:root {
    --bg-color: #1e1e1e;
    --container-bg: #2d2d30;
    --text-main: #f5f5f7;
    --text-muted: #a1a1aa;
    --accent: #0a84ff;
    --accent-hover: #0070e0;
    --border-color: #3f3f46;
    --input-bg: #3f3f46;
    --error: #ff453a;
    --success: #30d158;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-main);
    -webkit-tap-highlight-color: transparent; /* Remove tap highlight on mobile */
    /* safe area for notched devices like iPhone 13 */
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
}

.container {
    max-width: 600px;
    margin: 10px auto;
    padding: 15px;
    background-color: var(--container-bg);
    border-radius: 12px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

h1 {
    text-align: center;
    color: var(--accent);
    margin-top: 5px;
    margin-bottom: 20px;
    font-size: 1.6rem;
    font-weight: 600;
}

.form-group {
    margin-bottom: 12px;
    display: flex;
    flex-direction: column;
}

.form-row {
    display: flex;
    gap: 10px;
    margin-bottom: 0; /* Let form-group handle bottom margin */
}

.form-row .form-group {
    flex: 1;
    min-width: 0; /* Prevent flex items from overflowing */
}

label {
    margin-bottom: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
}

/* Base Inputs */
input[type="text"],
input[type="number"],
select,
textarea {
    width: 100%;
    padding: 10px;
    background-color: var(--input-bg);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem; /* 16px prevents iOS zoom */
    box-sizing: border-box;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus,
textarea:focus {
    border-color: var(--accent);
    outline: none;
    box-shadow: 0 0 0 2px rgba(10, 132, 255, 0.25);
}

/* Adjust Row 3 tight fit for Unit, Oil, Mileage */
.form-row:nth-of-type(3) input[type="number"] {
    padding: 10px 6px; /* slightly less horizontal padding */
    text-align: center;
}

select {
    appearance: none;
    -webkit-appearance: none;
    background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%22292.4%22%20height%3D%22292.4%22%3E%3Cpath%20fill%3D%22%23a1a1aa%22%20d%3D%22M287%2069.4a17.6%2017.6%200%200%200-13-5.4H18.4c-6.5%200-12.3%203.2-16.1%208.1-3.8%204.9-4.6%2011-2.4%2017.1l139.5%20180.6c7.9%2010.2%2023.5%2010.2%2031.4%200L289.4%2094c2.2-6.1%201.4-12.2-2.4-17.1z%22%2F%3E%3C%2Fsvg%3E');
    background-repeat: no-repeat;
    background-position: right 10px center;
    background-size: 10px;
    padding-right: 25px;
}

textarea {
    resize: vertical;
    min-height: 60px;
}

/* Custom Checkbox Styling */
.checkbox-group {
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--input-bg);
}

.group-label {
    margin-bottom: 8px;
    color: var(--text-main);
}

.checkboxes {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.checkbox-container {
    font-weight: normal;
    font-size: 0.95rem;
    color: var(--text-main);
    display: flex;
    align-items: center;
    cursor: pointer;
    position: relative;
    padding-left: 32px;
    margin-bottom: 0;
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    left: 0;
    height: 22px;
    width: 22px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.checkbox-container input:checked ~ .checkmark {
    background-color: var(--accent);
    border-color: var(--accent);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked ~ .checkmark:after {
    display: block;
}

.checkbox-container .checkmark:after {
    left: 7px;
    top: 3px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

button {
    display: block;
    width: 100%;
    padding: 14px 20px;
    background-color: var(--accent);
    color: white;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
    margin-top: 15px;
    margin-bottom: 10px;
}

button:hover {
    background-color: var(--accent-hover);
}

button:active {
    transform: scale(0.98);
}

.output-area {
    margin-top: 20px;
    padding: 15px;
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.output-area h3 {
    color: var(--accent);
    margin-top: 0;
    font-size: 1.1rem;
}

#reportText {
    white-space: pre-wrap;
    word-wrap: break-word;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    padding: 15px;
    border-radius: 6px;
    font-family: 'SF Mono', 'Courier New', Courier, monospace;
    font-size: 0.85rem;
    color: var(--text-main);
    max-height: 200px;
    overflow-y: auto;
}

#copyReport {
    background-color: var(--success);
    margin-bottom: 10px;
}
#copyReport:hover {
    background-color: #28a745;
}

#shareReport {
    background-color: #ff9f0a;
}
#shareReport:hover {
    background-color: #e08e09;
}

/* iPhone 13 Specific fine tuning max 390px */
@media (max-width: 395px) {
    .container {
        margin: 5px;
        padding: 12px;
    }
    
    h1 {
        font-size: 1.4rem;
        margin-bottom: 15px;
    }

    label {
        font-size: 0.8rem; /* slightly smaller labels */
    }

    input[type="text"],
    input[type="number"],
    select,
    textarea {
        padding: 10px 8px;
        font-size: 16px; /* Keep at 16px for iOS */
    }

    /* Tighter text for the 3 column row */
    .form-row:nth-of-type(3) .form-group label {
        font-size: 0.75rem; 
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
}