/* ── INPUT AREA ──────────────────────────── */
 .input-card {
     background: var(--header-bg);
     border: 1px solid var(--divider);
     border-radius: var(--radius-lg);
     box-shadow: var(--card-shadow);
     overflow: hidden;
     margin-bottom: 20px;
 }

 .input-card__header {
     padding: 14px 18px;
     border-bottom: 1px solid var(--divider);
     display: flex;
     align-items: center;
     justify-content: space-between;
     gap: 10px;
 }

 .input-card__title {
     display: flex;
     align-items: center;
     gap: 8px;
     font-size: 13px;
     font-weight: 600;
     color: var(--primary-text);
 }

 .input-card__title i {
     color: var(--primary-color);
     font-size: 17px;
 }

 .input-card__actions {
     display: flex;
     gap: 7px;
     flex-wrap: wrap;
 }

 .chip-btn {
     display: flex;
     align-items: center;
     gap: 5px;
     padding: 5px 12px;
     border-radius: 8px;
     border: 1px solid var(--divider);
     background: var(--section-bg);
     font-size: 11px;
     font-weight: 500;
     color: var(--gray-text);
     transition: all 0.2s;
 }

 .chip-btn:hover {
     border-color: var(--primary-color);
     color: var(--primary-color);
     background: #eef0fd;
 }

 [data-theme="dark"] .chip-btn:hover {
     background: #1e2240;
 }

 .input-card__body {
     padding: 14px 16px;
 }

 .b64-textarea {
     width: 100%;
     min-height: 140px;
     padding: 12px 14px;
     border: 1px solid var(--divider);
     border-radius: var(--radius-md);
     background: var(--input-bg);
     color: var(--primary-text);
     font-family: 'Courier New', monospace;
     font-size: 12px;
     line-height: 1.7;
     resize: vertical;
     outline: none;
     transition: border-color 0.2s, box-shadow 0.2s;
     word-break: break-all;
     scrollbar-width: thin;
 }

 .b64-textarea::placeholder {
     color: var(--gray-text);
     font-family: 'Poppins', sans-serif;
     font-size: 12px;
 }

 .b64-textarea:focus {
     border-color: var(--primary-color);
     box-shadow: 0 0 0 3px var(--primary-glow);
 }

 .textarea-meta {
     display: flex;
     align-items: center;
     justify-content: space-between;
     margin-top: 8px;
     padding: 0 2px;
     font-size: 10px;
     color: var(--gray-text);
     flex-wrap: wrap;
     gap: 6px;
 }

 .char-count {
     font-variant-numeric: tabular-nums;
 }

 .valid-indicator {
     display: flex;
     align-items: center;
     gap: 4px;
     font-weight: 500;
     font-size: 10px;
 }

 .valid-indicator.valid {
     color: #22c55e;
 }

 .valid-indicator.invalid {
     color: #ef4444;
 }

 .valid-indicator.idle {
     color: var(--gray-text);
 }

 .convert-bar {
     display: flex;
     gap: 10px;
     align-items: center;
     padding: 14px 16px;
     border-top: 1px solid var(--divider);
     flex-wrap: wrap;
 }

 .convert-btn {
     flex: 1;
     min-width: 120px;
     padding: 11px 20px;
     border-radius: var(--radius-md);
     border: none;
     background: var(--primary-color);
     color: #fff;
     font-size: 13px;
     font-weight: 600;
     display: flex;
     align-items: center;
     justify-content: center;
     gap: 8px;
     box-shadow: 0 8px 24px var(--primary-glow);
     transition: all 0.2s ease;
 }

 .convert-btn:hover {
     transform: translateY(-2px);
     box-shadow: 0 14px 32px rgba(99, 102, 241, 0.3);
 }

 .convert-btn:active {
     transform: scale(0.98);
 }

 .convert-btn:disabled {
     opacity: 0.5;
     cursor: not-allowed;
     transform: none;
 }

