#login-screen.active, #setup-screen.active {
    position: relative;
    display: flex; align-items: center; justify-content: center;
    background: var(--bg);
    overflow: hidden;
}

#particle-canvas {
    position: absolute; top: 0; left: 0; width: 100%; height: 100%;
    z-index: 0; pointer-events: none;
}

.login-container {
    position: relative; z-index: 1;
    width: 100%; max-width: 380px; padding: 40px 32px;
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.login-logo { text-align: center; margin-bottom: 36px; }
.logo-icon {
    width: 56px; height: 56px; margin: 0 auto 12px;
    border-radius: 16px;
    background: linear-gradient(135deg, var(--accent), var(--purple));
    display: flex; align-items: center; justify-content: center;
    font-size: 26px; font-weight: 900; color: #fff;
    box-shadow: var(--shadow-glow);
    animation: pulse-glow 3s ease-in-out infinite;
}
.logo-text {
    font-size: 1.6rem; font-weight: 700; letter-spacing: 1px;
}
.logo-text span { color: var(--accent-light); }
.logo-sub {
    font-size: 0.7rem; color: var(--text-muted);
    text-transform: uppercase; letter-spacing: 3px; margin-top: 4px;
}

/* floating label inputs */
.input-group {
    position: relative; margin-bottom: 24px;
}
.input-group input {
    width: 100%; padding: 14px 0 8px;
    background: none; border: none; outline: none;
    color: var(--text); font-size: 0.95rem;
    border-bottom: 2px solid var(--border);
    transition: border-color var(--transition);
}
.input-group label {
    position: absolute; left: 0; top: 14px;
    color: var(--text-muted); font-size: 0.9rem;
    pointer-events: none;
    transition: all var(--transition);
}
.input-group input:focus ~ label,
.input-group input:valid ~ label {
    top: -6px; font-size: 0.7rem; color: var(--accent-light);
}
.input-group input:focus {
    border-bottom-color: var(--accent);
}
.input-line {
    position: absolute; bottom: 0; left: 50%; width: 0; height: 2px;
    background: var(--accent); transition: all 0.3s ease;
}
.input-group input:focus ~ .input-line {
    width: 100%; left: 0;
}

/* login button */
.btn-login {
    position: relative; width: 100%; padding: 14px;
    margin-top: 8px;
    background: linear-gradient(135deg, var(--accent), var(--purple));
    color: #fff; font-weight: 600; font-size: 0.95rem;
    border-radius: var(--radius); border: none;
    cursor: pointer; overflow: hidden;
    transition: var(--transition);
}
.btn-login:hover { transform: translateY(-1px); box-shadow: var(--shadow-glow); }
.btn-login:active { transform: scale(0.98); }
.btn-pulse {
    position: absolute; top: 50%; left: 50%; width: 0; height: 0;
    border-radius: 50%; background: rgba(255,255,255,0.2);
    transform: translate(-50%, -50%);
}

/* error shake */
.login-error { color: var(--red); font-size: 0.8rem; text-align: center; margin-top: 12px; min-height: 20px; }
.shake { animation: shake 0.5s ease; }

/* language switcher */
.login-lang { display: flex; gap: 6px; justify-content: center; margin-top: 20px; }
.lang-btn {
    padding: 4px 10px; border-radius: var(--radius-sm);
    font-size: 0.7rem; font-weight: 600;
    color: var(--text-muted); transition: var(--transition);
    border: 1px solid transparent;
}
.lang-btn.active { color: var(--accent-light); border-color: var(--accent); }
.lang-btn:hover { color: var(--text); }