/* Rivulet Blog Styles - Ultra Modern Design */

:root {
    --primary-bg: #0a0a0b; /* Deep dark background */
    --secondary-bg: #111111; /* Subtle card background */
    --tertiary-bg: #1a1a1c; /* Even lighter sections */
    --accent-color: #00d9ff; /* Electric cyan */
    --accent-secondary: #ff6b6b; /* Coral accent */
    --accent-gradient: linear-gradient(135deg, #00d9ff 0%, #0099cc 100%);
    --text-color: #ffffff; /* Pure white text */
    --text-secondary: #b3b3b3; /* Secondary text */
    --text-muted: #666666; /* Muted text */
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-light: rgba(0, 217, 255, 0.1);
    --shadow-medium: rgba(0, 217, 255, 0.2);
    --shadow-heavy: rgba(0, 217, 255, 0.3);
    --shadow-dark: rgba(0, 0, 0, 0.8);
    --blur-amount: 20px;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background: var(--primary-bg);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Background animated gradient */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 80%, rgba(0, 217, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 107, 107, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(0, 217, 255, 0.05) 0%, transparent 50%);
    z-index: -1;
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(180deg); }
}

header {
    background: rgba(17, 17, 17, 0.8);
    -webkit-backdrop-filter: blur(var(--blur-amount));
    backdrop-filter: blur(var(--blur-amount));
    color: var(--text-color);
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
    border-bottom: 1px solid var(--border-color);
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--accent-gradient);
    opacity: 0.1;
    z-index: -1;
}

header h1 {
    margin: 0;
    font-size: 4.5rem;
    font-weight: 900;
    letter-spacing: -0.02em;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
    position: relative;
}

header h1::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background: var(--accent-gradient);
    border-radius: 2px;
}

header p {
    margin: 0;
    font-size: 1.4rem;
    color: var(--text-secondary);
    font-weight: 300;
    max-width: 600px;
    margin: 0 auto;
}

main {
    flex-grow: 1;
    max-width: 1400px;
    margin: 4rem auto;
    padding: 0 2rem;
    position: relative;
}

#slides-list {
    background: var(--secondary-bg);
    padding: 4rem;
    border-radius: 24px;
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

#slides-list::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 217, 255, 0.03) 0%, rgba(255, 107, 107, 0.03) 100%);
    z-index: 0;
}

#slides-list > * {
    position: relative;
    z-index: 1;
}

#slides-list h2 {
    color: var(--text-color);
    text-align: center;
    font-size: 3.5rem;
    margin-bottom: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    position: relative;
}

#slides-list h2::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--accent-gradient);
    border-radius: 2px;
}

ul {
    list-style: none;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
    margin: 0;
}

li {
    background: var(--tertiary-bg);
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    flex: 1 1 350px;
    max-width: 420px;
}

li::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--accent-gradient);
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: 0;
}

li:hover::before {
    opacity: 0.1;
}

li:hover {
    transform: translateY(-8px) scale(1.02);
    border-color: var(--accent-color);
    box-shadow: 
        0 20px 40px var(--shadow-dark),
        0 0 0 1px var(--accent-color),
        0 0 30px var(--shadow-light);
}

li a {
    text-decoration: none;
    color: var(--text-color);
    display: block;
    padding: 0;
    position: relative;
    z-index: 1;
}

.thumbnail {
    width: 100%;
    height: 240px;
    object-fit: cover;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border-bottom: 1px solid var(--border-color);
}

li:hover .thumbnail {
    transform: scale(1.05);
}

.content-area {
    padding: 2rem;
}

li h3 {
    margin: 0 0 1rem 0;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
    line-height: 1.3;
    letter-spacing: -0.01em;
}

li p {
    margin: 0;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
}

footer {
    text-align: center;
    padding: 3rem 2rem;
    background: var(--secondary-bg);
    color: var(--text-secondary);
    margin-top: 5rem;
    border-top: 1px solid var(--border-color);
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 217, 255, 0.02) 0%, rgba(255, 107, 107, 0.02) 100%);
}

footer > * {
    position: relative;
    z-index: 1;
}

footer p {
    margin: 0 0 1.5rem 0;
    font-size: 1rem;
    font-weight: 300;
}

.github-link {
    display: inline-flex;
    align-items: center;
    color: var(--text-color);
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: 500;
    padding: 0.8rem 2rem;
    border: 1px solid var(--border-color);
    border-radius: 50px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    background: var(--tertiary-bg);
}

.github-link:hover {
    background: var(--accent-color);
    color: var(--primary-bg);
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--shadow-light);
}

.github-link svg {
    margin-right: 0.8rem;
    width: 24px;
    height: 24px;
    fill: currentColor;
    transition: fill 0.3s ease;
}

/* Pagination styles */
.pagination {
    display: flex;
    justify-content: center;
    margin-top: 3rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.pagination button {
    background: var(--tertiary-bg);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.8rem 1.5rem;
    border-radius: 12px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    min-width: 44px;
}

.pagination button:hover {
    background: var(--accent-color);
    color: var(--primary-bg);
    border-color: var(--accent-color);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px var(--shadow-light);
}

.pagination button.active {
    background: var(--accent-color);
    color: var(--primary-bg);
    border-color: var(--accent-color);
}

.pagination button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.pagination button:disabled:hover {
    background: var(--tertiary-bg);
    color: var(--text-color);
    border-color: var(--border-color);
    transform: none;
    box-shadow: none;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    header {
        padding: 3rem 1.5rem;
    }
    
    header h1 {
        font-size: 3.5rem;
    }
    
    header p {
        font-size: 1.2rem;
    }
    
    #slides-list {
        padding: 2.5rem 2rem;
        border-radius: 20px;
    }
    
    #slides-list h2 {
        font-size: 2.8rem;
        margin-bottom: 2.5rem;
    }
    
    main {
        margin: 2rem auto;
        padding: 0 1rem;
    }
    
    ul {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    li {
        max-width: 100%;
    }
    
    .content-area {
        padding: 1.5rem;
    }
    
    li h3 {
        font-size: 1.3rem;
    }
    
    .github-link {
        padding: 0.7rem 1.5rem;
        font-size: 1.1rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 2.8rem;
    }
    
    header p {
        font-size: 1.1rem;
    }
    
    #slides-list {
        padding: 2rem 1.5rem;
    }
    
    #slides-list h2 {
        font-size: 2.2rem;
    }
    
    .pagination {
        gap: 0.5rem;
    }
    
    .pagination button {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
}

/* Scroll animations */
@media (prefers-reduced-motion: no-preference) {
    li {
        animation: slideUp 0.6s ease-out forwards;
        opacity: 0;
        transform: translateY(30px);
    }
    
    li:nth-child(1) { animation-delay: 0.1s; }
    li:nth-child(2) { animation-delay: 0.2s; }
    li:nth-child(3) { animation-delay: 0.3s; }
    li:nth-child(4) { animation-delay: 0.4s; }
    li:nth-child(5) { animation-delay: 0.5s; }
    li:nth-child(6) { animation-delay: 0.6s; }
}

@keyframes slideUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}