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

:root {
    --bg-primary: #0d0d0d;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2a2a2a;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;
    --accent: #10a37f;
    --accent-hover: #0d8a6a;
    --border-color: #333333;
    --input-bg: #1e1e1e;
}

body {
    font-family: 'Söhne', 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header / Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    background: transparent;
    z-index: 100;
}

.logo {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    width: 28px;
    height: 28px;
    background: var(--accent);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-icon svg {
    width: 18px;
    height: 18px;
    fill: white;
}

.sign-in-btn {
    padding: 10px 20px;
    background: var(--text-primary);
    color: var(--bg-primary);
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: opacity 0.2s ease;
}

.sign-in-btn:hover {
    opacity: 0.9;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 100px 24px 40px;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 48px;
}

.hero-title {
    font-size: 32px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.hero-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
}

/* Prompt Input Container */
.prompt-container {
    width: 100%;
    max-width: 680px;
    position: relative;
}

.prompt-wrapper {
    display: flex;
    align-items: flex-end;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 12px 16px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.prompt-wrapper:focus-within {
    border-color: var(--text-muted);
    box-shadow: 0 0 0 1px var(--text-muted);
}

.prompt-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 16px;
    line-height: 1.5;
    resize: none;
    max-height: 200px;
    min-height: 24px;
    font-family: inherit;
}

.prompt-input::placeholder {
    color: var(--text-muted);
}

.send-btn {
    width: 36px;
    height: 36px;
    background: var(--text-muted);
    border: none;
    border-radius: 8px;
    cursor: not-allowed;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-left: 12px;
    transition: background-color 0.2s ease, transform 0.1s ease;
    flex-shrink: 0;
}

.send-btn.active {
    background: var(--text-primary);
    cursor: pointer;
}

.send-btn.active:hover {
    transform: scale(1.05);
}

.send-btn svg {
    width: 18px;
    height: 18px;
    fill: var(--bg-primary);
}

/* Footer hint */
.footer-hint {
    margin-top: 16px;
    font-size: 12px;
    color: var(--text-muted);
    text-align: center;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.main-content {
    animation: fadeIn 0.5s ease;
}

/* Responsive */
@media (max-width: 640px) {
    .navbar {
        padding: 12px 16px;
    }

    .hero-title {
        font-size: 24px;
    }

    .hero-subtitle {
        font-size: 14px;
    }

    .prompt-wrapper {
        padding: 10px 12px;
    }

    .prompt-input {
        font-size: 14px;
    }
}