* {
    box-sizing: border-box;
}

:root {
    --panel-top: rgba(245, 250, 255, 0.86);
    --panel-mid: rgba(221, 235, 249, 0.78);
    --panel-bottom: rgba(190, 210, 232, 0.80);

    --bar-top: rgba(235, 244, 255, 0.82);
    --bar-mid: rgba(170, 200, 232, 0.72);
    --bar-bottom: rgba(120, 160, 205, 0.74);

    --text-main: #294363;
    --text-soft: #456487;
    --link-blue: #0d58d1;
    --link-hover: #2c7cff;

    --shadow-main: rgba(0, 0, 0, 0.18);
    --shadow-soft: rgba(255, 255, 255, 0.85);
}

/* =========================
   Base
========================= */
body {
    margin: 0;
    min-height: 100vh;
    font-family: "Segoe UI", Arial, sans-serif;
    background: url("https://frutigeraeroarchive.org/images/wallpapers/materialdictionary206/materialdictionary206_46.jpg") no-repeat center center fixed;
    background-size: cover;
    color: var(--text-main);
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    position: relative;
}

/* soft glow overlay */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    background:
        radial-gradient(circle at 20% 20%, rgba(255,255,255,0.14), transparent 28%),
        radial-gradient(circle at 75% 25%, rgba(190,220,255,0.12), transparent 30%),
        radial-gradient(circle at 50% 85%, rgba(160,200,255,0.08), transparent 24%);
    pointer-events: none;
    z-index: 0;
    animation: ambientShift 18s ease-in-out infinite alternate;
}

/* =========================
   Header
========================= */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 4px 14px;
    text-align: center;

    background: linear-gradient(
        to bottom,
        var(--bar-top) 0%,
        var(--bar-mid) 45%,
        var(--bar-bottom) 100%
    );
    border-bottom: 1px solid rgba(0,0,0,0.18);
    box-shadow:
        inset 0 1px 0 var(--shadow-soft),
        0 3px 12px var(--shadow-main);

    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

header::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(
        to bottom,
        rgba(255,255,255,0.45) 0%,
        rgba(255,255,255,0.10) 35%,
        rgba(255,255,255,0.00) 100%
    );
    pointer-events: none;
}

header h1 {
    margin: 0 0 6px 0;
    font-size: 1rem;
    color: #005499;
    text-shadow:
        0 1px 0 rgba(255,255,255,0.25),
        0 1px 3px rgba(0,0,0,0.28);
    position: relative;
    z-index: 1;
}

/* =========================
   Nav
========================= */
nav {
    position: relative;
    z-index: 1;
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;

    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: nowrap;
    overflow-x: auto;
    white-space: nowrap;
}

nav ul::-webkit-scrollbar {
    display: none;
}

nav ul li {
    display: flex;
    margin: 0;
}

nav ul li a {
    position: relative;
    overflow: hidden;

    display: flex;
    align-items: center;
    justify-content: center;
    gap: 5px;

    text-decoration: none;
    color: #ffffff;
    font-size: 11px;
    font-weight: 600;
    padding: 6px 12px;
    min-width: 88px;

    background: linear-gradient(
        to bottom,
        rgba(130, 190, 255, 0.95) 0%,
        rgba(70, 145, 225, 0.92) 45%,
        rgba(40, 100, 190, 0.98) 55%,
        rgba(26, 72, 155, 1) 100%
    );

    border-right: 1px solid rgba(255,255,255,0.20);
    border-left: 1px solid rgba(0,0,0,0.15);

    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.35),
        inset 0 -1px 0 rgba(0,0,0,0.12),
        0 1px 2px rgba(0,0,0,0.14);

    text-shadow: 0 1px 1px rgba(0,0,0,0.45);
    transition:
        transform 0.2s ease,
        box-shadow 0.25s ease,
        filter 0.25s ease,
        background 0.25s ease;
}

nav ul li:first-child a {
    border-top-left-radius: 7px;
    border-bottom-left-radius: 7px;
}

nav ul li:last-child a {
    border-top-right-radius: 7px;
    border-bottom-right-radius: 7px;
}

