:root {
    --primary-bg: #0f0c29;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: #a9a9a9;
    --accent-color: #ff00cc;
    --accent-gradient: linear-gradient(135deg, #ff00cc, #333399);
    --btn-bg: rgba(255, 255, 255, 0.05);
    --btn-hover: rgba(255, 255, 255, 0.15);
    --btn-active: rgba(255, 255, 255, 0.25);
    --op-btn-color: #ff9966;
    --eq-btn-bg: #ff00cc;
}

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

body {
    background: var(--primary-bg);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    color: var(--text-primary);
}

/* Background Animation */
.background-blobs {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    filter: blur(80px);
    border-radius: 50%;
    opacity: 0.6;
    animation: float 10s infinite ease-in-out alternate;
}

.blob-1 {
    top: -10%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: #ff00cc;
    animation-delay: 0s;
}

.blob-2 {
    bottom: -10%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: #333399;
    animation-delay: -2s;
}

.blob-3 {
    top: 40%;
    left: 40%;
    width: 300px;
    height: 300px;
    background: #00bcd4;
    animation-delay: -4s;
}

@keyframes float {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(20px, 40px) scale(1.1); }
}

/* Glass Container */
.app-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.glass-card {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 24px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

/* Header & Nav */
.app-header {
    margin-bottom: 24px;
}

.mode-switch {
    display: flex;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 12px;
    padding: 4px;
}

.nav-btn {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
}

.nav-btn.active {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* Sections */
.view {
    display: none;
    animation: fadeIn 0.3s ease;
}

.view.active {
    display: block;
}

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

/* Calculator Styles */
.display-container {
    text-align: right;
    margin-bottom: 24px;
    min-height: 80px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
}

.history {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
    min-height: 1.2em;
}

.current-input {
    font-size: 2.5rem;
    font-weight: 600;
    word-break: break-all;
}

.keypad {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
}

.btn {
    background: var(--btn-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    padding: 16px;
    border-radius: 16px;
    font-size: 1.25rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    user-select: none;
}

.btn:hover {
    background: var(--btn-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.btn:active {
    transform: translateY(0);
}

.btn-op {
    color: var(--op-btn-color);
    font-weight: 600;
}

.btn-eq {
    background: var(--eq-btn-bg);
    border: none;
    grid-column: span 2;
    font-weight: 600;
}

.btn-eq:hover {
    background: #ff33d4;
}

.btn-zero {
    grid-column: span 2;
}

/* Converter Styles */
.converter-wrapper {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.input-group, .select-wrapper {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

input[type="number"] {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 14px;
    color: var(--text-primary);
    font-size: 1.5rem;
    outline: none;
    width: 100%;
    transition: border-color 0.3s;
}

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

select {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    appearance: none; /* simple styling hack */
    cursor: pointer;
}

select option {
    background: var(--primary-bg);
    color: white;
}

.swap-container {
    display: flex;
    justify-content: center;
    margin-top: 8px;
}

.icon-btn {
    background: rgba(255,255,255,0.1);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.icon-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: rotate(180deg);
}

.unit-display {
    background: rgba(255,255,255,0.02);
    padding: 16px;
    border-radius: 12px;
    text-align: center;
}

.unit-box {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--op-btn-color);
}

.result-box {
    background: rgba(0,0,0,0.3);
    padding: 20px;
    border-radius: 16px;
    text-align: center;
    margin-top: 8px;
}

.result-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.result-value {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-primary);
    word-break: break-all;
}