:root{
    --bg-main: #08111f;
    --bg-soft: #0c1728;
    --text-main: #ffffff;
    --text-soft: #c6d2dd;
    --text-muted: #94a3b8;
    --accent: #00d9ff;
    --surface: rgba(255,255,255,0.04);
    --surface-strong: rgba(255,255,255,0.06);
    --line: rgba(255,255,255,0.1);
    --shadow: 0 18px 40px rgba(0,0,0,0.18);
}

html[data-theme="light"]{
    --bg-main: #eff4fa;
    --bg-soft: #ffffff;
    --text-main: #0d1724;
    --text-soft: #415164;
    --text-muted: #5c6e80;
    --accent: #006b9f;
    --surface: rgba(255,255,255,0.84);
    --surface-strong: rgba(255,255,255,0.96);
    --line: rgba(14, 25, 40, 0.12);
    --shadow: 0 18px 40px rgba(13, 23, 36, 0.08);
}

html[data-theme="light"] header{
    background: rgba(255, 255, 255, 0.76);
}

html[data-theme="light"] nav a{
    background: rgba(13, 23, 36, 0.05);
}

html[data-theme="light"] nav a:hover{
    background: rgba(0, 107, 159, 0.08);
}

html[data-theme="light"] .hero-card,
html[data-theme="light"] .card,
html[data-theme="light"] .mini-card,
html[data-theme="light"] .stat-box,
html[data-theme="light"] .workflow-box,
html[data-theme="light"] .dataset-preview__copy,
html[data-theme="light"] .dataset-preview__panel{
    box-shadow: 0 18px 40px rgba(13, 23, 36, 0.08);
}

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, Helvetica, sans-serif;
}

body{
    background: radial-gradient(circle at 0% 0%, rgba(0,217,255,0.12), transparent 30%), var(--bg-main);
    color: var(--text-main);
    overflow-x: hidden;
    line-height: 1.6;
    transition: background 220ms ease, color 220ms ease;
}

html{
    scroll-behavior: smooth;
}

/* HEADER */

header{
    width: 100%;
    padding: 20px 8%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
    background: rgba(0,0,0,0.2);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line);
    position: fixed;
    top: 0;
    z-index: 1000;
}

.logo{
    display: grid;
    gap: 4px;
    justify-items: start;
}

.logo img{
    width: min(360px, 42vw);
    max-width: 360px;
    height: auto;
    object-fit: contain;
    display: block;
}

nav ul{
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: 30px;
    list-style: none;
}

nav a{
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 40px;
    padding: 0 15px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.04);
    color: var(--text-main);
    text-decoration: none;
    transition: 0.3s;
    font-weight: bold;
    font-size: 0.95rem;
    white-space: nowrap;
}

.header-actions{
    display: flex;
    align-items: center;
    gap: 12px;
}

.theme-toggle{
    min-height: 40px;
    padding: 0 16px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--surface);
    color: var(--text-main);
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    white-space: nowrap;
}

.theme-toggle:hover{
    border-color: var(--accent);
    color: var(--accent);
}

nav a:hover{
    color: var(--accent);
    border-color: rgba(0, 217, 255, 0.28);
    background: rgba(0, 217, 255, 0.08);
}

/* HERO */

.hero{
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 120px 8% 60px;
    gap: 40px;
}

.hero-text{
    flex: 1;
}

.hero-text span{
    color: var(--accent);
    font-weight: bold;
}

.hero-text h2{
    font-size: clamp(2.15rem, 4vw, 3.5rem);
    margin: 20px 0;
    line-height: 1.1;
}

.hero-text p{
    color: var(--text-soft);
    line-height: 1.7;
    font-size: 1rem;
    margin-bottom: 35px;
}

.buttons{
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.btn-primary{
    background: var(--accent);
    color: black;
    padding: 15px 28px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 700;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn-secondary{
    border: 1px solid var(--line);
    color: var(--text-main);
    padding: 15px 28px;
    border-radius: 12px;
    text-decoration: none;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.btn-primary:hover,
.btn-secondary:hover{
    transform: translateY(-2px);
}

.btn-primary:hover{
    box-shadow: 0 10px 24px rgba(0,217,255,0.24);
}

.btn-secondary:hover{
    border-color: var(--accent);
}

/* CARD */

.hero-card{
    flex: 1;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 28px;
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
}

.dataset-preview{
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(360px, 0.92fr);
    gap: 24px;
    align-items: start;
    margin-top: 8px;
}

