:root {
    --bg: #ffffff;
    --bg-card: #ffffff;
    --bg-input: #f5f5f5;
    --border: #cccccc;
    --text: #000000;
    --text-dim: #444444;
    --accent: #4f8cff;
    --accent-hover: #6ba0ff;
    --accent-subtle: rgba(79,140,255,0.08);
    --success: #34d399;
    --warning: #fbbf24;
    --danger: #f87171;
    --radius: 10px;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
}

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

body {
    font-family: 'Inter', 'Segoe UI', -apple-system, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

/* Header */
.header {
    background: #ffffff;
    border-bottom: 2px solid #000000;
    padding: 18px 32px;
    display: flex;
    align-items: center;
    gap: 14px;
}

.header-icon {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
}

.header h1 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.3px;
}

.header .subtitle {
    color: var(--text-dim);
    font-size: 0.8rem;
    margin-top: 2px;
}

.header-nav {
    margin-left: auto;
    display: flex;
    gap: 8px;
}

.nav-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 16px;
    border-radius: 8px;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
    border: 1px solid var(--border);
    transition: all 0.15s;
    white-space: nowrap;
}

.nav-link:hover {
    border-color: var(--accent);
    color: var(--accent);
    background: var(--accent-subtle);
}

.live-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--success);
    animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(52,211,153,0.4); }
    50% { opacity: 0.6; box-shadow: 0 0 0 4px rgba(52,211,153,0); }
}

/* Layout */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px;
}

.panels {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 24px;
}

@media (max-width: 1100px) {
    .panels { grid-template-columns: 1fr; }
}

/* Card */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
}

.card-header h2 {
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: -0.2px;
}

.card-header .icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    color: var(--accent);
}

/* Forms */
label {
    display: block;
    font-size: 0.7rem;
    color: var(--text-dim);
    margin-bottom: 4px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.6px;
}

input, select {
    width: 100%;
    padding: 8px 12px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text);
    font-size: 0.88rem;
    transition: border-color 0.2s;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(79,140,255,0.1);
}

input[type="number"] { -moz-appearance: textfield; }
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; }

/* Table */
.soil-table-wrap {
    max-height: 380px;
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 12px;
}

.soil-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.84rem;
}

.soil-table thead {
    position: sticky;
    top: 0;
    z-index: 2;
}

.soil-table thead th {
    background: #f0f0f0;
    padding: 10px 6px;
    text-align: center;
    font-weight: 600;
    color: #444444;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    border-bottom: 2px solid var(--border);
    white-space: nowrap;
}

.soil-table tbody td {
    padding: 3px;
    text-align: center;
    border-bottom: 1px solid #cccccc;
}

.soil-table tbody td input,
.soil-table tbody td select {
    text-align: center;
    padding: 6px 4px;
    font-size: 0.84rem;
    border: 1px solid transparent;
    background: transparent;
}

.soil-table tbody td input:focus,
.soil-table tbody td select:focus {
    background: var(--bg-input);
    border-color: var(--accent);
}

.soil-table tbody tr:hover {
    background: var(--accent-subtle);
}

.soil-table .row-num {
    color: var(--text-dim);
    font-size: 0.72rem;
    width: 28px;
    font-variant-numeric: tabular-nums;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border: none;
    border-radius: 6px;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
    text-decoration: none;
}

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

.btn-danger {
    background: transparent;
    color: var(--danger);
    border: 1px solid rgba(248,113,113,0.3);
    padding: 3px 7px;
    font-size: 0.72rem;
}
.btn-danger:hover { background: rgba(248,113,113,0.1); }

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text);
}
.btn-outline:hover {
    border-color: var(--accent);
    color: var(--accent);
}

.btn-sm { padding: 5px 10px; font-size: 0.78rem; }

.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-group { display: flex; gap: 8px; flex-wrap: wrap; }

.btn-icon {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
}

/* Toolbar */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.toolbar-stats {
    color: var(--text-dim);
    font-size: 0.82rem;
    font-variant-numeric: tabular-nums;
}

/* Borehole Header */
.borehole-header {
    display: flex;
    align-items: flex-end;
    gap: 12px;
    margin-bottom: 14px;
}

