.calculator-page {
    min-height: 100vh;
    padding-top: 96px;
}

/* Mobile: make transitions instant and remove hover effects for better UX */
@media (max-width: 600px) {
    .chip,
    .chip-check,
    .calculator-card,
    .optional-selector-panel,
    .calculator-toolbar,
    .calculator-result {
        -webkit-animation-duration: 0.01s !important;
        animation-duration: 0.01s !important;
        -webkit-transition-duration: 0.05s !important;
        transition-duration: 0.05s !important;
        transition-delay: 0s !important;
    }

    .chip:hover, .calculator-card:hover, .optional-selector-panel:hover {
        transform: none !important;
        box-shadow: none !important;
    }
}

/* Calculator touch tweaks */
@media (max-width: 768px) {
    .calculator-card, .chip, .optional-selector-panel, .calculator-toolbar, .calculator-result {
        -webkit-tap-highlight-color: transparent;
        tap-highlight-color: transparent;
    }

    .chip:active, .calculator-card:active, .optional-selector-panel:active {
        transform: none !important;
        box-shadow: none !important;
    }
}

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 24px;
    font-size: 13px;
}

.breadcrumb a {
    color: var(--accent-light);
    text-decoration: none;
    transition: var(--transition);
    font-weight: 500;
}

.breadcrumb a:hover {
    color: var(--text-heading);
}

.breadcrumb [aria-current="page"] {
    color: var(--text-body);
    font-weight: 500;
}

.breadcrumb span[aria-hidden="true"] {
    color: var(--text-muted);
    margin: 0 4px;
}

.calculator-shell {
    max-width: 1120px;
    margin: 0 auto;
    padding: 48px 24px 80px;
    position: relative;
    z-index: 2;
}

.calculator-header {
    text-align: center;
    max-width: 760px;
    margin: 0 auto 36px;
}

.calculator-header h1 {
    font-family: 'Space Grotesk', sans-serif;
    color: var(--text-heading);
    font-size: clamp(34px, 5vw, 56px);
    line-height: 1.1;
    letter-spacing: -1.8px;
    margin-bottom: 14px;
}

.calculator-header p {
    font-size: 17px;
    color: var(--text-body);
}

.calculator-card {
    background: var(--bg-card);
    border: 1px solid var(--border-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow-card);
    backdrop-filter: blur(20px);
    overflow: hidden;
}

.calculator-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 22px;
    border-bottom: 1px solid var(--border-card);
}

.calculator-toolbar h2 {
    color: var(--text-heading);
    font-family: 'Space Grotesk', sans-serif;
    font-size: 22px;
}

/* ===== OPTIONAL SUBJECT SELECTOR PANEL ===== */
.optional-selector-panel {
    padding: 24px;
    border-bottom: 1px solid var(--border-card);
    background: linear-gradient(180deg, rgba(124, 92, 255, 0.04) 0%, transparent 100%);
}

.optional-selector-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 8px;
}

.optional-selector-title {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-heading);
    font-family: 'Space Grotesk', sans-serif;
    font-size: 16px;
    font-weight: 600;
}

.optional-selector-title svg {
    color: var(--accent-light);
    flex-shrink: 0;
}

.optional-counter {
    font-size: 12px;
    font-weight: 600;
    color: var(--accent-light);
    background: rgba(124, 92, 255, 0.1);
    padding: 5px 14px;
    border-radius: 100px;
    border: 1px solid rgba(124, 92, 255, 0.18);
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

.optional-counter.at-limit {
    color: #FCD34D;
    background: rgba(245, 158, 11, 0.12);
    border-color: rgba(245, 158, 11, 0.25);
}

/* Chip grid */
.optional-chips {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 10px;
    margin-bottom: 12px;
}

.chip-label {
    display: block;
    cursor: pointer;
    position: relative;
}

.chip-label input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
    pointer-events: none;
}

.chip {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: rgba(5, 8, 22, 0.55);
    border: 1px solid var(--border-card-hover);
    border-radius: 10px;
    color: var(--text-body);
    font-size: 13.5px;
    font-weight: 500;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    user-select: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.chip:hover {
    background: rgba(124, 92, 255, 0.08);
    border-color: rgba(124, 92, 255, 0.35);
    color: var(--text-heading);
}

