:root {
    --bpf-ink: #16241f;
    --bpf-muted: #5b6b64;
    --bpf-spruce: #1f3d36;
    --bpf-spruce-dark: #152b26;
    --bpf-marker: #f2c230;
    --bpf-field: #ffffff;
    --bpf-soft: #e6ece8;
    --bpf-line: #cfd9d3;
    --bpf-trail: #a9b9b1;
    --bpf-bg: #f1f4f2;
    --bpf-error: #b3261e;
    --bpf-radius: 14px;
}

* {
    box-sizing: border-box;
}

.bpf-preview-page {
    margin: 0;
    padding: 0;
    background: var(--bpf-bg);
    color: var(--bpf-ink);
    font-family: "Segoe UI Variable", "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.5;
}

.bpf-preview-container {
    --bpf-side: clamp(420px, 46vw, 760px);
    max-width: none;
    min-height: 100vh;
    margin: 0;
    padding-left: var(--bpf-side);
    counter-reset: bpf-stop;
}

.bpf-preview-header {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: var(--bpf-side);
    margin: 0;
    padding: 56px clamp(32px, 4vw, 64px);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    color: #fff;
    background:
        repeating-radial-gradient(
            circle at -10% 108%,
            transparent 0 22px,
            rgba(255, 255, 255, 0.07) 22px 23px
        ),
        var(--bpf-spruce);
}

.bpf-preview-header::before {
    content: "";
    flex: none;
    width: 48px;
    height: 6px;
    margin-bottom: 24px;
    background: var(--bpf-marker);
    border-radius: 3px;
}

.bpf-preview-header h1 {
    flex: none;
    margin: 0;
    font-size: clamp(1.8rem, 2.8vw, 2.5rem);
    line-height: 1.08;
    font-weight: 750;
    letter-spacing: -0.02em;
}

.bpf-preview-header-description {
    position: relative;
    flex: 1 0 auto;
    min-width: 0;
    margin-top: 48px;
    padding: 64px clamp(24px, 3vw, 44px) 40px;
    color: var(--bpf-ink);
    background: #fff;
    border-radius: var(--bpf-radius);
    font-size: clamp(1.15rem, 1.6vw, 1.45rem);
    font-weight: 500;
    line-height: 1.6;
    overflow-wrap: anywhere;
    box-shadow: 0 0 0 6px var(--bpf-marker);
}

.bpf-preview-header-description::before {
    content: "IMPORTANTE";
    position: absolute;
    top: 0;
    left: clamp(24px, 3vw, 44px);
    transform: translateY(-50%);
    padding: 10px 22px;
    font-size: 1.05rem;
    font-weight: 900;
    letter-spacing: 0.2em;
    color: #fff;
    background: var(--bpf-error);
    border: 4px solid var(--bpf-marker);
    border-radius: 999px;
}

.bpf-preview-header-description::after {
    content: "Cuando termines de leer, responde a la derecha →";
    display: block;
    margin-top: 32px;
    padding-top: 18px;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--bpf-muted);
    border-top: 2px dashed var(--bpf-line);
}

.bpf-preview-header-description:empty {
    display: none;
}

.bpf-preview-question {
    max-width: 760px;
    padding: 28px clamp(28px, 5vw, 72px);
    counter-increment: bpf-stop;
}

.bpf-preview-question:first-of-type {
    padding-top: 72px;
}

.bpf-preview-question::before {
    content: counter(bpf-stop, decimal-leading-zero);
    display: inline-block;
    margin-bottom: 12px;
    padding-bottom: 4px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    color: var(--bpf-muted);
    border-bottom: 3px solid var(--bpf-line);
    transition: color 0.15s ease, border-color 0.15s ease;
}

.bpf-preview-question:focus-within::before {
    color: var(--bpf-spruce);
    border-color: var(--bpf-marker);
}

.bpf-preview-question-heading {
    font-size: 1.4rem;
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.01em;
}

.bpf-preview-required {
    margin-left: 4px;
    color: var(--bpf-error);
    font-weight: 700;
}

.bpf-preview-description {
    margin-top: 6px;
    color: var(--bpf-muted);
    font-size: 0.95rem;
}

.bpf-preview-control {
    margin-top: 18px;
}

.bpf-preview-control input[type="text"],
.bpf-preview-control textarea,
.bpf-preview-control select {
    display: block;
    width: 100%;
    padding: 15px 18px;
    font: inherit;
    font-size: 1.05rem;
    color: var(--bpf-ink);
    background-color: var(--bpf-soft);
    border: 2px solid transparent;
    border-radius: var(--bpf-radius);
    transition: background-color 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.bpf-preview-control select {
    padding-right: 48px;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='9' viewBox='0 0 14 9' fill='none' stroke='%231f3d36' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M1 1.5l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 18px center;
    cursor: pointer;
}

.bpf-preview-control textarea {
    min-height: 140px;
    resize: vertical;
}

.bpf-preview-control input::placeholder,
.bpf-preview-control textarea::placeholder {
    color: #66756e;
}

.bpf-preview-control input[type="text"]:hover,
.bpf-preview-control textarea:hover,
.bpf-preview-control select:hover {
    background-color: #dce4df;
}

.bpf-preview-control input[type="text"]:focus,
.bpf-preview-control textarea:focus,
.bpf-preview-control select:focus {
    outline: none;
    background-color: var(--bpf-field);
    border-color: var(--bpf-spruce);
    box-shadow: 0 0 0 4px rgba(242, 194, 48, 0.55);
}