 .secondary-btn {
     padding: 11px 18px;
     border-radius: var(--radius-md);
     border: 1px solid var(--divider);
     background: var(--section-bg);
     color: var(--primary-text);
     font-size: 12px;
     font-weight: 500;
     display: flex;
     align-items: center;
     gap: 6px;
     transition: all 0.2s;
 }

 .secondary-btn:hover {
     border-color: var(--primary-color);
     color: var(--primary-color);
 }

 /* ── TABS (prefix strip selector) ────────── */
 .prefix-tabs {
     display: flex;
     gap: 5px;
     flex-wrap: wrap;
     padding: 12px 16px;
     border-bottom: 1px solid var(--divider);
     align-items: center;
 }

 .prefix-label {
     font-size: 11px;
     color: var(--gray-text);
     font-weight: 500;
     margin-right: 4px;
 }

 .prefix-tab {
     padding: 4px 12px;
     border-radius: 7px;
     border: 1px solid var(--divider);
     background: transparent;
     font-size: 11px;
     font-weight: 500;
     color: var(--gray-text);
     transition: all 0.2s;
 }

 .prefix-tab:hover {
     border-color: #c7d2fe;
     color: var(--primary-color);
 }

 .prefix-tab.active {
     background: var(--primary-color);
     color: #fff;
     border-color: var(--primary-color);
 }

 /* ── OUTPUT AREA ─────────────────────────── */
 .output-section {
     display: none;
     flex-direction: column;
     gap: 16px;
     animation: fadeSlideUp 0.4s cubic-bezier(.22, 1, .36, 1) both;
 }

 .output-section.visible {
     display: flex;
 }

 @keyframes fadeSlideUp {
     from {
         opacity: 0;
         transform: translateY(16px);
     }

     to {
         opacity: 1;
         transform: translateY(0);
     }
 }

 /* Image preview card */
 .preview-card {
     background: var(--header-bg);
     border: 1px solid var(--divider);
     border-radius: var(--radius-lg);
     box-shadow: var(--card-shadow);
     overflow: hidden;
 }

 .preview-card__header {
     padding: 13px 16px;
     border-bottom: 1px solid var(--divider);
     display: flex;
     align-items: center;
     justify-content: space-between;
     gap: 10px;
 }

 .preview-card__title {
     font-size: 12px;
     font-weight: 600;
     color: var(--gray-text);
     text-transform: uppercase;
     letter-spacing: 0.06em;
     display: flex;
     align-items: center;
     gap: 6px;
 }

 .preview-card__title i {
     font-size: 15px;
     color: var(--primary-color);
 }

 .preview-actions {
     display: flex;
     gap: 7px;
     flex-wrap: wrap;
 }

 .preview-action-btn {
     display: flex;
     align-items: center;
     gap: 5px;
     padding: 6px 12px;
     border-radius: 8px;
     border: 1px solid var(--divider);
     background: var(--section-bg);
     font-size: 11px;
     font-weight: 500;
     color: var(--gray-text);
     transition: all 0.2s;
 }

 .preview-action-btn:hover {
     border-color: var(--primary-color);
     color: var(--primary-color);
 }

 .preview-action-btn.success {
     background: #f0fdf4;
     border-color: #86efac;
     color: #16a34a;
 }

 .preview-body {
     padding: 16px;
     display: flex;
     align-items: flex-start;
     gap: 16px;
     flex-wrap: wrap;
 }

 .img-frame {
     flex-shrink: 0;
     background: repeating-conic-gradient(#e0e0e0 0% 25%, #f8f8f8 0% 50%) 0 0/16px 16px;
     border-radius: var(--radius-md);
     border: 1px solid var(--divider);
     overflow: hidden;
     display: flex;
     align-items: center;
     justify-content: center;
     min-width: 140px;
     min-height: 120px;
     max-width: 280px;
     max-height: 280px;
     position: relative;
 }