.chip-check {
    opacity: 0;
    transform: scale(0.5);
    transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
    flex-shrink: 0;
    color: var(--accent-light);
    width: 0;
    overflow: hidden;
}

/* Selected state */
.chip-label input:checked + .chip {
    background: rgba(124, 92, 255, 0.14);
    border-color: rgba(124, 92, 255, 0.5);
    color: var(--text-heading);
    box-shadow: 0 0 16px rgba(124, 92, 255, 0.1), inset 0 0 12px rgba(124, 92, 255, 0.06);
}

.chip-label input:checked + .chip .chip-check {
    opacity: 1;
    transform: scale(1);
    width: 14px;
}

/* Focus outline for keyboard nav */
.chip-label input:focus-visible + .chip {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.optional-hint {
    font-size: 12.5px;
    color: var(--text-muted);
    line-height: 1.5;
    transition: color 0.3s ease;
}

.optional-hint.at-limit {
    color: #FBBF24;
}

/* ===== LEGACY (science page) — keep backward compat ===== */
.optional-subject-select {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    flex-wrap: wrap;
}

.optional-subject-select > label {
    font-weight: 500;
    color: var(--text-muted);
    margin-right: 12px;
    white-space: nowrap;
}

.subject-dropdown {
    background: rgba(5, 8, 22, 0.7);
    border: 1px solid var(--border-card-hover);
    border-radius: 8px;
    color: var(--text-heading);
    padding: 8px 12px;
    font: inherit;
    outline: none;
    cursor: pointer;
    transition: all 0.2s ease;
    width: 100%;
    min-width: 0;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: linear-gradient(45deg, transparent 50%, var(--text-heading) 50%), linear-gradient(135deg, var(--text-heading) 50%, transparent 50%);
    background-position: calc(100% - 18px) calc(1em + 2px), calc(100% - 13px) calc(1em + 2px);
    background-size: 6px 6px, 6px 6px;
    background-repeat: no-repeat;
}

.subject-dropdown:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.14);
}

.subject-dropdown option {
    background: var(--bg-card);
    color: var(--text-heading);
}

/* Fix native select on iOS/Android: ensure options readable and dropdown fits container */
@media (max-width: 768px) {
    .subject-dropdown {
        padding-right: 36px; /* room for caret */
    }
    .subject-dropdown option {
        background: var(--bg-card) !important;
        color: var(--text-heading) !important;
    }
}

/* Small subject search input for calculator pages */
.subject-search-wrap {
    margin-left: 12px;
    display: inline-block;
}
.subject-search {
    font: inherit;
    padding: 6px 10px;
    border-radius: 8px;
    border: 1px solid var(--border-card);
    background: rgba(255,255,255,0.02);
    color: var(--text-heading);
    min-width: 160px;
    max-width: 260px;
}
.subject-search::placeholder { color: var(--text-muted); }

@media (max-width: 520px) {
    .subject-search-wrap { display: block; margin-top: 10px; margin-left: 0; }
    .subject-search { width: 100%; max-width: none; }
}

/* Calculator mobile tweaks */
@media (max-width: 760px) {
    .calculator-header h1 { font-size: 1.4rem; }
    .calculator-table th, .calculator-table td { padding: 10px; }
    .result-box { padding: 10px; }
    .back-link { margin-bottom: 18px; display: inline-flex; }
}

/* Remove tap highlight specifically for calculator controls */
.calculator-page input, .calculator-page select, .calculator-page button { -webkit-tap-highlight-color: transparent; }

/* ===== TABLE ===== */
.calculator-table {
    width: 100%;
    border-collapse: collapse;
}

.calculator-table th,
.calculator-table td {
    padding: 16px;
    border-bottom: 1px solid var(--border-card);
    text-align: left;
}

.calculator-table th {
    color: var(--accent-light);
    font-size: 12px;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.calculator-table input {
    width: 100%;
    background: rgba(5, 8, 22, 0.7);
    border: 1px solid var(--border-card-hover);
    border-radius: 12px;
    color: var(--text-heading);
    padding: 12px 14px;
    font: inherit;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.calculator-table input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.14);
}

