/**
 * GST Calculator — all styles (self-contained in gst-calculator/)
 * Scoped under .gst-app — does not affect header/footer.
 */

body.gst-calculator-page {
    background-color: #f3f5f9;
}

.gst-app {
    --gst-red: #d40000;
    --gst-red-dark: #b10000;
    --gst-text: #172033;
    --gst-muted: #5c6880;
    --gst-bg: #f3f5f9;
    --gst-card: #ffffff;
    --gst-border: #e2e8f3;
    --gst-success: #0f766e;
    --gst-radius: 14px;

    width: 100%;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    color: var(--gst-text);
    line-height: 1.5;
}

.gst-app *,
.gst-app *::before,
.gst-app *::after {
    box-sizing: border-box;
}

.gst-app h1,
.gst-app h2,
.gst-app h3,
.gst-app p,
.gst-app ol,
.gst-app ul,
.gst-app figure {
    margin: 0;
    padding: 0;
}

.gst-app button,
.gst-app input {
    font: inherit;
    color: inherit;
}

.gst-app button {
    margin: 0;
    padding: 0;
    background: none;
    border: none;
    cursor: pointer;
}

.gst-app a {
    color: inherit;
}

body.gst-calculator-page .gst-skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
    z-index: 9999;
}

body.gst-calculator-page .gst-skip-link:focus {
    left: 16px;
    top: 16px;
    width: auto;
    height: auto;
    padding: 10px 16px;
    background: #d40000;
    color: #fff;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
}

.gst-app .gst-calc-shell {
    position: relative;
    padding-bottom: 8px;
    width: 100%;
}

.gst-app .gst-breadcrumb {
    max-width: 420px;
    margin: 0 auto;
    padding: 12px 20px 0;
    background: var(--gst-bg);
}

.gst-app .gst-breadcrumb ol {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
    list-style: none;
    margin: 0;
    padding: 0;
    font-size: 0.8rem;
    color: var(--gst-muted);
}

.gst-app .gst-breadcrumb li + li::before {
    content: "/";
    margin-right: 6px;
    color: #9aa6ba;
}

.gst-app .gst-breadcrumb a {
    color: var(--gst-muted);
    text-decoration: none;
}

.gst-app .gst-breadcrumb a:hover {
    color: var(--gst-red);
}

.gst-app .gst-breadcrumb [aria-current="page"] {
    color: var(--gst-text);
    font-weight: 600;
}

.gst-app .gst-hero {
    background: linear-gradient(120deg, #101827 0%, #1d2c45 70%, #24344d 100%);
    color: #fff;
    padding: 20px 20px 52px;
    position: relative;
    overflow: hidden;
}

.gst-app .gst-hero::before,
.gst-app .gst-hero::after {
    content: "";
    position: absolute;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.08);
    pointer-events: none;
}

.gst-app .gst-hero::before {
    width: 240px;
    height: 240px;
    top: -70px;
    right: -60px;
}

.gst-app .gst-hero::after {
    width: 180px;
    height: 180px;
    bottom: -70px;
    left: -50px;
}

.gst-app .gst-hero-inner {
    max-width: 420px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
    text-align: center;
}

.gst-app .gst-hero h1 {
    font-size: clamp(1.35rem, 4vw, 1.75rem);
    line-height: 1.15;
    font-weight: 700;
}

.gst-app .gst-hero-sub {
    margin: 8px 0 0;
    color: #c8d3e8;
    font-size: 0.88rem;
    line-height: 1.45;
}

.gst-app .gst-main {
    max-width: 420px;
    margin: -20px auto 36px;
    padding: 0 20px;
    position: relative;
    z-index: 3;
}

.gst-app .gst-tool-card {
    background: var(--gst-card);
    border: 1px solid var(--gst-border);
    border-radius: 22px;
    padding: 22px 20px 18px;
    box-shadow: 0 14px 36px rgba(16, 24, 39, 0.12);
}

