:root {
    --sidebar-bg: #2c3e50;
    --ana-renk: #3498db;
    --yazi-renk: #2c3e50;
    --arkaplan: #f4f6f7;
    --kutu-golge: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--arkaplan);
    color: var(--yazi-renk);
    display: flex;
}

.sayfa-baslik {
    text-align: center;
    margin-bottom: 40px;
    color: var(--sidebar-bg);
    font-size: 2.5rem;
    font-weight: bold;
    border-bottom: 3px solid var(--ana-renk);
    padding-bottom: 15px;
    display: inline-block;
}

.sayfa-aciklama {
    text-align: center;
    margin-bottom: 50px;
    font-size: 1.1rem;
    color: #576574;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

aside.sidebar {
    background-color: var(--sidebar-bg);
    width: 80px;
    height: 100vh;
    position: sticky;
    top: 0;
    left: 0;
    padding-top: 275px;
    overflow: hidden;
    transition: width 0.4s ease;
    z-index: 100;
    flex-shrink: 0;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.2);
}

aside.sidebar:hover {
    width: 230px;
}

.sidebar ul {
    list-style: none;
    display: flex;
    flex-direction: column;
}

.sidebar a {
    text-decoration: none;
    color: #ecf0f1;
    display: flex;
    align-items: center;
    padding: 15px 0;
    border-left: 4px solid transparent;
    transition: all 0.3s;
    white-space: nowrap;
}

.sidebar a i {
    min-width: 80px;
    font-size: 20px;
    text-align: center;
}

.sidebar a .link-text {
    opacity: 0;
    transition: opacity 0.3s;
    margin-left: 10px;
}

aside.sidebar:hover a .link-text {
    opacity: 1;
}

.sidebar a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-left-color: var(--ana-renk);
    color: var(--ana-renk);
}

.sidebar a.aktif {
    background-color: rgba(255, 255, 255, 0.2);
    border-left-color: var(--ana-renk);
    color: var(--ana-renk);
}

.icerik {
    flex: 1;
    padding: 40px;
    width: 100%;
}

.ust-baslik {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    border-bottom: 2px solid #ddd;
    padding-bottom: 20px;
}

.site-logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--sidebar-bg);
}

.site-bilgi {
    background: linear-gradient(135deg, var(--sidebar-bg), var(--ana-renk));
    color: white;
    padding: 40px;
    border-radius: 15px;
    margin-bottom: 40px;
    box-shadow: var(--kutu-golge);
}

.site-bilgi h1 {
    font-size: 32px;
    margin-bottom: 10px;
}

.site-bilgi p {
    opacity: 0.9;
    font-size: 18px;
}

.tablo-aciklama {
    max-width: 1400px;
    margin: 20px auto 10px auto;
    padding-left: 20px;
    color: #666;
    font-size: 14px;
    font-style: italic;
}

.periyodik-tablo-container {
    display: grid;
    grid-template-columns: 30px repeat(18, 1fr);
    grid-template-rows: 30px repeat(7, 1fr) 20px repeat(2, 1fr);
    gap: 4px;
    padding: 20px;
    background-color: white;
    max-width: 1400px;
    margin: 0 auto;
    overflow-x: auto;
}

.tablo-no,
.tablo-baslik {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
    color: #999;
}

.tablo-no {
    justify-content: flex-end;
    padding-right: 5px;
}

.tablo-baslik {
    align-items: flex-end;
    padding-bottom: 5px;
    grid-row: 1;
}

.element {
    aspect-ratio: 1 / 1;
    border: 1px solid rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-decoration: none;
    color: #333;
    position: relative;
    transition: all 0.2s ease-in-out;
    cursor: pointer;
    border-radius: 3px;
    font-family: 'Arial', sans-serif;
}


.element:hover {
    transform: scale(1.2);
    z-index: 100;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    border: 1px solid #000;
    font-weight: bold;
}

.el-no {
    font-size: 10px;
    position: absolute;
    top: 2px;
    left: 4px;
    opacity: 0.7;
}

.el-sembol {
    font-size: 20px;
    font-weight: 700;
    margin-top: 5px;
}

.el-isim {
    font-size: 9px;
    margin-top: 2px;
    text-align: center;
}


.renk-ametal {
    background-color: #dcedc8;
    border-bottom: 3px solid #9ccc65;
    color: #33691e;
}

.renk-soygaz {
    background-color: #e1bee7;
    border-bottom: 3px solid #ab47bc;
    color: #4a148c;
}

.renk-alkali {
    background-color: #ffcdd2;
    border-bottom: 3px solid #e57373;
    color: #b71c1c;
}

.renk-toprakalkali {
    background-color: #fff9c4;
    border-bottom: 3px solid #fdd835;
    color: #f57f17;
}

.renk-gecis {
    background-color: #bbdefb;
    border-bottom: 3px solid #42a5f5;
    color: #0d47a1;
}

.renk-metal {
    background-color: #cfd8dc;
    border-bottom: 3px solid #78909c;
    color: #263238;
}

.renk-yarimetal {
    background-color: #b2dfdb;
    border-bottom: 3px solid #26a69a;
    color: #004d40;
}

.renk-lantanit {
    background-color: #f8bbd0;
    border-bottom: 3px solid #ec407a;
    color: #880e4f;
}

.renk-aktinit {
    background-color: #c5cae9;
    border-bottom: 3px solid #5c6bc0;
    color: #1a237e;
}

.renk-halojen {
    background-color: #ffe0b2;
    border-bottom: 3px solid #ffa726;
    color: #e65100;
}


.col-18 {
    grid-column-start: 19;
}

.col-H {
    grid-column-start: 2;
    grid-row-start: 2;
}

.col-13 {
    grid-column-start: 14;
}

.bosluk-satir {
    grid-column: 1 / -1;
    height: 20px;
}

.lantanit-baslangic {
    grid-column-start: 5;
}

.lejant-kutu {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.lejant-oge {
    display: flex;
    align-items: center;
    font-family: sans-serif;
    font-size: 14px;
    color: #555;
}

.lejant-oge .kutu {
    width: 20px;
    height: 20px;
    display: inline-block;
    margin-right: 8px;
    border-radius: 4px;
}

.geri-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background-color: var(--ana-renk);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    transition: all 0.3s ease;
    font-weight: 600;
}

.geri-btn:hover {
    background-color: #2980b9;
    transform: translateX(-5px);
}