:root {
    /* Colors */
    --color-bg: #1a1a1a;
    --color-container: rgba(45, 45, 45, 0.95);
    --color-text: #ffffff;
    --color-text-secondary: #cccccc;
    --color-nav-bg: #3d3d3d;
    --color-nav-hover: #4d4d4d;
    --color-nav-active: #ffffff;
    --color-ribbon-bg: rgba(45, 45, 45, 0.9);
    --color-copyright-bg: rgba(255, 255, 255, 0.9);

    /* Spacing */
    --spacing-xs: clamp(0.25rem, 1vw, 0.5rem);
    --spacing-sm: clamp(0.5rem, 2vw, 1rem);
    --spacing-md: clamp(1rem, 3vw, 1.5rem);
    --spacing-lg: clamp(1.5rem, 4vw, 2rem);
    --spacing-xl: clamp(2rem, 5vw, 3rem);

    /* Container */
    --container-width: min(90%, 1200px);
    --container-padding: clamp(1rem, 3vw, 2rem);

    /* Transitions */
    --transition-fast: 0.3s ease;
    --transition-slow: 0.5s ease;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);

    /* Z-index layers */
    --z-ribbon: 1000;
    --z-copyright: 1001;
}

a { text-decoration: none; color: #fff; }
a:hover { text-decoration: underline; }
.copyright { color: #fff; font-size:9pt; font-family:arial,sans serif; margin-top: 88px; }
.background { background: url('network-world.jpg'); width: 1024px; height: 400px; padding-top: 40px; }
.label_logo { color: #fff; font-size: 16pt; font-family:arial,sans serif; padding-top: 2px; padding-left: 36px; }
.label { padding: 30px; text-align: center; color: #fff; font-size: 18pt; font-family:arial,sans serif; margin-top: 5px; }
.label_right { text-align: center; color: #fff; font-size: 16pt; font-family:arial,sans serif; }
.box {
    border: 1px solid rgba(255, 255, 255, 0.8);
    padding: var(--spacing-sm);
    width: 80%;
    max-width: 500px;
    overflow-x: auto;
    margin: var(--spacing-md) 0;
    background-color: rgba(45, 45, 45, 0.5);
    border-radius: 8px;
}
.box div {
    color: var(--color-text);
    letter-spacing: 2px;
    font-size: 0.6rem;
    font-family: Arial, sans-serif;
    background-color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-xs) var(--spacing-sm);
    margin: var(--spacing-xs) 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    border-radius: 4px;
    max-width: 100%;
}
.layer { height: 90px; }

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

body {
    font-family: 'Arial', sans-serif;
    color: var(--color-text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: var(--color-bg);
    background-image: url('background.png');
    background-position: center center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
    position: relative;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.85);
    z-index: -1;
}

.ribbon {
    width: 100%;
    background-color: #ffffff;
    padding: var(--spacing-sm) var(--spacing-md);
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    left: 0;
    z-index: var(--z-ribbon);
}

.logo {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.logo-img {
    height: clamp(30px, 5vw, 40px);
    width: auto;
}

.container {
    width: var(--container-width);
    background-color: rgba(45, 45, 45, 0.85);
    border-radius: 10px;
    padding: var(--container-padding);
    box-shadow: var(--shadow-md);
    margin: clamp(60px, 10vh, 100px) auto 0;
    min-height: calc(150vh - clamp(60px, 10vh, 100px));
    display: flex;
    flex-direction: column;
}

.navigation {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.nav-btn {
    background-color: var(--color-nav-bg);
    color: var(--color-text);
    border: none;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: 5px;
    cursor: pointer;
    transition: var(--transition-fast);
    flex: 1;
    min-width: 120px;
    font-size: clamp(14px, 2vw, 16px);
}

.nav-btn:hover {
    background-color: var(--color-nav-hover);
}

.nav-btn.active {
    background-color: var(--color-nav-active);
    color: var(--color-bg);
}