.gst-app .gst-tool-inputs {
    display: flex;
    flex-direction: column;
}

.gst-app .gst-tool-results {
    margin-top: 18px;
    padding-top: 18px;
    border-top: 2px dashed #d8e0ed;
}

.gst-app .gst-field {
    margin-bottom: 16px;
}

.gst-app .gst-field-last {
    margin-bottom: 0;
    margin-top: 4px;
}

.gst-app .gst-field label,
.gst-app .gst-field-label {
    display: block;
    margin-bottom: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--gst-text);
}

.gst-app .gst-field-last .gst-field-label {
    margin-top: 2px;
    margin-bottom: 8px;
}

.gst-app .gst-input-wrap {
    position: relative;
}

.gst-app .gst-input-currency,
.gst-app .gst-input-suffix {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    color: var(--gst-muted);
    font-weight: 600;
    pointer-events: none;
}

.gst-app .gst-input-currency {
    left: 14px;
    font-size: 0.95rem;
}

.gst-app .gst-input-suffix {
    right: 14px;
}

.gst-app .gst-input {
    display: block;
    width: 100%;
    padding: 12px 40px 12px 32px;
    font-size: 1rem;
    border: 2px solid var(--gst-border);
    border-radius: var(--gst-radius);
    background: #fff;
    color: var(--gst-text);
    transition: border-color 0.2s, box-shadow 0.2s;
    -moz-appearance: textfield;
    appearance: textfield;
}

.gst-app .gst-input::-webkit-outer-spin-button,
.gst-app .gst-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.gst-app .gst-input:focus {
    outline: none;
    border-color: var(--gst-red);
    box-shadow: 0 0 0 4px rgba(212, 0, 0, 0.1);
}

.gst-app .gst-rate-presets {
    display: flex;
    flex-wrap: nowrap;
    gap: 6px;
    margin-top: 10px;
}

.gst-app .gst-preset-btn {
    flex: 1;
    min-width: 0;
    border: 1px solid var(--gst-border);
    background: #fff;
    color: var(--gst-text);
    padding: 6px 4px;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: border-color 0.2s, color 0.2s, background 0.2s;
}

.gst-app .gst-preset-btn:hover {
    border-color: var(--gst-red);
    color: var(--gst-red);
}

.gst-app .gst-preset-btn.gst-active {
    background: var(--gst-red);
    border-color: var(--gst-red);
    color: #fff;
}

.gst-app .gst-mode-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.gst-app .gst-mode-option {
    position: relative;
}

.gst-app .gst-mode-option input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.gst-app .gst-mode-label {
    display: block;
    padding: 10px 8px;
    border: 2px solid var(--gst-border);
    border-radius: var(--gst-radius);
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
    background: #fff;
}

.gst-app .gst-mode-label strong {
    display: block;
    font-size: 0.82rem;
    margin-bottom: 2px;
    font-weight: 700;
}

.gst-app .gst-mode-label span {
    display: block;
    font-size: 0.7rem;
    color: var(--gst-muted);
    line-height: 1.2;
}

.gst-app .gst-mode-option input:checked + .gst-mode-label {
    border-color: var(--gst-red);
    background: rgba(212, 0, 0, 0.04);
    box-shadow: 0 0 0 3px rgba(212, 0, 0, 0.08);
}

.gst-app .gst-mode-option input:checked + .gst-mode-label strong {
    color: var(--gst-red);
}

.gst-app .gst-mode-option input:focus-visible + .gst-mode-label {
    outline: 2px solid var(--gst-red);
    outline-offset: 2px;
}

.gst-app .gst-results-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 12px;
    min-height: 28px;
}

.gst-app .gst-results-header h2 {
    font-size: 1rem;
    line-height: 1;
    font-weight: 700;
}

.gst-app .gst-results-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 5px 10px;
    border-radius: 999px;
    background: rgba(15, 118, 110, 0.12);
    color: var(--gst-success);
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    line-height: 1;
    flex-shrink: 0;
}

