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

:root {
    --bg:        #0d0f0f;
    --surface:   #141717;
    --panel:     #191d1d;
    --border:    #252b2b;
    --accent:    #00e5b0;
    --accent2:   #005c47;
    --text:      #e8edec;
    --muted:     #5a6666;
    --label:     #8fa39e;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: 'DM Mono', monospace;
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* ── HEADER ── */
header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 28px;
    height: 52px;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
    flex-shrink: 0;
}

.logo {
    font-family: 'Syne', sans-serif;
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: 0.25em;
    color: var(--accent);
}

.logo span {
    color: var(--muted);
    font-weight: 400;
    font-size: 0.7rem;
    letter-spacing: 0.15em;
    margin-left: 16px;
    vertical-align: middle;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.status-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    animation: pulse 2.5s infinite;
}

.version {
    font-size: 0.65rem;
    color: var(--muted);
    letter-spacing: 0.1em;
}

/* ── LAYOUT ── */
.workspace {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* ── SIDEBAR ── */
aside {
    width: 280px;
    flex-shrink: 0;
    background: var(--panel);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    padding: 20px 16px;
    gap: 6px;
}

aside::-webkit-scrollbar { width: 4px; }
aside::-webkit-scrollbar-track { background: transparent; }
aside::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* ── SECTION LABELS ── */
.section-label {
    font-size: 0.6rem;
    letter-spacing: 0.2em;
    color: var(--muted);
    text-transform: uppercase;
    padding: 12px 4px 6px;
    border-top: 1px solid var(--border);
    margin-top: 6px;
}

.section-label:first-child {
    border-top: none;
    margin-top: 0;
    padding-top: 0;
}

/* ── UPLOAD BUTTON ── */
.upload-btn {
    width: 100%;
    padding: 14px;
    background: transparent;
    border: 1px solid var(--accent2);
    color: var(--accent);
    font-family: 'Syne', sans-serif;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
    text-align: left;
    display: flex;
    align-items: center;
    gap: 10px;
}

.upload-btn:hover {
    background: rgba(0, 229, 176, 0.06);
    border-color: var(--accent);
    box-shadow: 0 0 20px rgba(0, 229, 176, 0.08);
}

.upload-btn:active { transform: scale(0.99); }

.file-status {
    font-size: 0.65rem;
    color: var(--muted);
    padding: 6px 4px;
    letter-spacing: 0.05em;
}

.file-status.loaded { color: var(--accent); }

/* ── CHECKBOX ── */
.check-row {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 4px;
    cursor: pointer;
    border-radius: 3px;
    transition: background 0.15s;
}

.check-row:hover { background: rgba(255,255,255,0.03); }

.check-box {
    width: 14px;
    height: 14px;
    border: 1px solid var(--border);
    background: var(--bg);
    border-radius: 2px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
}

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

input[type="checkbox"]:checked + label .check-box {
    background: var(--accent);
    border-color: var(--accent);
}

input[type="checkbox"]:checked + label .check-box::after {
    content: '';
    width: 8px;
    height: 5px;
    border-left: 1.5px solid var(--bg);
    border-bottom: 1.5px solid var(--bg);
    transform: rotate(-45deg) translateY(-1px);
    display: block;
}

.check-label {
    font-size: 0.72rem;
    color: var(--label);
    letter-spacing: 0.05em;
}

.color-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: cyan;
    margin-left: auto;
    flex-shrink: 0;
}

/* ── INPUT ROWS ── */
.input-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 4px;
    gap: 8px;
}

.input-label {
    font-size: 0.65rem;
    color: var(--label);
    letter-spacing: 0.05em;
    flex: 1;
}

.input-field {
    width: 72px;
    background: var(--bg);
    border: 1px solid var(--border);
    color: var(--text);
    font-family: 'DM Mono', monospace;
    font-size: 0.75rem;
    padding: 5px 8px;
    text-align: right;
    outline: none;
    transition: border-color 0.15s;
    -moz-appearance: textfield;
}

