:root {
    --g-blue: #4285F4;
    --g-red: #EA4335;
    --g-yellow: #FBBC04;
    --g-green: #34A853;
    --bg-light: #f8f9fa;
    --text-dark: #202124;
    --text-gray: #5f6368;
    --card-bg: #ffffff;
}

body {
    font-family: 'Google Sans', Roboto, Arial, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

/* Iconic 4-color bar at the very top */
.google-bar {
    height: 6px;
    background: linear-gradient(90deg, var(--g-blue) 25%, var(--g-red) 25%, var(--g-red) 50%, var(--g-yellow) 50%, var(--g-yellow) 75%, var(--g-green) 75%);
}

header {
    background-color: var(--card-bg);
    padding: 15px 0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.header-content {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 700;
}

.g-blue { color: var(--g-blue); }
.g-red { color: var(--g-red); }
.g-yellow { color: var(--g-yellow); }
.g-green { color: var(--g-green); }

.badge {
    background-color: #e8f0fe;
    color: var(--g-blue);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.container {
    max-width: 800px;
    margin: 40px auto;
    padding: 0 20px;
}

.hero {
    text-align: center;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 10px;
    letter-spacing: -1px;
}

.subtitle {
    color: var(--text-gray);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Main App Card */
.app-card {
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    text-align: center;
    margin-bottom: 50px;
}

input[type="file"] {
    display: none;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 24px;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
    border: none;
}

.btn-primary {
    background-color: var(--card-bg);
    color: var(--g-blue);
    border: 1px solid #dadce0;
}

.btn-primary:hover {
    background-color: #f1f3f4;
}

.btn-action {
    background-color: var(--g-blue);
    color: white;
    margin-top: 20px;
    box-shadow: 0 2px 6px rgba(66, 133, 244, 0.4);
}

.btn-action:hover {
    background-color: #1a73e8;
    box-shadow: 0 4px 10px rgba(66, 133, 244, 0.5);
    transform: translateY(-1px);
}

#imagePreview {
    max-width: 100%;
    max-height: 300px;
    margin-top: 25px;
    border-radius: 8px;
    border: 1px solid #dadce0;
    box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

.results-box {
    margin-top: 25px;
    text-align: left;
    background-color: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    min-height: 50px;
}

.placeholder-text {
    text-align: center;
    color: var(--text-gray);
    margin: 0;
    font-style: italic;
}

.result-row {
    display: flex;
    justify-content: space-between;
    padding: 12px 16px;
    background: white;
    border-radius: 6px;
    margin-bottom: 8px;
    border: 1px solid #e8eaed;
    font-weight: 500;
}

/* Explanation Section */
.how-it-works h2 {
    text-align: center;
    margin-bottom: 30px;
}

.grid-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.card {
    background-color: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.card h3 {
    margin-top: 0;
    font-size: 1.1rem;
}

.card p {
    color: var(--text-gray);
    font-size: 0.9rem;
    margin-bottom: 0;
}

.border-blue { border-top: 4px solid var(--g-blue); }
.border-red { border-top: 4px solid var(--g-red); }
.border-green { border-top: 4px solid var(--g-green); }

footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-gray);
    font-size: 0.9rem;
    margin-top: 40px;
}