.dataset-preview__copy,
.dataset-preview__panel{
    border: 1px solid var(--line);
    border-radius: 20px;
    background: var(--surface);
    box-shadow: var(--shadow);
    backdrop-filter: blur(12px);
}

.dataset-preview__copy{
    display: grid;
    gap: 18px;
    padding: 28px;
}

.dataset-preview__copy span,
.dataset-preview__panel-head p{
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.dataset-preview__copy h2{
    font-size: clamp(1.8rem, 3vw, 2.6rem);
    line-height: 1.12;
    max-width: 700px;
}

.dataset-preview__copy p{
    color: var(--text-soft);
    max-width: 720px;
    line-height: 1.75;
}

.dataset-preview__stats{
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}

.dataset-preview__stats article{
    padding: 16px;
    border-radius: 16px;
    background: var(--surface-strong);
    border: 1px solid var(--line);
}

.dataset-preview__stats strong{
    display: block;
    color: var(--accent);
    font-size: 1.7rem;
    line-height: 1;
}

.dataset-preview__stats small{
    display: block;
    margin-top: 6px;
    color: var(--text-soft);
}

.dataset-preview__actions{
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.dataset-preview__panel{
    display: grid;
    gap: 16px;
    padding: 22px;
}

.dataset-preview__panel-head{
    display: flex;
    align-items: start;
    justify-content: space-between;
    gap: 12px;
}

.dataset-preview__panel-head strong{
    display: block;
    margin-top: 6px;
    font-size: 1.1rem;
}

.dataset-preview__panel-head a{
    color: var(--accent);
    text-decoration: none;
    white-space: nowrap;
}

.dataset-preview__bars{
    display: grid;
    gap: 12px;
}

.dataset-preview__bars article{
    padding: 14px;
    border-radius: 14px;
    border: 1px solid var(--line);
    background: var(--surface-strong);
}

.dataset-preview__bars-top{
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 10px;
}

.dataset-preview__bars-top span,
.dataset-preview__bars small{
    color: var(--text-soft);
    font-size: 0.88rem;
}

.dataset-preview__track{
    height: 9px;
    border-radius: 999px;
    overflow: hidden;
    background: var(--line);
}

.dataset-preview__track span{
    display: block;
    height: 100%;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--accent), rgba(0,217,255,0.45));
}

.dataset-preview__table{
    overflow: auto;
    border-radius: 14px;
    border: 1px solid var(--line);
}

.dataset-preview__table table{
    width: 100%;
    border-collapse: collapse;
    min-width: 340px;
    background: var(--surface-strong);
}

.dataset-preview__table th,
.dataset-preview__table td{
    padding: 12px 14px;
    text-align: left;
    border-bottom: 1px solid var(--line);
    font-size: 0.94rem;
    white-space: nowrap;
}

.dataset-preview__table th{
    color: var(--text-main);
}

.hero-card h3{
    margin-bottom: 25px;
    font-size: 1.55rem;
}

.grid{
    display: grid;
    grid-template-columns: repeat(2,1fr);
    gap: 15px;
}

.box{
    background: var(--surface-strong);
    border-radius: 12px;
    padding: 15px;
    border: 1px solid rgba(255,255,255,0.06);
    font-size: 0.95rem;
}

/* SECTIONS */

section{
    padding: 90px 8%;
    scroll-margin-top: 92px;
}

.problem{
    background: var(--bg-soft);
}

.section-title{
    font-size: clamp(1.8rem, 3vw, 2.6rem);
    margin-bottom: 30px;
}

.problem p,
.about p{
    color: var(--text-soft);
    line-height: 1.9;
}

/* CARDS */

.cards{
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(250px,1fr));
    gap: 25px;
    margin-top: 40px;
}

.card{
    background: var(--surface);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 16px;
    padding: 30px;
}

.card h4{
    margin-bottom: 15px;
    font-size: 1.5rem;
}

/* STATS */

.stats{
    background: var(--bg-soft);
}

.stats-container{
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(220px,1fr));
    gap: 25px;
    margin-top: 40px;
}

.stat-box{
    background: var(--surface-strong);
    padding: 35px;
    border-radius: 16px;
    text-align: center;
    border: 1px solid rgba(255,255,255,0.08);
}

.stat-box h3{
    font-size: 2.5rem;
    color: var(--accent);
}

/* FOOTER */

footer{
    padding: 40px;
    text-align: center;
    color: var(--text-muted);
}