.panels {
    position: relative;
    flex: 1;
    min-height: calc(100vh - clamp(60px, 10vh, 100px) - var(--spacing-lg));
    display: flex;
    align-items: flex-start;
    padding-top: var(--spacing-lg);
}

.panel {
    position: absolute;
    width: 100%;
    opacity: 0;
    transform: translateX(50px);
    transition: var(--transition-slow);
    pointer-events: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: flex-start;
    min-height: 100%;
}

.panel.active {
    opacity: 1;
    transform: translateX(0);
    pointer-events: all;
}

.panel h2 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
    text-align: left;
    width: 100%;
    font-size: clamp(20px, 3vw, 24px);
}

.panel p {
    line-height: 1.6;
    color: var(--color-text-secondary);
    text-align: left;
    width: 100%;
    margin-bottom: var(--spacing-md);
    font-size: clamp(14px, 2vw, 16px);
}

.logo-scroll-container {
    width: 100%;
    background-color: #000000;
    padding: var(--spacing-md) 0;
    overflow: hidden;
    display: flex;
    align-items: center;
    min-height: clamp(60px, 10vh, 100px);
    position: fixed;
    bottom: 0;
    left: 0;
    z-index: var(--z-ribbon);
}

.logo-scroll {
    width: 100%;
    overflow: hidden;
    position: relative;
    display: flex;
    align-items: center;
}

.logo-scroll-content {
    display: flex;
    animation: scroll 30s linear infinite;
    gap: var(--spacing-xl);
    padding: 0 var(--spacing-lg);
    align-items: center;
    will-change: transform;
}

.logo-scroll-content img {
    height: 35px;
    width: auto;
    object-fit: contain;
    opacity: 0.7;
    filter: grayscale(100%);
    transition: all 0.3s ease;
    margin: 0;
    pointer-events: auto;
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
    -ms-interpolation-mode: nearest-neighbor;
}

.logo-scroll-content img:hover {
    opacity: 1;
    filter: grayscale(0%);
}

@keyframes scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

a {
    color: #ffffff;
    text-decoration: none;
    transition: opacity 0.3s ease;
}

a:hover {
    opacity: 0.8;
}

.copyright-ribbon {
    position: fixed;
    top: clamp(40px, 8vh, 50px);
    right: -150px;
    background-color: var(--color-copyright-bg);
    color: var(--color-bg);
    padding: var(--spacing-xs) 150px;
    transform: rotate(45deg);
    z-index: var(--z-copyright);
    box-shadow: var(--shadow-sm);
    font-size: clamp(8px, 1.5vw, 9px);
    font-weight: 500;
    white-space: normal;
    width: 400px;
    text-align: center;
    transform-origin: center;
}

.copyright-ribbon span {
    display: inline-block;
    line-height: 1.2;
    padding: 0 var(--spacing-xs);
}

@media screen and (max-width: 1024px) {
    .container {
        margin: 80px auto 0;
        min-height: calc(100vh - 80px);
    }

    .panels {
        min-height: calc(100vh - 80px - var(--spacing-lg));
    }

    .copyright-ribbon {
        width: 350px;
        right: -120px;
        padding: var(--spacing-xs) 120px;
    }

    .tech-stack {
        max-width: 90%;
        padding: var(--spacing-lg);
    }

    .tech-item {
        padding: var(--spacing-sm);
    }
}

@media screen and (max-width: 768px) {
    .container {
        margin: 60px auto 0;
        min-height: calc(100vh - 60px);
    }

    .panels {
        min-height: calc(100vh - 60px - var(--spacing-lg));
    }

    .navigation {
        flex-direction: column;
    }

    .nav-btn {
        width: 100%;
    }

    .copyright-ribbon {
        width: 300px;
        right: -100px;
        padding: var(--spacing-xs) 100px;
    }

    .tech-stack {
        max-width: 95%;
        padding: var(--spacing-md);
        align-items: center;
        justify-content: center;
        border-radius: 12px;
    }

