* {
    box-sizing: border-box;
}

:root {
    --bg: #0b1220;
    --card: #111a2e;
    --accent: #38bdf8;
    --accent-2: #60a5fa;
    --text: #e2e8f0;
    --muted: #94a3b8;
    --border: #1f2a44;
    --border-soft: rgba(255, 255, 255, 0.06);
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Inter, system-ui, -apple-system, sans-serif;
    background:
        radial-gradient(circle at top, #0f172a 0%, #0b1220 45%, #070b14 100%);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 64px 16px 40px;
    overflow-x: hidden;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,0.45), transparent 80%);
    opacity: 0.35;
    z-index: 0;
}

.hub-link {
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 10;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border: 1px solid var(--border-soft);
    border-radius: 999px;
    color: var(--text);
    background: rgba(17, 26, 46, 0.85);
    text-decoration: none;
    backdrop-filter: blur(10px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.22);
    transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.hub-link:hover {
    transform: translateY(-1px);
    border-color: rgba(56, 189, 248, 0.35);
    background: rgba(17, 26, 46, 0.95);
}

.hero {
    text-align: center;
    max-width: 860px;
    margin: 18px auto 40px;
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: clamp(38px, 6vw, 58px);
    color: var(--accent);
    margin: 0 0 12px;
    letter-spacing: -0.04em;
    line-height: 1;
}

.subtitle {
    font-size: 16px;
    color: var(--muted);
    margin: 0 0 10px;
    line-height: 1.6;
}

.trust {
    font-size: 13px;
    color: #7c8aa3;
    letter-spacing: 0.02em;
}
main {
    width: 100%;
    max-width: 760px;
    display: flex;
    flex-direction: column;
    gap: 18px;
    position: relative;
    z-index: 1;
}

.card {
    width: 100%;
    max-width: 720px;
    margin: 0 auto;
    background: linear-gradient(145deg, rgba(17, 26, 46, 0.98), rgba(15, 23, 42, 0.98));
    border: 1px solid var(--border);
    padding: 1.5rem;
    border-radius: 18px;
    box-shadow: 0 18px 40px rgba(0, 0, 0, 0.32);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 14px;
}

.hero {
    text-align: center;
    max-width: 760px;
    margin: 18px auto 28px;
    position: relative;
    z-index: 1;
}

.card h2 {
    margin: 0;
    font-size: 18px;
    letter-spacing: -0.02em;
}

.seo-text {
    font-size: 13px;
    color: var(--muted);
    margin: 0;
    line-height: 1.6;
    max-width: 620px;
}

input[type="text"] {
    width: 100%;
    max-width: 560px;
    padding: 13px 15px;
    background: #0b1220;
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text);
    outline: none;
    text-align: center;
    transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

input[type="text"]::placeholder {
    color: #6b7a93;
}

input[type="text"]:focus {
    border-color: rgba(56, 189, 248, 0.8);
    box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.08);
}

#drop-zone {
    width: 100%;
    max-width: 560px;
    border: 1.5px dashed #2a3b5f;
    padding: 28px 20px;
    text-align: center;
    border-radius: 16px;
    cursor: pointer;
    transition: 0.25s ease;
    color: var(--muted);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(8, 15, 28, 0.45);
}

#drop-zone:hover {
    border-color: var(--accent);
    background: rgba(56, 189, 248, 0.06);
    transform: translateY(-1px);
}

#drop-zone p {
    margin: 0;
}

#file-info {
    margin-top: 10px;
    color: var(--text);
    font-size: 13px;
    line-height: 1.5;
}

button {
    width: 100%;
    max-width: 560px;
    padding: 13px 16px;
    background: linear-gradient(180deg, var(--accent), var(--accent-2));
    color: #08111f;
    border: none;
    border-radius: 12px;
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.15s ease, opacity 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 14px 24px rgba(56, 189, 248, 0.18);
}

button:hover {
    opacity: 0.95;
    transform: translateY(-1px);
}

button:active {
    transform: scale(0.98);
}

button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    box-shadow: none;
    transform: none;
}

.result-area {
    width: 100%;
    max-width: 560px;
    margin-top: 4px;
}

.info-card {
    align-items: flex-start;
    text-align: left;
}

.info-card h2 {
    align-self: center;
    text-align: center;
}

.info-card p {
    margin: 0;
    color: var(--text);
    line-height: 1.75;
    font-size: 14px;
}

.info-card ul {
    margin: 0;
    padding-left: 18px;
    color: var(--text);
    font-size: 14px;
    line-height: 1.8;
}

.info-card li {
    margin-bottom: 6px;
    color: var(--text);
}

footer {
    margin-top: 40px;
    font-size: 12px;
    color: #64748b;
    text-align: center;
    position: relative;
    z-index: 1;
}

@media (max-width: 640px) {
    body {
        padding-top: 72px;
    }

    .hub-link {
        top: 12px;
        left: 12px;
        padding: 9px 12px;
        font-size: 13px;
    }

    .card {
        padding: 20px;
        border-radius: 18px;
    }

    input[type="text"],
    button,
    #drop-zone,
    .result-area {
        max-width: 100%;
    }

    .hero h1 {
        line-height: 1.05;
    }
}