 [data-theme="dark"] .img-frame {
     background: repeating-conic-gradient(#1e2737 0% 25%, #151d29 0% 50%) 0 0/16px 16px;
 }

 .img-frame img {
     max-width: 280px;
     max-height: 280px;
     width: auto;
     height: auto;
     object-fit: contain;
     display: block;
     border-radius: 0;
 }

 .img-meta {
     flex: 1;
     min-width: 160px;
     display: flex;
     flex-direction: column;
     gap: 10px;
 }

 .meta-row {
     display: flex;
     flex-direction: column;
     gap: 3px;
 }

 .meta-label {
     font-size: 10px;
     color: var(--gray-text);
     font-weight: 500;
     text-transform: uppercase;
     letter-spacing: 0.05em;
 }

 .meta-value {
     font-size: 13px;
     font-weight: 600;
     color: var(--primary-text);
 }

 .badge {
     display: inline-flex;
     align-items: center;
     padding: 2px 9px;
     border-radius: 20px;
     font-size: 10px;
     font-weight: 700;
 }

 .badge-green {
     background: #f0fdf4;
     color: #16a34a;
 }

 .badge-blue {
     background: #eff6ff;
     color: #2563eb;
 }

 .badge-purple {
     background: #f5f3ff;
     color: #7c3aed;
 }

 [data-theme="dark"] .badge-green {
     background: #052e16;
     color: #4ade80;
 }

 [data-theme="dark"] .badge-blue {
     background: #1e3a5f;
     color: #60a5fa;
 }

 [data-theme="dark"] .badge-purple {
     background: #2e1065;
     color: #a78bfa;
 }

 /* Format selector */
 .format-row {
     display: flex;
     gap: 7px;
     flex-wrap: wrap;
     padding: 12px 16px;
     border-top: 1px solid var(--divider);
     align-items: center;
 }

 .format-label {
     font-size: 11px;
     color: var(--gray-text);
     font-weight: 500;
 }

 .format-chip {
     padding: 5px 13px;
     border-radius: 8px;
     border: 1px solid var(--divider);
     background: transparent;
     font-size: 11px;
     font-weight: 600;
     color: var(--gray-text);
     transition: all 0.2s;
 }

 .format-chip:hover {
     border-color: #c7d2fe;
     color: var(--primary-color);
 }

 .format-chip.active {
     background: var(--primary-color);
     color: #fff;
     border-color: var(--primary-color);
 }

 .download-bar {
     padding: 12px 16px;
     border-top: 1px solid var(--divider);
     display: flex;
     gap: 10px;
     flex-wrap: wrap;
 }

 .download-btn {
     flex: 1;
     min-width: 120px;
     padding: 11px 18px;
     border-radius: var(--radius-md);
     border: none;
     background: #10b981;
     color: #fff;
     font-size: 13px;
     font-weight: 600;
     display: flex;
     align-items: center;
     justify-content: center;
     gap: 7px;
     box-shadow: 0 8px 20px rgba(16, 185, 129, 0.25);
     transition: all 0.2s;
 }

 .download-btn:hover {
     transform: translateY(-2px);
     box-shadow: 0 12px 28px rgba(16, 185, 129, 0.35);
 }

 /* Error state */
 .error-card {
     background: #fff5f5;
     border: 1px solid #fca5a5;
     border-radius: var(--radius-md);
     padding: 14px 16px;
     display: flex;
     align-items: flex-start;
     gap: 10px;
     animation: fadeSlideUp 0.3s ease both;
     display: none;
 }

 [data-theme="dark"] .error-card {
     background: #1a0a0a;
     border-color: #7f1d1d;
 }

 .error-card.visible {
     display: flex;
 }

 .error-card i {
     color: #ef4444;
     font-size: 18px;
     flex-shrink: 0;
     margin-top: 1px;
 }

 .error-card__text {
     font-size: 12px;
     color: #dc2626;
     line-height: 1.6;
 }

