* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Elms Sans", serif;
    font-style: normal;
    line-height: 1.6;
    color: #333;
    display: flex;
    flex-direction: column;
    background-color: #FFFDFA;
}

.navbar {
    background-color: #FFFDFA;
    color: navy;
    padding: 1rem 0;
    position: sticky;
    z-index: 100;
}

.nav-container {
    max-width: 90%;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    height: 50px;
    width: minmax(auto, 100px);
    object-fit: contain;
    margin-top: 10px;
}

.nav-logo {
    font-size: 1.5rem; 
    text-decoration: none;
    letter-spacing: -0.02em;
    display: flex;
    flex-direction: column;
    line-height:1.3rem;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer; 
}

.logo-text-left {
    color: #ee604b;
}

.logo-text-right {
    color: #166082;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    text-decoration: none;
    color: #4b5563;
    font-size: 1rem;
    font-weight: 500;
    transition: color 0.3s ease;
    white-space: nowrap;
}

.nav-link:hover {
    color: #166082;
}

.nav-link:active {
    color: #ee604b;
    font-weight: 600;
}

.header {
    position: relative;
    display: flex;
    height: auto;
    min-height: 60vh;  
    flex-direction: column;
}

.main-title {
    font-size: 5vw;
    font-weight: 700;
    text-align: center;
    color: #111827;
    display: inline-block
}

.reversi {
    position: relative;
    display: flex;
    height: auto;
    min-height: 60vh;  
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.reversi-title {
    font-size: 3vw;
    font-weight: 800;
    text-align: center;
    color: #FF69B4;
    display: inline-block
}

.reversi-game-label {
    font-size: 2vw;
    font-weight: 600;
    text-align: center;
    color: #FF69B4;
    margin-top: 1rem;
    display: inline-block
}

.reversi-desc {
    font-size: 1.2vw;
    text-align: center;
    color: #374151;
    margin: 2rem;
    padding: 0 10%;
    display: inline-block
}

.reversi-gui {
    color: #FF69B4
}

.gui-image-row {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.gui-kirby {
    width: 32%;
    height: auto;
    object-fit: contain;
    margin: 2rem;
}

.gui-meta {
    width: 30%;
    height: auto;
    object-fit: contain;
    margin: 2rem;
}

.reversi-additional-features {
    text-align: center;
    color: #FF69B4;
    display: inline-block;
    margin: 2rem
}

.reversi-features-list {
    color: #FF69B4;
    text-align: center;
    margin: 1rem;
}

.reversi-features-desc {
    color:#111827;
    padding: 0 10%;
    margin: 1rem;
}

.reversi-square-pic {
    width: 25%;
    height: auto;
    object-fit: contain;
    padding: 1rem;
}

.reversi-hint-pic {
    width: 26%;
    height: auto;
    object-fit: contain;
    padding: 1rem;

}

.reversi-diffview-ours-pic {
    width: 25%;
    height: auto;
    object-fit: contain;
    padding: 1rem;

}

.reversi-diffview-theirs-pic {
    width: 20%;
    height: auto;
    object-fit: contain;
    padding: 1rem;

}

.reversi-og-pic {
    width: 25%;
    height: auto;
    object-fit: contain;
    padding: 1rem;

}

.reversi-fallback-pic {
    width: 21.3%;
    height: auto;
    object-fit: contain;
    padding: 1rem;

}

.klondike {
    position: relative;
    display: flex;
    height: auto;
    min-height: 60vh;  
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.klondike-title {
    color: #c54000;
    font-size: 3vw;
    font-weight: 800;
    text-align: center;
    display: inline-block
}

.klondike-game-label {
    font-size: 2vw;
    font-weight: 600;
    text-align: center;
    color: #c54000;
    margin-top: 1rem;
    display: inline-block
}

.klondike-desc {
    font-size: 1.2vw;
    text-align: center;
    color: #374151;
    margin: 2rem;
    padding: 0 10%;
    display: inline-block
}

.klondike-implementation {
    text-align: center;
    color: #c54000;
    display: inline-block;
    margin: 2rem
}

.klondike-impl-desc {
    color:#374151;
    padding: 0 10%;
}

.klondike-variants {
    text-align: center;
    color: #c54000;
    display: inline-block;
    margin: 2rem
}

.klondike-variant-item {
    color: #374151;
    text-align: center;
    margin: 1rem;
}

.klondike-variant-desc {
    color:#374151;
    padding: 0 10%;
    margin: 1rem;
}

.klondike-design {
    text-align: center;
    color: #c54000;
    display: inline-block;
    margin: 2rem
}

.klondike-design-desc {
    color:#374151;
    padding: 0 10%;
    margin: 1rem;
}

.klondike-design-subheading {
    color:#374151;
    padding: 0 10%;
    margin: 1rem;
    font-weight: 600;
}

.klondike-runthrough-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.klondike-runthrough {
    width: 20%;
    height: auto;
    object-fit: contain;
    margin: 2rem;
}

.nav-link.active {
    color: #3b82f6;           /* Blue color for active page */
    font-weight: 600;          /* Bold */
    border-bottom: 2px solid #3b82f6;  /* Optional: underline */
}

.puzzle-container {
    width: 100%;
    height: 50%;
    pointer-events: none;
    display: grid;
    grid-template-columns: 20% 20% 10% 10% 20% 20%; 
    grid-template-rows: 20% 20% 20% 20% 20%; 
}

.class-blocks {
    width: 100%;
    height: auto;
    object-fit: contain;
    padding-right: 2rem;
    grid-column-start: 5;
    grid-column-end: 7;
    grid-row-start: 4;
    grid-row-end: 5;
}

.puzzle-bg {
    grid-column-start: 1;
    grid-column-end: 5;
    grid-row-start: 1;
    grid-row-end: 5;
    width: 90%;
    height: auto;
    max-height: none;
    padding: 2rem;
    object-fit: contain;
}

.coms4995nrg-puzzle {
    grid-column-start: 4;
    grid-column-end: 5;
    grid-row-start: 2;
    grid-row-end: 3;
    width: 100%;
    height: auto;
    object-fit: contain;
}

.welcome {
    position: relative;
    display: flex;
    justify-content: center;
}

.welcome-content {
    max-width: 40%;
    text-align: center;
}

.welcome h2 {
    font-size: 3vw;
    margin-bottom: 2rem;
    color: #000;
}

.welcome p {
    font-size: 1.5vw;
    line-height: 1.8;
    color: #333;
    margin-bottom: 1.5rem;
}

.psyc3458-puzzle {
    width: 15%;
    height: auto;
    object-fit: contain;
}

.psyc3466-puzzle {
    width: 10%;
    height: auto;
    object-fit: contain;
}

.second-puzzle-container {
    width: 100%;
    height: auto;
    pointer-events: none;
    padding-top: 2rem;
}

.second-class-blocks {
    width: 40%;
    height: auto;
    object-fit: contain;
    padding-left: 2rem;

}

.footer {
    background-color: #FFFDFA;
    color: #666;
    text-align: center;
    padding: 20px 0;
    font-size: 0.9rem;
    margin-top: 40px;
}

.npuzzle-ai {
    width: 40%;
    height: auto;
    object-fit: contain;
    margin: 2rem;
}