.borehole-name-group {
    flex: 1;
}

.borehole-name-group input {
    font-size: 0.95rem;
    font-weight: 600;
    padding: 9px 12px;
    letter-spacing: -0.1px;
}

.borehole-actions {
    display: flex;
    gap: 6px;
    flex-shrink: 0;
}

.upload-csv-btn {
    cursor: pointer;
}

/* Format Guide (collapsible) */
.format-guide {
    margin-bottom: 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}
.format-guide summary {
    padding: 10px 14px;
    cursor: pointer;
    font-size: .85rem;
    font-weight: 600;
    color: var(--text-dim);
    background: var(--bg-input);
    user-select: none;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 6px;
}
.format-guide summary::-webkit-details-marker { display: none; }
.format-guide summary::after {
    content: '▸';
    margin-left: auto;
    transition: transform .2s;
    font-size: .75rem;
}
.format-guide[open] summary::after {
    transform: rotate(90deg);
}
.format-guide-body {
    padding: 12px 16px;
    font-size: .82rem;
    line-height: 1.6;
    color: var(--text-dim);
    border-top: 1px solid var(--border);
}
.format-guide-body p {
    margin-bottom: 6px;
}
.format-guide-body code {
    background: var(--bg-input);
    padding: 1px 5px;
    border-radius: 4px;
    font-size: .8rem;
}
.format-example-table {
    width: 100%;
    border-collapse: collapse;
    margin: 6px 0;
    font-size: .8rem;
}
.format-example-table th,
.format-example-table td {
    padding: 5px 10px;
    border: 1px solid var(--border);
    text-align: left;
}
.format-example-table th {
    background: var(--bg-input);
    font-weight: 600;
    color: var(--text);
}
.format-sample {
    background: #f8f8f8;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 8px 12px;
    font-family: 'Cascadia Code', 'Fira Code', monospace;
    font-size: .78rem;
    line-height: 1.5;
    overflow-x: auto;
    margin: 6px 0;
    color: var(--text);
}
.format-block {
    margin: 10px 0;
}
.format-block strong {
    color: var(--text);
    font-size: .82rem;
}
.format-label {
    display: block;
    font-size: .78rem;
    color: var(--text-dim);
    margin-top: 2px;
}
.format-note {
    margin-top: 8px;
    padding: 6px 10px;
    background: rgba(79,140,255,0.06);
    border-left: 3px solid var(--accent);
    border-radius: 0 6px 6px 0;
    font-size: .78rem;
    color: var(--text-dim);
}

/* CSV Drop Zone */
.csv-drop-zone {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    margin-bottom: 14px;
    border: 1.5px dashed var(--border);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--text-dim);
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
    overflow: hidden;
}

.csv-drop-zone:hover, .csv-drop-zone.drag-over {
    border-color: var(--accent);
    background: var(--accent-subtle);
    color: var(--accent);
}

.csv-drop-zone.success {
    border-color: var(--success);
    background: rgba(52,211,153,0.06);
    color: var(--success);
}

.csv-drop-icon {
    width: 22px;
    height: 22px;
    flex-shrink: 0;
}

/* File Upload */
.upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 28px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
}

.upload-zone:hover, .upload-zone.drag-over {
    border-color: var(--accent);
    background: var(--accent-subtle);
}

.upload-zone input[type="file"] {
    position: absolute;
    inset: 0;
    opacity: 0;
    cursor: pointer;
}

.upload-zone .upload-icon {
    width: 32px;
    height: 32px;
    color: var(--text-dim);
    margin: 0 auto 8px;
}

.upload-zone p {
    color: var(--text-dim);
    font-size: 0.82rem;
}

.upload-zone .ext-label {
    font-size: 0.7rem;
    margin-top: 6px;
    color: rgba(139,143,163,0.6);
}

/* Earthquake Preview */
.eq-info {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin: 14px 0;
}

.eq-stat {
    background: var(--bg-input);
    border-radius: 6px;
    padding: 10px 8px;
    text-align: center;
    border: 1px solid var(--border);
}

