/**
 * Animations & Transitions for DevBlog Theme
 * Subtle, professional animations with accessibility support
 */

/* ==========================================================================
   Keyframe Animations
   ========================================================================== */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes scrollIndicator {
    0%, 100% {
        transform: translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateY(10px);
        opacity: 0.5;
    }
}

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

/* ==========================================================================
   Hero Section Animations
   ========================================================================== */

.hero {
    position: relative;
    padding: var(--space-24) 0 var(--space-16);
    overflow: hidden;
}

.hero-gradient {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        135deg,
        var(--color-primary) 0%,
        var(--color-accent) 50%,
        var(--color-linux-green) 100%
    );
    background-size: 200% 200%;
    animation: gradientShift 15s ease infinite;
    opacity: 0.05;
    z-index: -1;
}

[data-theme="dark"] .hero-gradient {
    opacity: 0.1;
}

.hero-content {
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    animation: fadeInUp 0.8s ease-out 0.1s both;
}

.hero-description {
    animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-actions {
    animation: fadeInUp 0.8s ease-out 0.3s both;
    display: flex;
    gap: var(--space-4);
    flex-wrap: wrap;
    justify-content: center;
    margin-top: var(--space-8);
}

.scroll-indicator {
    position: absolute;
    bottom: var(--space-8);
    left: 50%;
    transform: translateX(-50%);
    animation: scrollIndicator 2s ease-in-out infinite;
    color: var(--color-text-secondary);
}

/* Typing animation for hero description */
.typing-text {
    overflow: hidden;
    border-right: 2px solid var(--color-primary);
    white-space: nowrap;
    animation: typing 3s steps(40, end), blink-caret 0.75s step-end infinite;
}

@keyframes typing {
    from {
        width: 0;
    }
    to {
        width: 100%;
    }
}

@keyframes blink-caret {
    from, to {
        border-color: transparent;
    }
    50% {
        border-color: var(--color-primary);
    }
}

/* ==========================================================================
   Post Card Animations
   ========================================================================== */

.post-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    animation: fadeIn 0.5s ease-out;
}

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.post-card-link {
    display: block;
    color: inherit;
    text-decoration: none;
}

.post-card-image {
    position: relative;
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.post-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.post-card:hover .post-card-image img {
    transform: scale(1.05);
}

.post-card-featured-badge {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    background: var(--color-accent);
    color: white;
    padding: var(--space-2);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    animation: pulse 2s ease-in-out infinite;
}

.post-card-content {
    padding: var(--space-6);
}

.post-card-title {
    transition: color var(--transition-fast);
}

.post-card:hover .post-card-title {
    color: var(--color-primary);
}

/* ==========================================================================
   Header Animations
   ========================================================================== */

.site-header {
    position: sticky;
    top: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    z-index: var(--z-sticky);
    transition: all var(--transition-base);
}

.site-header.is-scrolled {
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
    background: rgba(var(--color-surface), 0.95);
}

.site-header.is-hidden {
    transform: translateY(-100%);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) 0;
}

/* ==========================================================================
   Navigation Animations
   ========================================================================== */

.nav-list {
    display: flex;
    gap: var(--space-6);
    list-style: none;
    margin: 0;
}

.nav-link {
    position: relative;
    padding: var(--space-2) 0;
    color: var(--color-text);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link-active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link-active {
    color: var(--color-primary);
}

/* ==========================================================================
   Mobile Menu Animations
   ========================================================================== */

.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: var(--color-overlay);
    backdrop-filter: blur(10px);
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
}

.mobile-menu.is-open {
    opacity: 1;
    visibility: visible;
}

.mobile-menu-inner {
    position: absolute;
    top: 0;
    right: 0;
    width: 80%;
    max-width: 400px;
    height: 100%;
    background: var(--color-surface);
    padding: var(--space-8) var(--space-6);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    overflow-y: auto;
}

.mobile-menu.is-open .mobile-menu-inner {
    transform: translateX(0);
}

.hamburger {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    width: 24px;
    height: 20px;
}

.hamburger-line {
    width: 100%;
    height: 2px;
    background: var(--color-text);
    transition: all var(--transition-fast);
}

.mobile-menu-toggle.is-active .hamburger-line:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.mobile-menu-toggle.is-active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.is-active .hamburger-line:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* ==========================================================================
   Theme Toggle Animations
   ========================================================================== */

.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--color-surface);
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: scale(1.05);
}

.theme-icon {
    transition: transform var(--transition-fast);
}

.theme-toggle:hover .theme-icon {
    transform: rotate(20deg);
}

[data-theme="light"] .sun-icon {
    display: none;
}

[data-theme="light"] .moon-icon {
    display: block;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

/* ==========================================================================
   Button Animations
   ========================================================================== */

.btn {
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

/* ==========================================================================
   Back to Top Button - Aligned with content area
   ========================================================================== */

.back-to-top {
    position: fixed;
    bottom: var(--space-8);
    /* Align with content: on wide screens sit at right edge of content column */
    right: max(var(--space-8), calc((100vw - var(--container-width)) / 2 + var(--space-8)));
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-base);
    z-index: var(--z-fixed);
}

.back-to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.back-to-top:active {
    transform: translateY(0);
}

@media (max-width: 1280px) {
    .back-to-top {
        right: var(--space-8);
    }
}

/* ==========================================================================
   Reading Progress Bar
   ========================================================================== */

.reading-progress {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--color-border);
}

.reading-progress-bar {
    height: 100%;
    background: var(--color-primary);
    width: 0%;
    transition: width 0.1s ease-out;
}

/* ==========================================================================
   Loading States
   ========================================================================== */

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

/* ==========================================================================
   Fade-in on Scroll
   ========================================================================== */

.fade-in-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================================================
   Link Underline Animation
   ========================================================================== */

.post-content a {
    position: relative;
    text-decoration: none;
    background-image: linear-gradient(var(--color-primary), var(--color-primary));
    background-position: 0% 100%;
    background-repeat: no-repeat;
    background-size: 0% 2px;
    transition: background-size var(--transition-base);
}

.post-content a:hover {
    background-size: 100% 2px;
}

/* ==========================================================================
   Image Hover Effects
   ========================================================================== */

.post-content img {
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.post-content img:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-lg);
}

/* ==========================================================================
   Focus Indicators
   ========================================================================== */

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* ==========================================================================
   Easter Egg Animations
   ========================================================================== */

.coffee-toggle {
    cursor: pointer;
    display: inline-block;
    transition: transform var(--transition-fast);
}

.coffee-toggle:hover {
    animation: bounce 0.5s ease;
}

/* ==========================================================================
   Accessibility - Respect Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .hero-gradient {
        animation: none;
    }
    
    .typing-text {
        animation: none;
        border-right: none;
        white-space: normal;
    }
}