/* ============================================
   CSS Variables & Reset
   ============================================ */
:root {
    --bg-color: #0d0d0d;
    --text-color: #f0f0f0;
    --border-color: #f0f0f0;
    --border-width: 1px;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    --modal-bg: rgba(13, 13, 13, 0.95);
    --hover-bg: rgba(240, 240, 240, 0.1);
    --trail-color: rgba(240, 240, 240, 0.3);
}

/* Light theme */
[data-theme="light"] {
    --bg-color: #f0f0f0;
    --text-color: #0d0d0d;
    --border-color: #0d0d0d;
    --modal-bg: rgba(240, 240, 240, 0.95);
    --hover-bg: rgba(13, 13, 13, 0.1);
    --trail-color: rgba(13, 13, 13, 0.3);
}

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family);
}

/* ============================================
   Top Buttons (Theme Toggle & Search)
   ============================================ */
.top-buttons {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 100;
    display: flex;
    gap: 0.5rem;
}

.search-button,
.theme-toggle,
.home-button {
    background: transparent;
    border: var(--border-width) solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem;
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
}

/* Explicitly override link colors for home button */
.home-button,
.home-button:link,
.home-button:visited,
.home-button:active {
    color: var(--text-color);
}

.search-button:hover,
.search-button:focus,
.theme-toggle:hover,
.theme-toggle:focus,
.home-button:hover,
.home-button:focus {
    background-color: var(--text-color);
    color: var(--bg-color);
}

.search-button svg,
.theme-toggle svg,
.home-button svg {
    display: block;
}

/* Ensure SVG stroke color matches text color */
.home-button svg {
    stroke: currentColor;
}

/* Theme toggle icons */
.theme-toggle .icon-moon {
    display: none;
}

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

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

/* ============================================
   4x4 Grid Layout
   ============================================ */
.grid-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    grid-template-areas:
        "c0 c1 c2 c3"
        "c4 center center c5"
        "c6 center center c7"
        "c8 c9 c10 c11";
    height: 100vh;
    width: 100vw;
}

.grid-cell {
    border: var(--border-width) solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--text-color);
    padding: 1rem;
    text-align: center;
    transition: background-color 0.2s ease;
    gap: 0.5rem;
    overflow: hidden;
}

.grid-cell:hover:not(.center-cell) {
    background-color: var(--hover-bg);
}

/* Grid cell content */
.cell-title {
    font-size: clamp(1rem, 2.5vw, 1.5rem);
    font-weight: 400;
    line-height: 1.2;
}

.cell-description {
    font-size: clamp(0.7rem, 1.5vw, 0.875rem);
    opacity: 0.7;
    font-weight: 300;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Position each cell in the grid */
.grid-cell[data-position="0"] { grid-area: c0; }
.grid-cell[data-position="1"] { grid-area: c1; }
.grid-cell[data-position="2"] { grid-area: c2; }
.grid-cell[data-position="3"] { grid-area: c3; }
.grid-cell[data-position="4"] { grid-area: c4; }
.grid-cell[data-position="5"] { grid-area: c5; }
.grid-cell[data-position="6"] { grid-area: c6; }
.grid-cell[data-position="7"] { grid-area: c7; }
.grid-cell[data-position="8"] { grid-area: c8; }
.grid-cell[data-position="9"] { grid-area: c9; }
.grid-cell[data-position="10"] { grid-area: c10; }
.grid-cell[data-position="11"] { grid-area: c11; }

/* Center merged cell (2x2) */
.center-cell {
    grid-area: center;
    flex-direction: column;
    cursor: default;
}

.center-cell h1 {
    font-size: clamp(1.5rem, 5vw, 3rem);
    font-weight: 300;
    letter-spacing: 0.1em;
    margin-bottom: 0.5rem;
}

.center-cell p {
    font-size: clamp(0.75rem, 2vw, 1rem);
    opacity: 0.8;
    font-weight: 300;
}

/* ============================================
   Search Modal
   ============================================ */
.search-modal {
    position: fixed;
    inset: 0;
    background-color: var(--modal-bg);
    z-index: 200;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 15vh;
    opacity: 1;
    transition: opacity 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.search-modal[hidden] {
    display: none;
}