 [data-theme="dark"] .error-card__text {
     color: #f87171;
 }

 /* ── TOOLS INFO STRIP ────────────────────── */
 .info-strip {
     display: grid;
     grid-template-columns: repeat(3, 1fr);
     gap: 10px;
     margin-top: 6px;
 }

 .info-item {
     background: var(--header-bg);
     border: 1px solid var(--divider);
     border-radius: var(--radius-md);
     padding: 14px;
     display: flex;
     align-items: flex-start;
     gap: 10px;
 }

 .info-item__icon {
     width: 36px;
     height: 36px;
     flex-shrink: 0;
     border-radius: 9px;
     display: flex;
     align-items: center;
     justify-content: center;
     font-size: 17px;
 }

 .info-item__text {
     flex: 1;
 }

 .info-item__title {
     font-size: 12px;
     font-weight: 600;
     color: var(--primary-text);
     margin-bottom: 3px;
 }

 .info-item__desc {
     font-size: 11px;
     color: var(--gray-text);
     line-height: 1.6;
 }

 /* ── LOADING OVERLAY ─────────────────────── */
 .convert-btn .spinner {
     width: 14px;
     height: 14px;
     border: 2px solid rgba(255, 255, 255, 0.4);
     border-top-color: #fff;
     border-radius: 50%;
     animation: spin 0.6s linear infinite;
     display: none;
 }

 .convert-btn.loading .spinner {
     display: block;
 }

 .convert-btn.loading .btn-icon {
     display: none;
 }

 @keyframes spin {
     to {
         transform: rotate(360deg);
     }
 }

 /* ── RESPONSIVE ──────────────────────────── */
 @media (max-width: 640px) {
     .page {
         padding: 16px 12px 48px;
     }

     .hero h1 {
         font-size: 22px;
     }

     .hero p {
         font-size: 12px;
     }

     .input-card__header {
         flex-wrap: wrap;
         gap: 8px;
     }

     .input-card__actions {
         width: 100%;
         justify-content: flex-start;
     }

     .b64-textarea {
         min-height: 110px;
         font-size: 11px;
     }

     .convert-bar {
         flex-direction: column;
     }

     .convert-btn,
     .secondary-btn {
         width: 100%;
         justify-content: center;
     }

     .preview-body {
         flex-direction: column;
     }

     .img-frame {
         max-width: 100%;
         width: 100%;
     }

     .img-frame img {
         max-width: 100%;
     }

     .img-meta {
         width: 100%;
     }

     .info-strip {
         grid-template-columns: 1fr;
     }

     .preview-card__header {
         flex-wrap: wrap;
         gap: 8px;
     }

     .preview-actions {
         width: 100%;
     }

     .download-bar {
         flex-direction: column;
     }

     .download-btn {
         width: 100%;
         justify-content: center;
     }

     .format-row {
         gap: 5px;
     }

     .header__inner {
         padding: 8px 14px;
     }
 }

 @media (max-width: 420px) {
     .info-strip {
         gap: 8px;
     }

     .prefix-tabs {
         padding: 10px 12px;
     }

     .b64-textarea {
         min-height: 90px;
     }
 }




 
/* ── HOW TO USE SECTION ──────────────────── */
.howto-section {
    margin-top: 32px;
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--card-shadow);
    padding: 30px 26px 26px;
}

.howto-header {
    text-align: center;
    max-width: 480px;
    margin: 0 auto 28px;
}

.howto-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 14px;
    border-radius: 20px;
    background: var(--secondary-text, #eef0fd);
    color: var(--primary-color);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    margin-bottom: 12px;
}

[data-theme="dark"] .howto-tag {
    background: #1e2240;
}

.howto-tag i {
    font-size: 13px;
}

.howto-header h2 {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-text);
    margin-bottom: 8px;
    line-height: 1.3;
}

