:root {
    --bg-main: #1e1e1e;
    --bg-sidebar: #252526;
    --bg-panel: #2d2d2d;
    --bg-hover: #3e3e42;
    --bg-input: #3c3c3c;
    --border-color: #454545;
    --text-primary: #cccccc;
    --text-secondary: #969696;
    --text-white: #ffffff;
    --accent: #0e639c;
    --accent-hover: #1177bb;
    --error: #f48771;
    --success: #89d185;
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

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

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-family);
    height: 100vh;
    display: flex;
    overflow: hidden;
}

.app-container {
    display: flex;
    width: 100%;
    height: 100%;
}

/* Sidebar */
.sidebar {
    width: 250px;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h2 {
    color: var(--text-white);
    font-size: 1.25rem;
    font-weight: 600;
}

.version {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 4px;
    display: block;
}

.nav-links {
    list-style: none;
    padding: 10px 0;
    margin: 0;
}

.nav-links li {
    padding: 12px 20px;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    transition: background-color 0.2s ease;
}

.nav-links li:hover {
    background-color: var(--bg-hover);
}

.nav-links li.active {
    background-color: var(--bg-hover);
    color: var(--text-white);
    border-left: 3px solid var(--accent);
}

.nav-links li .icon {
    margin-right: 10px;
    font-size: 1.1rem;
}

/* Main Content Area */
.content-area {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
    background-color: var(--bg-main);
}

.tab-pane {
    display: none;
    max-width: 700px;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.15s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

header {
    margin-bottom: 30px;
}

header h2 {
    font-size: 1.8rem;
    color: var(--text-white);
    margin-bottom: 8px;
    font-weight: 500;
}

header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Process Tab - Upload */
.upload-box {
    border: 2px dashed var(--border-color);
    border-radius: 6px;
    padding: 50px 20px;
    text-align: center;
    background-color: var(--bg-panel);
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    margin-bottom: 20px;
}

.upload-box:hover, .upload-box.dragover {
    border-color: var(--accent);
    background-color: var(--bg-hover);
}

.upload-box input[type="file"] {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    opacity: 0;
    cursor: pointer;
}

.upload-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 15px;
}

.upload-content h3 {
    color: var(--text-white);
    margin-bottom: 5px;
    font-weight: 500;
}

.file-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-panel);
    padding: 12px 15px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    margin-bottom: 20px;
}

.file-info.hidden {
    display: none;
}

.action-bar {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 20px;
}

#status-message {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Settings Form */
.settings-form {
    background-color: var(--bg-panel);
    padding: 25px;
    border-radius: 6px;
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-size: 0.9rem;
    color: var(--text-white);
    margin-bottom: 8px;
    font-weight: 500;
}

.form-group input,
.form-group select {
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    padding: 10px 12px;
    color: var(--text-white);
    border-radius: 3px;
    font-size: 0.95rem;
    font-family: var(--font-family);
    transition: border-color 0.2s;
}

.form-group select {
    cursor: pointer;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent);
}

.form-group small {
    margin-top: 6px;
    color: var(--text-secondary);
    font-size: 0.8rem;
}

.form-row {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 10px;
}

/* Buttons */
.btn-primary, .btn-secondary {
    padding: 10px 20px;
    border: none;
    border-radius: 3px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    transition: background-color 0.2s;
}

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

.btn-primary:disabled {
    background-color: var(--border-color);
    color: var(--text-secondary);
    cursor: not-allowed;
}

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

.btn-secondary:hover {
    background-color: var(--bg-hover);
    color: var(--text-white);
}

.btn-clear {
    background: none;
    border: none;
    font-size: 0.85rem;
    cursor: pointer;
    text-decoration: underline;
}

/* Utilities */
.text-error { color: var(--error); }
.text-success { color: var(--success); }
.hidden { display: none !important; }

/* About Card */
.card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 25px;
}

.card h3 {
    color: var(--text-white);
    margin-bottom: 10px;
}

.divider {
    height: 1px;
    background-color: var(--border-color);
    margin: 15px 0;
}

.author {
    font-weight: 500;
}

.secondary-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Wood legend */
.wood-legend {
    margin-top: 20px;
}

.wood-legend .secondary-text {
    margin-top: 6px;
}

.wood-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
    gap: 8px 16px;
}

.wood-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
}

.wood-swatch {
    width: 16px;
    height: 16px;
    border-radius: 3px;
    border: 1px solid var(--border-color);
    flex: 0 0 auto;
}

.wood-name {
    color: var(--text-white);
}

.wood-match {
    width: 8px;
    height: 8px;
    margin-left: -4px;
    border-radius: 2px;
    border: 1px solid var(--border-color);
    flex: 0 0 auto;
}

.wood-value {
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
}

.wood-swatch.has-icon {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

/* Wood preview */
.preview-panel {
    margin-top: 20px;
}

.preview-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 10px;
    flex-wrap: wrap;
}