.gst-app .gst-results-badge i {
    font-size: 0.62rem;
}

.gst-app .gst-total-box {
    background: linear-gradient(135deg, #101827, #1d2c45);
    color: #fff;
    border-radius: 14px;
    padding: 14px 16px;
    margin-bottom: 10px;
}

.gst-app .gst-total-label {
    font-size: 0.75rem;
    color: #b8c5da;
    margin-bottom: 4px;
}

.gst-app .gst-total-amount {
    font-size: clamp(1.35rem, 5vw, 1.6rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    transition: transform 0.15s ease;
}

.gst-app .gst-total-amount.gst-pulse {
    animation: gst-app-pulse 0.35s ease;
}

@keyframes gst-app-pulse {
    0% { transform: scale(1); }
    40% { transform: scale(1.04); }
    100% { transform: scale(1); }
}

.gst-app .gst-breakdown {
    background: #fff;
    border: 1px solid var(--gst-border);
    border-radius: var(--gst-radius);
    overflow: hidden;
}

.gst-app .gst-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    padding: 11px 12px;
    font-size: 0.85rem;
    border-bottom: 1px solid var(--gst-border);
}

.gst-app .gst-row:first-child {
    background: #f3f6fa;
}

.gst-app .gst-row:last-child {
    border-bottom: none;
}

.gst-app .gst-row-label {
    color: var(--gst-muted);
}

.gst-app .gst-row-value {
    font-weight: 700;
    color: var(--gst-text);
    text-align: right;
    word-break: break-word;
}

.gst-app .gst-row-highlight .gst-row-value {
    color: var(--gst-red);
    font-weight: 800;
}

.gst-app .gst-split-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin-top: 8px;
}

.gst-app .gst-mini-row {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 10px 12px;
    background: #f8fafc;
    border: 1px solid var(--gst-border);
    border-radius: 12px;
    font-size: 0.8rem;
}

.gst-app .gst-mini-label {
    color: var(--gst-muted);
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.gst-app .gst-mini-value {
    font-weight: 700;
    color: var(--gst-text);
}

.gst-app .gst-formula-note {
    margin-top: 10px;
    margin-bottom: 0;
    padding: 10px 12px;
    background: #fff8f8;
    border: 1px solid #f5d0d0;
    border-radius: 10px;
    font-size: 0.72rem;
    color: #7a3b3b;
    line-height: 1.4;
}

.gst-app .gst-formula-note i {
    color: var(--gst-red);
    margin-right: 4px;
}

.gst-app .gst-sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* SEO / content sections */
.gst-app .gst-content {
    max-width: 1100px;
    margin: 0 auto 64px;
    padding: 0 20px;
}

.gst-app .gst-content-block {
    background: var(--gst-card);
    border: 1px solid var(--gst-border);
    border-radius: 24px;
    padding: 28px;
    margin-bottom: 20px;
    box-shadow: 0 10px 28px rgba(16, 24, 39, 0.05);
}

.gst-app .gst-content-block h2 {
    margin: 0 0 12px;
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    color: var(--gst-text);
    font-weight: 700;
    line-height: 1.3;
}

.gst-app .gst-content-block h3 {
    font-weight: 700;
    line-height: 1.3;
}

.gst-app .gst-content-block > p {
    color: var(--gst-muted);
    line-height: 1.65;
}

.gst-app .gst-steps {
    margin: 16px 0 0;
    padding-left: 20px;
    color: var(--gst-muted);
    line-height: 1.7;
}

.gst-app .gst-steps li {
    margin-bottom: 4px;
}

.gst-app .gst-formula-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 16px;
}

.gst-app .gst-formula-card {
    background: #f8fafc;
    border: 1px solid var(--gst-border);
    border-radius: 16px;
    padding: 18px;
}

.gst-app .gst-formula-card h3 {
    margin: 0 0 10px;
    font-size: 1rem;
    color: var(--gst-text);
}