.search-modal.fade-out {
    opacity: 0;
    pointer-events: none;
}

.search-modal-content {
    width: 90%;
    max-width: 600px;
    position: relative;
}

.search-close {
    position: absolute;
    top: -2rem;
    right: 0;
    background: transparent;
    border: none;
    color: var(--text-color);
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
}

.search-close:hover {
    opacity: 0.7;
}

.search-input {
    width: 100%;
    padding: 1rem;
    font-size: 1.25rem;
    background: transparent;
    border: var(--border-width) solid var(--border-color);
    color: var(--text-color);
    font-family: var(--font-family);
}

.search-input:focus {
    outline: none;
    border-color: var(--text-color);
}

.search-input::placeholder {
    color: rgba(240, 240, 240, 0.5);
}

.search-results {
    margin-top: 1rem;
    max-height: 50vh;
    overflow-y: auto;
}

.search-result-item {
    display: block;
    padding: 1rem;
    border: var(--border-width) solid var(--border-color);
    border-top: none;
    color: var(--text-color);
    text-decoration: none;
    transition: background-color 0.2s ease;
}

.search-result-item:first-child {
    border-top: var(--border-width) solid var(--border-color);
}

.search-result-item:hover {
    background-color: var(--hover-bg);
}

.search-result-item h3 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.search-result-item p {
    font-size: 0.875rem;
    opacity: 0.7;
}

.search-result-type {
    display: inline-block;
    font-size: 0.75rem;
    opacity: 0.5;
    margin-top: 0.25rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.search-no-results {
    padding: 1rem;
    text-align: center;
    opacity: 0.7;
}

/* ============================================
   Mobile Responsive (2-column layout)
   ============================================ */
@media (max-width: 768px) {
    html, body {
        overflow: auto;
    }

    .grid-container {
        grid-template-columns: repeat(2, 1fr);
        grid-template-rows: auto;
        grid-template-areas:
            "center center"
            "c0 c1"
            "c2 c3"
            "c4 c5"
            "c6 c7"
            "c8 c9"
            "c10 c11";
        height: auto;
        min-height: 100vh;
    }

    .center-cell {
        padding: 3rem 1rem;
    }

    .grid-cell:not(.center-cell) {
        min-height: 120px;
    }
}

/* ============================================
   Small mobile adjustments
   ============================================ */
@media (max-width: 480px) {
    .center-cell h1 {
        font-size: 1.75rem;
    }

    .center-cell p {
        font-size: 0.875rem;
    }

    .grid-cell:not(.center-cell) {
        min-height: 100px;
    }

    .cell-title {
        font-size: 0.9rem;
    }

    .cell-description {
        font-size: 0.7rem;
        -webkit-line-clamp: 2;
    }
}

/* ============================================
   Grid Trail Effect
   ============================================ */
.grid-trail-container {
    position: fixed;
    top: 0;
    left: 0;
    display: grid;
    pointer-events: none;
    z-index: 1;
}

.grid-trail-cell {
    border: 1px solid transparent;
    transition: border-color 0.4s ease-out;
}

.grid-trail-cell.active {
    border-color: var(--trail-color);
}

/* ============================================
   Back Button (Top Left)
   ============================================ */
.back-button {
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 100;
    background: transparent;
    border: var(--border-width) solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-button:hover,
.back-button:focus {
    background-color: var(--text-color);
    color: var(--bg-color);
}

.back-button[hidden] {
    display: none;
}

.back-button svg {
    display: block;
}

/* ============================================
   Page Transitions
   ============================================ */
.grid-container,
.post-view {
    transition: opacity 0.3s ease;
}

.grid-container.fade-out,
.post-view.fade-out {
    opacity: 0;
}

.grid-container.fade-in,
.post-view.fade-in {
    opacity: 1;
}

.grid-container[hidden],
.post-view[hidden] {
    display: none;
}

/* Post view specific styles (no header bar) */
.post-view {
    overflow: auto;
    height: 100vh;
}