/* ==========================================================================
   AMA Sheet
   Reader question submission — bottom sheet (mobile), centered modal (desktop).
   Uses design tokens from main.css. Shell-level — persists across SPA swaps.
   ========================================================================== */

/* Overlay — covers entire viewport */
.ama-sheet-overlay {
    position: fixed;
    inset: 0;
    z-index: var(--z-modal);
    display: flex;
    align-items: flex-end;
    justify-content: center;
}

.ama-sheet-overlay[hidden] {
    display: none;
}

/* Backdrop */
.ama-sheet-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    animation: amaFadeIn var(--transition-base) ease-out;
}

/* Sheet — mobile-first bottom sheet */
.ama-sheet {
    position: relative;
    width: 100%;
    max-height: 90vh;
    max-height: 90dvh;
    overflow-y: auto;
    background: var(--color-bg-primary);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    box-shadow: var(--shadow-xl);
    display: flex;
    flex-direction: column;
    animation: amaSlideUp var(--transition-base) ease-out;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */

.ama-sheet-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-4) var(--spacing-4) var(--spacing-2);
    border-bottom: 1px solid var(--color-border-light);
}

.ama-sheet-heading {
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-primary);
}

.ama-sheet-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    font-size: var(--font-size-xl);
    line-height: 1;
    color: var(--color-text-muted);
    cursor: pointer;
    padding: 0;
    border-radius: var(--radius-base);
}

.ama-sheet-close:hover {
    color: var(--color-text-primary);
    background: var(--color-bg-tertiary);
}

/* --------------------------------------------------------------------------
   Form
   -------------------------------------------------------------------------- */

.ama-sheet-form {
    padding: var(--spacing-4);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.ama-form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-1);
}

.ama-form-label {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
}

.ama-form-input {
    width: 100%;
    padding: var(--spacing-2) var(--spacing-3);
    font-family: var(--font-family-sans);
    font-size: var(--font-size-base);
    color: var(--color-text-primary);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    outline: none;
}

.ama-form-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 2px var(--color-focus-ring);
}

.ama-form-input::placeholder {
    color: var(--color-text-muted);
}

.ama-form-textarea {
    min-height: 100px;
    resize: vertical;
    line-height: 1.6;
}

/* --------------------------------------------------------------------------
   Character counter
   -------------------------------------------------------------------------- */

.ama-char-counter {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    text-align: right;
}

.ama-char-near-limit {
    color: var(--color-warning);
}

.ama-char-over-limit {
    color: var(--color-error-text);
}

/* --------------------------------------------------------------------------
   Captcha
   -------------------------------------------------------------------------- */

.ama-captcha-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.ama-captcha-question {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    white-space: nowrap;
}

.ama-captcha-input {
    width: 80px;
    text-align: center;
}

/* --------------------------------------------------------------------------
   Submit button
   -------------------------------------------------------------------------- */

.ama-submit-btn {
    padding: var(--spacing-3) var(--spacing-5);
    font-family: var(--font-family-sans);
    font-size: var(--font-size-base);
    font-weight: 600;
    color: var(--color-text-inverse);
    background-color: var(--color-primary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.ama-submit-btn:hover {
    background-color: var(--color-primary-dark);
}

.ama-submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* --------------------------------------------------------------------------
   Desktop — centered modal
   -------------------------------------------------------------------------- */

@media (min-width: 481px) {
    .ama-sheet-overlay {
        align-items: center;
    }

    .ama-sheet {
        max-width: 480px;
        border-radius: var(--radius-xl);
        animation-name: amaFadeScale;
    }
}

/* --------------------------------------------------------------------------
   Animations
   -------------------------------------------------------------------------- */

@keyframes amaFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes amaSlideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes amaFadeScale {
    from {
        transform: scale(0.95);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

/* --------------------------------------------------------------------------
   Reduced motion
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    .ama-sheet-backdrop {
        animation-duration: 0.01ms !important;
    }

    .ama-sheet {
        animation-duration: 0.01ms !important;
    }

    .ama-submit-btn {
        transition: none;
    }
}