.tool-shell {
    width: min(1200px, calc(100% - 2rem));
    margin: 0 auto;
    padding: var(--spacing-lg) 0 4rem;
    position: relative;
    z-index: 1;
}

.tool-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.4rem 0 1.75rem;
}

.tool-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.7rem;
    color: var(--text-primary);
    font-weight: 700;
    text-decoration: none;
}

.tool-brand-icon {
    font-size: 2rem;
    line-height: 1;
    animation: float 3s ease-in-out infinite;
}

.tool-brand-name {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.tool-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.35rem;
    padding: 0.3rem;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    background: rgba(26, 26, 36, 0.72);
    backdrop-filter: blur(12px);
}

.tool-nav a {
    padding: 0.5rem 0.7rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
}

.tool-nav a:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.06);
}

.tool-hero {
    text-align: center;
    max-width: 820px;
    margin: 2.25rem auto 2.5rem;
}

.tool-hero .feature-badge {
    margin-bottom: 1rem;
}

.tool-hero h1 {
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    font-size: clamp(2rem, 6vw, 3.25rem);
    font-weight: 800;
    letter-spacing: -0.035em;
    line-height: 1.08;
}

.tool-hero p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.7;
}

.tool-panel,
.tool-result-panel,
.tool-info-panel {
    position: relative;
    overflow: hidden;
    padding: clamp(1rem, 3vw, 2rem);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    background: var(--gradient-card), var(--bg-secondary);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(10px);
}

.tool-panel::before,
.tool-result-panel::before,
.tool-info-panel::before {
    content: '';
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08), transparent 45%);
}

.tool-result-panel,
.tool-info-panel {
    margin-top: var(--spacing-md);
}

.tool-panel > *,
.tool-result-panel > *,
.tool-info-panel > * {
    position: relative;
    z-index: 1;
}

.tool-drop-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.tool-drop-zone {
    position: relative;
    overflow: hidden;
    min-height: 190px;
    padding: 1.5rem;
    display: grid;
    place-items: center;
    text-align: center;
    border: 2px dashed rgba(99, 102, 241, 0.42);
    border-radius: var(--radius-xl);
    background: var(--gradient-card);
    cursor: pointer;
    transition: border-color var(--transition-normal), transform var(--transition-normal), box-shadow var(--transition-normal);
}

.tool-drop-zone:hover,
.tool-drop-zone.dragover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.tool-drop-zone.has-file {
    border-style: solid;
    border-color: var(--success);
    background: rgba(34, 197, 94, 0.08);
    box-shadow: 0 0 32px var(--success-glow);
}

.tool-drop-zone-content {
    display: grid;
    justify-items: center;
}

.tool-drop-icon {
    display: grid;
    place-items: center;
    width: 64px;
    height: 64px;
    margin-bottom: 0.75rem;
    color: var(--accent-secondary);
}

.tool-drop-icon svg {
    width: 56px;
    height: 56px;
}

.tool-drop-zone strong,
.tool-drop-zone span {
    display: block;
}

.tool-drop-zone span {
    margin-top: 0.5rem;
    color: var(--text-muted);
    font-size: 0.88rem;
    overflow-wrap: anywhere;
}

.tool-form-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.tool-field label {
    display: block;
    margin-bottom: 0.45rem;
    color: var(--text-primary);
    font-weight: 600;
}

.tool-field input,
.tool-field select {
    width: 100%;
    min-height: 46px;
    padding: 0.7rem 0.85rem;
    color: var(--text-primary);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    font: inherit;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.tool-field input:focus,
.tool-field select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.16);
}

.tool-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.25rem;
}

.tool-primary,
.tool-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 0.7rem 1.1rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 700;
    text-decoration: none;
    font-family: inherit;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
}

.tool-primary {
    border: 0;
    color: white;
    background: var(--gradient-primary);
    box-shadow: var(--shadow-md);
}

.tool-secondary {
    color: var(--text-primary);
    border: 1px solid var(--border-subtle);
    background: var(--bg-tertiary);
}