/* WORKFLOW */

.workflow{
    background: var(--bg-main);
}

.workflow-container{
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(220px,1fr));
    gap: 25px;
    margin-top: 40px;
}

.workflow-box{
    background: var(--surface);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 16px;
    padding: 30px;
    transition: 0.3s;
}

.workflow-box:hover{
    transform: translateY(-5px);
    border-color: #00d9ff;
}

.workflow-box h3{
    font-size: 2.1rem;
    color: var(--accent);
    margin-bottom: 15px;
}

.workflow-box h4{
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.workflow-box p{
    color: var(--text-soft);
    line-height: 1.7;
}

/* ABOUT PROJECT */

.about-project{
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 50px;
    background: var(--bg-soft);
}

.about-project-text{
    flex: 1;
}

.about-project-text span{
    color: var(--accent);
    font-weight: bold;
    letter-spacing: 1px;
}

.about-project-text h2{
    font-size: 3rem;
    margin: 20px 0;
}

.about-project-text p{
    color: var(--text-soft);
    line-height: 1.9;
    margin-bottom: 20px;
}

.about-project-card{
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.mini-card{
    background: var(--surface);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 14px;
    padding: 25px;
}

.mini-card h3{
    margin-bottom: 10px;
    color: var(--accent);
}

.mini-card p{
    color: var(--text-soft);
    line-height: 1.7;
}

/* CTA */

.cta{
    text-align: center;
    background: linear-gradient(
        135deg,
        var(--bg-main),
        var(--bg-soft)
    );
}

.cta h2{
    font-size: 3rem;
    margin-bottom: 25px;
}

.cta p{
    color: var(--text-soft);
    max-width: 700px;
    margin: auto;
    line-height: 1.8;
    margin-bottom: 35px;
}

/* RESPONSIVE */

@media(max-width: 950px){

    .about-project{
        flex-direction: column;
    }

    .about-project-text h2,
    .cta h2{
        font-size: 2.3rem;
    }

}

/* RESPONSIVE */

@media(max-width: 950px){

    .hero{
        flex-direction: column;
        text-align: center;
    }

    .buttons{
        justify-content: center;
    }

    nav ul{
        justify-content: center;
        gap: 12px;
    }

    .dataset-preview{
        grid-template-columns: 1fr;
    }

    .dataset-preview__stats{
        grid-template-columns: 1fr;
    }

}

@media(max-width: 760px){

    header{
        padding: 14px 5%;
        flex-wrap: wrap;
        align-items: flex-start;
    }

    .logo img{
        width: min(220px, 68vw);
    }

    nav{
        width: 100%;
        order: 3;
    }

    nav ul{
        justify-content: flex-start;
        gap: 8px;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding-bottom: 4px;
        scrollbar-width: none;
        -ms-overflow-style: none;
    }

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

    nav a{
        min-height: 36px;
        padding: 0 12px;
        font-size: 0.88rem;
    }

    .header-actions{
        width: 100%;
        order: 2;
        justify-content: flex-start;
    }

    .theme-toggle{
        width: auto;
        min-width: 124px;
    }

    .hero{
        padding: 118px 5% 42px;
        gap: 24px;
    }

    .hero-card,
    .dataset-preview__copy,
    .dataset-preview__panel{
        padding: 20px;
    }

    .grid{
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 10px;
    }

    .box{
        padding: 12px;
        font-size: 0.9rem;
    }

    .buttons{
        gap: 12px;
    }

    .btn-primary,
    .btn-secondary{
        width: 100%;
        text-align: center;
        padding: 14px 20px;
    }

    .dataset-preview__stats{
        gap: 10px;
    }

    .dataset-preview__table th,
    .dataset-preview__table td{
        padding: 10px 12px;
        font-size: 0.88rem;
    }

    section{
        padding: 70px 5%;
    }
}

@media(max-width: 520px){

    .hero{
        padding: 108px 5% 40px;
    }

    .hero-text h2{
        font-size: 1.9rem;
    }

    nav ul{
        gap: 8px;
    }

    nav a{
        padding: 0 11px;
        font-size: 0.86rem;
    }

    .theme-toggle{
        width: 100%;
        justify-content: center;
    }

    .buttons a{
        width: 100%;
        text-align: center;
    }

    section{
        padding: 64px 5%;
    }

    .section-title{
        font-size: 2rem;
    }

    .logo img{
        width: min(200px, 68vw);
    }

    .dataset-preview__stats{
        grid-template-columns: 1fr;
    }

    .grid{
        grid-template-columns: 1fr;
    }

}