:root {
    --bg-color: #ffffff;
    --text-color: #000000;
    --accent-color: #000000;
    --card-bg: #f9f9f9;
    --border-color: #e0e0e0;
    --transition-speed: 0.3s;
}

[data-theme="dark"] {
    --bg-color: #000000;
    --text-color: #ffffff;
    --accent-color: #ffffff;
    --card-bg: #111111;
    --border-color: #333333;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.app-logo {
    height: 40px;
    width: auto;
    transition: filter var(--transition-speed);
}

[data-theme="dark"] .app-logo,
[data-theme="dark"] .footer-logo {
    filter: invert(1);
}

.brand-name {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.05rem;
}

.controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

button.icon-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.5rem;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-speed);
}

button.icon-btn:hover {
    background-color: var(--text-color);
    color: var(--bg-color);
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.hero {
    text-align: center;
    margin-bottom: 3rem;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 1rem;
    letter-spacing: -0.1rem;
}

.hero p {
    font-size: 1.1rem;
    opacity: 0.7;
}

.download-box {
    width: 100%;
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid var(--border-color);
}

.input-group {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

input[type="text"] {
    flex: 1;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 1rem 1.5rem;
    border-radius: 12px;
    font-size: 1rem;
    outline: none;
    transition: border-color var(--transition-speed);
}

input[type="text"]:focus {
    border-color: var(--text-color);
}

.primary-btn {
    background: var(--text-color);
    color: var(--bg-color);
    border: none;
    padding: 1rem 2rem;
    border-radius: 12px;
    font-weight: 700;
    cursor: pointer;
    transition: opacity var(--transition-speed);
}

.primary-btn:hover {
    opacity: 0.8;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 2rem;
}

.option-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    opacity: 0.8;
}

select {
    width: 100%;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 0.8rem;
    border-radius: 8px;
    outline: none;
}

footer {
    padding: 3rem 2rem;
    text-align: center;
    border-top: 1px solid var(--border-color);
    margin-top: 4rem;
}

.footer-content {
    max-width: 800px;
    margin: 0 auto;
}

.footer-logo {
    height: 24px;
    width: auto;
    margin-bottom: 1.5rem;
    transition: filter var(--transition-speed);
}

.copyright {
    font-size: 0.9rem;
    opacity: 0.6;
    margin-bottom: 1rem;
}

.disclaimer {
    font-size: 0.8rem;
    opacity: 0.4;
    line-height: 1.4;
    max-width: 600px;
    margin: 0 auto;
}

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

    100% {
        transform: translateX(100%);
    }
}

.progress-bar-indefinite {
    position: relative;
    overflow: hidden;
}

.progress-bar-indefinite::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    animation: progress 1.5s infinite;
}

[data-theme="dark"] .progress-bar-indefinite::after {
    background: linear-gradient(90deg, transparent, rgba(0, 0, 0, 0.4), transparent);
}

.loader {
    width: 20px;
    height: 20px;
    border: 2px solid var(--bg-color);
    border-bottom-color: transparent;
    border-radius: 50%;
    display: inline-block;
    animation: rotation 1s linear infinite;
}

@keyframes rotation {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

@media (max-width: 600px) {
    .input-group {
        flex-direction: column;
    }

    .hero h1 {
        font-size: 2rem;
    }

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