.howto-header p {
    font-size: 13px;
    color: var(--gray-text);
    line-height: 1.6;
}

.howto-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
    position: relative;
}

.howto-step {
    position: relative;
    background: var(--section-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    padding: 18px 16px 16px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.howto-step:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
    box-shadow: 0 14px 28px -10px var(--primary-glow, rgba(99, 102, 241, 0.25));
}

.howto-step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 32px;
    right: -18px;
    width: 18px;
    height: 1px;
    background: repeating-linear-gradient(to right, var(--divider) 0 5px, transparent 5px 8px);
    z-index: 1;
}

.howto-step__top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 14px;
}

.howto-step__number {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: var(--primary-color);
    color: #fff;
    font-size: 12px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 4px 10px var(--primary-glow, rgba(99, 102, 241, 0.35));
}

.howto-step__icon {
    width: 38px;
    height: 38px;
    border-radius: 11px;
    background: var(--header-bg);
    border: 1px solid var(--divider);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 17px;
    color: var(--primary-color);
}

.howto-step h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-text);
    margin-bottom: 6px;
}

.howto-step p {
    font-size: 12px;
    line-height: 1.65;
    color: var(--gray-text);
}

.howto-step p strong {
    color: var(--primary-text);
    font-weight: 600;
}

.howto-note {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-top: 22px;
    padding: 13px 16px;
    border-radius: var(--radius-md);
    background: #eff6ff;
    border: 1px solid #bfdbfe;
}

[data-theme="dark"] .howto-note {
    background: #0f1d33;
    border-color: #1e3a5f;
}

.howto-note i {
    color: #2563eb;
    font-size: 17px;
    flex-shrink: 0;
    margin-top: 1px;
}

[data-theme="dark"] .howto-note i {
    color: #60a5fa;
}

.howto-note span {
    font-size: 12px;
    line-height: 1.65;
    color: #1e3a8a;
}

[data-theme="dark"] .howto-note span {
    color: #bfdbfe;
}

.howto-note span strong {
    font-weight: 700;
}

/* ── RESPONSIVE: HOW TO USE ──────────────── */
@media (max-width: 900px) {
    .howto-steps {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .howto-step:nth-child(2)::after,
    .howto-step:nth-child(4)::after {
        display: none;
    }
}

@media (max-width: 640px) {
    .howto-section {
        padding: 24px 16px 20px;
    }

    .howto-header h2 {
        font-size: 19px;
    }

    .howto-steps {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .howto-step::after {
        display: none;
    }

    .howto-note {
        flex-direction: row;
    }
}




/* ── FEATURES SECTION ────────────────────── */
.features-section {
    margin-top: 28px;
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--card-shadow);
    padding: 30px 26px 28px;
}

.features-header {
    text-align: center;
    max-width: 480px;
    margin: 0 auto 26px;
}

.features-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 14px;
    border-radius: 20px;
    background: var(--secondary-text, #eef0fd);
    color: var(--primary-color);
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    margin-bottom: 12px;
}

[data-theme="dark"] .features-tag {
    background: #1e2240;
}

.features-tag i {
    font-size: 13px;
}

.features-header h2 {
    font-size: 22px;
    font-weight: 700;
    color: var(--primary-text);
    margin-bottom: 8px;
    line-height: 1.3;
}

.features-header p {
    font-size: 13px;
    color: var(--gray-text);
    line-height: 1.6;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.feature-card {
    background: var(--section-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    padding: 18px 16px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
    box-shadow: 0 14px 28px -10px var(--primary-glow, rgba(99, 102, 241, 0.25));
}

.feature-icon {
    width: 40px;
    height: 40px;
    border-radius: 11px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    margin-bottom: 14px;
}

.feature-card h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-text);
    margin-bottom: 6px;
}

.feature-card p {
    font-size: 12px;
    line-height: 1.65;
    color: var(--gray-text);
}

