:root {
    --primary: #10b981;
    --primary-hover: #059669;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --danger: #ef4444;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

header p {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Upload Section */
.upload-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
    text-align: center;
    background: var(--card-bg);
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.drop-zone:hover:not(.has-file) {
    border-color: var(--primary);
    background: #f0fdf4;
}

.drop-zone.has-file {
    cursor: default;
    border-style: solid;
    padding: 1rem;
}

.upload-prompt {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.upload-icon {
    width: 48px;
    height: 48px;
    color: var(--text-muted);
}

.upload-title {
    font-weight: 600;
    font-size: 1.125rem;
}

.upload-subtitle {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.preview-container {
    width: 100%;
    height: 100%;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.image-preview {
    max-width: 100%;
    max-height: 400px;
    border-radius: 0.5rem;
    object-fit: contain;
}

/* Buttons */
button {
    font-family: 'Inter', sans-serif;
    font-weight: 600;
    padding: 0.875rem 1.5rem;
    border-radius: 0.5rem;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
    width: 100%;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(16, 185, 129, 0.2);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-secondary {
    background: white;
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: #f8fafc;
}

.remove-btn {
    width: auto;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Results Section */
.result-card {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color);
}

.score-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.score-header h2 {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.score-value {
    font-size: 4rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
}

.score-value .unit {
    font-size: 1.25rem;
    color: var(--text-muted);
    font-weight: 600;
}

.breakdown h3 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
}

.item-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.item-list li {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    background: #f8fafc;
    border-radius: 0.5rem;
    font-weight: 500;
}

.item-co2 {
    color: var(--text-muted);
}

.reset-btn {
    margin-top: 1rem;
}

.error-message {
    background: #fef2f2;
    color: var(--danger);
    padding: 1rem;
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
}

.no-items {
    text-align: center;
    color: var(--text-muted);
    padding: 2rem;
    background: #f8fafc;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
}