.preview-head h3 {
    margin-bottom: 0;
}

.preview-stage {
    margin-top: 14px;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    /* checkerboard so transparent cells read as empty */
    background-color: #1b1b1b;
    background-image:
        linear-gradient(45deg, #232323 25%, transparent 25%, transparent 75%, #232323 75%),
        linear-gradient(45deg, #232323 25%, transparent 25%, transparent 75%, #232323 75%);
    background-size: 16px 16px;
    background-position: 0 0, 8px 8px;
    overflow: auto;
    max-height: 460px;
    text-align: center;
}

.preview-stage img {
    display: inline-block;
    max-width: 100%;
    height: auto;
    image-rendering: pixelated;
    border-radius: 2px;
}

.preview-note {
    margin-top: 10px;
}

.wood-letter {
    margin-left: auto;
    color: var(--accent);
    font-weight: 600;
    font-size: 0.75rem;
    min-width: 20px;
    text-align: right;
}

/* ============================================================
   Mobile / tablet — same VS Code-dark style, app-like layout.
   Sidebar becomes a top app bar, the nav becomes a fixed
   bottom tab bar, and content scrolls in between.
   ============================================================ */
@media (max-width: 860px) {
    body {
        height: 100vh;
        height: 100dvh;
    }

    .app-container {
        flex-direction: column;
    }

    /* Top app bar (was the sidebar header) */
    .sidebar {
        width: 100%;
        flex: 0 0 auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding-top: env(safe-area-inset-top);
    }

    .sidebar-header {
        display: flex;
        align-items: baseline;
        gap: 8px;
        padding: 14px 18px;
    }

    .sidebar-header h2 {
        font-size: 1.05rem;
    }

    .version {
        margin-top: 0;
    }

    /* Bottom tab bar */
    .nav-links {
        position: fixed;
        left: 0;
        right: 0;
        bottom: 0;
        display: flex;
        padding: 0 0 env(safe-area-inset-bottom);
        background-color: var(--bg-sidebar);
        border-top: 1px solid var(--border-color);
        z-index: 20;
    }

    .nav-links li {
        flex: 1 1 0;
        flex-direction: column;
        justify-content: center;
        gap: 3px;
        padding: 9px 4px;
        min-height: 54px;
        font-size: 0.7rem;
        text-align: center;
        border-left: none;
        border-top: 3px solid transparent;
        background-color: transparent;
    }

    .nav-links li .icon {
        margin-right: 0;
        font-size: 1.15rem;
        line-height: 1;
    }

    .nav-links li.active {
        background-color: var(--bg-hover);
        border-left: none;
        border-top: 3px solid var(--accent);
        color: var(--text-white);
    }

    .content-area {
        flex: 1 1 auto;
        padding: 22px 18px;
        /* clears the fixed bottom tab bar */
        padding-bottom: calc(78px + env(safe-area-inset-bottom));
        -webkit-overflow-scrolling: touch;
    }

    .tab-pane {
        max-width: none;
    }

    header {
        margin-bottom: 22px;
    }

    header h2 {
        font-size: 1.4rem;
    }

    .upload-box {
        padding: 34px 16px;
    }

    .upload-icon {
        font-size: 2.4rem;
        margin-bottom: 10px;
    }

    .action-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    #status-message {
        text-align: center;
    }

    .btn-primary,
    .btn-secondary {
        width: 100%;
        padding: 13px 20px;
        font-size: 1rem;
    }

    .form-row {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }

    #settings-status {
        text-align: center;
    }

    .settings-form,
    .card {
        padding: 18px;
    }

    .preview-stage {
        max-height: 320px;
        padding: 8px;
    }

    /* Stops iOS Safari from auto-zooming on focus */
    .form-group input,
    .form-group select {
        font-size: 16px;
    }

    .file-info {
        flex-wrap: wrap;
        gap: 8px;
    }

    #file-name {
        word-break: break-all;
        flex: 1 1 100%;
    }

    /* Bigger tap target for Remove without shifting layout */
    .btn-clear {
        padding: 12px 10px;
        margin: -12px -10px;
    }

    .wood-list {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
        gap: 10px 12px;
    }
}

@media (max-width: 430px) {
    .sidebar-header {
        padding: 12px 14px;
    }

    .content-area {
        padding: 18px 14px;
        padding-bottom: calc(78px + env(safe-area-inset-bottom));
    }

    header h2 {
        font-size: 1.25rem;
    }

    .upload-box {
        padding: 26px 14px;
    }

    .wood-list {
        grid-template-columns: 1fr 1fr;
    }

    .wood-item {
        gap: 6px;
        font-size: 0.8rem;
    }

    .settings-form,
    .card {
        padding: 16px 14px;
    }
}