:root {
    --bg-light: #f4f6f9;
    --bg-dark: linear-gradient(135deg, #0f0f0f, #292929, #2F2F2F);

    --text-light: #212529;
    --text-dark: white;

    --container-bg-light: white;
    --container-bg-dark: #1e1e1e;

    --button-bg-primary: #005AB8;
    --button-bg-hover: #EF7F1A;
    --link-color: #EF7F1A;

    --toggle-on: #005AB8;
    --toggle-off: #6c757d;

    --shadow-dark: 0 2px 5px rgba(0, 0, 0, 0.5);
    --shadow-light: 0 4px 10px rgba(0, 90, 184, 0.5);

    --input-bg-dark: #444;
    --input-bg-light: #eee;
    --input-text-dark: white;
    --input-text-light: #212529;
    --input-border-dark: #666;
    --input-border-light: #ccc;

    --table-bg-dark: #3a3a3a;
    --table-header-dark: #4a4a4a;
    --table-bg-light: #f8f8f8;
    --table-header-light: #ddd;
    --table-border-dark: #555;
    --table-border-light: #ccc;

    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: 'Inter', Arial, sans-serif;
    background: var(--bg-light);
    color: var(--text-light);
    text-align: center;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: all 0.5s ease-in-out;
    padding: 20px;
}
body.dark {
    background: var(--bg-dark);
    background-size: 400% 400%;
    animation: bgAnim 10s infinite alternate;
    color: var(--text-dark);
}
body.light {
    background: var(--bg-light);
    color: var(--text-light);
    animation: none;
}
@keyframes bgAnim {
    0% { background-position: 0% 50%; }
    100% { background-position: 100% 50%; }
}
@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}
@keyframes loadingEffect {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}
.tire {
    width: 120px;
    animation: rotate 8s linear infinite;
    margin-top: 10px;
    filter: grayscale(100%) brightness(0.8);
}
body.dark .tire {
    filter: none;
}
.logo {
    width: 150px;
    margin: 10px auto;
    display: block;
}
.container {
    text-align: center;
    padding: 30px;
    max-width: 900px;
    width: 100%;
    position: relative;
    background-color: var(--container-bg-light);
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    border: 1px solid rgba(0, 0, 0, 0.1);
    transition: all 0.5s ease-in-out;
    margin: 20px auto;
}
body.dark .container {
    background-color: var(--container-bg-dark);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.1);
}
.container.wide {
    max-width: 1100px;
}
.top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 15px;
    gap: 8px;
    min-height: 40px;
}
.top-bar-left {
    display: flex;
    align-items: center;
    gap: 8px;
}
.top-bar-right {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: auto;
}
.nav-btn {
    padding: 6px 14px;
    font-size: 0.8em;
    font-weight: 600;
    color: white;
    background-color: var(--toggle-off);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(108, 117, 125, 0.6);
    transition: all 0.3s ease;
    min-width: auto;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
body.dark .nav-btn {
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
}
.nav-btn:hover {
    background-color: var(--button-bg-hover);
    transform: scale(1.05);
    box-shadow: 0 4px 10px rgba(239, 127, 26, 0.5);
}
.nav-btn.nav-btn-danger {
    background-color: var(--danger-color);
}
.nav-btn.nav-btn-danger:hover {
    background-color: #c82333;
}
.section-title {
    font-size: 0.85em;
    font-weight: 600;
    opacity: 0.7;
    padding: 0 4px;
}
.toggle-button {
    padding: 6px 14px;
    font-size: 0.8em;
    font-weight: 600;
    color: white;
    background-color: var(--toggle-off);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(108, 117, 125, 0.6);
    transition: all 0.3s ease;
    min-width: auto;
}
body.dark .toggle-button {
    background-color: var(--toggle-on);
    box-shadow: 0 2px 6px rgba(0, 90, 184, 0.6);
}
.toggle-button:hover {
    transform: scale(1.05);
}
h1 {
    margin: 15px 0 10px 0;
    font-size: 1.8em;
}
h2 {
    margin: 20px 0 10px 0;
    font-size: 1.4em;
}
h3 {
    margin: 15px 0 8px 0;
    font-size: 1.15em;
}
p {
    margin: 8px 0;
    line-height: 1.6;
}
input, select {
    width: 100%;
    max-width: 320px;
    padding: 12px 15px;
    background-color: var(--input-bg-light);
    color: var(--input-text-light);
    border: 2px solid var(--input-border-light);
    border-radius: 8px;
    font-size: 16px;
    text-align: center;
    transition: all 0.3s ease;
    outline: none;
    font-family: 'Inter', Arial, sans-serif;
}
body.dark input, body.dark select {
    background-color: var(--input-bg-dark);
    color: var(--input-text-dark);
    border-color: var(--input-border-dark);
}
input:focus, select:focus {
    border-color: var(--button-bg-primary);
    box-shadow: 0 0 0 3px rgba(0, 90, 184, 0.15);
}
body.dark input:focus, body.dark select:focus {
    box-shadow: 0 0 0 3px rgba(0, 90, 184, 0.3);
}
label {
    font-size: 14px;
    font-weight: 600;