.input-field::-webkit-inner-spin-button,
.input-field::-webkit-outer-spin-button { -webkit-appearance: none; }

.input-field:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(0,229,176,0.1);
}

.input-unit {
    font-size: 0.6rem;
    color: var(--muted);
    width: 20px;
    text-align: left;
}

/* ── CALCULATE BUTTON ── */
.calc-btn {
    width: 100%;
    padding: 14px;
    background: var(--accent);
    border: none;
    color: var(--bg);
    font-family: 'Syne', sans-serif;
    font-size: 0.8rem;
    font-weight: 800;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s;
    margin-top: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.calc-btn::after {
    content: '→';
    font-size: 1rem;
}

.calc-btn:hover {
    background: #00ffc4;
    box-shadow: 0 0 30px rgba(0,229,176,0.3);
    transform: translateY(-1px);
}

.calc-btn:active { transform: translateY(0); }

.calc-btn:disabled {
    background: var(--border);
    color: var(--muted);
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

/* ── COST DISPLAY ── */
.cost-display {
    margin-top: 8px;
    padding: 12px;
    background: var(--bg);
    border: 1px solid var(--border);
    display: none;
}

.cost-display.visible { display: block; }

.cost-label {
    font-size: 0.6rem;
    color: var(--muted);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    margin-bottom: 4px;
}

.cost-value {
    font-family: 'Syne', sans-serif;
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 0.05em;
}

.cost-value span {
    font-size: 0.8rem;
    color: var(--muted);
}

/* ── PREVIEW PANEL ── */
main {
    flex: 1;
    background: var(--bg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.preview-title {
    font-size: 0.65rem;
    letter-spacing: 0.2em;
    color: var(--muted);
    text-transform: uppercase;
}

.preview-tabs {
    display: flex;
    gap: 1px;
}

.tab {
    padding: 5px 14px;
    font-size: 0.6rem;
    letter-spacing: 0.1em;
    color: var(--muted);
    cursor: pointer;
    border: 1px solid transparent;
    transition: all 0.15s;
}

.tab.active {
    color: var(--accent);
    border-color: var(--border);
    background: var(--surface);
}

.tab:hover:not(.active) {
    color: var(--label);
}

/* ── CANVAS ── */
.preview-canvas {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.preview-canvas::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.4;
}

.preview-canvas::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at center, transparent 40%, var(--bg) 100%);
}

.empty-state {
    text-align: center;
    position: relative;
    z-index: 1;
}

.empty-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    border: 1px solid var(--border);
    border-radius: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.empty-icon::before, .empty-icon::after {
    content: '';
    position: absolute;
    background: var(--border);
}

.empty-icon::before { width: 1px; height: 100%; left: 50%; }
.empty-icon::after  { width: 100%; height: 1px; top: 50%; }

.empty-title {
    font-family: 'Syne', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: 0.15em;
    margin-bottom: 8px;
}

.empty-sub {
    font-size: 0.65rem;
    color: var(--border);
    letter-spacing: 0.1em;
}

/* ── LAYERS PREVIEW ── */
.layers-preview {
    position: absolute;
    bottom: 24px;
    right: 24px;
    z-index: 2;
    display: flex;
    flex-direction: column-reverse;
    gap: 3px;
    opacity: 0.4;
}

.layer-bar {
    height: 4px;
    background: var(--accent);
    border-radius: 1px;
}

/* ── FOOTER ── */
footer {
    height: 26px;
    border-top: 1px solid var(--border);
    background: var(--surface);
    display: flex;
    align-items: center;
    padding: 0 20px;
    gap: 24px;
    flex-shrink: 0;
}

.status-item {
    font-size: 0.58rem;
    color: var(--muted);
    letter-spacing: 0.08em;
    display: flex;
    align-items: center;
    gap: 6px;
}

.status-item b {
    color: var(--label);
    font-weight: 500;
}

/* ── ANIMATIONS ── */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50%       { opacity: 0.4; }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to   { opacity: 1; transform: translateY(0); }
}

aside > * {
    animation: fadeIn 0.3s ease both;
}