.gst-app .gst-formula-card p {
    margin: 0 0 8px;
    font-size: 0.92rem;
    color: var(--gst-muted);
    line-height: 1.55;
}

.gst-app .gst-example {
    margin-top: 10px !important;
    padding-top: 10px;
    border-top: 1px dashed var(--gst-border);
    color: var(--gst-text) !important;
    font-size: 0.88rem !important;
}

.gst-app .gst-table-wrap {
    overflow-x: auto;
    margin-top: 16px;
}

.gst-app .gst-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.92rem;
}

.gst-app .gst-table th,
.gst-app .gst-table td {
    padding: 12px 14px;
    text-align: left;
    border-bottom: 1px solid var(--gst-border);
}

.gst-app .gst-table th {
    background: #f8fafc;
    color: var(--gst-text);
    font-weight: 700;
}

.gst-app .gst-table td:first-child {
    font-weight: 700;
    color: var(--gst-red);
    white-space: nowrap;
}

.gst-app .gst-faq-list {
    margin-top: 16px;
    display: grid;
    gap: 10px;
}

.gst-app .gst-faq-item {
    border: 1px solid var(--gst-border);
    border-radius: 14px;
    background: #f8fafc;
    overflow: hidden;
}

.gst-app .gst-faq-item summary {
    cursor: pointer;
    padding: 14px 16px;
    font-weight: 600;
    color: var(--gst-text);
    list-style: none;
}

.gst-app .gst-faq-item summary::-webkit-details-marker {
    display: none;
}

.gst-app .gst-faq-item summary::after {
    content: "+";
    float: right;
    color: var(--gst-red);
    font-weight: 700;
}

.gst-app .gst-faq-item[open] summary::after {
    content: "−";
}

.gst-app .gst-faq-item p {
    padding: 0 16px 14px;
    color: var(--gst-muted);
    line-height: 1.6;
    font-size: 0.92rem;
}

.gst-app .gst-cta {
    text-align: center;
    background: linear-gradient(135deg, #101827, #1d2c45);
    color: #fff;
    border: none;
}

.gst-app .gst-cta h2 {
    color: #fff;
}

.gst-app .gst-cta p {
    color: #c8d3e8 !important;
    margin-top: 8px;
}

.gst-app .gst-cta-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    margin-top: 20px;
}

.gst-app .gst-cta-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 22px;
    border-radius: 999px;
    font-weight: 700;
    text-decoration: none;
    font-size: 0.92rem;
    transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.gst-app .gst-cta-btn:hover {
    transform: translateY(-1px);
}

.gst-app .gst-cta-primary {
    background: var(--gst-red);
    color: #fff;
    box-shadow: 0 8px 20px rgba(212, 0, 0, 0.25);
}

.gst-app .gst-cta-primary:hover {
    background: var(--gst-red-dark);
}

.gst-app .gst-cta-secondary {
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.25);
}

/* ── Tablet (521px+) ── */
@media (min-width: 521px) {
    .gst-app .gst-breadcrumb {
        max-width: 580px;
        padding: 14px 24px 0;
    }

    .gst-app .gst-hero {
        padding: 28px 24px 56px;
    }

    .gst-app .gst-hero-inner {
        max-width: 580px;
    }

    .gst-app .gst-hero h1 {
        font-size: clamp(1.5rem, 3vw, 2rem);
    }

    .gst-app .gst-hero-sub {
        font-size: 0.95rem;
    }

    .gst-app .gst-main {
        max-width: 580px;
        margin: -24px auto 40px;
        padding: 0 24px;
    }

    .gst-app .gst-tool-card {
        padding: 24px 24px 20px;
    }

    .gst-app .gst-tool-inputs {
        display: grid;
        grid-template-columns: 1fr 1fr;
        column-gap: 16px;
        row-gap: 0;
    }