nav ul li a::before {
    content: "";
    position: absolute;
    top: 0;
    left: -130%;
    width: 60%;
    height: 100%;
    background: linear-gradient(
        to right,
        rgba(255,255,255,0),
        rgba(255,255,255,0.28),
        rgba(255,255,255,0)
    );
    transform: skewX(-20deg);
    transition: left 0.42s ease;
}

nav ul li a:hover {
    transform: translateY(-2px);
    filter: brightness(1.06);
    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.40),
        0 0 10px rgba(110,180,255,0.45),
        0 4px 12px rgba(0,0,0,0.18);
}

nav ul li a:hover::before {
    left: 130%;
}

nav ul li a:active {
    transform: translateY(1px);
}

nav ul li a img {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    transition: transform 0.2s ease;
}

nav ul li a:hover img {
    transform: scale(1.08) rotate(-3deg);
}

/* =========================
   Main
========================= */
main {
    flex: 1;
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 95px 20px 60px 20px;
    position: relative;
    z-index: 1;
}

/* =========================
   Welcome Card
========================= */
.welcome-card {
    width: min(760px, 100%);
    margin: 0 auto;
    padding: 28px 24px;
    text-align: center;

    background: linear-gradient(
        to bottom,
        var(--panel-top) 0%,
        var(--panel-mid) 50%,
        var(--panel-bottom) 100%
    );
    border: 1px solid rgba(0, 0, 0, 0.92);
    border-radius: 20px;

    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.95),
        inset 0 -1px 0 rgba(140,170,205,0.24),
        0 18px 40px rgba(0,0,0,0.22);

    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);

    animation: fadeLiftIn 0.8s ease both;
}

.welcome-card h2 {
    margin-top: 0;
    margin-bottom: 18px;
    color: var(--text-main);
    font-size: 2rem;
    text-shadow: 0 1px 0 rgba(255,255,255,0.55);
}

.welcome-card h2 img {
    width: 20px;
    height: 20px;
    vertical-align: middle;
    margin-right: 6px;
}

.welcome-card h4 {
    margin: 18px 0 10px;
    font-size: 1.35rem;
    color: #35557d;
    text-shadow: 0 1px 0 rgba(255,255,255,0.45);
}

.welcome-card ul {
    list-style-position: inside;
    padding: 0;
    margin: 0 0 6px 0;
}

.welcome-card li {
    margin: 7px 0;
    color: var(--text-soft);
}

.welcome-card a {
    color: var(--link-blue);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease, text-shadow 0.2s ease;
}

.welcome-card a:hover {
    color: var(--link-hover);
    text-shadow: 0 0 6px rgba(120,180,255,0.35);
    text-decoration: underline;
}

hr.dashed {
    border: none;
    height: 2px;
    margin: 24px 0;
    background: linear-gradient(
        to right,
        transparent,
        rgba(70,100,140,0.35),
        transparent
    );
}

/* =========================
   Footer
========================= */
footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    z-index: 1000;

    text-align: center;
    padding: 3px 8px;
    min-height: 22px;
    font-size: 12px;
    color: #000000;

    background: linear-gradient(
        to bottom,
        rgba(230,240,255,0.78),
        rgba(180,210,240,0.68)
    );
    border-top: 1px solid rgba(0,0,0,0.14);
    box-shadow:
        inset 0 1px 0 rgba(255,255,255,0.6),
        0 -3px 10px rgba(0,0,0,0.12);

    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

footer a {
    color: #2c5ca8;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* =========================
   Mobile
========================= */
@media (max-width: 900px) {
    header h1 {
        font-size: 0.95rem;
    }

    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }

    nav ul li a {
        min-width: 110px;
        flex: 1 1 auto;
    }

    main {
        padding-top: 120px;
    }

    .welcome-card {
        width: 100%;
        padding: 22px 16px;
    }

    .welcome-card h2 {
        font-size: 1.6rem;
    }

    .welcome-card h4 {
        font-size: 1.15rem;
    }
}

/* =========================
   Animations
========================= */
@keyframes fadeLiftIn {
    from {
        opacity: 0;
        transform: translateY(18px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes ambientShift {
    from {
        transform: translateY(0) scale(1);
        opacity: 0.9;
    }
    to {
        transform: translateY(-10px) scale(1.03);
        opacity: 1;
    }
}