.tool-primary:not(:disabled):hover,
.tool-secondary:not(:disabled):hover {
    transform: translateY(-2px);
}

.tool-primary:not(:disabled):hover {
    box-shadow: var(--shadow-glow);
}

.tool-secondary:not(:disabled):hover {
    border-color: var(--accent-primary);
}

.tool-primary:disabled,
.tool-secondary:disabled {
    opacity: 0.55;
    cursor: not-allowed;
}

.tool-primary:focus-visible,
.tool-secondary:focus-visible,
.tool-drop-zone:focus-visible,
.tool-nav a:focus-visible {
    outline: 3px solid var(--accent-secondary);
    outline-offset: 3px;
}

.tool-progress {
    height: 10px;
    margin-top: 1rem;
    overflow: hidden;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.05);
}

.tool-progress > span {
    display: block;
    width: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--accent-primary), var(--success));
    transition: width 0.2s ease;
}

.tool-status-line {
    margin-top: 0.6rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.tool-alert {
    margin-top: 1rem;
    padding: 0.85rem 1rem;
    border-radius: var(--radius-sm);
    color: #fecaca;
    border: 1px solid rgba(239, 68, 68, 0.35);
    background: rgba(239, 68, 68, 0.12);
}

.tool-summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1rem;
}

.tool-summary-badge,
.check-badge {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 0.3rem 0.65rem;
    font-size: 0.78rem;
    font-weight: 800;
    text-transform: uppercase;
}

.status-pass {
    color: #86efac;
    background: rgba(34, 197, 94, 0.14);
}

.status-warning {
    color: #fde68a;
    background: rgba(245, 158, 11, 0.14);
}

.status-fail {
    color: #fca5a5;
    background: rgba(239, 68, 68, 0.14);
}

.tool-check-list,
.tool-diff-list {
    display: grid;
    gap: 0.75rem;
}

.tool-check,
.tool-diff-card {
    padding: 1rem;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    background: rgba(26, 26, 36, 0.82);
}

.tool-check-head,
.tool-diff-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
}

.tool-check p,
.tool-diff-card p,
.tool-diff-card li {
    color: var(--text-secondary);
    line-height: 1.55;
}

.diff-columns {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.75rem;
    margin-top: 0.75rem;
}

.diff-added {
    color: #86efac;
}

.diff-removed {
    color: #fca5a5;
}

.tool-kpis {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 0.75rem;
    margin: 1rem 0;
}

.tool-kpi {
    padding: 1rem;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    background: rgba(26, 26, 36, 0.82);
}

.tool-kpi span,
.tool-kpi strong {
    display: block;
}

.tool-kpi span {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.tool-kpi strong {
    margin-top: 0.35rem;
    color: var(--text-primary);
    overflow-wrap: anywhere;
}

.tool-footer {
    padding-top: 2rem;
    color: var(--text-muted);
    text-align: center;
    font-size: 0.85rem;
}

.hidden {
    display: none !important;
}

@media (max-width: 720px) {
    .tool-header {
        align-items: center;
        flex-direction: column;
    }

    .tool-summary {
        align-items: flex-start;
        flex-direction: column;
    }

    .tool-nav {
        width: 100%;
        justify-content: center;
    }

    .tool-nav a {
        flex: 1 1 auto;
        text-align: center;
    }

    .tool-hero {
        margin-top: 1.25rem;
    }

    .tool-drop-grid,
    .tool-form-grid,
    .diff-columns {
        grid-template-columns: 1fr;
    }

    .tool-drop-zone {
        min-height: 175px;
        padding: 1.25rem 1rem;
    }
}

@media (max-width: 480px) {
    .tool-shell {
        width: min(100% - 1rem, 1200px);
        padding-top: 1rem;
    }

    .tool-brand-name {
        font-size: 1.05rem;
    }

    .tool-nav {
        display: grid;
        grid-template-columns: 1fr;
    }

    .tool-hero p {
        font-size: 0.95rem;
    }

    .tool-primary,
    .tool-secondary {
        width: 100%;
    }
}