    .gst-app .gst-field-last {
        grid-column: 1 / -1;
        margin-top: 8px;
    }

    .gst-app .gst-field label,
    .gst-app .gst-field-label {
        font-size: 0.9rem;
    }

    .gst-app .gst-input {
        padding: 14px 44px 14px 34px;
        font-size: 1.05rem;
    }

    .gst-app .gst-preset-btn {
        padding: 8px 6px;
        font-size: 0.82rem;
    }

    .gst-app .gst-mode-label {
        padding: 12px 10px;
    }

    .gst-app .gst-mode-label strong {
        font-size: 0.88rem;
    }

    .gst-app .gst-total-amount {
        font-size: 1.75rem;
    }
}

/* ── Desktop (901px+) ── */
@media (min-width: 901px) {
    .gst-app .gst-calc-shell {
        max-width: 1040px;
        margin: 0 auto;
        padding-bottom: 16px;
    }

    .gst-app .gst-breadcrumb {
        max-width: none;
        padding: 16px 32px 0;
    }

    .gst-app .gst-hero {
        padding: 40px 32px 72px;
        border-radius: 0 0 24px 24px;
    }

    .gst-app .gst-hero-inner {
        max-width: 720px;
    }

    .gst-app .gst-hero h1 {
        font-size: 2.25rem;
    }

    .gst-app .gst-hero-sub {
        font-size: 1.05rem;
        max-width: 560px;
        margin-left: auto;
        margin-right: auto;
    }

    .gst-app .gst-main {
        max-width: none;
        margin: -36px auto 48px;
        padding: 0 32px;
    }

    .gst-app .gst-tool-card {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 0 36px;
        align-items: start;
        padding: 32px 36px;
        border-radius: 24px;
    }

    .gst-app .gst-tool-inputs {
        display: grid;
        grid-template-columns: 1fr 1fr;
        column-gap: 20px;
        row-gap: 0;
    }

    .gst-app .gst-field-last {
        grid-column: 1 / -1;
        margin-top: 8px;
    }

    .gst-app .gst-tool-results {
        margin-top: 0;
        padding-top: 0;
        border-top: none;
        border-left: 2px dashed #d8e0ed;
        padding-left: 36px;
        min-height: 100%;
    }

    .gst-app .gst-results-header h2 {
        font-size: 1.1rem;
    }

    .gst-app .gst-total-box {
        padding: 18px 20px;
        margin-bottom: 14px;
    }

    .gst-app .gst-total-amount {
        font-size: 2rem;
    }

    .gst-app .gst-row {
        padding: 13px 14px;
        font-size: 0.92rem;
    }

    .gst-app .gst-mini-row {
        padding: 12px 14px;
    }

    .gst-app .gst-formula-note {
        font-size: 0.78rem;
    }

    .gst-app .gst-content {
        padding: 0 32px;
    }

    .gst-app .gst-content-block {
        padding: 32px 36px;
    }
}

/* ── Large desktop (1200px+) ── */
@media (min-width: 1200px) {
    .gst-app .gst-calc-shell {
        max-width: 1120px;
    }

    .gst-app .gst-tool-card {
        gap: 0 48px;
        padding: 36px 40px;
    }

    .gst-app .gst-tool-results {
        padding-left: 48px;
    }
}

@media (max-width: 720px) {
    .gst-app .gst-formula-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 520px) {
    .gst-app .gst-hero {
        padding: 16px 16px 44px;
    }

    .gst-app .gst-main {
        margin-top: -16px;
        padding: 0 14px;
        margin-bottom: 28px;
    }

    .gst-app .gst-tool-card {
        padding: 18px 16px 16px;
        border-radius: 20px;
    }

    .gst-app .gst-breadcrumb {
        padding: 10px 14px 0;
    }

    .gst-app .gst-content {
        padding-left: 14px;
        padding-right: 14px;
    }

    .gst-app .gst-content-block {
        padding: 22px 18px;
        border-radius: 20px;
    }
}