:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-primary: #38bdf8;
    --accent-secondary: #818cf8;
    --btn-primary-bg: linear-gradient(135deg, #38bdf8, #818cf8);
    --btn-hover-shadow: 0 10px 20px -10px rgba(56, 189, 248, 0.5);
    --font-family: 'Inter', sans-serif;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--bg-color);
    background-image: 
        radial-gradient(at 0% 0%, rgba(56, 189, 248, 0.1) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(129, 140, 248, 0.1) 0px, transparent 50%);
    font-family: var(--font-family);
    color: var(--text-primary);
}

.container {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 24px;
    padding: 3rem;
    width: 90%;
    max-width: 480px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(to right, #38bdf8, #c084fc);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 0 0 0.5rem 0;
}

header p {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-bottom: 2rem;
}

.display-area {
    background: rgba(15, 23, 42, 0.5);
    border-radius: 16px;
    padding: 2rem;
    min-height: 120px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
    overflow: hidden;
}

.placeholder {
    color: var(--text-secondary);
    font-style: italic;
}

.result-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    animation: fadeIn 0.5s ease-out;
}

.result-list {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 100%;
    text-align: left;
    max-height: 200px;
    overflow-y: auto;
}

.result-list li {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
    font-size: 1rem;
}

.result-list li:last-child {
    border-bottom: none;
}

.controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    border: none;
    border-radius: 12px;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn.primary {
    background: var(--btn-primary-bg);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--btn-hover-shadow);
}

.btn.secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn.secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--accent-primary);
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Scrollbar styles */
.result-list::-webkit-scrollbar {
    width: 6px;
}

.result-list::-webkit-scrollbar-track {
    background: transparent;
}

.result-list::-webkit-scrollbar-thumb {
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 20px;
}