/* ── RESPONSIVE: FEATURES ────────────────── */
@media (max-width: 900px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .features-section {
        padding: 24px 16px 20px;
    }

    .features-header h2 {
        font-size: 19px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
}

.how_to_use{
    padding: 20px;
}
.features_section{
    /* margin-top: 28px; */
    padding: 20px;
}

.content__section{
    /* background-color: var(--body-background); */
}





.bti-example-section {
    margin-top: 34px;
    padding: 20px;

}

.bti-example-head {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 18px;
}

.bti-kicker {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 6px 13px;
    border-radius: 999px;
    background: #eef0fd;
    color: var(--primary-color);
    font-size: 11px;
    font-weight: 600;
    margin-bottom: 10px;
}

.bti-example-head h2 {
    font-size: 26px;
    line-height: 1.3;
    color: var(--primary-text);
    margin-bottom: 8px;
}

.bti-example-head p {
    font-size: 13px;
    line-height: 1.8;
    color: var(--gray-text);
}

.bti-example-card {
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-lg);
    box-shadow: var(--card-shadow);
    padding: 16px;
    display: grid;
    grid-template-columns: 1fr 74px 1fr;
    gap: 14px;
    align-items: center;
    overflow: hidden;
}

.bti-code-panel,
.bti-preview-panel {
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    background: var(--section-bg);
    overflow: hidden;
}

.bti-panel-top {
    padding: 12px 14px;
    border-bottom: 1px solid var(--divider);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.bti-panel-top span {
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: 12px;
    font-weight: 600;
    color: var(--primary-text);
}

.bti-panel-top i {
    color: var(--primary-color);
    font-size: 16px;
}

.bti-panel-top small {
    font-size: 10px;
    color: var(--gray-text);
    font-weight: 500;
}

.bti-code-box {
    margin: 14px;
    padding: 14px;
    min-height: 158px;
    border-radius: 12px;
    background: var(--input-bg);
    border: 1px solid var(--divider);
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 9px;
    font-family: "Courier New", monospace;
    font-size: 12px;
    line-height: 1.5;
    color: var(--gray-text);
    word-break: break-all;
    position: relative;
}

.bti-code-box::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: 12px;
    background: linear-gradient(90deg, transparent, rgba(99, 102, 241, 0.08), transparent);
    pointer-events: none;
}

.bti-code-box span:first-child {
    color: var(--primary-color);
    font-weight: 700;
}

.bti-mini-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 7px;
    padding: 0 14px 14px;
}

.bti-mini-tags span {
    padding: 5px 9px;
    border-radius: 999px;
    background: var(--header-bg);
    border: 1px solid var(--divider);
    color: var(--gray-text);
    font-size: 10px;
    font-weight: 600;
}

.bti-flow-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
}

.bti-flow-arrow span {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-color);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 12px 30px var(--primary-glow);
    font-size: 22px;
}

.bti-image-preview {
    padding: 14px;
}

.bti-fake-image {
    height: 190px;
    border-radius: 14px;
    border: 1px solid var(--divider);
    background: linear-gradient(180deg, #dbeafe 0%, #eef2ff 58%, #dcfce7 58%, #bbf7d0 100%);
    position: relative;
    overflow: hidden;
}

.bti-sun {
    position: absolute;
    top: 24px;
    right: 32px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: #facc15;
    box-shadow: 0 0 30px rgba(250, 204, 21, 0.55);
}

.bti-mountain {
    position: absolute;
    bottom: 0;
    width: 160px;
    height: 100px;
    background: #6366f1;
    transform: rotate(45deg);
    border-radius: 16px;
}

.bti-mountain-one {
    left: 34px;
    bottom: -54px;
}

.bti-mountain-two {
    right: 24px;
    bottom: -62px;
    background: #8b5cf6;
}

.bti-image-badge {
    position: absolute;
    left: 12px;
    top: 12px;
    padding: 5px 10px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.82);
    color: var(--primary-color);
    font-size: 10px;
    font-weight: 800;
    backdrop-filter: blur(8px);
}