.eq-stat .value {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
}

.eq-stat .label {
    font-size: 0.65rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 2px;
}

/* Chart Container */
.chart-container {
    background: var(--bg-input);
    border-radius: 6px;
    padding: 12px;
    margin: 12px 0;
    height: 200px;
    border: 1px solid var(--border);
}

.chart-container canvas {
    width: 100% !important;
    height: 100% !important;
}

/* Run Section */
.run-section {
    text-align: center;
    padding: 20px;
}

.run-btn-big {
    padding: 13px 44px;
    font-size: 0.95rem;
    font-weight: 700;
    border-radius: 8px;
    background: var(--accent);
    color: white;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    letter-spacing: 0.2px;
}

.run-btn-big:hover {
    background: var(--accent-hover);
    box-shadow: 0 4px 20px rgba(79,140,255,0.3);
}

.run-btn-big:disabled { opacity: 0.4; cursor: not-allowed; }

.run-btn-big svg {
    width: 18px;
    height: 18px;
}

/* Status Bar */
.status-bar {
    display: none;
    margin-top: 14px;
    padding: 10px 16px;
    border-radius: 6px;
    font-size: 0.85rem;
    text-align: left;
}

.status-bar.running {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(79,140,255,0.08);
    border: 1px solid rgba(79,140,255,0.3);
    color: var(--accent);
}

.status-bar.completed {
    display: block;
    background: rgba(52,211,153,0.08);
    border: 1px solid rgba(52,211,153,0.3);
    color: var(--success);
}

.status-bar.error {
    display: block;
    background: rgba(248,113,113,0.08);
    border: 1px solid rgba(248,113,113,0.3);
    color: var(--danger);
}

/* Spinner */
.spinner {
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    flex-shrink: 0;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Results Section */
.results-section { display: none; }
.results-section.visible { display: block; }

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 10px;
    margin-bottom: 20px;
}

.result-metric {
    background: var(--bg-input);
    border-radius: 8px;
    padding: 14px 12px;
    text-align: center;
    border: 1px solid var(--border);
}

.result-metric .value {
    font-size: 1.35rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: var(--text);
}

.result-metric .label {
    font-size: 0.68rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 4px;
}

.result-metric.highlight .value { color: var(--accent); }

.figures-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-bottom: 20px;
}

@media (max-width: 900px) {
    .figures-grid { grid-template-columns: 1fr; }
}

.figure-card {
    background: var(--bg-input);
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}

.figure-card:hover { border-color: var(--accent); }

.figure-card img {
    width: 100%;
    display: block;
    cursor: pointer;
}

.figure-card .fig-caption {
    padding: 8px 12px;
    font-size: 0.78rem;
    color: var(--text-dim);
    text-align: center;
    border-top: 1px solid var(--border);
}

/* Interactive Charts */
.chart-large {
    background: var(--bg-input);
    border-radius: 8px;
    padding: 14px;
    margin-bottom: 14px;
    border: 1px solid var(--border);
    height: 340px;
}

.chart-large canvas { width: 100% !important; height: 100% !important; }

/* Download Row */
.download-row {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-top: 10px;
}

/* Soil Column Preview */
.soil-column-preview {
    margin-top: 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.soil-layer-bar {
    display: flex;
    align-items: center;
    padding: 3px 12px;
    font-size: 0.72rem;
    color: #000000;
    min-height: 22px;
    border-bottom: 1px solid var(--border);
    font-variant-numeric: tabular-nums;
}

.soil-layer-bar.sand { background: #f0dda0; }
.soil-layer-bar.silt { background: #e0d0b8; }
.soil-layer-bar.clay { background: #c8e0c8; }

/* Tabs */
.tabs {
    display: flex;
    gap: 2px;
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.tab {
    padding: 9px 18px;
    cursor: pointer;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-dim);
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: all 0.15s;
}

.tab:hover { color: var(--text); }

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

.tab-content { display: none; }
.tab-content.active { display: block; }

/* Param Info Box */
.param-box {
    margin-top: 20px;
    padding: 14px 16px;
    background: var(--bg-input);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.param-box h3 {
    font-size: 0.82rem;
    margin-bottom: 10px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 8px;
}