.bpf-preview-control input[type="text"]:user-invalid,
.bpf-preview-control textarea:user-invalid,
.bpf-preview-control select:user-invalid {
    border-color: var(--bpf-error);
}

.bpf-preview-control input[type="file"] {
    width: 100%;
    padding: 28px 20px;
    font: inherit;
    color: var(--bpf-muted);
    background: var(--bpf-soft);
    border: 2px dashed var(--bpf-trail);
    border-radius: var(--bpf-radius);
}

.bpf-preview-control input[type="file"]::file-selector-button {
    margin-right: 14px;
    padding: 10px 18px;
    font: inherit;
    font-weight: 600;
    color: #fff;
    background: var(--bpf-spruce);
    border: 0;
    border-radius: 999px;
    cursor: pointer;
}

.bpf-preview-help {
    margin: 8px 0 0;
    color: var(--bpf-muted);
    font-size: 0.85rem;
}

.bpf-preview-options {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
    gap: 12px;
}

.bpf-preview-option {
    position: relative;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    font-weight: 550;
    background: var(--bpf-soft);
    border: 2px solid transparent;
    border-radius: var(--bpf-radius);
    cursor: pointer;
    transition: background-color 0.15s ease, border-color 0.15s ease;
}

.bpf-preview-option::before {
    content: "";
    flex: none;
    display: grid;
    place-items: center;
    width: 24px;
    height: 24px;
    font-size: 0.85rem;
    font-weight: 800;
    color: var(--bpf-spruce);
    background: var(--bpf-field);
    border: 2px solid var(--bpf-trail);
    border-radius: 50%;
    transition: background-color 0.15s ease, border-color 0.15s ease;
}

.bpf-preview-option:has(input[type="checkbox"])::before {
    border-radius: 7px;
}

.bpf-preview-option input {
    position: absolute;
    opacity: 0;
    width: 1px;
    height: 1px;
    margin: 0;
}

.bpf-preview-option:hover {
    background: #dce4df;
}

.bpf-preview-option:has(input:checked) {
    background: var(--bpf-field);
    border-color: var(--bpf-spruce);
}

.bpf-preview-option:has(input:checked)::before {
    content: "✓";
    background: var(--bpf-marker);
    border-color: var(--bpf-marker);
}

.bpf-preview-option:has(input:focus-visible) {
    box-shadow: 0 0 0 4px rgba(242, 194, 48, 0.7);
}

.bpf-preview-submit {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    margin: 16px clamp(28px, 5vw, 72px) 96px;
    padding: 16px 32px;
    font: inherit;
    font-size: 1.05rem;
    font-weight: 700;
    color: #fff;
    background: var(--bpf-spruce);
    border: 0;
    border-radius: 999px;
    cursor: pointer;
    transition: background-color 0.15s ease, color 0.15s ease, transform 0.1s ease;
}

.bpf-preview-submit::after {
    content: "→";
    color: var(--bpf-marker);
    font-size: 1.2em;
    transition: color 0.15s ease;
}

.bpf-preview-submit:hover {
    color: var(--bpf-spruce);
    background: var(--bpf-marker);
}

.bpf-preview-submit:hover::after {
    color: var(--bpf-spruce);
}

.bpf-preview-submit:active {
    transform: translateY(1px);
}

.bpf-preview-submit:focus-visible {
    outline: 3px solid var(--bpf-spruce);
    outline-offset: 3px;
}

.bpf-text-xs { font-size: 12px; }
.bpf-text-sm { font-size: 14px; }
.bpf-text-md { font-size: 16px; }
.bpf-text-lg { font-size: 18px; }
.bpf-text-xl { font-size: 24px; }
.bpf-text-2xl { font-size: 32px; }

@media (max-width: 960px) {
    .bpf-preview-container {
        padding-left: 0;
    }

    .bpf-preview-header {
        position: static;
        width: auto;
        padding: 40px 20px 48px;
        overflow: visible;
    }

    .bpf-preview-header-description {
        flex: none;
        margin-top: 40px;
        padding: 56px 20px 28px;
    }

    .bpf-preview-header-description::before {
        left: 20px;
    }

    .bpf-preview-header-description::after {
        content: "Cuando termines de leer, responde abajo ↓";
    }

    .bpf-preview-question {
        padding: 24px 20px;
    }

    .bpf-preview-question:first-of-type {
        padding-top: 40px;
    }

    .bpf-preview-question-heading {
        font-size: 1.25rem;
    }

    .bpf-preview-options {
        grid-template-columns: 1fr;
    }

    .bpf-preview-submit {
        display: flex;
        justify-content: center;
        margin: 8px 20px 64px;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
    }
}

.bpf-preview-header-description img.bpf-content-image,
.bpf-preview-description img.bpf-content-image {
    display: block;
    max-width: 100%;
    height: auto;
    object-fit: contain;
    margin: 16px auto;
    border-radius: 6px;
}

.bpf-preview-header-description img.bpf-image-25,
.bpf-preview-description img.bpf-image-25 {
    width: 25%;
}

.bpf-preview-header-description img.bpf-image-50,
.bpf-preview-description img.bpf-image-50 {
    width: 50%;
}

.bpf-preview-header-description img.bpf-image-75,
.bpf-preview-description img.bpf-image-75 {
    width: 75%;
}

.bpf-preview-header-description img.bpf-image-100,
.bpf-preview-description img.bpf-image-100 {
    width: 100%;
}

.bpf-preview-description img.bpf-content-image {
    max-height: 300px;
}

.bpf-preview-header-description img.bpf-content-image {
    max-height: 420px;
}