.subject-col {
    min-width: 240px;
}

.number-col {
    width: 140px;
}

.grade-col {
    width: 120px;
    color: var(--text-heading);
    font-weight: 700;
}

.remove-row {
    background: rgba(239, 68, 68, 0.12);
    color: #FCA5A5;
    border: 1px solid rgba(239, 68, 68, 0.25);
    border-radius: 10px;
    padding: 9px 12px;
    cursor: pointer;
}

/* ===== ACTIONS & RESULTS ===== */
.calculator-actions {
    display: flex;
    justify-content: space-between;
    gap: 14px;
    flex-wrap: wrap;
    padding: 22px;
}

.calculator-result {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    padding: 22px;
    background: rgba(124, 92, 255, 0.05);
    border-top: 1px solid var(--border-card);
}

.result-box {
    background: rgba(5, 8, 22, 0.55);
    border: 1px solid var(--border-card);
    border-radius: var(--radius-sm);
    padding: 20px;
    text-align: center;
    transition: border-color 0.3s ease;
}

.result-label {
    color: var(--text-muted);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.result-value {
    color: var(--text-heading);
    font-family: 'Space Grotesk', sans-serif;
    font-size: 30px;
    font-weight: 800;
}

.calculator-note {
    margin-top: 20px;
    color: var(--text-muted);
    font-size: 14px;
    text-align: center;
}

.back-link {
    display: inline-flex;
    color: var(--accent-light);
    text-decoration: none;
    margin-bottom: 24px;
    font-weight: 600;
    transition: color 0.2s ease;
}

.back-link:hover {
    color: var(--accent);
}

/* ===== RESPONSIVE: TABLET & MOBILE ===== */
@media (max-width: 760px) {
    .calculator-shell {
        padding: 32px 16px 60px;
    }

    .calculator-toolbar {
        flex-direction: column;
        align-items: flex-start;
    }

    .calculator-actions {
        flex-direction: column;
        gap: 10px;
    }

    .calculator-actions .btn-primary,
    .calculator-actions .btn-secondary {
        width: 100%;
        justify-content: center;
    }

    .calculator-result {
        grid-template-columns: 1fr;
    }

    .calculator-table {
        display: block;
        overflow-x: auto;
    }

    /* Mobile card layout for science/management tables */
    .science-table thead {
        display: none;
    }

    .science-table tbody {
        display: flex;
        flex-direction: column;
        gap: 12px;
        padding: 16px;
    }

    .science-table tr {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 12px;
        background: rgba(5, 8, 22, 0.4);
        border: 1px solid var(--border-card);
        border-radius: 12px;
        padding: 16px;
    }

    .science-table td {
        padding: 0;
        border: none;
        display: flex;
        flex-direction: column;
    }

    .science-table .subject-col {
        grid-column: 1 / -1;
        font-weight: 600;
        color: var(--text-heading);
        font-size: 15px;
        min-width: 0;
    }

    .science-table .number-col {
        width: 100%;
        gap: 6px;
    }

    .science-table .number-col::before {
        content: attr(data-label);
        font-size: 11px;
        color: var(--text-muted);
        text-transform: uppercase;
        letter-spacing: 0.5px;
    }

    /* Optional chips responsive */
    .optional-selector-panel {
        padding: 18px 16px;
    }

    .optional-chips {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .chip {
        font-size: 13px;
        padding: 9px 12px;
    }

    .optional-subject-select {
        width: 100%;
        flex-direction: column;
        gap: 10px;
    }

    .subject-dropdown {
        flex-grow: 1;
        max-width: 100%;
    }

    .result-value {
        font-size: 26px;
    }
}

/* Extra small screens */
@media (max-width: 400px) {
    .calculator-shell {
        padding: 24px 12px 48px;
    }

    .optional-chips {
        grid-template-columns: 1fr;
    }

    .optional-selector-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .calculator-header h1 {
        letter-spacing: -1px;
    }
}