:hover {
    background-color: #1b66c9;
    box-shadow: 0 1px 2px rgba(66,133,244,0.3), 0 1px 3px 1px rgba(66,133,244,0.15);
    text-decoration: none;
}

/* Main Content - Hero Screen */
.main-content {
    min-height: calc(100vh - 60px - 100px); /* 减去header和大致的footer高度 */
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding-bottom: 60px;
    position: relative;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    color: #5f6368;
    animation: bounce 2s infinite;
    cursor: pointer;
    font-size: 24px;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {transform: translateX(-50%) translateY(0);}
    40% {transform: translateX(-50%) translateY(-10px);}
    60% {transform: translateX(-50%) translateY(-5px);}
}

/* Introduction Sections */
.intro-section {
    padding: 80px 20px;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

.section-title {
    font-size: 36px;
    font-weight: 400;
    text-align: center;
    margin-bottom: 20px;
    color: #202124;
    font-family: 'Product Sans', Arial, sans-serif;
}

.section-subtitle {
    font-size: 18px;
    text-align: center;
    color: #5f6368;
    margin-bottom: 60px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    padding: 0 20px;
}

.feature-card {
    background: #fff;
    border: 1px solid #dadce0;
    border-radius: 12px;
    padding: 40px 30px;
    transition: box-shadow 0.3s ease, transform 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    cursor: pointer;
}

.feature-card:hover {
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transform: translateY(-5px);
    border-color: transparent;
}

.card-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 24px;
    color: #fff;
}

.icon-blue { background-color: #4285f4; }
.icon-red { background-color: #ea4335; }
.icon-yellow { background-color: #fbbc05; }
.icon-green { background-color: #34a853; }

.card-title {
    font-size: 22px;
    font-weight: 500;
    margin-bottom: 12px;
    color: #202124;
}

.card-desc {
    font-size: 16px;
    color: #5f6368;
    line-height: 1.6;
    margin-bottom: 20px;
}

.card-link {
    color: #1a73e8;
    font-weight: 500;
    font-size: 16px;
    margin-top: auto;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

/* Mission Section */
.mission-container {
    background-color: #f8f9fa;
    padding: 100px 20px;
    text-align: center;
    margin-top: 40px;
}

.mission-text {
    font-size: 48px;
    font-weight: 500;
    line-height: 1.2;
    color: #202124;
    max-width: 900px;
    margin: 0 auto 40px;
    font-family: 'Product Sans', Arial, sans-serif;
}

.mission-btn {
    background-color: #1a73e8;
    color: white;
    padding: 12px 32px;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 500;
    display: inline-block;
    transition: background 0.3s;
}

.mission-btn:hover {
    background-color: #1b66c9;
    text-decoration: none;
    box-shadow: 0 2px 6px rgba(0,0,0,0.15);
}

/* Logo */
.logo-container {
    font-family: 'Product Sans', Arial, sans-serif; /* Product Sans is Google's font, fallback to Arial */
    font-size: 90px;
    font-weight: bold;
    letter-spacing: -3px;
    margin-bottom: 10px; /* Reduced margin to fit promo box */
    user-select: none;
}

.g-blue { color: #4285f4; }
.g-red { color: #ea4335; }
.g-yellow { color: #fbbc05; }
.g-green { color: #34a853; }

/* Download CTA Container */
.download-cta-container {
    text-align: center;
    max-width: 600px;
    margin-bottom: 30px;
}

.cta-title {
    font-size: 48px;
    font-weight: 400;
    margin-bottom: 10px;
    color: #202124;
}

.cta-subtitle {
    font-size: 18px;
    color: #5f6368;
    margin-bottom: 30px;
    line-height: 1.5;
}

.btn-download {
    display: inline-block;
    background-color: #1a73e8;
    color: white;
    font-size: 16px;
    font-weight: 500;
    padding: 12px 32px;
    border-radius: 4px;
    text-decoration: none;
    transition: background-color 0.2s, box-shadow 0.2s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.12);
}

.btn-download:hover {
    background-color: #1765cc;
    box-shadow: 0 2px 6px rgba(0,0,0,0.2);
}

.cta-info {
    font-size: 12px;
    color: #5f6368;
    margin-top: 15px;
}
/* Search Bar Styles (Removed) */
.search-container {
    width: 100%;
    max-width: 584px;
    padding: 0 20px;
}

.search-bar {
    display: flex;
    align-items: center;
    background: #fff;
    border: 1px solid #dfe1e5;
    box-shadow: none;
    border-radius: 24px;
    height: 46px;
    width: 100%;
    margin: 0 auto;
    padding: 0 14px;
    transition: all 0.3s cubic-bezier(0.25,0.8,0.25,1);
}

.search-bar:hover, .search-bar:focus-within {
    background-color: #fff;
    box-shadow: 0 1px 6px rgba(32,33,36,0.28);
    border-color: rgba(223,225,229,0);
}

.search-icon {
    color: #9aa0a6;
    font-size: 16px;
    margin-right: 12px;
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    font-size: 16px;
    color: rgba(0,0,0,0.87);
    background: transparent;
    height: 100%;
}

.search-tools {
    display: flex;
    align-items: center;
    gap: 12px;
}

.tool-icon {
    cursor: pointer;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mic-icon, .camera-icon {
    width: 24px;
    height: 24px;
}

/* Search Buttons */
.search-buttons {
    margin-top: 30px;
    display: flex;
    justify-content: center;
    gap: 12px;
}

.btn {
    background-color: var(--btn-bg);
    border: 1px solid var(--btn-border);
    color: #3c4043;
    font-family: arial, sans-serif;
    font-size: 14px;
    padding: 0 16px;
    height: 36px;
    min-width: 127px;
    border-radius: 4px;
    cursor: pointer;
    user-select: none;
}

.btn:hover {
    box-shadow: 0 1px 1px rgba(0,0,0,0.1);
    background-color: var(--btn-hover);
    border: 1px solid var(--btn-border-hover);
    color: #202124;
}

.language-offer {
    margin-top: 25px;
    font-size: 13px;
    color: #4d5156;
}

.language-offer a {
    color: #1a0dab;
    padding: 0 3px;
}

/* Footer */
.footer {
    background-color: var(--footer-bg);
    color: #70757a;
    font-size: 14px;
}

.footer-location {
    padding: 15px 30px;
    border-bottom: 1px solid var(--border-color);
    font-size: 15px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 0 20px;
}

.links-left, .links-right {
    display: flex;
    flex-wrap: wrap;
}

.footer-links a {
    display: block;
    padding: 15px 15px;
    color: #70757a;
    white-space: nowrap;
}

/* Responsive */
@media screen and (max-width: 800px) {
    .footer-links {
        justify-content: center;
    }
}

@media screen and (max-width: 400px) {
    .footer-links a {
        padding: 15px 10px;
    }
}