.tab-content {
    display: none;
    padding: 20px;
    color:aliceblue;
}

#about {
    display: block;
}

html, body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    margin: 0;
    padding: 0;
    height: 100%;
    overflow-x: hidden;
}
#background-video,
#calendar-background-video,
#bucketlist-background-video,
#yuukabot-background-video {
    position: fixed;
    right: 0%;
    left: 0%;
    min-width: 100%;
    min-height: 100%;
    z-index: -1;
    object-fit: cover;
}
#top-line {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 115px; /* other tabs are spaced for this height */
    box-sizing: border-box;
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
    z-index: 10;
    display: flex;
    justify-content: flex-start;
    align-items:center;
    background-color: #1111;
    padding: 10px;
}

#nav-tabs {
    display: flex;
    align-items: center;
}

#nav-tabs button {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    border-bottom: 2px solid #5b6fde;
    border-left: 2px solid #5b6fde; 
    border-right: 2px solid #5b6fde;
    border-top: transparent;
    color:#153dee;
    font-size: large;
    padding: 30px;
    margin: 30px;
    border-radius: 4px;
    cursor: pointer;
    font-weight: bold;
    background-color: transparent;
    transition: box-shadow 0.3s ease, background-color 0.3s ease, border-color 0.4s ease, color 0.4s ease;
}

#nav-tabs button:hover {
    text-decoration: underline;
}

/* calendar theme */
#top-line.cal-theme #nav-tabs button {
    border-bottom-color: #FBC4CC;
    border-left-color: #FBC4CC;
    border-right-color: #FBC4CC;
    color: #F4F2F5;
    transition: border-color 0.4s ease, color 0.4s ease;
}

/* bucketlist theme */
#top-line.bucketlist-theme #nav-tabs button {
    border-bottom-color: #B5B1C6;
    border-left-color: #B5B1C6;
    border-right-color: #B5B1C6;
    color: #B84457;
    transition: border-color 0.4s ease, color 0.4s ease;
}

h1 {
    font-size: 3rem;
    color: #000000;
    font-weight: bold;
    margin-top: 150px;
}
p {
    font-size: 2rem;
    color:rgb(0, 0, 0);
    max-width: 800px;
    margin: 0 auto 40px auto;
    line-height: 1.5;
}
img {
    display:block;
}

/* mobile only */
#nav-current,
#nav-hamburger {
    display: none;
}

/* mobile, same setup as userevolt.app */
@media (max-width: 1300px) {
    #nav-tabs button {
        padding: 22px 18px;
        margin: 30px 8px;
    }
}

@media (max-width: 900px) {
    #top-line {
        height: 56px;
        padding: 0 8px 0 16px;
        justify-content: space-between;
        background: rgba(13, 17, 23, 0.75);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }

    #nav-current {
        display: block;
        color: #fff;
        font-weight: bold;
        font-size: 1.1rem;
    }

    #nav-hamburger {
        display: flex;
        flex-direction: column;
        justify-content: center;
        gap: 5px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 8px;
        width: 40px;
        height: 40px;
        flex-shrink: 0;
    }
    #nav-hamburger span {
        display: block;
        width: 22px;
        height: 2px;
        background: #fff;
        border-radius: 1px;
        transition: transform 0.25s, opacity 0.25s;
    }
    /* turns into an X */
    #top-line.nav-open #nav-hamburger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
    #top-line.nav-open #nav-hamburger span:nth-child(2) { opacity: 0; }
    #top-line.nav-open #nav-hamburger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

    #nav-tabs {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        align-items: stretch;
        background: rgba(13, 17, 23, 0.95);
        backdrop-filter: blur(16px);
        -webkit-backdrop-filter: blur(16px);
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        padding: 8px 0;
    }
    #top-line.nav-open #nav-tabs {
        display: flex;
    }

    #nav-tabs button,
    #top-line.cal-theme #nav-tabs button,
    #top-line.bucketlist-theme #nav-tabs button {
        width: 100%;
        margin: 0;
        padding: 12px 24px;
        min-height: 44px;
        border: none;
        border-left: 3px solid transparent;
        border-radius: 0;
        color: rgba(255, 255, 255, 0.85);
        font-size: 1rem;
        text-align: left;
    }
    #nav-tabs button:hover {
        text-decoration: none;
        background: rgba(255, 255, 255, 0.06);
        border-left-color: #5b6fde;
    }
    #top-line.cal-theme #nav-tabs button:hover { border-left-color: #FBC4CC; }
    #top-line.bucketlist-theme #nav-tabs button:hover { border-left-color: #B84457; }

    /* keep the video centered on tall screens */
    #background-video,
    #calendar-background-video,
    #bucketlist-background-video,
    #yuukabot-background-video {
        top: 0;
        width: 100%;
        height: 100%;
    }

    .tab-content { padding: 12px; }

    h1 { font-size: 2.2rem; }
    p  { font-size: 1.2rem; }
}