.bti-file-info {
    padding: 0 14px 14px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
}

.bti-file-info div {
    padding: 10px;
    border-radius: 12px;
    background: var(--header-bg);
    border: 1px solid var(--divider);
}

.bti-file-info span {
    display: block;
    font-size: 10px;
    color: var(--gray-text);
    margin-bottom: 4px;
}

.bti-file-info strong {
    display: block;
    font-size: 12px;
    color: var(--primary-text);
}

.bti-example-steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-top: 12px;
}

.bti-step {
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    padding: 14px;
    display: flex;
    gap: 10px;
    align-items: flex-start;
}

.bti-step i {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: #eef0fd;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 17px;
}

.bti-step h3 {
    font-size: 12px;
    color: var(--primary-text);
    margin-bottom: 3px;
}

.bti-step p {
    font-size: 11px;
    line-height: 1.6;
    color: var(--gray-text);
}

[data-theme="dark"] .bti-kicker,
[data-theme="dark"] .bti-step i {
    background: #1e2240;
}

[data-theme="dark"] .bti-fake-image {
    background: linear-gradient(180deg, #172554 0%, #1e1b4b 58%, #052e16 58%, #064e3b 100%);
}

[data-theme="dark"] .bti-image-badge {
    background: rgba(15, 20, 32, 0.82);
}

@media (max-width: 820px) {
    .bti-example-card {
        grid-template-columns: 1fr;
    }

    .bti-flow-arrow span {
        transform: rotate(90deg);
    }

    .bti-example-steps {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .bti-example-head h2 {
        font-size: 22px;
    }

    .bti-example-card {
        padding: 10px;
    }

    .bti-file-info {
        grid-template-columns: 1fr;
    }

    .bti-fake-image {
        height: 160px;
    }
}




.bti-faq-section {
    margin-top: 34px;
    margin-bottom: 40px;
    padding: 20px;
}

.bti-faq-head {
    text-align: center;
    max-width: 650px;
    margin: 0 auto 18px;
}

.bti-faq-kicker {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 6px 13px;
    border-radius: 999px;
    background: #eef0fd;
    color: var(--primary-color);
    font-size: 11px;
    font-weight: 600;
    margin-bottom: 10px;
}

.bti-faq-head h2 {
    font-size: 26px;
    line-height: 1.3;
    color: var(--primary-text);
    margin-bottom: 8px;
}

.bti-faq-head p {
    font-size: 13px;
    line-height: 1.8;
    color: var(--gray-text);
}

.bti-faq-list {
    max-width: 850px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.bti-faq-item {
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
    overflow: hidden;
    transition: border-color 0.25s ease, transform 0.25s ease;
}

.bti-faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 15px 17px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    color: var(--primary-text);
    font-size: 13px;
    font-weight: 600;
}

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

.bti-faq-item summary i {
    color: var(--primary-color);
    font-size: 17px;
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.bti-faq-content {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.35s ease;
}

.bti-faq-content > p {
    overflow: hidden;
    padding: 0 17px;
    font-size: 12px;
    line-height: 1.8;
    color: var(--gray-text);
    transition: padding 0.35s ease, opacity 0.25s ease;
    opacity: 0;
}

.bti-faq-item[open] summary {
    border-bottom: 1px solid var(--divider);
}

.bti-faq-item[open] summary i {
    transform: rotate(180deg);
}

.bti-faq-item[open] .bti-faq-content {
    grid-template-rows: 1fr;
}

.bti-faq-item[open] .bti-faq-content > p {
    padding: 14px 17px 16px;
    opacity: 1;
}

.bti-faq-item strong {
    color: var(--primary-color);
    font-weight: 600;
}

.bti-faq-item:hover {
    border-color: rgba(99, 102, 241, 0.35);
    transform: translateY(-1px);
}