    display: block;
    margin-bottom: 5px;
    margin-top: 10px;
}
button, .btn {
    background-color: var(--button-bg-primary);
    color: white;
    padding: 16px 36px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    min-width: 200px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    box-shadow: var(--shadow-light);
    font-family: 'Inter', Arial, sans-serif;
    text-decoration: none;
    gap: 8px;
}
body.dark button, body.dark .btn {
    box-shadow: var(--shadow-dark);
}
button:hover, .btn:hover {
    background-color: var(--button-bg-hover);
    transform: scale(1.05);
    box-shadow: 0 6px 15px rgba(239, 127, 26, 0.5);
}
button.btn-sm, .btn.btn-sm {
    padding: 10px 20px;
    min-width: auto;
    font-size: 14px;
}
button.btn-success, .btn.btn-success {
    background-color: var(--success-color);
}
button.btn-warning, .btn.btn-warning {
    background-color: var(--warning-color);
    color: #212529;
}
button.btn-danger, .btn.btn-danger {
    background-color: var(--danger-color);
}
.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin: 20px 0;
}
a {
    color: var(--link-color);
    text-decoration: none;
    font-weight: 600;
    transition: opacity 0.2s;
}
a:hover {
    text-decoration: underline;
    opacity: 0.9;
}
.card {
    background: var(--container-bg-light);
    border-radius: 12px;
    padding: 25px;
    margin: 15px 0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border: 1px solid rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
}
body.dark .card {
    background: var(--container-bg-dark);
    border-color: rgba(255, 255, 255, 0.08);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
.card.highlight {
    border-left: 4px solid var(--button-bg-primary);
}
body.dark .card.highlight {
    border-left-color: var(--button-bg-hover);
}
table {
    width: 100%;
    border-collapse: collapse;
    margin: 15px 0;
    font-size: 15px;
}
th, td {
    padding: 10px 12px;
    text-align: center;
    border: 1px solid var(--table-border-light);
    transition: all 0.3s ease;
}
body.dark th, body.dark td {
    border-color: var(--table-border-dark);
}
th {
    background-color: var(--table-header-light);
    font-weight: 700;
}
body.dark th {
    background-color: var(--table-header-dark);
}
td {
    background-color: var(--table-bg-light);
}
body.dark td {
    background-color: var(--table-bg-dark);
}
.form-row {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    margin: 15px 0;
}
.form-row > div {
    flex: 1;
    min-width: 180px;
    max-width: 280px;
}
.form-row > div.full {
    max-width: 100%;
    min-width: 100%;
}
.result-box {
    font-size: 18px;
    font-weight: bold;
    padding: 15px;
    margin: 10px 0;
    border-radius: 8px;
    background: rgba(0, 90, 184, 0.08);
    border: 1px solid rgba(0, 90, 184, 0.2);
}
body.dark .result-box {
    background: rgba(0, 90, 184, 0.15);
    border-color: rgba(0, 90, 184, 0.3);
}
.result-box.success {
    background: rgba(40, 167, 69, 0.1);
    border-color: rgba(40, 167, 69, 0.3);
}
.result-box.warning {
    background: rgba(255, 193, 7, 0.1);
    border-color: rgba(255, 193, 7, 0.3);
    color: #856404;
}
body.dark .result-box.warning {
    color: #ffc107;
}
.tag {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}
.tag.agricultural {
    background: #28a745;
    color: white;
}
.tag.truck {
    background: #005AB8;
    color: white;
}
.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin: 10px 0;
    font-size: 15px;
}
.alert.info {
    background: rgba(0, 90, 184, 0.1);
    border: 1px solid rgba(0, 90, 184, 0.3);
}
.alert.success {
    background: rgba(40, 167, 69, 0.1);
    border: 1px solid rgba(40, 167, 69, 0.3);
}
.search-wrapper {
    position: relative;
    display: inline-block;
    width: 100%;
    max-width: 320px;
}
.search-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: 250px;
    overflow-y: auto;
    background: var(--container-bg-light);
    border: 2px solid var(--button-bg-primary);
    border-top: none;
    border-radius: 0 0 8px 8px;
    z-index: 1000;
    display: none;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}
body.dark .search-dropdown {
    background: var(--container-bg-dark);
    border-color: var(--button-bg-primary);
}
.search-dropdown.show {
    display: block;
}
.search-dropdown-item {
    padding: 10px 15px;
    cursor: pointer;
    text-align: left;
    font-size: 14px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: background 0.2s;
}
body.dark .search-dropdown-item {
    border-color: rgba(255, 255, 255, 0.05);
}
.search-dropdown-item:hover {
    background: rgba(0, 90, 184, 0.1);
}
.search-dropdown-item .highlight {
    color: var(--button-bg-hover);
    font-weight: 700;
}
.search-dropdown-item .type-tag {
    float: right;
    font-size: 11px;
}
.alternatives-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
