/* ============================================
   Utility Classes
   Reusable helper classes for common patterns
   ============================================ */

/* ============================================
   CONTAINER
   ============================================ */

.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--container-padding);
    padding-right: var(--container-padding);
    box-sizing: border-box;
}

@media (max-width: 768px) {
    .container {
        padding-left: var(--container-padding-mobile);
        padding-right: var(--container-padding-mobile);
    }
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 0.75rem 1.5rem;
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-md);
    line-height: 1;
    border-radius: var(--border-radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    text-decoration: none;
    border: 2px solid transparent;
    white-space: nowrap;
}

.btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Button Variants */
.btn-primary {
    background: var(--gradient-primary);
    color: var(--color-text-on-primary);
    border-color: transparent;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
    filter: brightness(1.1);
}

.btn-primary:active {
    transform: translateY(0);
}

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

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: var(--color-text-on-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}

.btn-secondary:active {
    transform: translateY(0);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-text-primary);
    border-color: var(--color-border);
}

.btn-outline:hover {
    background-color: var(--color-surface);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* Button Sizes */
.btn-small {
    padding: 0.5rem 1rem;
    font-size: var(--font-size-sm);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: var(--font-size-lg);
}

.btn-full {
    width: 100%;
}

/* Button States */
.btn:disabled,
.btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* Button with loader */
.btn-loader {
    display: none;
}

.btn .spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

/* ============================================
   SECTION UTILITIES
   ============================================ */

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    text-align: center;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    text-align: center;
    color: var(--color-text-secondary);
    max-width: 700px;
    margin: 0 auto var(--spacing-xl);
}

@media (max-width: 768px) {
    .section-title {
        font-size: var(--font-size-3xl);
    }

    .section-subtitle {
        font-size: var(--font-size-md);
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: var(--font-size-2xl);
    }

    .section-subtitle {
        font-size: var(--font-size-sm);
    }
}

/* ============================================
   SPACING UTILITIES
   ============================================ */

/* Margin */
.m-0 { margin: 0; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.ml-0 { margin-left: 0; }
.mr-0 { margin-right: 0; }

.m-xs { margin: var(--spacing-xs); }
.mt-xs { margin-top: var(--spacing-xs); }
.mb-xs { margin-bottom: var(--spacing-xs); }

.m-sm { margin: var(--spacing-sm); }
.mt-sm { margin-top: var(--spacing-sm); }
.mb-sm { margin-bottom: var(--spacing-sm); }

.m-md { margin: var(--spacing-md); }
.mt-md { margin-top: var(--spacing-md); }
.mb-md { margin-bottom: var(--spacing-md); }

.m-lg { margin: var(--spacing-lg); }
.mt-lg { margin-top: var(--spacing-lg); }
.mb-lg { margin-bottom: var(--spacing-lg); }

.m-xl { margin: var(--spacing-xl); }
.mt-xl { margin-top: var(--spacing-xl); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* Padding */
.p-0 { padding: 0; }
.pt-0 { padding-top: 0; }
.pb-0 { padding-bottom: 0; }

.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* ============================================
   DISPLAY UTILITIES
   ============================================ */

.d-none { display: none; }
.d-block { display: block; }
.d-inline { display: inline; }
.d-inline-block { display: inline-block; }
.d-flex { display: flex; }
.d-inline-flex { display: inline-flex; }
.d-grid { display: grid; }

/* ============================================
   FLEX UTILITIES
   ============================================ */

.flex-row { flex-direction: row; }
.flex-column { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.align-start { align-items: flex-start; }
.align-center { align-items: center; }
.align-end { align-items: flex-end; }
.align-stretch { align-items: stretch; }

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* ============================================
   PLACEHOLDER ELEMENTS (Development)
   ============================================ */

.placeholder-image,
.placeholder-video,
.placeholder-logo {
    background: linear-gradient(135deg, #1E293B 0%, #0F172A 100%);
    border: 1px solid rgba(59, 130, 246, 0.12);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

.placeholder-image::after,
.placeholder-video::after,
.placeholder-logo::after {
    content: 'Image Placeholder';
    position: absolute;
    color: rgba(96, 165, 250, 0.4);
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.placeholder-video::after {
    content: 'Video Placeholder';
}

.placeholder-logo::after {
    content: 'Logo';
}

/* Placeholder sizes */
.placeholder-image {
    width: 100%;
    aspect-ratio: 16 / 10;
}

.placeholder-video {
    width: 100%;
    aspect-ratio: 16 / 9;
}

.placeholder-logo {
    width: 120px;
    height: 60px;
}

/* ============================================
   SKIP LINK (Accessibility)
   ============================================ */

.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--color-primary);
    color: var(--color-text-on-primary);
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    z-index: 9999;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
}

/* ============================================
   RESPONSIVE UTILITIES
   ============================================ */

@media (max-width: 768px) {
    .hide-mobile {
        display: none !important;
    }
}

@media (min-width: 769px) {
    .hide-desktop {
        display: none !important;
    }

    .show-mobile {
        display: none !important;
    }
}

/* ============================================
   MISC UTILITIES
   ============================================ */

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.overflow-hidden {
    overflow: hidden;
}

.overflow-auto {
    overflow: auto;
}

.relative {
    position: relative;
}

.absolute {
    position: absolute;
}

.fixed {
    position: fixed;
}

.sticky {
    position: sticky;
}

.w-full {
    width: 100%;
}

.h-full {
    height: 100%;
}

.rounded {
    border-radius: var(--border-radius-md);
}

.rounded-lg {
    border-radius: var(--border-radius-lg);
}

.rounded-full {
    border-radius: var(--border-radius-full);
}

.shadow {
    box-shadow: var(--shadow-md);
}

.shadow-lg {
    box-shadow: var(--shadow-lg);
}

.cursor-pointer {
    cursor: pointer;
}