[data-theme="dark"] .bti-faq-kicker {
    background: #1e2240;
}

@media (max-width: 520px) {
    .bti-faq-head h2 {
        font-size: 22px;
    }

    .bti-faq-item summary {
        padding: 13px 14px;
        font-size: 12px;
    }

    .bti-faq-item p {
        padding: 12px 14px 14px;
        font-size: 11px;
    }
}


.bti-faq-item.is-closing .bti-faq-content {
    grid-template-rows: 0fr;
}

.bti-faq-item.is-closing .bti-faq-content > p {
    padding-top: 0;
    padding-bottom: 0;
    opacity: 0;
}


.bti-related-section {
    margin-top: 34px;
    margin-bottom: 42px;
    padding: 20px;
}

.bti-related-head {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 18px;
}

.bti-related-kicker {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 6px 13px;
    border-radius: 999px;
    background: #eef0fd;
    color: var(--primary-color);
    font-size: 11px;
    font-weight: 600;
    margin-bottom: 10px;
}

.bti-related-head h2 {
    font-size: 26px;
    line-height: 1.3;
    color: var(--primary-text);
    margin-bottom: 8px;
}

.bti-related-head p {
    font-size: 13px;
    line-height: 1.8;
    color: var(--gray-text);
}

.bti-related-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.bti-tool-card {
    position: relative;
    background: var(--header-bg);
    border: 1px solid var(--divider);
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
    padding: 15px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    overflow: hidden;
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.bti-tool-card::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.10), transparent 55%);
    opacity: 0;
    transition: opacity 0.25s ease;
    pointer-events: none;
}

.bti-tool-card:hover {
    transform: translateY(-4px);
    border-color: rgba(99, 102, 241, 0.35);
    box-shadow: 0 14px 34px rgba(99, 102, 241, 0.14);
}

.bti-tool-card:hover::before {
    opacity: 1;
}

.bti-tool-icon {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 19px;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
}

.bti-tool-content {
    flex: 1;
    min-width: 0;
    position: relative;
    z-index: 1;
}

.bti-tool-content h3 {
    font-size: 13px;
    color: var(--primary-text);
    font-weight: 600;
    margin-bottom: 5px;
}

.bti-tool-content p {
    font-size: 11px;
    line-height: 1.65;
    color: var(--gray-text);
}

.bti-tool-arrow {
    width: 28px;
    height: 28px;
    border-radius: 9px;
    border: 1px solid var(--divider);
    background: var(--section-bg);
    color: var(--gray-text);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
    transition: all 0.25s ease;
}

.bti-tool-card:hover .bti-tool-arrow {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: #fff;
    transform: translateX(3px);
}

.bti-purple {
    background: #eef0fd;
    color: #6366f1;
}

.bti-blue {
    background: #eff6ff;
    color: #2563eb;
}

.bti-green {
    background: #f0fdf4;
    color: #16a34a;
}

.bti-orange {
    background: #fff7ed;
    color: #ea580c;
}

.bti-cyan {
    background: #ecfeff;
    color: #0891b2;
}

.bti-red {
    background: #fef2f2;
    color: #dc2626;
}

[data-theme="dark"] .bti-related-kicker,
[data-theme="dark"] .bti-purple {
    background: #1e2240;
}

[data-theme="dark"] .bti-blue {
    background: #10213f;
}

[data-theme="dark"] .bti-green {
    background: #052e16;
}

[data-theme="dark"] .bti-orange {
    background: #30180a;
}

[data-theme="dark"] .bti-cyan {
    background: #083344;
}

[data-theme="dark"] .bti-red {
    background: #2a0d0d;
}

@media (max-width: 900px) {
    .bti-related-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 560px) {
    .bti-related-head h2 {
        font-size: 22px;
    }

    .bti-related-grid {
        grid-template-columns: 1fr;
    }

    .bti-tool-card {
        padding: 13px;
    }
}