    .tech-item {
        flex-direction: column;
        text-align: center;
        padding: var(--spacing-md);
    }

    .tech-item .logo {
        margin-right: 0;
        margin-bottom: var(--spacing-sm);
    }

    .panel {
        justify-content: flex-start;
        padding-top: var(--spacing-lg);
    }

    .panel .tech-stack {
        margin-top: var(--spacing-lg);
    }
}

@media screen and (max-width: 480px) {
    .container {
        margin: 40px auto 0;
        min-height: calc(100vh - 40px);
    }

    .panels {
        min-height: calc(100vh - 40px - var(--spacing-lg));
    }

    .copyright-ribbon {
        width: 250px;
        right: -80px;
        padding: var(--spacing-xs) 80px;
        top: 30px;
    }

    .panel h2 {
        font-size: 18px;
    }

    .panel p {
        width: 100%;
        padding: 0;
    }

    .tech-stack {
        max-width: 100%;
        padding: var(--spacing-sm);
        border-radius: 8px;
    }

    .tech-item {
        padding: var(--spacing-sm);
    }
}

.panel .tech-stack {
    display: flex;
    flex-direction: column;
    gap: calc(var(--spacing-unit) * 2);
    padding: calc(var(--spacing-unit) * 2);
    background: url('network-world.jpg') center/cover;
    min-height: min(400px, 80vh);
    position: relative;
    width: 100%;
    max-width: 1000px;
    margin: 0 auto;
    overflow: hidden;
    align-self: center;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
}

.tech-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    position: relative;
    z-index: 2;
    text-decoration: none;
    color: white;
    gap: var(--spacing-unit);
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
    background-color: rgba(0, 0, 0, 0.5);
    border-radius: 8px;
}

.tech-box {
    flex: 1;
    margin: 0 var(--spacing-unit);
    border: 1px solid;
    padding: calc(var(--spacing-unit) * 0.75) calc(var(--spacing-unit) * 2);
    border-radius: 4px;
    min-width: 0;
    width: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 80px;
}

.tech-box div {
    color: #fff;
    letter-spacing: 2px;
    font-size: 0.6rem;
    font-family: Arial, sans-serif;
    background-color: rgba(255, 255, 255, 0.8);
    padding: var(--spacing-xs) var(--spacing-sm);
    margin: var(--spacing-xs) 0;
    white-space: normal;
    overflow: visible;
    text-overflow: clip;
    border-radius: 4px;
    max-width: 100%;
    font-weight: bold;
    text-align: center;
    width: 100%;
    line-height: 1.4;
}

.cloudme .tech-box div {
    color: #000;
}

.cloudtop .tech-box div {
    color: #fff;
}

.xios .tech-box div {
    color: #fff;
}

.backend .tech-box div {
    color: #fff;
}

.tech-item .logo {
    width: 120px;
    height: 120px;
    object-fit: contain;
    margin-right: var(--spacing-md);
}

.tech-item .description {
    flex: 1;
    padding: var(--spacing-sm);
}

.tech-item .description h3 {
    font-size: clamp(16px, 2vw, 20px);
    margin-bottom: var(--spacing-xs);
    color: var(--color-text);
}

.tech-item .description p {
    font-size: clamp(14px, 1.5vw, 16px);
    color: var(--color-text-secondary);
    line-height: 1.4;
}

.tech-logo {
    width: min(210px, 30%);
    height: 70px;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-shrink: 0;
}

.tech-logo img {
    max-height: 40px;
    max-width: 160px;
    width: auto;
    height: auto;
    object-fit: contain;
}

.cloudme .tech-logo img {
    max-height: 55px;
    max-width: 200px;
}

.cloudtop .tech-logo img {
    max-height: 50px;
    max-width: 180px;
}

.xios .tech-logo img {
    max-height: 40px;
}

.backend .tech-logo img {
    max-height: 40px;
}