:root {
    --ink: #1c1c1e;
    --ink-soft: #55565c;
    --paper: #faf9f7;
    --panel: #ffffff;
    --line: #e3e1dc;
    --accent: #b71c1c;
    --accent-dark: #8f1515;
    --success-bg: #eaf6ec;
    --success-text: #1e6b2e;
    --error-bg: #fdecec;
    --error-text: #b71c1c;
    --radius: 10px;
    font-size: 16px;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--paper);
    color: var(--ink);
    line-height: 1.5;
}

.container {
    max-width: 760px;
    margin: 0 auto;
    padding: 2.5rem 1.5rem 4rem;
}

header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.main-logo {
    max-width: 180px;
    max-height: 70px;
    object-fit: contain;
    margin-bottom: 1.25rem;
}

.eyebrow {
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent);
    margin: 0 0 0.6rem;
}

h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0 0 0.6rem;
    letter-spacing: -0.01em;
}

header p {
    color: var(--ink-soft);
    max-width: 46ch;
    margin: 0 auto;
}

.form-section {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 1.5rem 1.5rem 1.75rem;
    margin-bottom: 1.5rem;
}

.form-section h2 {
    font-size: 1.05rem;
    margin: 0 0 0.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--accent);
    display: inline-block;
}

.form-section h3 {
    font-size: 0.92rem;
    color: var(--ink-soft);
    margin: 1rem 0 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.subtitle {
    color: var(--ink-soft);
    font-size: 0.88rem;
    margin: 0.25rem 0 1rem;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem 1.25rem;
    margin-top: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.grid-full-width { grid-column: 1 / -1; }

label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--ink-soft);
}

input, select {
    font: inherit;
    padding: 0.6rem 0.7rem;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: var(--paper);
    color: var(--ink);
    width: 100%;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(183, 28, 28, 0.12);
}

input.error {
    border-color: var(--error-text);
    background: var(--error-bg);
}

input[type="file"] {
    padding: 0.4rem;
    background: var(--panel);
}

#logo-preview, #proveedor-logo {
    max-height: 70px;
    max-width: 220px;
    object-fit: contain;
    margin-top: 0.75rem;
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 0.4rem;
    background: #fff;
}

.submit-button, .secondary-button {
    font: inherit;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.15s ease, transform 0.05s ease;
}

.submit-button {
    width: 100%;
    padding: 0.9rem;
    background: var(--accent);
    color: #fff;
    font-size: 1rem;
    margin-top: 0.5rem;
}

.submit-button:hover { background: var(--accent-dark); }
.submit-button:active { transform: scale(0.99); }

.secondary-button {
    padding: 0.6rem 1rem;
    background: var(--ink);
    color: #fff;
    white-space: nowrap;
}

.secondary-button:hover { background: #000; }

#form-feedback, #result-box {
    margin-top: 1.25rem;
    padding: 1.1rem 1.25rem;
    border-radius: var(--radius);
    display: none;
}

#form-feedback.success {
    background: var(--success-bg);
    color: var(--success-text);
    border: 1px solid #b9e0bf;
}

#form-feedback.error-msg {
    background: var(--error-bg);
    color: var(--error-text);
    border: 1px solid #f3c2c2;
}

#result-box {
    background: var(--panel);
    border: 1px solid var(--line);
    display: block;
}

.link-row {
    display: flex;
    gap: 0.6rem;
    margin: 1rem 0;
}

.link-row input {
    flex: 1;
    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
    font-size: 0.8rem;
}

.qr-box {
    display: inline-block;
    padding: 0.75rem;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    margin-top: 0.5rem;
}

.logo-toggle {
    display: flex;
    gap: 1.5rem;
    margin: 0.75rem 0 1.25rem;
    flex-wrap: wrap;
}

.radio-option {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--ink);
    cursor: pointer;
}

.radio-option input { width: auto; }

.size-hint {
    font-size: 0.8rem;
    color: var(--ink-soft);
    margin: 0.4rem 0 0;
}

.size-hint.warn {
    color: #7a5b00;
    font-weight: 600;
}

.warning-msg {
    background: #fff6e5;
    border: 1px solid #f0dba0;
    color: #7a5b00;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-size: 0.85rem;
}

#invalid-link-box {
    text-align: center;
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 3rem 1.5rem;
}

#invalid-link-box h1 { font-size: 1.4rem; }

footer {
    text-align: center;
    color: var(--ink-soft);
    font-size: 0.82rem;
    margin-top: 2.5rem;
}

@media (max-width: 600px) {
    .form-grid { grid-template-columns: 1fr; }
    .link-row { flex-direction: column; }
}