    margin: 15px 0;
}
.alternative-card {
    padding: 15px;
    border-radius: 10px;
    background: rgba(0, 90, 184, 0.06);
    border: 1px solid rgba(0, 90, 184, 0.15);
    text-align: center;
    transition: all 0.3s ease;
}
body.dark .alternative-card {
    background: rgba(0, 90, 184, 0.1);
    border-color: rgba(0, 90, 184, 0.25);
}
.alternative-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}
.alternative-card .tire-code {
    font-size: 18px;
    font-weight: 700;
    color: var(--button-bg-primary);
}
.alternative-card .tire-dims {
    font-size: 13px;
    color: #666;
    margin: 5px 0;
}
body.dark .alternative-card .tire-dims {
    color: #aaa;
}
.alternative-card .tire-diff {
    font-size: 12px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 10px;
    display: inline-block;
}
.tire-diff.good {
    background: rgba(40, 167, 69, 0.15);
    color: var(--success-color);
}
.tire-diff.ok {
    background: rgba(255, 193, 7, 0.15);
    color: #856404;
}
body.dark .tire-diff.ok {
    color: #ffc107;
}
.tire-diff.info {
    background: rgba(0, 90, 184, 0.1);
    color: var(--button-bg-primary);
    margin-top: 4px;
}
.contact-info {
    margin-top: 20px;
    padding: 15px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}
body.dark .contact-info {
    border-top-color: rgba(255, 255, 255, 0.1);
}
.contact-info a {
    color: var(--link-color);
    text-decoration: none;
    font-weight: bold;
    opacity: 0.8;
    transition: opacity 0.2s;
}
.contact-info a:hover {
    text-decoration: underline;
    opacity: 1;
}
.home-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
}
.home-btn {
    flex-direction: column !important;
    gap: 6px !important;
    padding: 20px 16px !important;
    min-width: 0 !important;
    width: calc(33.333% - 15px) !important;
    max-width: 320px;
    height: 140px !important;
}
.home-btn-icon {
    font-size: 1.6em;
    line-height: 1;
}
.home-btn-logo {
    height: 30px;
    filter: brightness(0) invert(1);
}
.home-btn-title {
    font-size: 0.95em;
    font-weight: 700;
}
.home-btn-desc {
    font-size: 0.75em;
    font-weight: 400;
    opacity: 0.8;
    line-height: 1.3;
}
@media (max-width: 700px) {
    .home-btn {
        width: calc(50% - 15px) !important;
        height: 130px !important;
    }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    .container, .container.wide {
        padding: 15px 12px;
    }
    h1 {
        font-size: 1.3em;
    }
    .top-bar {
        flex-wrap: wrap;
        gap: 6px;
        margin-bottom: 10px;
    }
    .top-bar-left, .top-bar-right {
        gap: 5px;
    }
    .nav-btn, .toggle-button {
        padding: 5px 10px;
        font-size: 0.75em;
    }
    .section-title {
        font-size: 0.75em;
    }
    .form-row {
        flex-direction: column;
        align-items: center;
    }
    .form-row > div {
        max-width: 100%;
        width: 100%;
        min-width: unset;
    }
    .button-group {
        flex-direction: column;
        align-items: center;
    }
    .button-group .btn, .button-group button {
        width: 100%;
        max-width: 320px;
    }
    .alternatives-grid {
        grid-template-columns: 1fr;
    }
    .search-wrapper, #tireSearch, .search-wrapper input {
        max-width: 100% !important;
        width: 100%;
    }
    table {
        font-size: 13px;
        overflow-x: auto;
        display: block;
    }
    th, td {
        padding: 6px 8px;
        font-size: 12px;
    }
    .alternative-card {
        padding: 12px;
    }
    .home-btn {
        width: calc(50% - 15px) !important;
        height: 130px !important;
    }
}
@media (max-width: 480px) {
    .container, .container.wide {
        padding: 12px 8px;
        border-radius: 10px;
    }
    .top-bar {
        gap: 4px;
    }
    .nav-btn, .toggle-button {
        padding: 4px 8px;
        font-size: 0.7em;
    }
    h1 {
        font-size: 1.15em;
        margin: 10px 0 6px;
    }
    .logo {
        width: 100px;
        margin: 5px auto;
    }
    .home-btn {
        width: 100% !important;
        max-width: 100%;
        height: 115px !important;
        padding: 14px 12px !important;
    }
    .home-btn-icon {
        font-size: 1.3em;
    }
    .home-btn-logo {
        height: 24px;
    }
    .home-btn-title {
        font-size: 0.85em;
    }
    .home-btn-desc {
        font-size: 0.7em;
    }
    .card {
        padding: 15px 10px;
    }
    input, select {
        padding: 10px 12px;
        font-size: 15px;
    }
    .result-box {
        font-size: 15px;
        padding: 10px;
    }
    table {
        font-size: 12px;
    }
    th, td {
        padding: 4px 6px;
        font-size: 11px;
    }
    .search-dropdown {
        max-height: 180px;
    }
    .search-dropdown-item {
        padding: 8px 12px;
        font-size: 13px;
    }
}