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

:root {
    --ana: #6d5dfc;
    --ana2: #5144d8;
    --koyu: #202033;
    --gri: #73738a;
    --acik: #f6f6fb;
    --beyaz: #ffffff;
    --yesil: #20a464;
    --kirmizi: #e5484d;
    --golge: 0 15px 45px rgba(30, 30, 60, 0.10);
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background: var(--acik);
    color: var(--koyu);
    min-height: 100vh;
}

button,
input,
select {
    font: inherit;
}

button {
    cursor: pointer;
    border: none;
}

.navbar {
    height: 75px;
    background: white;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 7%;
    box-shadow: 0 2px 15px rgba(0,0,0,.05);
    position: sticky;
    top: 0;
    z-index: 20;
}

.logo {
    font-size: 20px;
    font-weight: 800;
}

nav {
    display: flex;
    gap: 8px;
}

nav button {
    background: transparent;
    padding: 11px 15px;
    border-radius: 10px;
    color: var(--gri);
    transition: .2s;
}

nav button:hover {
    background: #f0efff;
    color: var(--ana);
}

main {
    width: min(1150px, 92%);
    margin: auto;
}

.sayfa {
    display: none;
    padding: 45px 0 80px;
}

.sayfa.aktif {
    display: block;
}

.hero {
    margin-top: 40px;
    min-height: 390px;
    border-radius: 30px;
    background: linear-gradient(135deg, #eeeeff, #ffffff);
    padding: 55px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    overflow: hidden;
}

.etiket {
    color: var(--ana);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 1px;
}

.hero h1 {
    font-size: clamp(42px, 7vw, 70px);
    line-height: 1.02;
    margin: 20px 0;
}

.hero h1 span {
    color: var(--ana);
}

.hero p {
    max-width: 550px;
    color: var(--gri);
    font-size: 18px;
    line-height: 1.6;
    margin-bottom: 25px;
}

.heroKitap {
    font-size: 180px;
    transform: rotate(-8deg);
    filter: drop-shadow(0 25px 25px rgba(0,0,0,.12));
}

.buyukButon {
    background: var(--ana);
    color: white;
    padding: 14px 22px;
    border-radius: 12px;
    font-weight: 700;
    transition: .2s;
}

.buyukButon:hover {
    background: var(--ana2);
    transform: translateY(-2px);
}

.istatistikler {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
    margin: 25px 0 50px;
}

.istatistik {
    background: white;
    border-radius: 18px;
    padding: 25px;
    box-shadow: var(--golge);
}

.istatistikIcon {
    font-size: 25px;
    margin-bottom: 12px;
}

.istatistik strong {
    display: block;
    font-size: 32px;
}

.istatistik span {
    color: var(--gri);
}

.baslikSatiri {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.baslikSatiri h2 {
    margin-bottom: 5px;
}

.baslikSatiri p,
.sayfaBaslik p {
    color: var(--gri);
}

.linkButon {
    background: transparent;
    color: var(--ana);
    font-weight: 700;
}

.sayfaBaslik {
    margin-bottom: 30px;
}

.sayfaBaslik h1 {
    font-size: 48px;
    margin: 12px 0;
}

.aramaAlani {
    display: flex;
    gap: 12px;
    margin-bottom: 25px;
}

.aramaAlani input,
.aramaAlani select,
.loginBox input,
.yonetimKart input {
    width: 100%;
    padding: 15px;
    border: 1px solid #dddde8;
    border-radius: 12px;
    background: white;
    outline: none;
}

.aramaAlani input:focus,
.loginBox input:focus,
.yonetimKart input:focus {
    border-color: var(--ana);
}

.aramaAlani select {
    max-width: 200px;
}

.kartGrid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.kitapKart,
.ogrenciKart {
    background: white;
    border-radius: 18px;
    padding: 22px;
    box-shadow: var(--golge);
}

.kitapEmoji {
    height: 110px;
    background: #f1efff;
    border-radius: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 55px;
    margin-bottom: 18px;
}

.kitapKart h3,
.ogrenciKart h3 {
    margin-bottom: 7px;
}

.kitapKart p,
.ogrenciKart p {
    color: var(--gri);
    margin-bottom: 15px;
}

.durum {
    display: inline-block;
    padding: 7px 10px;
    border-radius: 30px;
    font-size: 12px;
    font-weight: 700;
}

.rafta {
    background: #e7f8ee;
    color: var(--yesil);
}

.oduncte {
    background: #fff0df;
    color: #bd6b00;
}

.kartButon {
    width: 100%;
    margin-top: 14px;
    padding: 12px;
    border-radius: 10px;
    background: #f0efff;
    color: var(--ana);
    font-weight: 700;
}

.kartButon:hover {
    background: var(--ana);
    color: white;
}

.ogrenciAvatar {
    width: 65px;
    height: 65px;
    background: #f0efff;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 30px;
    margin-bottom: 15px;
}

.loginBox {
    max-width: 450px;
    background: white;
    padding: 30px;
    border-radius: 20px;
    box-shadow: var(--golge);
}

.loginBox p {
    color: var(--gri);
    margin: 10px 0 20px;
    line-height: 1.5;
}

.loginBox input {
    margin-bottom: 12px;
}

#loginMesaj {
    margin-top: 12px;
    color: var(--kirmizi);
}

.yonetimGrid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.yonetimKart {
    background: white;
    padding: 25px;
    border-radius: 18px;
    box-shadow: var(--golge);
}

.yonetimKart h2 {
    margin-bottom: 20px;
}

.yonetimKart input {
    margin-bottom: 10px;
}

.yonetimKart .buyukButon {
    width: 100%;
}

.tehlikeli {
    border: 1px solid #ffd1d1;
}

.tehlikeli p {
    color: var(--gri);
    line-height: 1.5;
    margin-bottom: 15px;
}

.silButon {
    width: 100%;
    background: var(--kirmizi);
    color: white;
    padding: 13px;
    border-radius: 10px;
    font-weight: 700;
}

.cikisButon {
    margin-top: 25px;
    background: #222;
    color: white;
    padding: 12px 18px;
    border-radius: 10px;
}

.bos {
    background: white;
    padding: 35px;
    border-radius: 18px;
    color: var(--gri);
    text-align: center;
    grid-column: 1 / -1;
}

footer {
    background: #202033;
    color: white;
    padding: 30px 7%;
    display: flex;
    justify-content: space-between;
    gap: 15px;
}

footer span {
    color: #aaaabd;
}

@media(max-width: 800px) {

    .navbar {
        height: auto;
        padding: 15px 4%;
        flex-direction: column;
        gap: 12px;
    }

    nav {
        width: 100%;
        overflow-x: auto;
    }

    nav button {
        white-space: nowrap;
    }

    .hero {
        padding: 35px 25px;
        margin-top: 20px;
    }

    .heroKitap {
        display: none;
    }

    .istatistikler,
    .kartGrid,
    .yonetimGrid {
        grid-template-columns: 1fr;
    }

    .sayfaBaslik h1 {
        font-size: 38px;
    }

    .aramaAlani {
        flex-direction: column;
    }

    .aramaAlani select {
        max-width: none;
    }

    footer {
        flex-direction: column;
    }
}