.param-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px 16px;
    font-size: 0.78rem;
    color: var(--text-dim);
}

.param-grid strong { color: var(--text); }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cccccc; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #999999; }

/* Lightbox */
.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.85);
    z-index: 1000;
    cursor: pointer;
    justify-content: center;
    align-items: center;
}

.lightbox.active { display: flex; }

.lightbox img {
    max-width: 95%;
    max-height: 95%;
    border-radius: 8px;
    box-shadow: 0 8px 40px rgba(0,0,0,0.5);
}

/* Empty state */
.empty-state {
    padding: 20px;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.85rem;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 8px;
    pointer-events: none;
}

.toast {
    pointer-events: auto;
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 10px 16px;
    font-size: 0.82rem;
    color: #000000;
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    gap: 8px;
    animation: slideIn 0.25s ease-out;
    max-width: 360px;
}

.toast.success { border-color: var(--success); }
.toast.success .toast-icon { color: var(--success); }
.toast.error { border-color: var(--danger); }
.toast.error .toast-icon { color: var(--danger); }
.toast.info { border-color: var(--accent); }
.toast.info .toast-icon { color: var(--accent); }

.toast-icon { width: 18px; height: 18px; flex-shrink: 0; }

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Validation */
.soil-table tbody td input:invalid {
    border-color: var(--danger) !important;
    box-shadow: 0 0 0 2px rgba(248,113,113,0.15);
}

/* Step indicator for run */
.step-list {
    text-align: left;
    margin-top: 10px;
    font-size: 0.8rem;
}

.step-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 4px 0;
    color: var(--text-dim);
}

.step-item.active { color: var(--accent); font-weight: 600; }
.step-item.done { color: var(--success); }
.step-item.error-step { color: var(--danger); }

.step-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: 2px solid currentColor;
    flex-shrink: 0;
}

.step-item.active .step-dot { background: var(--accent); }
.step-item.done .step-dot { background: var(--success); }
.step-item.error-step .step-dot { background: var(--danger); }

/* Improved upload zone loaded state */
.upload-zone.loaded {
    border-color: var(--success);
    border-style: solid;
}

.upload-zone.loaded .upload-icon { color: var(--success); }

.file-loaded-info {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    background: rgba(52,211,153,0.05);
    border: 1px solid rgba(52,211,153,0.2);
    border-radius: 8px;
    margin-top: 10px;
    font-size: 0.8rem;
    color: var(--success);
}

.file-loaded-info svg { width: 16px; height: 16px; flex-shrink: 0; }

/* ── Shaking Simulation ── */
.shaking-wrapper {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.shaking-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.speed-group {
    display: flex;
    align-items: center;
    gap: 6px;
}

.speed-group select {
    width: auto;
    padding: 4px 8px;
    font-size: 0.78rem;
}

.shaking-time-display {
    margin-left: auto;
    font-size: 0.88rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: var(--accent);
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 4px 12px;
}

.shaking-timeline {
    position: relative;
}

.shaking-timeline input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    background: #e0e0e0;
    border: 1px solid #000000;
    border-radius: 3px;
    outline: none;
    cursor: pointer;
}

.shaking-timeline input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid #fff;
    cursor: pointer;
    box-shadow: 0 1px 4px rgba(0,0,0,0.3);
}

.shaking-timeline input[type="range"]::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    border: 2px solid #fff;
    cursor: pointer;
}

.timeline-accel {
    height: 40px;
    margin-top: 4px;
    background: #ffffff;
    border: 1px solid #000000;
    border-radius: 4px;
    overflow: hidden;
}

.shaking-stage {
    position: relative;
}

.shaking-stage canvas {
    width: 100%;
    height: auto;
    border-radius: 8px;
    border: 1px solid #000000;
    background: #ffffff;
    display: block;
}

.shaking-legend {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-top: 8px;
    font-size: 0.72rem;
    color: var(--text-dim);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

.legend-swatch {
    width: 12px;
    height: 12px;
    border-radius: 2px;
    flex-shrink: 0;
}